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Title:
METHODS FOR TREATMENT OF REFRACTORY GENERALIZED MYASTHENIA GRAVIS
Document Type and Number:
WIPO Patent Application WO/2017/205101
Kind Code:
A1
Abstract:
The disclosure provides methods of treating myasthenia gravis (MG) in a subject in need thereof by administering to the subject a substance that specifically binds complement component 5 (C5). In certain embodiments, the substance that specifically binds C5 is a binding protein, such as an anti-C5 antibody.

Inventors:
BEDROSIAN, Camille (41 Grouse Lane, Woodbridge, CT, 06525, US)
O'BRIEN, Fanny (21 Ridge Hill Road, Norwell, MA, 02061, US)
WANG, Jing, Jing (7 Marion Lane, Woodbridge, CT, 06525, US)
Application Number:
US2017/032767
Publication Date:
November 30, 2017
Filing Date:
May 15, 2017
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
ALEXION PHARMACEUTICALS, INC. (100 College Street, New Haven, CT, 06510, US)
International Classes:
A61K39/395; A61P21/04; C07K16/18; C07K16/28; C07K16/46
Foreign References:
US20150299305A12015-10-22
Other References:
ECULIZUMAB (SOLIRIS) FOR REFRACTORY MYASTHENIA GRAVIS, March 2016 (2016-03-01), pages 1 - 7, Retrieved from the Internet [retrieved on 20171002]
STEGALL, M: "Dosing Regimen of Eculizumab Added to Conventional Treatment in Positive Cross Match Living Donor Kidney Transplant", CLINICAL TRIALS., 8 June 2015 (2015-06-08), pages 1 - 6, XP055441566, Retrieved from the Internet [retrieved on 20171002]
"Scientific Discussion- Soliris", INN: ECULIZUMAB., 2007, pages 1 - 41, XP055444787, Retrieved from the Internet [retrieved on 20171002]
HOWARD, JF ET AL.: "A Randomized, Double-Blind, Placebo-Controlled Phase II Study of Eculizumab in Patients with Refractory Generalized Myasthenia Gravis", MUSCLE AND NERVE., vol. 48, no. 1, 30 April 2013 (2013-04-30), pages 76 - 84, XP055444788
GATAULT, P ET AL., THERAPEUTIC DRUG MONITORING OF ECULIZUMAB: RATIONALE FOR AN INDIVIDUALIZED DOSING SCHEDULE., vol. 7, no. 6, 4 September 2015 (2015-09-04), pages 1205 - 1211, XP055444790
TAPIA, CB, DEVELOPMENT AND VALIDATION OF A NEW MEASURE OF IMPAIRMENT IN MYASTHENIA GRAVIS: THE MYASTHENIA GRAVIS IMPAIRMENT INDEX, 2015, pages 34, XP055444789, Retrieved from the Internet
LAI, JS ET AL.: "Quality-of-Life Measures in Children with Neurological Conditions: Pediatric Neuro-QOL", NEUROREHABILITATION, AND NEURAL REPAIR, vol. 26, no. 1, 25 July 2011 (2011-07-25), pages 1 - 19, XP055444793
WINTER, Y ET AL.: "Health-Related Quality of Life in ALS, Myasthenia Gravis and Facioscapulohumeral Muscular Dystrophy", JOURNAL OF NEUROLOGY., vol. 257, no. 9, 10 April 2010 (2010-04-10), pages 1473 - 1481, XP019847874
SANDERS, DB ET AL.: "Immunosuppressive Therapies in Myasthenia Gravis", AUTOIMMUNITY., vol. 43, no. 5-6, August 2010 (2010-08-01), pages 428 - 435, XP009513819, ISSN: 0891-6934, DOI: 10.3109/08916930903518107
Attorney, Agent or Firm:
FENDRICK, Sarah, E. (Mcdonnell Boehnen Hulbert & Berghoff LLP, 300 South Wacker DriveChicago, IL, 60606, US)
Download PDF:
Claims:
CLAIMS

What is claimed is:

1. A method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering a therapeutically effective amount of eculizumab to the patient; wherein the patient is positive for auto-antibodies binding to nicotinic acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and immunosuppressant therapy (1ST) and requires chronic plasma exchange or chronic IVIg to maintain clinical stability; and

wherein the patient is administered eculizumab for at least 26 weeks.

2. The method of claim 1, wherein eculizumab is administered using a phased dosing schedule with an induction phase comprising administering a 900 mg induction dose of eculizumab on day 1, administering 900 mg doses of eculizumab on days 7, 14, and 21, and administering 1200 mg of eculizumab as a fifth induction dose on day 28; and

wherein the patient is administered eculizumab for at least 26 weeks.

3. The method of claim 2, wherein the 28 day induction phase of eculizumab treatment is followed by a maintenance phase comprising administering 1200 mg of eculizumab 14 days after the fifth induction dose and administering 1200 mg of eculizumab every 14 ± 2 days thereafter.

4. The method of claim 3, further comprising performing plasmapheresis on the patient and administering eculizumab at a dose of between 300 mg and 1200 mg to the patient within 4 hours of completion of plasmapheresis.

5. The method of claim 3, further comprising performing plasmapheresis on the patient and administering eculizumab at a dose of between 600 mg and 900 mg to the patient within 90 minutes of completion of plasmapheresis.

6. The method of claim 3, further comprising performing plasmapheresis on the patient and administering eculizumab at a dose of 600 mg to the patient within 1 hour of completion of plasmapheresis.

7. The method of claim 1, wherein the patient experiences a clinically meaningful improvement (reduction) in Myasthenia Gravis Activities of Daily Living (MG-ADL) score after 26 weeks of treatment.

8. The method of claim 7, wherein the clinically meaningful improvement the patient experiences is at least a 3 point reduction in the patient's MG-ADL score after 26 weeks of treatment.

9. The method of claim 1, wherein the patient experiences a clinically meaningful improvement (reduction) in quantitative Myasthenia Gravis score (QMG) after 26 weeks of treatment.

10. The method of claim 9, wherein the clinically meaningful improvement the patient experiences is at least a 4 point reduction in the patient's QMG score after 26 weeks of treatment.

11. The method of claim 1, wherein the patient experiences a clinically meaningful improvement (reduction) in Myasthenia Gravis Composite (MGC) score after 26 weeks of treatment.

12. The method of claim 11, wherein the clinically meaningful improvement the patient experiences is at least a 6 point reduction in the patient's MGC score after 26 weeks of treatment.

13. The method of claim 1, wherein the patient experiences a clinically meaningful improvement (reduction) in quality of life as measured by Myasthenia Gravis Quality of Life (MG-QOL-15) score after 26 weeks of treatment.

14. The method of claim 13, wherein the clinically meaningful improvement the patient experiences is at least a 6 point reduction in the patient's MG-QOL-15 score after 26 weeks of treatment.

15. The method of claim 1, wherein the patient experiences a clinically meaningful improvement (reduction) in neuro-fatigue as measured by Neuro-QOL Fatigue score after 26 weeks of treatment.

16. The method of claim 15, wherein the clinically meaningful improvement the patient experiences is at least an 8 point reduction in the patient's Neuro-QOL score after 26 weeks of treatment.

17. The method of claim 1, wherein the patient experiences a clinically meaningful improvement (increase) in health status as measured by EQ-5D health status score after 26 weeks of treatment.

18. A method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering eculizumab to the patient;

wherein the patient is positive for auto-antibodies binding to nicotinic acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and immunosuppressant therapy (1ST) and requires chronic plasma exchange or chronic IVIg to maintain clinical stability;

wherein eculizumab is administered using a phased dosing schedule with an induction phase comprising administering a 900 mg induction dose of eculizumab on day 1, administering 900 mg doses of eculizumab on days 7, 14, and 21, and administering 1200 mg of eculizumab as a fifth induction dose on day 28;

wherein the patient is administered eculizumab for at least 26 weeks;

wherein the 28 day induction phase of eculizumab treatment is followed by a

maintenance phase comprising administering 1200 mg of eculizumab 14 days after the fifth induction dose and administering 1200 mg of eculizumab every 14 ± 2 days thereafter; and

wherein the patient has a clinically meaningful improvement (reduction) in at least two measurements of generalized myasthenia gravis severity selected from the group consisting of MG-ADL, QMG, MGC, MG-QOL, and Neuro-QOL.

19. A method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering eculizumab to the patient;

wherein the patient is positive for auto-antibodies binding to nicotinic acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and immunosuppressant therapy (1ST) and requires chronic plasma exchange or chronic IVIg to maintain clinical stability;

wherein eculizumab is administered using a phased dosing schedule with an induction phase comprising administering a 900 mg induction dose of eculizumab on day 1, administering 900 mg doses of eculizumab on days 7, 14, and 21, and administering 1200 mg of eculizumab as a fifth induction dose on day 28;

wherein the patient is administered eculizumab for at least 26 weeks;

wherein the 28 day induction phase of eculizumab treatment is followed by a

maintenance phase comprising administering 1200 mg of eculizumab 14 days after the fifth induction dose and administering 1200 mg of eculizumab every 14 ± 2 days thereafter; and

wherein the patient has a clinically meaningful improvement (reduction) in five measurements of generalized myasthenia gravis severity, wherein the five measurements of generalized myasthenia gravis severity are a reduction in MG-ADL of at least 3 points, a reduction of QMG of at least 4 points, a reduction in MGC of at least 6 points, a reduction in MG-QOL of at least 6 points, and a reduction in Neuro-QOL of at least 8 points.

20. The method of claim 19, wherein the patient has a clinically meaningful improvement (reduction) in five measurements of generalized myasthenia gravis, wherein the five measurements of generalized myasthenia gravis severity are a reduction in MG-ADL of at least 4 points, a reduction of QMG of at least 5 points, a reduction in MGC of at least 10 points, a reduction in MG-QOL of at least 11 points, and a reduction in Neuro-QOL of at least 16 points.

21. The method of claim 1, wherein eculizumab is administered by intravenous infusion.

22. The method of claim 1, wherein eculizumab is administered subcutaneously.

23. The method of claim 1, wherein the eculizumab comprises a heavy chain amino acid sequence according to SEQ ID NO: 10 and a light chain amino acid sequence according to SEQ ID NO: 11.

24. The method of claim 1, wherein the eculizumab is an eculizumab variant comprising a heavy chain amino acid sequence according to SEQ ID NO: 14 and a light chain amino acid sequence according to SEQ ID NO: 11.

25. The method of claim 1, wherein the patient has failed treatment over one year or more with two or more ISTs in sequence or in combination.

26. The method of claim 1, wherein the patient has failed at least one 1ST and requires chronic plasma exchange or IVIg to control symptoms.

27. The method of claim 1, wherein the therapeutically effective amount of eculizumab is maintained at a concentration of between 50-100 μg/mL in the patient's serum.

28. The method of claim 1, wherein the patient experiences a reduction in the administration of one or more 1ST following at least 26 weeks of treatment.

29. The method of claim 1, wherein the patient experiences a reduction in 1ST dosing following at least 26 weeks of treatment.

30. The method of claim 1, wherein the patient experiences a reduction in one or more 1ST dosing and a discontinuation in one or more 1ST following at least 26 of treatment.

Description:
METHODS FOR TREATMENT OF

REFRACTORY GENERALIZED MYASTHENIA GRAVIS

BACKGROUND

Myasthenia Gravis (MG) is a rare, debilitating, acquired autoimmune neurologic disorder of the neuromuscular junction (NMJ) caused by the failure of neuromuscular transmission, which results from the binding of auto-antibodies (Abs) to proteins involved in signaling at the NMJ. These proteins include the nicotine acetylcholine receptors

(AChRs) or, less frequently, a muscle-specific tyrosine kinase (MuSK) involved in AChR clustering.

MG has a prevalence of 14-20 per 100,000 in the U.S., affecting roughly 60,000 Americans. It affects males and females in equal ratio, although the incidence in females peaks in the 3rd decade as compared to males in whom the peak age at onset is in the 6th or 7th decade. Mortality from MG is approximately 4%, mostly due to respiratory failure.

Myasthenia gravis is clinically characterized by weakness and fatigability of voluntary skeletal muscles. MG may initially present with ocular muscle weakness affecting eye and eyelid movement, referred to as ocular MG (oMG). Ten percent of subjects have disease limited to ocular muscles. Ninety percent of subjects have generalized MG, with muscle weakness involving neck, head, spine, bulbar, respiratory, or limb muscles. Bulbar weakness refers to muscles controlled by nerves originating from the bulb-like part of the brainstem and manifests as difficulty in talking, chewing, swallowing, and control of the head. MG may cause life-threatening respiratory failure, referred to as myasthenic crisis. About 15% to 20% of subjects will experience a myasthenic crisis during the course of their disease, 75% within 2 years of diagnosis, requiring hospitalization and ventilatory support.

While there is no cure for MG, there are a variety of therapies that reduce muscle weakness and improve neuromuscular function. Current available treatments for myasthenia gravis aim to modulate neuromuscular transmission, inhibit the production or effects of pathogenic antibodies, or inhibit inflammatory cytokines. There is currently no specific treatment that targets the underlying pathophysiology of NMJ injury specifically: anti-AChR antibody- AChR interactions resulting in complement activation via the classical pathway and inflammation, with the resultant destruction of the NMJ. There is no specific treatment that corrects the autoimmune defect in MG. With immunosuppressive therapies (ISTs) the current standard of care, which usually combines cholinesterase inhibitors, corticosteroids and immunosuppressive drugs (most commonly azathioprine [AZA], cyclosporin, and mycophenolate mofetil [MMF]), the majority of subjects with MG have their disease reasonably well controlled. However, there is a cohort of refractory subjects who do not respond adequately to ISTs, or cannot tolerate ISTs, and those who require repeated treatments with plasma exchange (PE) and/or intravenous immunoglobulin (IVIg) to maintain clinical stability. For these subjects, an alternative therapy is needed.

SUMMARY

This disclosure provides methods of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering a therapeutically effective amount of an anti- complement component 5 (C5) antibody or an antigen binding fragment thereof to the patient, wherein the patient is administered the anti-C5 antibody or antigen binding fragment thereof for at least 26 weeks.

In certain embodiments, this disclosure provides a method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering a

therapeutically effective amount of an anti-C5 antibody or an antigen binding fragment thereof to the patient, wherein the anti-C5 antibody, or an antigen binding fragment thereof is eculizumab or an eculizumab variant and wherein the patient is administered eculizumab or eculizumab variant for at least 26 weeks.

In another embodiment, this disclosure provides a method comprising administering a therapeutically effective amount of eculizumab to a patient, wherein the patient is positive for auto-antibodies binding to nicotinic acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and

immunosuppressant therapy (1ST) and requires chronic plasma exchange or chronic IVIg to maintain clinical stability; and wherein the patient is administered eculizumab for at least 26 weeks.

In one embodiment, this disclosure provides a method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering eculizumab to the patient, wherein the patient is positive for auto-antibodies binding to nicotinic acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and immunosuppressant therapy (1ST) and had previously failed treatment with at least two immunosuppressive agents or failed treatment with at least one immunosuppressive agent and required chronic plasma exchange or IVIg, and had an MG-ADL total score >6 at study entry; wherein eculizumab is administered using a phased dosing schedule with an induction phase comprising administering a 900 mg induction dose of eculizumab on day 1, administering 900 mg doses of eculizumab on days 7, 14, and 21, and administering 1200 mg as a fifth induction dose on day 28, wherein the patient is administered eculizumab for at least 26 weeks; wherein the 28 day induction phase of eculizumab treatment is followed by a

maintenance phase comprising administering 1200 mg of eculizumab 14 days after the fifth induction dose and administering 1200 mg of eculizumab every 14 ± 2 days thereafter, and wherein the patient has a clinically meaningful improvement (reduction) in two measurements of generalized myasthenia gravis severity selected from the group consisting of MG-ADL, QMG, and MGC.

In a particular embodiment, this disclosure provides a method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering eculizumab to the patient, wherein the patient is positive for auto-antibodies binding to nicotinic

acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and immunosuppressant therapy (1ST) or requires chronic plasma exchange or chronic IVIg to maintain clinical stability; wherein eculizumab is

administered using a phased dosing schedule with an induction phase comprising administering a 900 mg induction dose of eculizumab on day 1, administering 900 mg doses of eculizumab on days 7, 14, and 21, and administering 1200 mg of eculizumab as a fifth induction dose on day 28, and wherein the patient is administered eculizumab for at least 26 weeks.

In a further embodiment, this disclosure provides a method wherein the 28 day induction phase of eculizumab treatment is followed by a maintenance phase comprising administering 1200 mg of eculizumab 14 days after the fifth induction dose and 1200 mg of eculizumab every 14 ± 2 days thereafter.

In certain embodiments, this disclosure provides a method wherein the dosing regimen further comprises a third phase and wherein the third phase comprises performing

plasmapheresis on the patient and administering eculizumab at a dose of between 300 and 1200 mg to the patient within 4 hours of completion of plasmapheresis. In other embodiments, the third phase comprises performing plasmapheresis on the patient and administering eculizumab at a dose of between 600 and 900 mg to the patient within 90 minutes of completion of plasmapheresis. In yet other embodiments, the third phase comprises performing plasmapheresis on the patient and administering eculizumab at a dose of 600 mg to the patient within 1 hour of completion of plasmapheresis.

In one embodiment, the patient being treated by the methods provided herein experiences a clinically meaningful improvement (reduction) in Myasthenia Gravis Activities of Daily Living (MG-ADL) score after 26 weeks of treatment. In a particular embodiment, the clinically meaningful improvement the patient experiences is at least a 3 point reduction in the patient's MG-ADL score after 26 weeks of treatment. In another embodiment, the clinically meaningful improvement the patient experiences is at least a 4 point reduction in the patient's MG-ADL score after 26 weeks of treatment.

In another embodiment, the patient being treated by the methods provided herein experiences a clinically meaningful improvement (reduction) in quantitative Myasthenia Gravis score (QMG) after 26 weeks of treatment. In a particular embodiment, the clinically meaningful improvement the patient experiences is at least a 4 point reduction in the patient's QMG score after 26 weeks of treatment. In another embodiment, the clinically meaningful improvement the patient experiences is a 5 point reduction in the patient's QMG score after 26 weeks of treatment.

In another embodiment, the patient being treated by the methods provided herein experiences a clinically meaningful improvement (reduction) in Myasthenia Gravis Composite (MGC) score after 26 weeks of treatment. In a particular embodiment, the clinically meaningful improvement the patient experiences is at least a 6 point reduction in the patient's MGC score after 26 weeks of treatment. In another embodiment, the clinically meaningful improvement the patient experiences is at least a 10 point reduction in the patient's MGC score after 26 weeks of treatment.

In another embodiment, the patient being treated by the methods provided herein experiences a clinically meaningful improvement (reduction) in quality of life as measured by the Myasthenia Gravis Quality of Life (MG-QOL-15) score after 26 weeks of treatment. In a particular embodiment, the clinically meaningful improvement the patient experiences is at least a 6 point reduction in the patient's MG-QOL-15 score after 26 weeks of treatment. In another embodiment, the clinically meaningful improvement the patient experiences is at least an 11 point reduction in the patient's MG-QOL-15 score after 26 weeks of treatment.

In another embodiment, the patient being treated by the methods provided herein experiences a clinically meaningful improvement (reduction) in neuro-fatigue as measured by the Neuro-QOL Fatigue score after 26 weeks of treatment. In a particular embodiment, the clinically meaningful improvement the patient experiences is at least an 8 point reduction in the patient's Neuro-QOL score after 26 weeks of treatment. In another embodiment, the clinically meaningful improvement the patient experiences is at least a 16 point reduction in the patient's Neuro-QOL score after 26 weeks of treatment.

In a certain embodiment, the patient being treated by the methods provided herein experiences a clinically meaningful improvement (increase) in health status as measured by the EQ-5D health status score after 26 weeks of treatment.

In a particular embodiment, this disclosure provides a method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering eculizumab to the patient, wherein the patient is positive for auto-antibodies binding to nicotinic

acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and immunosuppressant therapy (1ST) or requires chronic plasma exchange or chronic IVIg to maintain clinical stability; wherein eculizumab is

administered using a phased dosing schedule comprising administering a 900 mg induction dose of eculizumab on day 1, administering 900 mg doses of eculizumab on days 7, 14, and 21, and administering 1200 mg of eculizumab as a fifth dose on day 28, wherein the patient is administered eculizumab for at least 26 weeks; wherein the 28 day induction phase of eculizumab treatment is followed by a maintenance phase comprising administering 1200 mg of eculizumab 14 days after the fifth induction dose and administering 1200 mg of eculizumab every 14 ± 2 days thereafter, and wherein the patient has a clinically meaningful improvement (reduction) in at least one measurement of generalized myasthenia gravis severity selected from the group consisting of MG-ADL, QMG, MGC, MG-QOL, and Neuro-QOL.

In another embodiment, this disclosure provides a method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering eculizumab to the patient, wherein the patient is positive for auto-antibodies binding to nicotinic

acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and immunosuppressant therapy (1ST) and requires chronic plasma exchange or chronic IVIg to maintain clinical stability; wherein eculizumab is

administered using a phased dosing schedule comprising administering a 900 mg induction dose on day 1, administering 900 mg doses of eculizumab on days 7, 14, and 21, and administering 1200 mg of eculizumab as a fifth dose on day 28, wherein the patient is administered eculizumab for at least 26 weeks; wherein the 28 induction phase of eculizumab treatment is followed by a maintenance phase comprising administering 1200 mg of eculizumab 14 days after the fifth induction dose and administering 1200 mg of eculizumab every 14 ± 2 days thereafter, and wherein the patient has a clinically meaningful improvement (reduction) in two measurements of generalized myasthenia gravis severity selected from the group consisting of MG-ADL, QMG, MGC, MG-QOL, and Neuro-QOL.

In another embodiment, this disclosure provides a method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering eculizumab to the patient, wherein the patient is positive for auto-antibodies binding to nicotinic

acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and immunosuppressant therapy (1ST) or requires chronic plasma exchange or chronic IVIg to maintain clinical stability; wherein eculizumab is administered using a phased dosing schedule comprising administering a 900 mg induction dose on day 1, administering 900 mg doses of eculizumab on days 7, 14, and 21, and administering 1200 mg as a fifth dose on day 28, wherein the patient is administered eculizumab for at least 26 weeks; wherein the 28 day induction phase of eculizumab treatment is followed by a

maintenance phase comprising administering 1200 mg of eculizumab 14 days after the fifth induction dose and administering 1200 mg of eculizumab every 14 ± 2 days thereafter, and wherein the patient has a clinically meaningful improvement (reduction) in three measurements of generalized myasthenia gravis severity selected from the group consisting of MG-ADL, QMG, MGC, MG-QOL, and Neuro-QOL. In certain embodiments, the patient has a clinically meaningful improvement (reduction) in four measurements of generalized myasthenia gravis severity selected from the group consisting of MG-ADL, QMG, MGC, MG-QOL, and Neuro- QOL. In another embodiment, the patient has a clinically meaningful improvement (reduction) in five measurements of generalized myasthenia gravis severity, wherein the five measurements of generalized myasthenia gravis severity are MG-ADL, QMG, MGC, MG-QOL, and Neuro- QOL.

In another embodiment, this disclosure provides a method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering eculizumab to the patient, wherein the patient is positive for auto-antibodies binding to nicotinic

acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while therapy for myasthenia gravis including anticholinesterase inhibitor therapy and immunosuppressant therapy (1ST) or requires chronic plasma exchange or chronic IVIg to maintain clinical stability; wherein eculizumab is administered using a phased dosing schedule comprising administering a 900 mg induction dose on day 1, administering 900 mg doses of eculizumab on days 7, 14, and 21, and administering 1200 mg as a fifth dose on day 28, wherein the patient is administered eculizumab for at least 26 weeks; wherein the 28 day induction phase of eculizumab treatment is followed by a maintenance phase comprising administering 1200 mg of eculizumab 14 days after the fifth induction dose and administering 1200 mg every 14 ± 2 days thereafter, and wherein the patient has a clinically meaningful improvement (reduction) in five measurements of generalized myasthenia gravis severity, wherein the five measurements of generalized myasthenia gravis severity are a reduction in MG- ADL of at least 3 points, a reduction in QMG of at least 4 points, a reduction in MGC of at least 6 points, a reduction in MG-QOL of at least 6 points, and a reduction in Neuro-QOL of at least 8 points. In certain embodiments, the patient has a clinically meaningful improvement (reduction) in five measurements of generalized myasthenia gravis severity, wherein the five measurements of generalized myasthenia gravis severity are a reduction in MG-ADL of at least 4 points, a reduction in QMG of at least 5 points, a reduction in MGC of at least 10 points, a reduction in MG-QOL of at least 11 points, and a reduction in Neuro-QOL of at least 16 points.

In a further embodiment, this disclosure provides a method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering eculizumab by intravenous infusion. In another embodiment, eculizumab is administered subcutaneously. In another embodiment, the eculizumab comprises a heavy chain amino acid sequence according to SEQ ID NO: 10 and a light chain amino acid sequence according to SEQ ID NO: 11. In yet another embodiment, the eculizumab is an eculizumab variant comprising a heavy chain amino acid sequence according to SEQ ID NO: 14 and a light chain amino acid sequence according to SEQ ID NO: 11. In certain embodiments, the eculizumab is an eculizumab variant comprising a heavy chain variable region amino acid sequence according to SEQ ID NO: 12 and a light chain amino acid sequence according to SEQ ID NO: 11.

In yet another embodiment, this disclosure provides a method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering an anti-C5 antibody, or antigen binding fragment thereof, wherein the antibody is an anti-C5 antibody or an antigen binding fragment thereof comprising a heavy chain variable region amino acid sequence according to SEQ ID NO: 27 and a light chain variable region amino acid sequence according to SEQ ID NO: 28. In yet another embodiment, the antibody is an anti-C5 antibody or an antigen binding fragment thereof comprising a heavy chain variable region amino acid sequence according to SEQ ID NO: 35 and a light chain variable region amino acid sequence according to SEQ ID NO: 36. In yet another embodiment, the antibody is an anti-C5 antibody or antigen binding fragment thereof comprising a heavy chain variable region amino acid sequence according to SEQ ID NO: 37 and a light chain variable region amino acid sequence according to SEQ ID NO: 38.

In one embodiment, this disclosure provides a method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering an anti-C5 antibody or antigen binding fragment thereof, wherein the patient has failed treatment over one year or more with two or more ISTs in sequence or in combination.

In one embodiment, this disclosure provides a method of treating refractory

generalized myasthenia gravis in a patient in need thereof comprising administering an anti-C5 antibody or antigen binding fragment thereof, wherein the patient has failed at least one 1ST and requires chronic plasma exchange or IVIg to control symptoms of myasthenia gravis.

In one embodiment, this disclosure provides a method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering a therapeutically effective amount of eculizumab is maintained at a concentration of between 50-100 μg/mL in the patient's serum.

In one embodiment, this disclosure provides a method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering a therapeutically effective amount of eculizumab, wherein the patient experiences a discontinuation in the administration of one or more 1ST following at least 26 weeks of treatment.

In one embodiment, this disclosure provides a method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering a therapeutically effective amount of eculizumab, wherein the patient experiences a reduction in 1ST dosing following at least 26 weeks of treatment.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic of the overall design of the clinical trial disclosed herein.

Figures 2A and 2B are a schematic of the EUROQOL (EQ-5D) survey of health status questionnaire used in the clinical trial disclosed herein.

Figure 3 is a schematic of the N. meningitidis vaccination schedule used in the clinical trial disclosed herein. Figure 4 is a schematic of the dosing schedule used in the clinical trial disclosed herein.

Figure 5 is a schematic of the dosing, clinical evaluation and safety follow-up schedule, used in the clinical trial disclosed herein.

Figure 6 is a schematic of the dosing schedule used in the clinical trial also including the extension period disclosed herein.

Figure 7 is a graphical depiction of the changes from baseline in MG-ADL values obtained for placebo and eculizumab groups over the initial 26 weeks of the trial.

Figure 8 is a graphical depiction of the changes from baseline in QMG values obtained for placebo and eculizumab groups over the initial 26 weeks of the trial.

Figure 9 is a graphical depiction of the changes from baseline in MGC values obtained for placebo and eculizumab groups over the initial 26 weeks of the trial.

Figure 10 is a graphical depiction of the changes from baseline in MG-QOL 15 values obtained for placebo and eculizumab groups over the initial 26 weeks of the trial.

Figure 11 is a graphical depiction of the numbers of patients in both the placebo and eculizumab treated groups achieving between a 5 and 10 point reduction in QMG score over the initial 26 weeks of the trial.

Figure 12 is a schematic of the REGAIN study design.

Figure 13 is a graphical depiction of responder analyses (MG-ADL and QMG) illustrating the proportion of patients with improvement in total score and no rescue therapy at week 26 from baseline.

Figure 14 is a graphical depiction of the proportion of patients with a >3, >5, or >8-point reduction in MG-ADL total score and no rescue therapy over time from baseline to week 26.

Figure 15 is a graphical depiction of the proportion of patients with >5, >7, or >10-point reduction in QMG total score and no rescue over time from baseline to week 26.

Figure 16 is a graphical depiction of dual responders (assessed by MG-ADL and QMG total scores) with no rescue therapy at week 26.

Figure 17 is a graphical depiction of the proportion of patients with at least 3-point improvement in MG-ADL total score and >5-point improvement in QMG total score and no rescue therapy assessed over time from baseline to week 26.

Figure 18 is a graphical depiction of the percentage of patients who simultaneously met increasingly stringent criteria based on MG-ADL and QMG. The bottom row describes a threshold for both scales above the MCID (minimal clinically meaningful difference: 3 for MG- ADL and 5 for QMG). Higher bars represent increasing thresholds. The right-most panel displays odds ratios for meeting each threshold for eculizumab vs. placebo treated patients.

Figure 19 is a graphical depiction of the change from baseline in MG-ADL total score (LS Mean and 95% CI) by treatment arm over time from ECU-MG-302 baseline to week 52 in study ECU-MG-302 using a repeated-measures model.

Figure 20 is a graphical depiction of the change from baseline in MG-ADL total score (Mean and 95% CI) by treatment arm over time from ECU-MG-301 baseline to week 52 in study ECU-MG-302.

DETAILED DESCRIPTION

The disclosure provides methods of treating myasthenia gravis (MG) in subjects or patients in need thereof by administering an antibody that specifically binds complement component 5 (C5). In certain embodiments, the antibody that specifically binds C5 reduces the rate at which C5 is cleaved, in vivo, into C5a and C5b. In other embodiments, the antibody that specifically binds C5, binds to one or both of the C5a and/or C5b fragments. In any of these embodiments, the antibody that specifically binds C5 blocks the complement cascade at C5, thereby reducing the release of proinflammatory mediators such as C5a and the formation of a C5b-9 Membrane Attack Complex (MAC).

In certain embodiments, the antibody that specifically binds C5 is eculizumab. In more specific embodiments, eculizumab is an antibody or a fragment thereof.

Eculizumab (h5Gl . l-mAb) is a humanized monoclonal antibody (mAb) that was derived from the murine anti-human C5 antibody m5Gl . l . Eculizumab specifically binds the terminal complement protein C5, thereby inhibiting its cleavage to C5a and C5b during complement activation. This strategic blockade of the complement cascade at C5 prevents the release of proinflammatory mediators and the formation of the Membrane Attack Complex or cytolytic pore, while preserving the early components of complement activation that are essential for the opsonization of microorganisms and clearance of immune complexes.

C5 binding proteins are described in U.S. Patent No. 6,355,245, which is hereby incorporated herein by reference in its entirety. In certain embodiments, the anti-C5 antibody is a monoclonal antibody having a hybrid IgG2/4 isotype. In other embodiments, the anti-C5 antibodies are effective in reducing the cell-lysing ability of complement present in human blood. This property of the antibodies can be determined by methods well known in the art such as, for example, by the chicken erythrocyte hemolysis method described in U.S. Patent No. 6,355,245. In certain embodiments, anti-C5 antibodies bind to C5 or fragments thereof, e.g., C5a or C5b. In other embodiments, the anti-C5 antibodies recognize and bind epitopes on either the alpha chain or the beta chain of purified human complement component C5 and are capable of blocking the conversion of C5 into C5a and C5b by C5 convertase. See Wurzner et al, Complement. Inflamm. 8(5-6): 328-40 (1991).

In other embodiments, the anti-C5 antibodies recognize and bind epitopes within the alpha chain of purified human complement component C5. In this embodiment, the antibodies are capable of blocking the conversion of C5 into C5a and C5b by C5 convertase. In one example of this embodiment, the antibodies can provide this blockade at substantially the same concentrations needed to block hemolytic activity.

In some embodiments, the antibodies specifically bind to an amino-terminal region within the alpha chain, however, they do not specifically bind to free C5a. In certain embodiments, the C5 antibody is able to substantially inhibit complement hemolytic activity and to substantially inhibit the conversion of C5 to produce C5a. In some embodiments, the C5 antibodies provide these functions when used at a molar ratio of antibody to antigen (C5) of 3 : 1 or less.

As used herein, the term "antibodies" refers to immunoglobulins produced in vivo, as well as those produced in vitro by a hybridoma, and antigen binding fragments {e.g., Fab' preparations) of such immunoglobulins, as well as to recombinantly expressed antibodies or antigen binding proteins, including immunoglobulins, chimeric immunoglobulins,

"humanized" immunoglobulins, antigen binding fragments of such immunoglobulins, single chain antibodies, and other recombinant proteins containing antigen binding domains derived from immunoglobulins such as DVD-Ig and CODV-Ig. See U.S. Patent Nos. 7, 161,181 and 9, 181,349. "Specificity" refers to the ability of a binding protein to selectively recognize and bind an antigen at a particular location or structure, known as an epitope, often found on the surface of the antigen.

The term "specifically binds," means that a binding protein or fragment thereof forms a complex with an antigen that is relatively stable under physiologic conditions. Specific binding can be characterized by a dissociation constant of at least about lxlO "6 M or smaller. In other embodiments, the dissociation constant is at least about lxlO "7 M, lxlO "8 M, lxlO "9 M, or lxlO "10 M. Methods for determining whether two molecules specifically bind are well known in the art and include, for example, equilibrium dialysis, surface plasmon resonance, and the like. The anti-C5 antibodies described herein bind to complement component C5 (e.g., human C5) and inhibit the cleavage of C5 into fragments C5a and C5b. Anti-C5 antibodies (or VH/VL domains derived therefrom) suitable for use in the invention can be generated using methods known in the art.

An exemplary anti-C5 antibody is eculizumab comprising heavy and light chains having the sequences shown in SEQ ID NOs: 10 and 1 1, respectively, or antigen binding fragments and variants thereof. Eculizumab (also known as SOLIRIS®) is described in U. S. Patent No.

6,355,245. Eculizumab is a humanized monoclonal antibody that is a terminal complement inhibitor.

In other embodiments, the antibody comprises the heavy and light chain complementarity determining regions (CDRs) or variable regions of eculizumab. Accordingly, in one

embodiment, the antibody comprises the CDRl, CDR2, and CDR3 domains of the VH region of eculizumab having the sequence set forth in SEQ ID NO: 7, and the CDRl, CDR2, and CDR3 domains of the VL region of eculizumab having the sequence set forth in SEQ ID NO: 8. In another embodiment, the antibody comprises heavy chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 1, 2, and 3, respectively, and light chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 4, 5, and 6, respectively. In another embodiment, the antibody comprises VH and VL regions having the amino acid sequences set forth in SEQ ID NO: 7 and SEQ ID NO: 8, respectively.

Empirical data indicate that serum eculizumab concentrations greater than 50 μg/mL and closer to at least 100 μg/mL are required to significantly reduce free C5 concentrations.

Specifically, free C5 concentration was reduced significantly with increasing concentrations of eculizumab beginning at >50 μg/mL and was at near zero levels with eculizumab concentrations above 100 μg/ml. Thus, in various embodiments, the method comprises administering a therapeutically effective amount of eculizumab to the subject, wherein the therapeutically effective amount of eculizumab is maintained at a concentration of at least 50 μg/mL of eculizumab in serum of the subject. In another embodiment, the method comprises administering a therapeutically effective amount of eculizumab to the subject, wherein the therapeutically effective amount of eculizumab is maintained at a concentration of at least 60 μg/mL of eculizumab in serum of the subject. In one embodiment, the method comprises administering a therapeutically effective amount of eculizumab to the subject, wherein the therapeutically effective amount of eculizumab is maintained at a concentration of at least 70 μg/mL of eculizumab in serum of the subject. In another embodiment, the method comprises administering a therapeutically effective amount of eculizumab to the subject, wherein the therapeutically effective amount of eculizumab is maintained at a concentration of at least 80 μg/mL of eculizumab in serum of the subject. In another embodiment, the method comprises administering a therapeutically effective amount of eculizumab to the subject, wherein the therapeutically effective amount of eculizumab is maintained at a concentration of at least 90 μg/mL of eculizumab in serum of the subject. In another embodiment, the method comprises administering a therapeutically effective amount of eculizumab to the subject, wherein the therapeutically effective amount of eculizumab is maintained at a concentration of at least 100 μg/mL of eculizumab in serum of the subject.

Another exemplary anti-C5 antibody is an eculizumab variant, known as antibody BNJ441, and engineered to have a longer half-life (Tl/2) in humans comprising heavy and light chains having the sequences shown in SEQ ID NOs: 14 and 1 1, respectively, or antigen binding fragments and variants thereof. BNJ441 (also known as ALXN1210) is described in

International Publication No. WO 2015/134894 Al and U.S. Patent No. 9,079,949, the teachings or which are hereby incorporated by reference. BNJ441 is a humanized monoclonal antibody that is structurally related to eculizumab (SOLIRIS®). BNJ441 selectively binds to human complement protein C5, inhibiting its cleavage to C5a and C5b during complement activation. This inhibition prevents the release of the proinflammatory mediator C5a and the formation of the cytolytic pore-forming membrane attack complex C5b-9 while preserving the proximal or early components of complement activation (e.g., C3 and C3b) essential for the opsonization of microorganisms and clearance of immune complexes.

In other embodiments, the antibody comprises the heavy and light chain CDRs or variable regions of BNJ441. Accordingly, in one embodiment, the antibody comprises the CDRl, CDR2, and CDR3 domains of the VH region of BNJ441 having the sequence set forth in SEQ ID NO: 12, and the CDRl, CDR2, and CDR3 domains of the VL region of BNJ441 having the sequence set forth in SEQ ID NO: 8. In another embodiment, the antibody comprises heavy chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 19, 18, and 3, respectively, and light chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 4, 5, and 6, respectively. In another embodiment, the antibody comprises VH and VL regions having the amino acid sequences set forth in SEQ ID NO: 12 and SEQ ID NO: 8, respectively. In another embodiment, the antibody may comprise the heavy chain constant region of BNJ441 having the amino acid sequence set forth in SEQ ID NO: 13.

In various embodiments, eculizumab is administered in a multiphase dosing regimen. For example, the multiphase dosing regimen comprises a first phase and a second phase in various embodiments. In certain embodiments, the first phase is an induction phase and comprises administration of eculizumab at between 900 mg once a week to the subject for between 1-10 weeks. The induction phase is concluded by administering the first maintenance phase dose of 1200 mg one week after the last 900 mg dose.

In other embodiments, the second phase is a maintenance phase and comprises administration of eculizumab at between 1000 and 1400 mg once every two weeks to the subject for 2 weeks, 4 weeks, 6 weeks, 8 weeks, 12, weeks, 26 weeks, or as long as myasthenia gravis persists. In other embodiments, the maintenance phase comprises administration of eculizumab at between 1000 and 1400 mg once every two weeks to the subject for 2 months, 4 months, 6 months, 8 months, 12 months, 2 years, three years, 4 years, 5 years, or for the remaining lifetime of the patient. In other embodiments, the maintenance phase comprises administration of eculizumab at about 1200 mg twice a month (biweekly) once the induction phase is complete.

In another embodiment, the method comprises administering a therapeutically effective amount of eculizumab or an eculizumab variant to the subject, wherein the therapeutically effective amount of eculizumab or eculizumab variant is maintained at a concentration of between 50-100 μg/mL, between 60-100 μg/mL, between 70-100 μg/mL, between 80-100 μg/mL, or between 90-100 μg/mL of eculizumab in serum of the subject.

Another exemplary anti-C5 antibody is antibody BNJ421 comprising heavy and light chains having the sequences shown in SEQ ID NOs: 20 and 11, respectively, or antigen binding fragments and variants thereof. BNJ421 (also known as ALXN1211) is described in

International Publication No. WO 2015/134894 Al and U.S. Patent No. 9,079,949, the teachings or which are hereby incorporated by reference.

In other embodiments, the antibody comprises the heavy and light chain CDRs or variable regions of BNJ421. Accordingly, in one embodiment, the antibody comprises the CDRl, CDR2, and CDR3 domains of the VH region of BNJ421 having the sequence set forth in SEQ ID NO: 12, and the CDRl, CDR2, and CDR3 domains of the VL region of BNJ421 having the sequence set forth in SEQ ID NO: 8. In another embodiment, the antibody comprises heavy chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 19, 18, and 3, respectively, and light chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 4, 5, and 6, respectively. In another embodiment, the antibody comprises VH and VL regions having the amino acid sequences set forth in SEQ ID NO: 12 and SEQ ID NO: 8, respectively. In another embodiment, the antibody may comprise the heavy chain constant region of BNJ421 having the amino acid sequence set forth in SEQ ID NO: 9.

Another exemplary anti-C5 antibody is the 7086 antibody described in U.S. Patent Nos. 8,241,628 and 8,883,158. In one embodiment, the antibody may comprise the heavy and light chain CDRs or variable regions of the 7086 antibody. See U.S. Patent Nos. 8,241,628 and 8,883, 158. In another embodiment, the antibody, or a fragment thereof, may comprise heavy chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 21, 22, and 23, respectively, and light chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 24, 25, and 26, respectively. In another embodiment, the antibody or fragment thereof may comprise the VH region of the 7086 antibody having the sequence set forth in SEQ ID NO: 27, and the VL region of the 7086 antibody having the sequence set forth in SEQ ID NO: 28.

Another exemplary anti-C5 antibody is the 8110 antibody also described in U.S. Patent Nos. 8,241,628 and 8,883, 158. In one embodiment, the antibody may comprise the heavy and light chain CDRs or variable regions of the 8110 antibody. The antibody, or fragment thereof may comprise heavy chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 29, 30, and 31, respectively, and light chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 32, 33, and 34, respectively. In another embodiment, the antibody may comprise the VH region of the 8110 antibody having the sequence set forth in SEQ ID NO: 35, and the VL region of the 8110 antibody having the sequence set forth in SEQ ID NO: 36.

Another exemplary anti-C5 antibody comprises a heavy chain variable region amino acid sequence according to SEQ ID NO: 37 and a light chain variable region amino acid sequence according to SEQ ID NO: 38.

In various embodiments, eculizumab, an eculizumab variant such as BNJ441, or other anti-C5 antibody is administered to the subject once a month, once every two months, or once every three months depending on the dose. In another embodiment, the eculizumab, eculizumab variant such as BNJ441, or other anti-C5 antibody is administered once every two weeks, once a week, twice a week, or three times a week. In other embodiments, eculizumab, eculizumab variant such as BNJ441, or other anti-C5 antibody is administered once a week, once every two weeks, once every three weeks, once every four weeks, once every five weeks, once every six weeks, or once every eight weeks depending on the needs of the patient. In certain embodiments, eculizumab, eculizumab variant such as BNJ441, or other anti-C5 antibody in administered intravenously (IV) or subcutaneously (SubQ).

Also, provided herein are pharmaceutical compositions comprising an anti-C5 antibody or antigen binding fragment thereof with a pharmaceutically acceptable excipient for treating MG. In one embodiment, the composition comprises an antibody comprising the CDRl, CDR2, and CDR3 domains of the VH region of eculizumab having the sequence set forth in SEQ ID NO: 7, and the CDRl, CDR2, and CDR3 domains of the VL region of eculizumab having the sequence set forth in SEQ ID NO: 8. In another embodiment, the antibody comprises heavy chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 1, 2, and 3, respectively, and light chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 4, 5, and 6, respectively. In another embodiment, the antibody comprises VH and VL regions having the amino acid sequences set forth in SEQ ID NO: 7 and SEQ ID NO: 8, respectively.

In some embodiment, the antibody comprises the heavy and light chain CDRs or variable regions of BNJ441. In one embodiment, the antibody comprises the CDRl, CDR2, and CDR3 domains of the VH region of BNJ441 having the sequence set forth in SEQ ID NO: 12, and the CDRl, CDR2, and CDR3 domains of the VL region of BNJ441 having the sequence set forth in SEQ ID NO: 8. In another embodiment, the antibody comprises heavy chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 19, 18, and 3, respectively, and light chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 4, 5, and 6, respectively. In another embodiment, the antibody comprises VH and VL regions having the amino acid sequences set forth in SEQ ID NO: 12 and SEQ ID NO: 8, respectively.

In some embodiment, the antibody comprises the heavy and light chain CDRs or variable regions of BNJ421. In one embodiment, the antibody comprises the CDRl, CDR2, and CDR3 domains of the VH region of BNJ421 having the sequence set forth in SEQ ID NO: 12, and the CDRl, CDR2, and CDR3 domains of the VL region of BNJ421 having the sequence set forth in SEQ ID NO: 8. In another embodiment, the antibody comprises heavy chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 19, 18, and 3, respectively, and light chain CDRl, CDR2, and CDR3 domains having the sequences set forth in SEQ ID NOs: 4, 5, and 6, respectively. In another embodiment, the antibody comprises VH and VL regions having the amino acid sequences set forth in SEQ ID NO: 12 and SEQ ID NO: 8, respectively. 1. Methods of Treating Myasthenia Gravis

The disclosure provides methods of treating subjects suffering from myasthenia gravis (MG) by administering an antibody that specifically binds C5. In other embodiments, the subject is a mammalian subject.

As used herein, the term "subject" and "patient" are interchangeable. In certain embodiments, subjects and/or patients are mammals. According to certain embodiments, primates include humans. Thus, in certain embodiments, the subjects or patients suffering from MG described herein are humans.

In certain embodiments, MG includes refractory generalized myasthenia gravis. In some embodiments, refractory generalized myasthenia gravis is characterized as including subjects or patients positive for auto-antibodies binding to nicotinic acetylcholine receptor (anti-AChR) who continue to show marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving current standard of care for myasthenia gravis such as cholinesterase inhibitor therapy and immunosuppressant therapy (1ST) or who require chronic plasma exchange or chronic IVIg to maintain clinical stability. In other embodiments, refractory generalized myasthenia gravis is characterized as including subjects or patients who continue to show marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving current standard of care for myasthenia gravis such as cholinesterase inhibitor therapy and immunosuppressant therapy (1ST) or who require chronic plasma exchange or chronic IVIg to maintain clinical stability.

In other embodiments, MG includes refractory generalized myasthenia gravis. In some embodiments, refractory generalized myasthenia gravis is characterized as including subjects or patients positive for auto-antibodies binding to nicotinic acetylcholine receptor (anti-AChR) who continue to show marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving cholinesterase inhibitor therapy and immunosuppressant therapy (1ST) and who require chronic plasma exchange or chronic IVIg to maintain clinical stability. In other embodiments, refractory generalized myasthenia gravis is characterized as including subjects or patients who continue to show marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving cholinesterase inhibitor therapy and immunosuppressant therapy (1ST) and who require chronic plasma exchange or chronic IVIg to maintain clinical stability.

As used herein, the phrase "requires chronic plasma exchange" to maintain clinical stability refers to the use of plasma exchange therapy on a patient on a regular basis for the management of muscle weakness at least every 3 months over the last 12 months.

As used herein, the phrase "requires chronic IVIg" to maintain clinical stability refers to the use of IVIg therapy on a patient on a regular basis for the management of muscle weakness at least every 3 months over the last 12 months.

In certain embodiments, treatment of MG includes the amelioration or improvement of one or more symptoms associated with MG. Symptoms associated with MG include muscle weakness and fatigability. Muscles primarily affected by MG include muscles that control eye and eyelid movement, facial expressions, chewing, talking, swallowing, breathing, neck movements, and limb movements.

In other embodiments, treatment of MG includes the improvement of a clinical marker for MG progression. These markers include MG activity of daily living profile (MG-ADL), quantitative Myasthenia Gravis (QMG) score for disease severity, Myasthenia Gravis composite (MGC), negative inspiratory force (NIF), forced vital capacity, MGFA post- intervention status, and other quality of life measurements. In certain embodiments, MG-ADL is the primary score for measuring improvement of MG.

The MG-ADL is an 8-point questionnaire that focuses on relevant symptoms and functional performance of activities of daily living (ADL) in MG subjects (see Table 1). The 8 items of the MG-ADL were derived from symptom -based components of the original 13- item QMG to assess disability secondary to ocular (2 items), bulbar (3 items), respiratory (1 item), and gross motor or limb (2 items) impairment related to effects from MG. In this functional status instrument, each response is graded 0 (normal) to 3 (most severe). The range of total MG-ADL score is 0 - 24. A clinically meaningful improvement in a patient's MG- ADL would be a 3 point or greater reduction in score after 26 weeks of treatment.

The current QMG scoring system consists of 13 items: ocular (2 items), facial (1 item), bulbar (2 items), gross motor (6 items), axial (1 item), and respiratory (1 item); each graded 0 to 3, with 3 being the most severe (see Table 2). The range of total QMG score is 0— 39. The QMG scoring system is considered to be an objective evaluation of therapy for MG and is based on quantitative testing of sentinel muscle groups. The MGFA task force has recommended that the QMG score be used in prospective studies of therapy for MG. A clinically meaningful improvement in a patient's QMG would be a 5 point or greater reduction in score after 26 weeks of treatment. T It ABLE 1 MG A G CT d IV 0 IT G Y O d F 1 DAILY G LIV d IN 2 G (MG G AD d L) 3 PROF S ILE (0123) 1 Tlkig N l Ilt l igi p ttt h C lt t

b l l it

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t d p i d ffi htd 2 Chig N l F l t i i d g fd ith F f t t ig fd ith Gti Tb 3 Sllig N l Rhkipgidf Fhqkigt

h git iti Gt

d g i Tb

i t

4 Bthig N l S b h tt t ihith f S b h t t ht f t V dp til d t 5 tbi I tlhity p t i bb t h h f i N E b pt t id ff t t dd R d t p d id C ff thti t d 6 bi I hlityi p t i i t f f N Mild ti M l d y t S qiit

7 Dblii N O dily btt Dily t b t tt Ctt 8 Eylid dp N O dily btt Dily t b t tt Ctt

1 9 The MGC is a validated assessment tool for measuring clinical status of subjects with MG (16). The MGC assesses 10 important functional areas most frequently affected by MG and the scales are weighted for clinical significance that incorporates subject-reported outcomes. See Table 3. MGC will be administered at Screening, Day 1, Weeks 1-4, 8, 12, 16, 20, and 26 or ET (Visits 1-6, 8, 10, 12, 14, and 17 or ET). A clinically meaningful

improvement in a patient's MGC would be a 3 point or greater reduction in score after 26 weeks of treatment.

The 15-item Myasthenia Gravis Qualify of Life 15 scale (MG-QOL 15) is a health- related quality of life evaluative instrument specific to subjects with MG. See Table 4. MG- QOL 15 was designed to provide information about subjects' perception of impairment and disability and the degree to which disease manifestations are tolerated and to be easy to administer and interpret. The range of total scores is from 0 to 60. Higher scores translate into a greater extent of a patient's dissatisfaction with MG related dysfunction. The MG-QOL 15 is completed by the subject. Higher scores indicate greater extent of and dissatisfaction with MG-related dysfunction. A clinically meaningful improvement in a patient's MG-QOL 15 would be a decrease in score after 26 weeks of treatment.

The Neuro-QOL Fatigue is a reliable and validated brief 19-item survey of fatigue completed by the subject. Higher scores indicate greater fatigue and greater impact of MG on activities (see Table 5). A clinically meaningful improvement in a patient's Neuro-QQL Fatigue score would be reflected in a decrease in score after 26 weeks of treatment.

The EUROQOL (EQ-5D) is a reliable and validated survey of health status in 5 areas: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression, completed by the subject. Each area has 3 levels: level 1 (no problems), level 2 (some problems), and level 3 (extreme problems) (see Figures 2A and 2B). The EQ VAS records the subject's self-rated health on a vertical, 20 cm visual analogue scale where the endpoints are labeled "Best imaginable health state, marked as 100" and "Worst imaginable health state, marked as 0." The EQ-5D is administered at Day 1, Weeks 4, 8, 12, 16, 20, and 26 or ET (Visits 2, 6, 8, 10, 12, 14, and 17 or ET). A clinically meaningful improvement in a patient's EQ-5D would be reflected as an increase in score after 26 weeks of treatment.

Subjects with increasingly severe MG can suffer from potentially fatal respiratory complications including profound respiratory muscle weakness. Respiratory function is monitored closely for evidence of respiratory failure in MG subjects and ventilator support is recommended in the event of consistent declines in serial measurements of Forced Vital Capacity (FVC) or Negative Inspiratory Force (NIF), loss of upper airway integrity (difficulty handling oral secretions, swallowing, or speaking) or in the setting of emerging respiratory failure. FVC as one of the test items in QMG is performed when QMG is performed. NIF was performed using the NIF Meter.

The MG clinical state is assessed using the MGFA Post-Intervention Status. Change in status categories of Improved, Unchanged, Worse, Exacerbation and Died of MG as well as the Minimal Manifestation (MM) can be assessed.

According to certain embodiments, patients administered eculizumab show a reduced MG-ADL. In certain embodiments, the subjects have an initial MG-ADL score of greater than 6 points. In other embodiments, the subjects have an initial MG-ADL score greater than 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, or 23 points. In certain embodiments, after a course of treatment with eculizumab, the MG-ADL score of the subject has been reduced to less than 6 points. In other embodiments, the MG-ADL score has been reduced at least 1 point, at least 2 points, at least 3 points, at least 4 points, at least 5 points, at least 6 points, at least 7 points, at least 8 points, at least 9 points, at least 10 points, at least 11 points, at least 12 points, at least 13 points, at least 14 points, at least 15 points, at least 16 points, at least 17 points, at least 18 points, at least 19 points, at least 20 points, at least 21 points, at least 22 points, at least 23 points, or at least 24 points after treatment with eculizumab. In certain embodiments, the MG-ADL score of the patient is reduced by at least 1 point after a course of treatment with eculizumab. In other embodiments, the MG-ADL of the patient is reduced by 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24 points after a course of treatment with eculizumab.

According to certain embodiments, the course of treatment with eculizumab lasts for 26 weeks. According to other embodiments, the course of treatment lasts for 26-52, 26-78, 26-104, 26-130, 26-156, 26-182, 26-208 weeks, or more. In other embodiments, the course of treatment lasts for greater than 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 78, 104, 130, 156, or 182 weeks. According to other embodiments, the course of treatment lasts for greater than 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, or more years. In certain embodiments, the course of treatment lasts for the remainder of the subject's life.

According to certain embodiments, during the course of treatment, one or more symptoms or scores associated with MG improves during the course of treatment and is maintained at the improved level throughout treatment. For example, MG-ADL can improve after 26 weeks of treatment with a therapeutic antibody that specifically binds C5 and then remain at the improved level for the duration of the treatment, which is 52 weeks of treatment with a therapeutic antibody that specifically binds C5. One example of a therapeutic antibody that binds C5 is eculizumab.

In certain embodiments, the first sign of improvement occurs by 26 weeks of treatment with a therapeutic antibody that specifically binds C5. According to other embodiments, the first sign of improvement occurs between weeks 1-26, 26-52, 52-78, 78-104, 104-130, 130- 156, 156-182, or 182-208 of treatment with a therapeutic antibody that specifically binds C5. In other embodiments, the first sign of improvement occurs at week 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 78, 104, 130, 156, or 182.

According to certain embodiments, the first sign of improvement is maintained for a number of weeks during treatment with a binding protein that specifically binds C5, such as eculizumab or an eculizumab variant such as BNJ441. According to certain embodiments, this number of weeks is at least 26. According to other embodiments, this number of weeks is 1-26, 26-52, 52-78, 78-104, 104-130, 130-156, 156-182, or 182-208. In other embodiments, this number of weeks is at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 78, 104, 130, 156, or 182.

According to certain embodiments, eculizumab or other anti-C5 antibodies such as BNJ441, BNJ421, 7086, and 8110 can be administered to a subject suffering from MG at between 600 and 6000 mg. According to other embodiments, the induction dose of eculizumab or other anti-C5 antibodies such as BNJ441, BNJ421, 7086, and 8110 is between 900 and 1500 mg, 900 and 1200 mg, 900 mg, or 1200 mg. According to other embodiments, the maintenance dose of eculizumab or other anti-C5 antibodies such as BNJ441, BNJ 421, 7086, and 8110 is about 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 3000, 4000, 5000, or 6000 mg.

These doses can be administered once a month, once every two weeks, once a week, twice a week, or daily. According to certain embodiments, the dose is administered once every two weeks or once a week. According to other embodiments, eculizumab is

administered to a subject suffering from MG in a multiphase dosing regimen. According to certain embodiments, the multiphase dosing regimen has 2, 3, 4, 6, 7, 8, 9, 10, or more phases. In certain embodiments, each phase provides a higher dose than the phase before it.

In certain embodiments, the eculizumab multiphase dosing regimen has two phases. The first phase is an induction phase. This phase provides a dose of 600, 900, 1200, 1500, or 1800 mg per week. In certain embodiments, this phase lasts for 2, 3, 4, 5, 6, 7, 8, 9, or 10 weeks. In other embodiments, this phase lasts between 2 and 6 weeks. In other embodiments, the phase lasts for 5 weeks. According to certain embodiments, the dose given any week is higher than the previous week. In other embodiments, the dose remains the same for a number of weeks and is then increased. In some embodiments, the dose remains the same for the first 1, 2, 3, 4, 5, 6, 7, 8, or 9 weeks and is then increased. In other embodiments, the dose remains the same for the first 4 weeks. According to some embodiments, the eculizumab dose is administered at between 600 and 1200 mg, 800 and 1500 mg, 900 and 1200 mg, 900 and 1100 mg, 900 and 1000 mg, 800 and 1000 mg, 800 and 1100 mg, or 800 and 1200 mg for a number of weeks and is then increased. In one embodiment, the eculizumab dose is administered at about 900 mg on day 1 and is followed by doses of 900 mg on day 7, 900 mg on day 14, 900 mg on day 21, and then is increased to 1200 mg for the fifth dose on day 28, and then 1200 mg is administered every 14 ± 2 days thereafter.

In one particular embodiment, the eculizumab induction phase dosing regimen comprises five administered doses on the following schedule:

900 mg on day 1; 900 mg on day 7 (week 1); 900 mg on day 14 (week 2), 900 mg on day 21 (week 3), and 1200 mg on day 28 (week 4), and then 1200 mg is administered every 14 ± 2 days thereafter. The actual days between each dose may vary during the induction by 1 or 2 days to accommodate unexpected events in the patients' schedule.

According to this embodiment, the second phase of eculizumab dosing is the maintenance phase. The maintenance phase of eculizumab dosing can last for between 6 weeks and the life of the subject. According to other embodiments, the maintenance phase lasts for 26-52, 26-78, 26-104, 26-130, 26-156, 26-182, 26-208 weeks, or more. In other embodiments, the maintenance phase lasts for greater than 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 78, 104, 130, 156, or 182 weeks. According to other embodiments, the maintenance phase lasts for greater than 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80 years, or more years. In certain embodiments, the maintenance phase lasts for the remainder of the subject's life.

In certain embodiments, the eculizumab multiphase dosing regimen includes a third phase. This third phase is used when an MG patient must undergo a rescue procedure to maintain clinical stability and includes administering plasma exchange and/or dosing with IVIg. In this phase after plasma is exchanged a dose of eculizumab is administered to replace the drug lost in plasma exchange. According to certain embodiments, this post-rescue eculizumab dose is between 300 and 1200 mg, 400 and 1500 mg, 500 and 1000 mg, 400 and 800 mg, or 500 and 700 mg. According to certain embodiments, this post-rescue eculizumab dose is about 600 mg. In another embodiment, in this post-rescue or third phase a 600 mg eculizumab dose is administered within 1 hour after completion of plasmapheresis. In another embodiment, in the third phase a 600 mg dose is administered within 2 hours after completion of plasmapheresis. In another embodiment, in the third phase a 600 mg dose is administered within 3 hours after completion of plasmapheresis. In another embodiment, in the third phase a 600 mg dose is administered within 4 hours after completion of plasmapheresis. In another embodiment, in the third phase a 600 mg dose is administered within 5 hours after completion of plasmapheresis. In another embodiment, in the third phase a 600 mg dose is administered within 6 hours after completion of plasmapheresis.

2. Pharmaceutical Compositions

Pharmaceutical compositions comprising eculizumab, either alone or in combination with prophylactic agents, therapeutic agents, and/or pharmaceutically acceptable carriers are provided. The pharmaceutical compositions comprising eculizumab provided herein are for use in, but not limited to, diagnosing, detecting, or monitoring a disorder, in preventing, treating, managing, or ameliorating a disorder or one or more symptoms thereof, and/or in research. The formulation of pharmaceutical compositions, either alone or in combination with prophylactic agents, therapeutic agents, and/or pharmaceutically acceptable carriers, is known to one skilled in the art.

An exemplary, non-limiting range for a therapeutically or prophylactically effective amount of eculizumab or other anti-C5 antibodies such as BNJ441, BNJ 421, 7086, and 8110 provided herein is 600-5000 mg, for example, 900-2000 mg. It is to be noted that dosage values may vary with the type and severity of the condition to be alleviated. It is to be further understood that for any particular subject, specific dosage regimens may be adjusted over time according to the individual need and the professional judgment of the person administering or supervising the administration of the compositions, and that dosage ranges set forth herein are exemplary only and are not intended to limit the scope or practice of the claimed methods.

3. Combination Therapy

An anti-C5 antibody provided herein also can also be administered with one or more additional medicaments or therapeutic agents useful in the treatment of MG. For example, the additional agent can be a therapeutic agent art-recognized as being useful to treat myasthenia gravis or condition being treated by the antibody provided herein. The combination can also include more than one additional agent, e.g., two or three additional agents.

The binding agent in various embodiments is administered with an agent that is a protein, a peptide, a carbohydrate, a drug, a small molecule, or a genetic material (e.g., DNA or RNA). In various embodiments, the agent is one or more cholinesterase inhibitors, one or more corticosteroids, and/or one or more immunosuppressive drugs (most commonly

azathioprine [AZA], cyclosporin, and/or mycophenolate mofetil [MMF]).

Without limiting the disclosure, a number of embodiments of the disclosure are described below for purpose of illustration.

Item 1 : A method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering a therapeutically effective amount of an anti-complement component 5 (C5) antibody or antigen binding fragment thereof to the patient, wherein the patient is administered the anti-C5 antibody or antigen binding fragment thereof for at least 26 weeks.

Item 2: A method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering a therapeutically effective amount of an anti-C5 antibody or antigen binding fragment thereof to the patient, wherein the anti-C5 antibody or antigen binding fragment thereof is eculizumab or an eculizumab variant, and

wherein the patient is administered eculizumab or eculizumab variant for at least 26 weeks.

Item 3 : The method of either items 1 or 2, wherein the patient is positive for autoantibodies binding to nicotinic acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and

immunosuppressant therapy (1ST) and requires chronic plasma exchange or chronic IVIg to maintain clinical stability, and

wherein the patient is administered eculizumab for at least 26 weeks.

Item 4: A method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering eculizumab to the patient:

wherein the patient is positive for auto-antibodies binding to nicotinic acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and immunosuppressant therapy (1ST) and requires chronic plasma exchange or chronic IVIg to maintain clinical stability;

wherein eculizumab is administered using a phased dosing schedule with an induction phase comprising administering a 900 mg induction dose of eculizumab on day 1, administering 900 mg doses of eculizumab on days 7, 14, and 21, and administering 1200 mg of eculizumab as a fifth induction dose on day 28; and

wherein the patient is administered eculizumab for at least 26 weeks.

Item 5: The method of any one of items 1-4, wherein the 28 day induction phase of eculizumab treatment is followed by a maintenance phase comprising administering 1200 mg of eculizumab 14 days after the fifth induction dose and administering 1200 mg of eculizumab every 14 ± 2 days thereafter.

Item 6: The method of any one of items 1-5, wherein the dosing regimen further comprises a third phase.

Item 7: The method of any one of items 1-6, wherein the third phase comprises performing plasmapheresis on the patient and administering eculizumab at a dose of between 300 mg and 1200 mg to the patient within 4 hours of completion of plasmapheresis.

Item 8: The method of any one of items 1-7, wherein the third phase comprises performing plasmapheresis on the patient and administering eculizumab at a dose of between 600 mg and 900 mg to the patient within 90 minutes of completion of plasmapheresis.

Item 9: The method of any one of items 1-8, wherein the third phase comprises performing plasmapheresis on the patient and administering eculizumab at a dose of 600 mg to the patient within 1 hour of completion of plasmapheresis.

Item 10: The method of any one of items 1-9, wherein the patient experiences a clinically meaningful improvement (reduction) in Myasthenia Gravis Activities of Daily Living (MG- ADL) score after 26 weeks of treatment.

Item 11 : The method of any one of items 1-10, wherein the clinically meaningful improvement the patient experiences is at least a 3 point reduction in the patient's MG-ADL score after 26 weeks of treatment.

Item 12: The method of any one of items 1-11, wherein the clinically meaningful improvement the patient experiences is at least a 4 point reduction in the patient's MG-ADL score after 26 weeks of treatment.

Item 13 : The method of any one of items 1-12, wherein the patient experiences a clinically meaningful improvement (reduction) in quantitative Myasthenia Gravis score (QMG) after 26 weeks of treatment.

Item 14: The method of any one of items 1-13, wherein the clinically meaningful improvement the patient experiences is at least a 4 point reduction in the patient's QMG score after 26 weeks of treatment.

Item 15: The method of any one of items 1-14, wherein the clinically meaningful improvement the patient experiences is at least a 5 point reduction in the patient's QMG score after 26 weeks of treatment.

Item 16: The method of any one of items 1-15, wherein the patient experiences a clinically meaningful improvement (reduction) in Myasthenia Gravis Composite (MGC) score after 26 weeks of treatment.

Item 17: The method of any one of items 1-16, wherein the clinically meaningful improvement the patient experiences is at least a 6 point reduction in the patient's MGC score after 26 weeks of treatment.

Item 18: The method of any one of items 1-17, wherein the clinically meaningful improvement the patient experiences is at least a 10 point reduction in the patient's MGC score after 26 weeks of treatment.

Item 19: The method of any one of items 1-18, wherein the patient experiences a clinically meaningful improvement in quality of life as measured by Myasthenia Gravis Quality of Life (MG-QOL-15) score after 26 weeks of treatment.

Item 20: The method of any one of items 1-19, wherein the clinically meaningful improvement the patient experiences is at least a 6 point reduction in the patient's MG-QOL-15 score after 26 weeks of treatment.

Item 21 : The method of any one of items 1-20, wherein the clinically meaningful improvement the patient experiences is at least an 11 point reduction in the patient's MG-QOL- 15 score after 26 weeks of treatment.

Item 22: The method of any one of items 1-21, wherein the patient experiences a clinically meaningful improvement (reduction) in neuro-fatigue as measured by Neuro-QOL Fatigue score after 26 weeks of treatment.

Items 23 : The method of any one of items 1-22, wherein the clinically meaningful improvement the patient experiences is at least an 8 point reduction in the patient's Neuro-QOL score after 26 weeks of treatment.

Item 24: The method of any one of items 1-23, wherein the clinically meaningful improvement the patient experiences is at least a 16 point reduction in the patient's Neuro-QOL score after 26 weeks of treatment.

Item 25: The method of any one of items 1-24, wherein the patient experiences a clinically meaningful improvement (increase) in health status as measured by EQ-5D health status score after 26 weeks of treatment.

Item 26: A method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering eculizumab to the patient:

wherein the patient is positive for auto-antibodies binding to nicotinic acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and immunosuppressant therapy (1ST) and requires chronic plasma exchange or chronic IVIg to maintain clinical stability;

wherein eculizumab is administered using a phased dosing schedule comprising administering a 900 mg induction dose of eculizumab on day 1, administering 900 mg doses of eculizumab on days 7, 14, and 21, and administering 1200 mg as a fifth dose on day 28;

wherein the patient is administered eculizumab for at least 26 weeks;

wherein the 28 day induction phase of eculizumab treatment is followed by

a maintenance phase comprising administering 1200 mg of eculizumab 14 days after the fifth induction dose and administering 1200 mg of eculizumab every 14 ± 2 days thereafter; and wherein the patient has a clinically meaningful improvement (reduction) in at least two measurements of generalized myasthenia gravis severity selected from the group consisting of MG-ADL, QMG, MGC, MG-QOL, and Neuro-QOL.

Item 27: A method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering eculizumab to the patient:

wherein the patient is positive for auto-antibodies binding to nicotinic acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and immunosuppressant therapy (1ST) and requires chronic plasma exchange or chronic IVIg to maintain clinical stability;

wherein eculizumab is administered using a phased dosing schedule comprising administering a 900 mg induction dose of eculizumab on day 1, administering 900 mg doses of eculizumab on days 7, 14, and 21, and administering 1200 mg of eculizumab as a fifth induction dose on day 28;

wherein the patient is administered eculizumab for at least 26 weeks;

wherein the 28 day induction phase of eculizumab treatment is followed by a

maintenance phase comprising administering 1200 mg of eculizumab 14 days after the fifth induction dose and administering 1200 mg of eculizumab every 14 ± 2 days thereafter; and

wherein the patient has a clinically meaningful improvement (reduction) in at least three measurements of generalized myasthenia gravis severity selected from the group consisting of MG-ADL, QMG, MGC, MG-QOL, and Neuro-QOL.

Item 28: The method of any one of items 1-27, wherein the patient has a clinically meaningful improvement (reduction) in at least four measurements of generalized myasthenia gravis severity selected from the group consisting of MG-ADL, QMG, MGC, MG-QOL, and Neuro-QOL.

Item 29: The method of any one of items 1-28, wherein the patient has a clinically meaningful improvement (reduction) in five measurements of generalized myasthenia gravis severity, wherein the five measurements of generalized myasthenia gravis severity are MG-ADL, QMG, MGC, MG-QOL, and Neuro-QOL.

Item 30: A method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering eculizumab to the patient:

wherein the patient is positive for auto-antibodies binding to nicotinic acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and immunosuppressant therapy (1ST) and requires chronic plasma exchange or chronic IVIg to maintain clinical stability;

wherein eculizumab is administered using a phased dosing schedule comprising administering a 900 mg induction dose of eculizumab on day 1, administering 900 mg doses of eculizumab on days 7, 14, and 21, and administering 1200 mg as a fifth induction dose on day 28;

wherein the patient is administered eculizumab for at least 26 weeks;

wherein the 28 day induction phase of eculizumab treatment is followed by a

maintenance phase comprising administering 1200 mg of eculizumab 14 days after the fifth induction dose and administering 1200 mg of eculizumab every 14 ± 2 days thereafter; and

wherein the patient has a clinically meaningful improvement (reduction) in five measurements of generalized myasthenia gravis severity, wherein the five measurements of generalized myasthenia gravis severity are a reduction in MG-ADL of at least 3 points, a reduction in QMG of at least 4 points, a reduction in MGC of at least 6 points, a reduction in MG-QOL of at least 6 points, and a reduction in Neuro-QOL of at least 8 points.

Item 31 : The method of any one of items 1-30, wherein the patient has a clinically meaningful improvement (reduction) in five measurements of generalized myasthenia gravis severity, wherein the five measurements of generalized myasthenia gravis severity are a reduction in MG-ADL of at least 4 points, a reduction in QMG of at least 5 points, a reduction in MGC of at least 10 points, a reduction in MG-QOL of at least 11 points, and a reduction in Neuro-QOL of at least 16 points.

Item 32: The method of any one of items 1-31, wherein eculizumab is administered by intravenous infusion.

Item 33 : The method of any one of items 1-32, wherein eculizumab is administered subcutaneously.

Item 34: The method of any one of items 1-33, wherein the eculizumab comprises a heavy chain amino acid sequence according to SEQ ID NO: 10 and a light chain amino acid sequence according to SEQ ID NO: 11.

Item 35: The method of any one of items 1-34, wherein the eculizumab is an eculizumab variant comprising a heavy chain amino acid sequence according to SEQ ID NO: 14 and a light chain amino acid sequence according to SEQ ID NO: 11. Item 36: The method of any one of items 1-35, wherein the eculizumab is an eculizumab variant comprising a heavy chain variable region amino acid sequence according to SEQ ID NO: 12 and a light chain amino acid sequence according to SEQ ID NO: 11.

Item 37: The method of any one of items 1-36, wherein the anti-C5 antibody or antigen binding fragment thereof comprises a heavy chain variable region amino acid sequence according to SEQ ID NO: 27 and a light chain variable region amino acid sequence according to SEQ ID NO: 28.

Item 38: The method of any one of items 1-37, wherein the anti-C5 antibody or antigen binding fragment thereof comprises a heavy chain variable region amino acid sequence according to SEQ ID NO: 35 and a light chain variable region amino acid sequence according to SEQ ID NO: 36.

Item 39: The method of any one of items 1-38, wherein the patient has failed treatment over one year or more with two or more ISTs in sequence or in combination.

Item 40: The method of any one of items 1-39, wherein the patient has failed at least one 1ST and requires chronic plasma exchange or IVIg to control symptoms of myasthenia gravis.

Item 41 : A method of treating refractory generalized myasthenia gravis in a patient in need thereof comprising administering eculizumab to the patient:

wherein the patient is positive for auto-antibodies binding to nicotinic acetylcholine receptor (anti-AChR) and shows marked generalized weakness or bulbar signs and symptoms of myasthenia gravis while receiving therapy for myasthenia gravis including anticholinesterase inhibitor therapy and immunosuppressant therapy (1ST) and wherein the patient had previously failed treatment with at least two immunosuppressive agents or failed treatment with at least one immunosuppressive agent and required chronic plasma exchange or IVIg, and had an MG-ADL total score >6 at study entry;

wherein eculizumab is administered using a phased dosing schedule with an induction phase comprising administering a 900 mg induction dose of eculizumab on day 1, administering 900 mg doses of eculizumab on days 7, 14, and 21, and administering 1200 mg of eculizumab as a fifth induction dose on day 28;

wherein the patient is administered eculizumab for at least 26 weeks;

wherein the 28 day induction phase of eculizumab treatment is followed by

a maintenance phase comprising administering 1200 mg of eculizumab 14 days after the fifth induction dose and administering 1200 mg of eculizumab every 14 ± 2 days thereafter; and wherein the patient has a clinically meaningful improvement (reduction) in at least two measurements of generalized myasthenia gravis severity selected from the group consisting of MG-ADL, QMG, and MGC.

Item 42: The method of any one of items 1-41, wherein the therapeutically effective amount of eculizumab or eculizumab variant administered to the patient is maintained at a concentration of between 50-100 μg/mL in the patient's serum.

Item 43 : The method of any one of items 1-42, wherein the patient experiences a discontinuation in the administration of one or more 1ST following at least 26 weeks of treatment.

Item 44: The method of any one of items 1-43, wherein the patient experiences a reduction in 1ST dosing following at least 26 weeks of treatment.

Item 45: The method of any one of items 1-44, wherein the patient experiences a reduction in one or more 1ST dosing and a discontinuation in one or more 1ST following at least 26 of treatment.

EXAMPLES

Example 1: Effectiveness of eculizimab in treating myasthenia gravis in human subjects.

The primary objective of this trial is to assess the efficacy of eculizumab as compared with placebo in the treatment of refractory gMG based on the improvement in the MG-specific Activities of Daily Living profile (MG-ADL).

The secondary objectives of this trial include the following:

• Characterize the overall safety and tolerability of eculizumab as compared

with placebo in gMG subjects

• Assess the efficacy of eculizumab as compared with placebo by additional

efficacy measures including:

• Quantitative MG (QMG) Score for Disease Severity

• Myasthenia Gravis Composite (MGC)

• Improvement in primary symptoms that are most clinically meaningful to the subjects

• MG-ADL subcategories for bulbar, respiratory, limb and ocular

• Characterize the effect of eculizumab as compared with placebo on Quality of life measures

• Describe the PK and PD of eculizumab in gMG subjects. 1. Investigational Plan

1.1. Overall Trial Design and Plan

Described herein is a randomized, double-blind, parallel-group, placebo-controlled, multicenter (-100 sites in North America, South America, Europe, Asian Pacific) approximately two year trial to evaluate the safety and efficacy of eculizumab for the treatment in subjects with refractory gMG. Approximately 92 eligible subjects are randomized on Day 1 on a 1 : 1 ratio to one of two treatment arms (1) eculizumab infusion or (2) placebo infusion. Subjects may continue to receive stable dose/type of

immunosuppressive therapy (1ST), but no new ISTs and no increase in 1ST dosage are permitted during the trial. There are 3 periods in this study: Screening Period, Study Period, and Follow-up Period (for subjects who withdraw from this trial or who do not enter the extension trial). See Figure 1. The overall trial duration for an individual subject is estimated to take up to 38 weeks including enrollment and Follow-up. Subjects may be provided the opportunity to participate in an extension trial (separate protocol) to receive eculizumab after completion of this trial. A schedule of assessments for the screening, study and follow-up period is provided in Table 6.

1.1.1. Screening Period (2-4 Weeks)

At the screening visit, after obtaining the informed consent from the subject, the subject is screened for trial eligibility through medical history review, demographic data, and laboratory assessments. The medical history review includes confirmation of MG diagnosis as defined in the inclusion criteria of this protocol, history of previous treatment / therapies for MG, e.g., thymectomy, 1ST including corticosteroids, IVIg and plasma exchange, history of MG exacerbation or crisis including the duration of each exacerbation/crisis, the medication taken at the time of each exacerbation/crisis and the treatment for each exacerbation/ crisis.

If all inclusion criteria and none of the exclusion criteria are met, subjects are vaccinated against N. meningitidis, if not already vaccinated within the time period of active coverage specified by the vaccine manufacturer or vaccinate according to current

medical/country guidelines. Subjects must be vaccinated at least 14 days prior to receiving the first dose of study medication or be vaccinated and receive treatment with appropriate antibiotics until 14 days after the vaccination. See Figure 3.

Use of cholinesterase inhibitor and supportive 1ST are allowed during the trial under certain restrictions {see Concomitant Medications, below). The washout period for IVIg is 4 weeks prior to randomization. The washout period for PE is also 4 weeks prior to randomization. If a subject experiences an MG Crisis during the Screening Period, the sponsor must be notified. Following discussion with the sponsor, a decision is made about whether the subject may continue in the trial, be withdrawn and possibly, re-screened at a later date.

1.1.2. Randomization

All subjects who are vaccinated, and continue to meet the MG-ADL entry criteria, i.e., MG-ADL total score > 6 at Randomization (Day 1), and have been cleared for randomization by their respective Principal Investigator (PI), will be randomized on Day 1 on a 1 : 1 basis to the Eculizumab Arm or the Placebo Arm. The randomization stratification is based on the assessment of clinical classification by the Myasthenia Gravis Foundation of America (MGFA) {see Table 7) performed at the Screening Visit according to the following 4 groupings: a. MGFA Class Ila and

Ilia

b. MGFA Class IVa

c. MGFA Class lib and Illb, and

d. MGFA Class IVb

1.1.3. Study Period (26 Weeks)

Subjects receive IP, either eculizumab or placebo, according to the randomization and the regimen described in the Investigational Product and Administration, described below. The treatment duration for each subject is 26-weeks. Subjects must be informed of potential signs and symptoms of MG crisis and instructed to contact the Investigator as soon as possible at onset of symptom. Every effort is made for the subject reporting Clinical Deterioration to be evaluated as soon as possible and within 48 hours of notification of the Investigator of the symptom onset. At the evaluation visit, the Investigator or his/her designee performs the assessments as specified by this protocol. The Investigator determines whether or not the subject meets the definition of Clinical Deterioration as defined by this protocol and treats the subject accordingly.

After completing the 26-week Study Period, subjects may be provided an opportunity to enter an extension trial (separate protocol) to receive open-label eculizumab. The visit interval between this trial and the extension trial is 2 weeks from the last of IP administration (Visit 17) so there is no interruption in IP dosing. Subjects entering the extension trial undergo a blinded eculizumab induction phase similar to the induction in this trial in order to maintain the blinded treatment assignment of this trial. If a subject withdraws from this trial at any time after receiving any amount of IP or does not wish to enter the extension trial after completion of this trial, the subject is required to complete the Follow-up Visit for safety measures. 1.1.4. Follow-up Period (8 Weeks Post-Treatment)

If a subject withdraws or is discontinued from this trial at any time after receiving any amount of IP or does not wish to enter the extension trial after completion of this trial, the subject will be required to complete the Follow-up Visit for safety measures 8 weeks after the last IP dose administration. If a subject is discontinued due to an AE, the event will be followed until it is resolved or in the opinion of the PI is medically stable.

1.2. Standard Protocol Definitions

Abbreviations and definitions for the study and follow-up period are provided in Table

8.

1. Clinical Deterioration

For this protocol, Clinical Deterioration is defined as follows:

• Subjects who experience an MG Crisis, which is defined as weakness from MG that is severe enough to necessitate intubation or to delay extubation following surgery. The respiratory failure is due to weakness of respiratory muscles. Severe bulbar (oropharyngeal) muscle weakness often accompanies the respiratory muscle weakness, or may be the predominant feature in some subjects; or,

• Significant symptomatic worsening to a score of 3 or a 2-point worsening on any one of the individual MG-ADL items other than double vision or eyelid droop; or,

• Subjects for whom the treating physician believes that the subject's health is in jeopardy if rescue therapy is not given (e.g., emergency situations).

1.2.2. Clinical Evaluation

The Clinical Evaluators are study staff that have been trained and certified in administering the MG-ADL, QMG and MGC. The Clinical Evaluator may be a neurologist, physical therapist or other study team member delegated by the PI. Clinical Evaluator training and certification for this protocol will take place either at the Investigator's meeting or via the sponsor's designated on-line training portal.1.2.3.

RESPONSIBILITIES FOR MG ASSESSMENTS

Responsibilities for MG assessments are listed in Table 9. Throughout the trial, MG assessments should be performed at approximately the same time of day by a properly trained evaluator, preferably the same evaluator.

1.4. Trial Visit Procedures

1.4.1. Screening Visit

(Days -28 to -14 prior to Baseline [Visit 2 Day 1])

After obtaining a signed informed consent form, the following tests and evaluations are performed within 2-4 weeks prior to randomization at the Baseline Visit (Visit 2/Day 1) to determine subject eligibility for participation in this trial:

• Review inclusion and exclusion criteria; Register the subj ect in the IXRS system to get the subject identification number in the study and trigger drug shipment if necessary; Record medical history and demographics; Record MGFA Clinical Classification

• Record MG history:

a. Confirm MG diagnosis as defined by the protocol inclusion criterion #2 b. Record the initial MG clinical presentation {i.e., oMG or gMG). If

the initial clinical presentation was oMG, record the time (date) to

onset of gMG

c. Record the maximum MGFA classification since diagnosis, if

available

d. Record whether the subject ever required ventilatory support since the

diagnosis

e. Record the number of hospitalizations, including number of ICU

stays (days) and any ventilatory support associated with the

hospitalization within the last 2 years prior to screening

f. Record number and duration of all previous MG exacerbations or record

number and duration of all previous MG exacerbations or crisis, the medication / therapy taken at the time of each exacerbation or crisis, and medication / therapy use for treatment of each exacerbation or crisis, if applicable.

Record MG Therapy Status {see Table 9)

Measure body weight and height

Measure vital signs, including assessments of systolic and diastolic blood pressure

(BP), temperature, respiration rate (RR) and heart rate (HR)

Complete physical examination including assessments of the following

organ/body systems: skin, head, ears, eyes, nose, throat, neck, lymph nodes, chest, heart, abdomen, extremities, musculoskeletal, and general neurologic examination.

Perform a 12-Lead ECG

Record concomitant medications, including prior 1ST, IVIg, and/or PE for MG from the time of diagnosis up to screening and all other concomitant medications within 30 days prior to the Screening Visit.

Administer MG-ADL by a properly trained evaluator. The recall period is the preceding 7 days.

Administer clinical assessments QMG, NIF, and MGC; these should be performed at approximately the same time of day by a properly trained evaluator. If the subject is taking a cholinesterase inhibitor, the dose must be withheld for at least 10 hours prior to the QMG and MGC tests. • Administer MG-QOL15 questionnaire to evaluate quality of life.

• Obtain blood sample for AChR Abs test.

• Obtain blood samples for laboratory tests (chemistry and hematology) (see Table 6)

• Obtain pregnancy test (serum) for all women of childbearing potential. Note: if the subject is taking/using contraceptive medication/device, please be sure to record the medication or device on the appropriate electronic case report form (eCRF) pages (concomitant medication or procedure).

• If all inclusion criteria and none of the exclusion criteria are met, subjects will be vaccinated against N. meningitides, if not already vaccinated within the time period of active coverage specified by the vaccine manufacturer or according to current medical/country guidelines. Subjects must be vaccinated at least 14 days prior to receiving the first dose of study medication or be vaccinated and receive treatment with appropriate antibiotics until 14 days after the vaccination.

• If a subject experiences an MG Crisis during the Screening Period, the sponsor should be notified. Following discussion with the sponsor, a decision will be made about whether the subject may continue in the trial, be withdrawn and possibly, re- screened at a later date.

1.4.2. Study Period

Visit intervals during Induction Phase (Visits 2, 3, 4, 5 and 6) are weekly (every 7 ± 2 days after the last visit). Visit intervals during the Maintenance Phase (Visits 7 - 17) are every 2 weeks (every 14 days ± 2 days since the last visit). Subjects who fail to return for a scheduled visit must be contacted by the site study staffs to determine the reason for missing the appointment. Subjects are strongly encouraged to return to the investigational site for evaluation if Clinical Deterioration or an AE is suspected to have occurred. In the exceptional circumstance where a subject cannot or does not come to the study site for examination, then the subject will be instructed to see his or her local neurologist or physician. In this event, the investigational site obtains relevant medical records as documentation from the local physician's examination, and enters relevant data in the eCRF as appropriate.

As it is vital to obtain information on any subject's missing visit to assure the missing appointment was not due to a clinical deterioration or an AE, every effort must be made to undertake protocol -specified follow-up procedures (see Table 6). Follow-up due diligence documentation consists of 3 phone calls followed by 1 registered letter to the subject's last known address. The study period is summarized in Table 6 and Figure 6.

1.4.2.1. Induction Phase (Baseline [Visit 2/Day 1] until Visit 6 [Week 4])

1.4.2.1.1. Baseline (Visit 2 Day 1)

Once all of the eligibility criteria have been confirmed by the PI, the subject is randomized on Day 1. The following tests and procedures are completed at the Baseline Visit (Visit 2 Day 1):

Measure vital signs, including assessments of systolic and diastolic BP,

temperature, RR and HR

Record MG Therapy Status (see Table 9)

Record any new medications or changes to concomitant medications

Evaluate and record AEs since the previous visit

Administer questionnaires to evaluate quality of life (MG-QOL 15, Neuro- QOL Fatigue, and EuroQoL [EQ-5D])

Administer MG-ADL by a properly trained evaluator, preferably the same

evaluator, throughout the trial. The recall period is the preceding 7 days. If the number of days since the last visit was <7, the recall period is since the last visit.

• Administer clinical assessments QMG, NIF, and MGC; these should be performed at approximately the same time of day by a properly trained evaluator, preferably the same evaluator, throughout the trial. If the subject is taking a cholinesterase inhibitor, the dose must be withheld for at least 10 hours prior to the QMG and MGC tests.

• Perform Columbia-Suicide Severity Rating Scale (C-SSRS)

• Obtain blood samples for clinical laboratory tests (chemistry and hematology)

• Obtain pregnancy test (serum) for all women of childbearing potential.

• Collect baseline blood samples for PK, PD, free C5, and HAHA assays 5-90

minutes before the infusion of IP.

• Instruct the subject on the signs and symptoms of N. meningitis. Provide the Patient Safety Information Card describing the IP and emergency contact information to the subject prior to the first dose of IP.

• Randomize the subject using the IXRS.

• Administer the IP infusion over approximately 35 minutes according to the

regimen described in Section 4.5, and observe subjects for 1 hour after the end of the IP infusion.

• Collect peak blood samples for PK, PD, and free C5 assays at least 60

minutes after completion of the IP infusion. 2. Visits 3-5 (Weeks 1-3)

The following tests and procedures are completed:

• Measure vital signs, including assessments of systolic and diastolic BP,

temperature, RR, and HR

• Record any new medications or changes to concomitant medications

• Evaluate and record any new AEs or changes in AEs since the previous visit.

• Administer MG-ADL by a properly trained evaluator, preferably the same

evaluator, throughout the trial. The recall period is the preceding 7 days. If the number of days since the last visit was <7, the recall period is since the last visit.

• Administer clinical assessments QMG, NIF, and MGC; these should be performed at approximately the same time of day by a properly trained evaluator, preferably the same evaluator, throughout the trial. If the subject is taking a cholinesterase inhibitor, the dose must be withheld for at least 10 hours prior to the QMG and MGC tests.

• At Visit 3 (Week 1) only, collect trough (before IP infusion) blood samples for PK, PD, and free C5 assays. Trough blood samples are to be taken 5-90 minutes before the IP infusion.

Ensure that the subject has the Patient Safety Information Card that describes the

IP and emergency contact information.

Obtain study drug kit assignation through the IXRS.

• Administer the IP infusion over approximately 35 minutes according to the regimen described in Section 4.5, and observe subjects for 1 hour after the end of the IP infusion.

• At Visit 3 (Week 1) only, collect peak (after IP infusion) blood samples for PK, PD, and free C5 assays. Peak blood samples are to be taken at least 60 minutes after the completion of the IP infusion. 3. Visit 6 (Week 4)

The following tests and procedures are completed at this visit:

• Measure vital signs, including assessments of systolic and diastolic BP,

temperature, RR, and HR

• Record any new medications or changes to concomitant medications

• Evaluate and record any new AEs or changes in AEs since the previous visit

• Administer questionnaires to evaluate quality of life (MG-QOL 15, Neuro- QOL Fatigue, and EQ-5D)

• Administer MG-ADL by a properly trained evaluator, preferably the same

evaluator, throughout the trial. The recall period is the preceding 7 days. If the number of days since the last visit was <7, the recall period is since the last visit.

• Administer clinical assessments QMG, NIF, and MGC; these should be performed at approximately the same time of day by an appropriately trained evaluator, preferably the same evaluator, throughout the trial. If the subject is taking a cholinesterase inhibitor, the dose must be withheld for at least 10 hours prior to the QMG and MGC tests.

• Assess change from baseline in the MGFA Post-Intervention Status (see Table 10).

• Collect blood samples for clinical laboratory tests (chemistry and hematology).

• Collect trough blood samples for PK, PD, free C5, and HAHA assays 5-90

minutes before the infusion of IP. • Ensure that the subject has the Patient Safety Information Card that describes the IP and emergency contact information.

• Obtain study drug kit assignation through the IXRS.

• Administer the IP infusion over approximately 35 minutes according to the

regimen described in Section 4.5, and observe subjects for 1 hour after the end of the IP infusion.

• Collect peak blood samples for PK, PD, and free C5 assays at least 60

minutes after completion of the IP infusion.

1.4.2.2. Maintenance Phase (Visit 7 [Week 6] until End of Study Period Visit 17 [Week 26] or Early Termination of Visit)

During the Maintenance Phase, subjects return for infusions of IP every 2 weeks (14 ± 2 days), according to the regimen described in Section 4.5. The following tests and procedures are completed at every visit beginning at Visit 7 (Week 6) and continuing until the End of Study (EOS), Visit 17 (Week 26) or at Early Termination (ET):

• Measure vital signs, including assessments of systolic and diastolic BP,

temperature, RR, and HR

• Record any new medications or changes to concomitant medications

• Evaluate and record any new AEs or changes in AEs since the previous visit.

• Ensure that the subject has the Patient Safety Information Card that describes the IP and emergency contact information.

• Administer the IP and observe subjects for 1 hour after the end of the IP infusion.

IP will be administered after completion of other tests and procedures, excluding the peak blood sampling for PK/PD and free C5 assay.

At Visit 8 (Week 8), Visit 10 (Week 12), Visit 12 (Week 16), Visit 14 (Week 20), and until the EOS, Visit 17 (Week 26) or at ET, the following procedures are also

completed, in addition to the 5 preceding procedures listed for the maintenance phase:

• Administer questionnaires to evaluate quality of life (MG-QOL 15, Neuro- QOL Fatigue, and EQ-5D)

• Administer MG-ADL by a properly trained evaluator, preferable the same

evaluator, throughout the trial. The recall period is the preceding 7 days.

• Administer clinical assessments QMG, NIF, and MGC; these should be performed at approximately the same time of day by a properly trained evaluator, preferably the same evaluator, throughout the trial. If the subject is taking a cholinesterase inhibitor, the dose must be withheld for at least 10 hours prior to the QMG and MGC tests.

• Perform C-SSRS only at Visit 10 (Week 12) and Visit 17 (Week 26)/ET. The blood sample for the HAHA assay is to be collected 5-90 minutes before the infusion of IP.

• Obtain blood sample for clinical laboratory tests (chemistry and hematology).

• Obtain blood sample for the AChR Abs test and HAHA assay only at Visit 10 (Week

12) and Visit 17 (Week 26)/ET.

• Collect trough blood samples for PK, PD, and free C5 assays 5-90 minutes before the infusion of IP only at Visits 8, 10, 14 and 17/ET (Weeks 8, 12, 20, and 26).

• Collect peak blood samples for PK, PD, and free C5 assays at least 60 minutes after completion of the IP infusion only at Visits 8, 10, 14 and 17/ET (Weeks 8, 12, 20, and

26).

• Measure body weight only at Visit 17 (Week 26)/ET.

• Perform a 12-Lead ECG only at Visit 17 (Week 26)/ET.

• Record MG Therapy Status (see Table 9) only at Visit 17 (Week 26)/ET.

• Obtain pregnancy test must for all women of childbearing potential at Visit 17

(Week 26)/ET.

• Assess change from baseline in the MGFA Post-Intervention Status only at Visit 10 (Week 12) and Visit 17 (Week 26)/ET.

1.4.2.3. Visits for MG Crisis or Clinical Deterioration

The evaluation visit for an MG crisis or Clinical Deterioration must be performed as soon as possible, within 48 hours of notification of the Investigator of the symptom onset. Additional evaluation visits can be scheduled at the discretion of the investigator. The following tests and procedures are completed at this visit:

• Measure vital signs, including assessments of systolic and diastolic BP,

temperature, RR, and HR

• Record any new medications or changes to concomitant medications, including all treatments for MG

• Evaluate and record any new AEs or changes in AEs since the previous visit

• Administer MG-ADL by a properly trained evaluator, preferably the same evaluator, throughout the trial. The recall period is the preceding 7 days or since the last visit whichever occurs earlier.

• Administer clinical assessments QMG, NIF, and MGC; these should be

performed at approximately the same time of day by a properly trained evaluator, preferably the same evaluator, throughout the trial.

• Collect blood sample for the AChR Abs test

• Collect blood samples for clinical laboratory tests (chemistry and hematology)

• If medically indicated for evaluation of Clinical Deterioration, additional tests

may be performed at the discretion of the Investigator.

• PK, PD sampling at or during crisis or deterioration Visit:

• Collect one blood sample for PK, PD, and free C5 assays if no IP is administered.

• If IP is administered at the MG Crisis evaluation visit or at the visit for Clinical Deterioration, according to the protocol schedule, collect two blood samples, trough and peak, at [1] 5-90 minutes before the IP infusion and [2] at least 60 minutes after completion of the IP infusion.

• If the subject receives PE at the time of a crisis or Clinical Deterioration, a

supplemental dose of IP will be administered. Collect three blood samples for PK, PD, and free C5 at [1] 5-90 minutes before PE, [2] 60 minutes after PE and before IP infusion, and [3] at least 60 minutes after completion of the IP infusion.

• IP administration:

• Subject will continue IP administration in accordance with protocol specified IP administration schedule.

• If the crisis or Clinical Deterioration Visit coincides with a regular visit per

protocol, subject will receive the regular scheduled IP administration per protocol schedule.

• If subjects undergo PE, a supplemental dose (2 vials IP) must be administered within 60 minutes after each PE session. If the subject is scheduled to receive the protocol-scheduled dose on the day of a PE session, then the scheduled dose should be administered within 60 minutes after the end of the PE.

1.4.2.4 Unscheduled Visit

Additional (Unscheduled) visits outside the specified visits are permitted at the

discretion of the Investigator. Procedures, tests, and assessments are performed at the discretion of the Investigator. If an Unscheduled Visit is performed, any tests, procedures, or assessments performed at the Unscheduled Visits must be recorded on the eCRFs.

1.4.3. Safety Follow-Up Period (Post-Treatment +Week 4) Safety Follow-Up Period (Post-Treatment +Week 8)

If a subject withdraws from the trial at any time during the Study Period after receiving any amount of IP (eculizumab or placebo) or does not wish to enter the extension trial after completion of this trial, a follow up visit for safety assessment is required at 4 weeks after the last dose of IP. The following tests and procedures will be completed at the safety follow-up visit:

• Measure vital signs, including assessments of systolic and diastolic BP,

temperature, RR, and HR

• Record any new medications or changes to concomitant medications

• Evaluate and record any new AEs or changes in AEs since the previous visit.

• Administer MG-QOL15

• Administer MG-ADL by a properly trained evaluator, preferably the same

evaluator, throughout the trial. The recall period is the preceding 7 days.

• Administer clinical assessments QMG, NIF, and MGC; these should be performed at approximately the same time of day by a properly trained evaluator, preferably the same evaluator, throughout the trial. If the subject is taking a cholinesterase inhibitor, the dose must be withheld for at least 10 hours prior to the QMG and MGC tests.

• Assess change from baseline in MGFA Post-Intervention Status (see Table 10).

If a subject is discontinued due to an AE, the AE will be followed until it is resolved or, in the opinion of the PI, is determined medically stable.

1.5. Number of Subjects

Approximately 92 subj ects with refractory gMG are randomized in a 1 : 1

(eculizumab: placebo) ratio at approximately 100 centers. Randomization is across centers and is stratified based on MGFA clinical classifications (Class a vs. Class b and Classes II and III vs. Class IV) (see Table 7).

1.6. Treatment Assignment

Approximately 92 subjects with refractory gMG are randomized, 46 subjects to eculizumab and 46 subjects to placebo. All patients will remain on assigned double-blind treatment until the EOS/ET visit. Randomized subjects who discontinue after initiation of study treatment are not being replaced. Assignment will be performed through the IXRS at each visit.

2. Selection and Withdrawal of Subjects

2.1. Subject Inclusion Criteria

1. Male or female subj ects > 18 years old

2. Diagnosis of MG must be made by the following tests:

• Positive serologic test for anti-AChR Abs as confirmed at screening, and

• One of the following:

a. History of abnormal neuromuscular transmission test demonstrated by single- fiber electromyography (SFEMG) or repetitive nerve stimulation, or b. History of positive anticholinesterase test, e.g., edrophonium chloride test, or c. Subject has demonstrated improvement in MG signs on oral

cholinesterase

inhibitors, as assessed by the treating

physician.

3. MGFA Clinical Classification Class II to IV at screening.

4. MG-ADL total score must be >6 at screening and Randomization (Day 1)

5. Subj ects who have

a. Failed treatment over one year or more with 2 or more ISTs* (either in

combination or as mono-therapy), i.e., continue to have impairment ADLs (persistent weakness, experience crisis, or unable to tolerate 1ST) despite ISTs. Or, b. Failed at least one 1ST and require chronic plasma exchange or IVIg to

control symptoms, i.e., subjects who require PE or IVIg on a regular basis for the management of muscle weakness at least every 3 months over last 12 months.

* Immunosuppressant's include, but are not limited to, corticosteroids AZA,

MMF, methotrexate (MTX), cyclosporine, tacrolimus, or cyclophosphamide. If subjects who enter the study are receiving AZA they must have been on AZA for >6 months and have been on a stable dose for >2 months prior to screening.

If subjects who enter the study are receiving other ISTs, i.e., MMF, MTX,

cyclosporine, tacrolimus, or cyclophosphamide, they must have been on the 1ST for >3 months and have been on a stable dose for >1 month prior to screening.

If subjects who enter the study are receiving oral corticosteroids, they must have been on a stable dose for > 4 weeks (28 days) prior to screening.

If subjects who enter the study are receiving a cholinesterase inhibitor they must have been on a stable dose for >2 weeks prior to screening.

Female subjects of child-bearing potential must have a negative pregnancy test

(serum human chorionic gonadotropin [HCG]). All subjects must practice an effective, reliable and medically approved contraceptive regimen during the study and for up to 5 months following discontinuation of treatment.

Subject must give written informed consent.

Subject must be able and willing to comply with study procedures. Subject Exclusion Criteria

History of thymoma or other neoplasms of thymus.

History of thymectomy within 12 months prior to screening.

Weakness only affecting ocular or peri-ocular muscles (MGFA Class I).

MG crisis at screening (MGFA Class V)

Pregnancy or lactation.

Any systemic bacterial or other infection, which is clinically significant in the opinion of the Investigator and has not been treated with appropriate antibiotics

Unresolved meningococcal infection.

Use of IVIg within 4 weeks prior to Randomization (Day 1).

Use of PE within 4 weeks prior to Randomization (Day 1).

Use of rituximab within 6 months prior to screening. 11. Participation in any other investigational drug trial or exposure to other investigational agent, device, or procedures within 30 days prior to screening.

12. Subjects who have received previous treatment with eculizumab.

13. Hypersensitivity to murine proteins or to one of the excipients of eculizumab.

14. Any medical condition that, in the opinion of the Investigator, might interfere with the subject's participation in the study, poses any added risk for the subject, or confounds the assessment of the subjects.

2.3. Subject Withdrawal Criteria

2.3.1. Withdrawal of Subjects from the Trial

Subjects are allowed to withdraw consent at any time. Every effort should be made to ensure subjects are willing to comply with trial participation prior to conducting the screening procedures and the subjects should be fully informed of the restrictions related to the change of concomitant medications during the trial. Investigators may choose to discontinue a subject's treatment because of AEs, as well as conditions or illnesses that preclude compliance with the protocol from the standpoint of the subject's safety or well-being. The study staff should notify the Sponsor and their site monitor of all trial withdrawals as soon as possible.

Reproduction and development studies with eculizumab have not been performed; therefore, eculizumab should not be administered to pregnant women. At the time of the last follow-up visit, all subjects of childbearing potential must continue to use adequate contraception for up to 5 months following discontinuation of eculizumab treatment. If a subject becomes pregnant, the IP must be immediately discontinued and the Sponsor must be notified. Each pregnancy will be followed to term and the Sponsor notified regarding the outcome.

2.3.2. Handling of Withdrawals

When a subject withdraws or is withdrawn from the trial, the Investigator shall record the withdrawal reason(s). Whenever possible, all subjects who prematurely withdraw from the trial will undergo all assessments at the ET visit for safety as per the Schedule of

Assessments (Table 6). A follow-up visit for safety assessment is required at 8 weeks after the last dose of IP administration (Table 6).

If a subject is discontinued due to an AE, the event will be followed until it is resolved or in the opinion of the PI the subject is determined to be medically stable. Every effort will be made to undertake protocol-specified safety follow-up procedures. Subjects who fail to return for final assessments will be contacted by the site study staffs in an attempt to have them comply with the protocol. As it is vital to obtain follow-up data on any subject withdrawn because of an AE or SAE, follow-up due diligence

documentation will consist of 3 phone calls followed by 1 registered letter to the subject's last known address. In any case, every effort must be made to undertake protocol-specified safety follow-up procedures.

2.3.3. Sponsor's Termination of Trial

Alexion Pharmaceuticals, Inc. or a regulatory authority may discontinue the trial at any time for any reason including, for example, clinical or administrative reasons.

2.3.4. End of Trial Definition

The end of trial is defined as the last visit completed by the last patient.

3. Treatment of Subjects

3.1. Description of Investigational Product

Eculizumab (600 mg, 900 mg or 1200 mg) or matching placebo is administered intravenously over approximately 35 minutes according to the regimen shown in Table 11.

Induction Phase

Eculizumab or placebo: 3 vials of IP (equivalent to 900 mg of eculizumab) weekly for 4 weeks (every 7 days ± 2 days) followed by 4 vials of IP (equivalent to 1200 mg of eculizumab) one week later for the fifth dose (Visit 6/Week 4).

Maintenance Phase

Eculizumab or placebo: 4 vials of IP (equivalent to 1200 mg of eculizumab) every 2 weeks (14 days ± 2 days)

* Supplemental Doses

If PE is administered due to a Clinical Deterioration (as defined by this protocol), supplemental IP (2 vials, equivalent to 600 mg of eculizumab or matching placebo) will be administered within 60 minutes after the end of each PE session. If PE is administered on a day of regularly scheduled IP administration, subjects will receive the regularly scheduled number of vials (3 vials on Visits 2 - 4; 4 vials on all other visits) within 60 minutes after each PE session.

3.2. Concomitant Medications

3.2.1. Allowed Medications

3.2.1.1. Palliative and Supportive Care

Palliative and supportive care is permitted during the course of the trial for underlying conditions.

The following medications are allowed under certain circumstances and

restrictions. .2.1.2. Cholinesterase Inhibitors

• For subjects who enter the trial receiving a cholinesterase inhibitor for at least two weeks prior to screening, the dose and schedule of their cholinesterase inhibitor is maintained stable throughout the entire Study Period, unless there is compelling medical need. Increases in cholinesterase therapy that are required as a result of inter-current illness or other medical cause of deterioration are permitted but dosing should be returned to dosing levels at trial entry as soon as feasible and the trial sponsor should be notified of the change.

• Cholinesterase inhibitor treatment must be withheld for at least 10 hours prior to QMG and MGC tests.

• If a decrease in cholinesterase inhibitor is considered based on clinical evaluation, sponsor approval must be obtained prior to the change in dose in order for the subject to remain on study. Dose increase as a result of inter-current illness or other medical cause is permitted, but dose should be returned to dose level at trial entry as soon as feasible and the trial sponsor should be notified. .2.1.3. Immunosuppressive Agents

The following immunosuppressive agents are allowed during the trial: corticosteroid, AZA, MMF, MTX, tacrolimus, cyclosporine, or cyclophosphamide. The immunosuppressive agent(s) and its appropriate dose level to be used for an individual subject is at the discretion of the treating physician.

• Corticosteroid - for subjects who enter the trial receiving oral corticosteroid, e.g., prednisone, the dose/schedule must have been stable for four weeks prior to trial and may not be changed during the entire double-blind Study Period. If a decrease or taper in steroid dose is considered during the Study Period based on clinical evaluation, sponsor approval must be obtained prior to the change in order for the subject to remain on trial. If the dose level subsequently must be increased, the dose level increase cannot be above the dose level reported at the baseline (at the start of randomized treatment).

High-dose steroid should be reserved for subjects that experience Clinical Deterioration as defined by this protocol. Every effort should be made to notify the Sponsor within 24 hours of administration should a subject require a rescue therapy for Clinical Deterioration.

• AZA, MMF, MTX, tacrolimus, cyclosporine or cyclophosphamide - for subjects who enter the trial receiving above mentioned immunosuppressive agents, the dose regimen of the immunosuppressive agent may not be changed during the entire double-blind Study Period. If a change in the dose regimen is considered due to known toxicity or side effects associated with the given immunosuppressive agent, sponsor approval must be obtained prior to the dose change in order for the subject to remain on the trial. A different immunosuppressive agent cannot be added or substituted during the 26-week double-blind Study Period.

3.2.1.4. Plasma Exchange / Plasmapheresis (PE) / IVIg

Use of PE or IVIg will be allowed for subjects who experience a Clinical

Deterioration as defined by this protocol. The rescue therapy used for a particular subject is at the discretion of the treating physician. Every effort should be made to notify the Sponsor within 24 hours should a subject require a rescue therapy.

If PE is administered as a rescue therapy, supplemental IP (2 vials) are administered within 60 minutes after the end of each PE session. Routine (per protocol schedule) IP administration is continued per the specified dose-administration schedule for the subject. If the subject is scheduled to receive the protocol-scheduled dose on the day of a PE session, then the scheduled dose is administered within 60 minutes after the end of the PE session. 3.2.2. Disallowed Medications

The following concurrent medications are prohibited during the trial:

• Use of

rituximab

3.3. Treatment Compliance

The infusion of IP into subjects is under the supervision of the Pi/Sub-Investigator or their designee, to ensure that the subject receives the appropriate dose at the appropriate time-points during the trial.

Subjects who fail to return for a scheduled visit within the accepted intervals must be contacted by the site study staffs to determine the reason for missing the appointment.

Instructions for handling of missing visits are provided in Section 1.4.2.

3.4. Randomization and Blinding

3.4.1. Randomization

Subjects are randomized on Day 1 after the Investigator has verified that they are eligible. Subjects are randomized in a 1 : 1 ratio of eculizumab infusion to placebo infusion. The randomization will be across centers using an IXRS. The randomization stratification will be based on MGFA clinical classification assessed at the Screening Visit according to the following 4 groupings:

a. MGFA Class Ila and Ilia

b. MGFA Class IVa

c. MGFA Class lib and Illb, and

d. MGFA Class IVb

The MGFA clinical classifications are described in Table 7.

3.4.2. Blinding and Unblinding

All trial subjects, investigational site personnel, sponsor staff, sponsor designees, and all staff directly associated with the conduct of the trial are blinded to the subject treatment assignments. The double blind is maintained by using identical IP kits and labels for eculizumab and placebo. The placebo has an identical appearance to that of eculizumab. The random code is maintained by Almac Clinical Services. There is no antidote to reverse the effects of eculizumab.

Therefore, unblinding would not be helpful in the planning of patient treatment for a given event. Unblinding should only be considered for the safety of the subject. If unblinding is deemed necessary by the Investigator, the Investigator can unblind the patient's treatment allocation using IXRS. The Investigator must note the date, time and reason for unblinding.

The Investigator should inform the Medical Monitor that the patient was unblinded, however they are not required to reveal to the Medical Monitor the patients' treatment allocation.

When an AE is an unexpected related serious AE, the blind will be broken by the Sponsor only for that specific subject. The blind will be maintained for persons responsible for the ongoing conduct of the study (such as the management, monitors, investigators, etc.) and those responsible for data analysis and interpretation of results at the conclusion of the study, such as biometrics personnel. Unblinded information will only be accessible to those who need to be involved in the safety reporting to Health Authorities, Ethics Committees and/or IRBs.

Investigators will receive only blinded information unless unblinded information is judged necessary for safety reasons.

4. Investigational Product Materials and Management

4.1. Investigational Product

Each vial of IP contains eculizumab 300 mg or matching placebo for IV administration.

4.2. Investigational Product Packaging and Labeling

The active IP, eculizumab is manufactured and supplied by Alexion in single 30 mL vials as a solution concentration of 10 mg/ml. The comparator product is manufactured by Alexion Pharmaceuticals, Inc., as a matching sterile, clear, colorless solution with the same buffer components but without active ingredient, in an identical 30 ml vial. See Table 12.

All study medication is prepared in vials, packaged in kits, labeled in an identical manner.

IP vials will be individually packaged into a kit. Both vials and kits will be labeled according to the protocol and local regulatory requirements. Each kit will have a label describing the contents and a place for the pharmacist to record the subject number and initials.

Study medication is shipped and released to each participating trial center upon receipt of all required essential documents based upon federal, state, and local regulations (Table 12).

4.3. Investigational Product Storage

IP is released to the site upon receipt of all required essential documents based upon federal, state, and local regulations. See Table 12.

Upon arrival at the center, the IP is promptly removed from the shipping cooler and stored in refrigerated conditions at 2 to 8°C. The pharmacist should immediately record the reception of the IP and notify the distributor if vials are damaged and/or if temperature excursions have occurred during transportation. IP must be stored in a secure, limited-access storage area and temperature must be monitored daily.

Diluted solutions of IP may be stored at 2 to 8°C (36-46°F) for up to 24 hours prior to administration. If the IP is prepared more than 4 hours in advance of a subject's visit, the diluted material should be stored at 2 to 8°C. The solution should be allowed to warm to room temperature prior to administration. The material must not be heated {e.g., by using a microwave or other heat source) other than by ambient air temperature.

4.4. Investigational Product Preparation

Infusions of IP are prepared using aseptic technique. Each vial of IP contains 300 mg of active ingredient in 30 mL of product solution or matching placebo.

Withdraw the required amount of IP from the vials. Transfer the recommended dose to an infusion bag. Dilute the IP to a final concentration of 5 mg/mL by addition to the infusion bag of the appropriate amount (equal volume) of 0.9% Sodium Chloride Injection, USP; 0.45% Sodium Chloride Injection, USP; 5% Dextrose in Water Injection, USP; or Ringer's Injection, USP. The final volume of a 5 mg/mL diluted IP solution is 120 mL for 600 mg doses (2 vials), 180 mL for 900 mg doses (3 vials) and 240 mL for 1200 mg doses (4 vials) as shown in Table 13.

Gently invert the infusion bag containing the diluted IP solution to ensure thorough mixing of the product and diluents. Discard any unused portion left in a vial, as the product contains no preservatives. The diluted solution should be allowed to warm to room

temperature by exposure to ambient air prior to administration.

4.5. Administration

DO NOT ADMINISTER AS AN IV PUSH OR BOLUS INJECTION

IP is only administered via IV infusion and must be diluted to a final concentration of 5 mg/mL prior to administration. Prior to administration, if the diluted solution is refrigerated, it is allowed to warm to room temperature by exposure to ambient air. The diluted solution must not be heated in a microwave or with any heat source other than ambient air temperature. Parenteral drug products are inspected visually for particulate matter and discoloration prior to administration.

The diluted IP is intravenously administered over 35 minutes (range 25 to 45 minutes). It is not necessary to protect the infusion bags from light while IP is being administered to the subject. At the site's discretion, the diluted IP may be administered via gravity feed, a syringe- type pump, or an infusion pump. The subjects are monitored for 1 hour following infusion.

If an AE occurs during the administration of the IP, the infusion may be slowed or stopped at the discretion of the Investigator, depending upon the nature and severity of the event. The overall time of infusion should not exceed 2 hours. The AE must be captured in the subject's source document and CRT.

5. Assessment of Efficacy

Duration of treatment commences with the first infusion of IP (eculizumab or placebo). The 26-week Study Period defines the time period for assessment of the study endpoints (specified in Table 6, the schedule of assessments). Efficacy will be assessed comparing eculizumab outcomes to placebo outcomes. Statistical analyses of the efficacy endpoints are summarized below and described in more detail in the statistical analysis plan. For all scales noted below except the EQ Visual Analog Scale (VAS) and Myasthenia Gravis Foundation of America (MGFA) Post-Intervention Status (PIS) the higher the score the greater the impairment.

5.1. MG Activities of Daily Living Profile (MG- ADL)

The MG-ADL is an 8-point questionnaire that focuses on relevant symptoms and functional performance of activities of daily living (ADL) in MG subjects (see Table 1). The 8 items of the MG-ADL were derived from symptom -based components of the original 13 -item QMG to assess disability secondary to ocular (2 items), bulbar (3 items), respiratory (1 item), and gross motor or limb (2 items) impairment related to effects from MG. In this functional status instrument, each response is graded 0 (normal) to 3 (most severe). The range of total MG-ADL score is 0 - 24. A clinically meaningful improvement in a patient's MG-ADL would be a 3 point or greater reduction in score after 26 weeks of treatment. The recall period for MG-ADL is the preceding 7 days. MG-ADL will be performed at Screening, Day 1, Weeks 1- 4, 8, 10, 12, 16, 20, and 26 or ET (Visits 2-6, 8, 10, 12, 14, and 17, or ET) by a properly trained evaluator, preferably the same evaluator throughout the study.

5.2. QMG Scoring System

The current QMG scoring system consists of 13 items: ocular (2 items), facial (1 item), bulbar (2 items), gross motor (6 items), axial (1 item) and respiratory (1 item); each graded 0 to 3, with 3 being the most severe (see Table 2). The range of total QMG score is 0 - 39. The QMG scoring system is considered to be an objective evaluation of therapy for MG and is based on quantitative testing of sentinel muscle groups. The MGFA task force has

recommended that the QMG score be used in prospective studies of therapy for MG(15). A clinically meaningful improvement in a patient's QMG would be a 4 point or greater reduction in score after 26 weeks of treatment. The QMG will be administered at Screening, Day 1, Weeks 1-4, 8, 12, 16, 20, and 26 or ET (Visits 1-6, 8, 10, 12, 14, and 17 or ET).

5.3. MGC Score

The MGC is a validated assessment tool for measuring clinical status of subjects with MG (16). The MGC assesses 10 important functional areas most frequently affected by MG and the scales are weighted for clinical significance that incorporate subject-reported outcomes (see Table 3). A clinically meaningful improvement in a patient's MGC would be a 3 point or greater reduction in score after 26 weeks of treatment. MGC will be administered at Screening, Day 1, Weeks 1-4, 8, 12, 16, 20, and 26 or ET (Visits 1-6, 8, 10, 12, 14, and 17 or ET). 5.4. Quality of Life Assessments

5.4.1. MG-QOL 15

The 15-item Myasthenia Gravis Qualify of Life scale (MG-QOL 15) (see Figure 1) is a health-related quality of life evaluative instrument specific to subjects with MG. MG- QOL15 was designed to provide information about subjects' perception of impairment and disability and the degree to which disease manifestations are tolerated and to be easy to administer and interpret (17). The MG-QOL 15 is completed by the subject. Higher scores indicate greater extent of and dissatisfaction with MG-related dysfunction. A clinically meaningful improvement in a patient's MG-QOL 15 would be an increase in score after 26 weeks of treatment. The MG-QOL 15 is administered at Screening, Day 1, Weeks 4, 8, 12, 16, 20, and 26 or ET (Visits 1-2, 6, 8, 10, 12, 14, and 17 or ET).

5.4.2. Neuro-QOL Fatigue

The Neuro-QOL Fatigue is a reliable and validated brief 19-item survey of fatigue, completed by the subject (18). Higher scores indicate greater fatigue and greater impact of MG on activities (see Table 5). A clinically meaningful improvement in a patient's Neuro- QQL Fatigue score would be reflected in a decrease in score after 26 weeks of treatment. The Neuro-QOL Fatigue is administered at Day 1, Weeks 4, 8, 12, 16, 20, and 26 or ET (Visits 2, 6, 8, 10, 12, 14, and 17 or ET).

5.4.3. EUROQOL (EQ-5D)

The EUROQOL (EQ-5D) is a reliable and validated survey of health status in 5 areas: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression, completed by the subject (19). Each area has 3 levels: level 1 (no problems), level 2 (some problems), and level 3 (extreme problems) (see Figures 2A and 2B). The EQ VAS records the subject's self- rated health on a vertical, 20 cm visual analogue scale where the endpoints are labeled "Best imaginable health state, marked as 100" and "Worst imaginable health state, marked as 0." A clinically meaningful improvement in a patient's EQ-5D would be reflected as an increase in score after 26 weeks of treatment. The EQ-5D is administered at Day 1, Weeks 4, 8, 12, 16, 20, and 26 or ET (Visits 2, 6, 8, 10, 12, 14, and 17 or ET).

5.5. Other Efficacy Assessments

5.5.1. Negative Inspiratory Force NIF and Forced Vital Capacity

Subjects with increasingly severe MG can suffer from potentially fatal respiratory complications including profound respiratory muscle weakness. Respiratory function is monitored closely for evidence of respiratory failure in MG subjects and ventilator support is recommended in the event of consistent declines in serial measurements of Forced Vital Capacity (FVC) or Negative Inspiratory Force (NIF), loss of upper airway integrity (difficulty handling oral secretions, swallowing, or speaking) or in the setting of emerging respiratory failure. FVC as one of the test items in QMG is performed when QMG is performed. NIF was to be performed using the NIF Meter. It is measured at Screening, Day 1, Weeks 1-4, 8, 12, 16, 20, and 26 or ET (Visits 1-6, 8, 10, 12, 14, and 17 or ET).

5.5.2. MGFA Post-Intervention Status

The MG clinical state is assessed using the MGFA Post-Intervention Status. See Table 10. Change in status categories of Improved, Unchanged, Worse, Exacerbation and Died of MG as well as the Minimal manifestation (MM) is assessed and recorded at Weeks 4, 12 and 26 or ET (Visits 6, 10 and 17 or ET) by the PI or the same neurologist skilled in the evaluation of MG subjects throughout the trial. The sub-scores of MM, i.e., MM-0, MM-1, and MM-3, will not be used in this protocol.

6.2. Determination of Sample Size

The study design is a randomized, double blind, placebo-controlled design. Subjects will be randomly assigned 1 : 1 to eculizumab or placebo. The randomization stratification variable will be based on MG clinical classification by the Myasthenia Gravis Foundation of America (MGFA) according to the following 4 groupings (Class Ila and Ilia, Class IVa, Class lib and Illb and Class IVb).

The sample size and power calculation assumptions are as follows:

1 : 1 randomization (eculizumab: placebo)

• Power 90% for both the primary and the first secondary endpoints

• Two-sided 5% level of significance

• Drop-out rate 15%

• Mean changes from baseline for MG-ADL are assumed to be 4 for eculizumab and 1.5 for placebo with a standard deviation of 3.25, mean changes in QMG total score of 7 for eculizumab and 3 for placebo with a standard deviation of 6, and mean ranked differences between the treatment groups is assumed to be 3 with a standard deviation of 4 for both endpoints. Sample size calculations based on t- test.

With these assumptions, a sample size of approximately 92 subjects (46

eculizumab and 46 placebos) provides 90% power to detect a treatment difference at 26 weeks.

6.3. Analyses Sets

Analyses are produced for the double-blind Study Period in order to compare the eculizumab group with placebo group. The analyses include efficacy, safety, and PK/PD analyses.

6.3.1. Full Analysis Set

The full analysis set (FAS) is the population on which primary, secondary, and tertiary efficacy analyses is performed and consists of all subjects who are randomized to IP and who have received at least 1 dose of IP (eculizumab or placebo treatment) and have at least one efficacy assessment post IP infusion. Subjects are compared for efficacy according to the treatment they were randomized to receive, irrespective of the treatment they actually received.

6.3.2. Per-Protocol Set

The Per-Protocol (PP) Set is a subset of the Full Analysis Set (FAS) population, excluding subjects with major protocol deviations. The possible categories of major protocol deviations are defined in the statistical analysis plan. The per-protocol population will include all subjects who:

• Have no major protocol deviations or inclusion/ex elusion criteria deviations

that might potentially affect efficacy,

• Subjects who took at least 80% of the required doses and remained enrolled in the trial for 26 weeks or subjects who took at least 80% of the required doses up to the time of being discontinued for Clinical Deterioration (e.g., MG cri si s/exacerb ati on) .

The PP population will be fully described in the statistical analysis plan, and subjects identified prior to database lock. Efficacy analyses will also be performed on the PP data set.

6.7. Efficacy Analyses

Note: During the Study Period, Baseline is defined as the last available

assessment prior to treatment for all subjects, regardless of treatment group.

6.7.1. Primary Efficacy Endpoint

The primary efficacy endpoint is change from baseline in the MG-ADL total score at Week 26 of the Study Period. The primary efficacy analysis is conducted on the available 26 week data from the Study Period for all subjects. The trial is considered to have met its primary efficacy objective if a statistically significant difference (p< 0.05) between the eculizumab treatment group and placebo group is observed for change from baseline in the MG-ADL total score at Week 26. Confidence intervals and p-values will be presented. For the primary analysis concerning the change from baseline in the MG-ADL total score at Week 26, treatment groups are compared using a worst-rank score analysis (i.e., analysis of covariance [ANCOVA] analysis with ranks) with effects for treatment. The baseline MG-ADL total score and the randomization stratification variables are also to be covariates in the model. In this analysis, the actual changes from baseline are ranked from highest (best improvement in MG- ADL score) to lowest (least improvement / most worsening in MG-ADL score) across all subjects who did not need rescue therapy. Then, any subject who needed rescue therapy would be given lower ranks. These lower ranks are based on the time to rescue therapy from the start of investigational product (Day 1). The subject with the shortest time to rescue therapy would get the absolute lowest rank in the analysis and the subject with the longest time to rescue therapy would get a rank that is one lower than the lowest ranked subject without rescue therapy. Last observation carried-forward is used for missing changes from baseline at Week 26 for patients with missing Week 26 who did not require rescue therapy.

A sensitivity analysis for the actual change from baseline in the MG-ADL total score at Week 26 is also performed. Treatment groups are compared using ANCOVA analysis using the actual change from baseline in the MG-ADL total score at Week 26 with effects for treatment. The baseline MG-ADL total score and the randomization stratification variable are also covariates in the model. Last observation carried-forward is used for missing changes from baseline at Week 26.

A sensitivity analysis for the actual change from baseline in the MG-ADL total score at Week 26 is also performed. In the sensitivity analysis, treatment groups are compared using repeated measures model with effects for treatment and visits. The baseline MG-ADL total score, the randomization stratification variable, and an indicator for the 1ST treatment status of the subject are also covariates in the model. Subjects have an 1ST treatment status variable defined based on the 1ST treatments the subject receives.

In addition, summaries of changes from baseline in the MG-ADL total score at Week 26 are produced by treatment group for subjects who have failed ISTs.

• Subjects who have failed treatment over one year or more with 2 or more ISTs

in sequence or in combination.

• Subjects who have failed at least one 1ST and require chronic plasma exchange or IVIg to control symptoms.

6.7.2. Secondary Efficacy Analysis

Unless otherwise specified, the secondary efficacy analyses use the available 26-week data from the Study Period. Hypothesis testing comparing eculizumab treatment with placebo treatment for the secondary efficacy analyses are performed using a closed testing procedure with the following rank order:

1. Change from baseline in QMG total score at Week 26

2. Proportion of subjects with at least a 3-point reduction in the MG-ADL total score from baseline to Week 26 and with no rescue therapy

3. Proportion of subjects with at least a 5-point reduction in the QMG total score

from baseline to Week 26 and with no rescue therapy

4. Change from baseline in the MGC score at Week 26

5. Change from baseline in MG-QOL15 at Week 26

The hypothesis testing will proceed from highest rank (#1) Change from baseline in QMG total score at Week 26 to (#5) Change from baseline in MG-QOL-15, and if statistical significance is not achieved at an endpoint (p< 0.05), then endpoints of lower rank are not considered to be statistically significant. Confidence intervals and p-values are presented for all secondary efficacy endpoints for descriptive purposes, regardless of the outcome of the closed testing procedure.

The secondary endpoints that involve changes from baseline are analyzed using a worst-case ranked analysis of covariance (ANCOVA) like that described for the primary efficacy endpoints as the primary analysis for the particular secondary endpoint. The ranked ANCOVA will have effects for treatment, the baseline for the particular endpoint, and the randomization stratification variable.

A sensitivity analysis for the change from baseline in QMG at Week 26 is analyzed using repeated measures model with effects for treatment, visits, and baseline QMG score in order to compare treatment groups. The randomization stratification variable is also a covariate in the model. A sensitivity analysis for the actual change from baseline in QMG score at Week 26 will also be performed. Treatment groups are compared using ANCOVA analysis using the actual change from baseline in the QMG score at Week 26 with effects for treatment. The baseline QMG score and the randomization stratification variable are also covariates in the model. Last observation carried-forward will be used for missing changes from baseline at Week 26. A sensitivity analysis for the change from baseline in MGC at Week 26 is analyzed using repeated measures model with effects for treatment, visits, and baseline MGC score in order to compare treatment groups. The randomization stratification variable is also a covariate in the model.

A sensitivity analysis for the change from baseline in MG-QOL-15 at Week 26 is analyzed using repeated measures model with effects for treatment, visits, and baseline MG- QOL-15 score in order to compare treatment groups. The randomization stratification variable is also a covariate in the model.

The proportion of subjects with at least a 3 point reduction in the MG-ADL total score from baseline to Week 26 with no rescue therapy are analyzed by the Cochran-Mantel- Haenszel test stratified by randomization stratification variable in order to compare eculizumab versus placebo.

The proportion of subjects with at least a 5 point reduction in the QMG total score from baseline to Week 26 with no rescue therapy are analyzed by the Cochran-Mantel- Haenszel test stratified by randomization stratification variable in order to compare eculizumab versus placebo.

Additional sensitivity analyses are performed in order that assess the impact of 1ST treatment status on the various secondary endpoints. A sensitivity analysis for the change from baseline in the secondary endpoints (i.e., QMG, MGC, and MG-QOL-15) at Week 26 are analyzed using repeated measures model with effects for treatment, visits, and baseline score in order to compare treatment groups. The randomization stratification variable and an indicator for the 1ST treatment status of the subject are also covariates in the model. Subjects will have an 1ST treatment status variable defined based on the 1ST treatments the subject receives.

In addition, summaries of changes from baseline in QMG, MGC, and MG-QOL-15 at Week 26 are produced by treatment group for subjects who have failed ISTs.

Subjects who have failed treatment over one year or more with 2 or more ISTs in sequence or in combination

• Subjects who have failed at least one 1ST and require chronic plasma exchange or IVIg to control symptoms.

6.7.3. Tertiary Efficacy Endpoints

The tertiary efficacy analyses for the Study Period include the following:

1. Time to response as measured by the reduction in the MG-ADL total score (3- point reduction from baseline)

2. Change from baseline in Neuro-QOL Fatigue at Week 26

3. Change from baseline in EQ-5D at 26 weeks

4. Change from baseline in NIF at Week 26 in subjects with abnormal NIF at baseline

5. Change from baseline in FVC at Week 26 in subjects with abnormal FVC at baseline

6. Change from baseline in the MG-ADL individual items and change from baseline in the MG-ADL sub-categories for the bulbar (items 1, 2 and 3), respiratory (item 4), limb (items 5 and 6) and ocular (items 7 and 8) at Week 26 in subjects with an abnormal baseline score for the particular item or sub-category

7. Change from baseline in the MGFA Post-Intervention Status at Week 26.

For the time to response on the MG-ADL total score (3 -point reduction in MG- ADL from baseline), treatment groups are compared using Cox PH regression with robust variance estimation. The randomization stratification variable is also a covariate in the model. Inference is based on the Wald test of the log hazard ratio.

Quality of life is summarized as appropriate to the quality of life instrument and treatment group comparisons is performed as specified in the statistical analysis plan (SAP).

The tertiary endpoints that involve changes from baseline are analyzed using a worst-case ranked ANCOVA like that described for the primary efficacy endpoints as the primary analysis for the particular tertiary endpoint. The ranked ANCOVA has effects for treatment, the baseline for the particular endpoint, and the randomization stratification variable.

A sensitivity analysis for the change from baseline in NIF at Week 26 for subjects with abnormal NIF at baseline is analyzed using repeated measures model with effects for treatment, visits, and baseline NIF in order to compare treatment groups. The randomization stratification variables are also covariates in the model.

A sensitivity analysis for the change from baseline in FVC is analyzed using repeated measures model with effects for treatment, visits, and baseline FVC in order to compare treatment groups. The randomization stratification variable is also a covariate in the model.

A sensitivity analysis for the change from baseline in the MG-ADL individual items and sub-categories at Week 26 in subjects that are abnormal at baseline are analyzed using repeated measures model with effects for treatment, visits, and baseline MG-ADL individual item and sub-categories, as applicable for the analysis, in order to compare treatment groups. The randomization stratification variable is also a covariate in the model. In addition, for all full analysis set (FAS) and all PP subjects, a sensitivity analysis for the change from baseline in the MG-ADL individual items and subcategories at Week 26 are performed using repeated measures model with effects for treatment, visits, and baseline MG-ADL individual item or sub-categories score, as applicable for the analysis, in order to compare treatment groups. The randomization stratification variable is also a covariate in the model. Finally, similar sensitivity analyses and/or summaries are produced (depending on the number of subjects) in the subset of subjects who were normal at baseline and became abnormal after baseline in the MG- ADL individual items and sub-categories.

A summary of subjects going from normal to abnormal for NIF and FVC are presented. A summary of subjects going from normal to abnormal for a particular MG-ADL individual items and sub-categories are produced.

6.11. Other Statistical Issues

6.11.1. Significance Levels

For all analyses, the eculizumab treated group is compared to the placebo group and all hypothesis testing is two-sided and performed at the 0.05 level of significance, unless otherwise specified. Estimates of treatment effect on efficacy parameters are accompanied by two-sided 95% confidence intervals for the effect size.

6.11.2. Missing or Invalid Data

For efficacy and safety analyses, missing post-baseline efficacy and safety data are not imputed unless indicated in the described analysis in the SAP.

6.11.3. Interim Analysis

There is no interim analysis planned for this trial.

Example 2: Extension Trial

An extension trial is described herein that was run to evaluate the long-term safety of eculizumab in subjects with refractory gMG. Other secondary objectives include:

Evaluation of the long-term efficacy as measured by MG-ADL

Evaluation of long-term efficacy by additional efficacy measures including: • QMG, MGC,

• MG-ADL individual items and subcategories

• Quality of life

Description of the PK and PD of eculizumab in refractory gMG patients.

The extension trial lasts for 4 years (FPFV to LPLV). The first visit occurs within 2 weeks of Visit 17 (Week 26) in the trial described above. To maintain the blind of the previous trial, all subjects undergo a blind induction phase, followed by an open label maintenance phase. This is summarized in Figures 6 and 7. "Home infusion" at selected visits is performed with permission of the primary investigator in accordance with

regulations. Assessments, Treatment, Concomitant/Prohibited medications were performed as in the study described above.

The inclusion criteria for the extension trial was completion of the previous trial.

Exclusion criteria were withdrawing from the previous trial and pregnancy or intention to get pregnant. 1ST treatment could be changed at the treating physician's discretion but rituximab was prohibited.

Efficacy was measured by MG-ADL, QMG, MGC, NIF, FVC, QOL, G-QOL15, Neuro-QOL Fatigue, EQ-5D and MGFA Post-Intervention Status.

Example 3: Results from REGAIN Study Comprising ECU-MG-301 26 Week (301) Trial and ECU-MG-302 Extension (302) Trial

The REGAIN study is a randomized, double-blind, placebo-controlled, multicenter trial evaluating the safety and efficacy of eculizumab in patients with refractory gMG. The study enrolled and treated 125 adult patients across North America, South America, Europe, and Asia. Patients had a confirmed MG diagnosis with positive serologic test for anti-AChR antibodies. All patients had previously failed treatment with at least two immunosuppressive agents or failed treatment with at least one immunosuppressive agent and required chronic plasma exchange or IVIg, and had an MG-ADL total score >6 at study entry.

As discussed above the patients were initially randomized according to MGFA

Clinical Classification shown in Table 7 into the following four groups:

MGFA Ila/IIIa

MGFA Ilb/IIIB

MGFA IVa

MGFA IVb The breakdown of the MGFA classification at screening was as follows: Class Ila 25 total patients; Class lib 22 total patients; Class Ilia 36 total patients; Class Illb 30 total patients; Class IVa 6 total patients; and Class IVb 6 total patients.

The patients were assigned to the placebo group as follows: Class Ila 15 (23.8%) total patients; Class lib 14 (22.2%) total patients; Class Ilia 16 (25.4%) total patients; Class Illb 13 (20.6%) total patients; Class IVa 2 (3.2%) total patients; and Class IVb 3 (4.8%) total patients.

The patients were assigned to the eculizumab group were as follows: Class Ila 10 (16.1%) total patients; Class lib 8 (12.9%) total patients; Class Ilia 20 (32.3%) total patients; Class Illb 17 (27.4%) total patients; Class IVa 4 (6.5%) total patients; and Class IVb 3 (4.8%) total patients.

The disposition of patients completing the 301 trial and entering the 302 trial is shown below in Table 14.

Therefore 96.8 % of the placebo patients and 88.9% of the eculizumab patients proceeded into the extension trial. The demographics of the 301 trial participants were as is shown below in Table

15.

The protocol defines clinical deterioration as a subject who has one of the following:

1. MG Crisis

2. Significant symptomatic worsening, defined as worsening on any one of the MG- ADL individual items excluding ocular (i.e., talking, chewing, swallowing, breathing, upper and lower extremity weakness):

- To Grade 3, or

-2-point worsening in MG-ADL

3. The treating physician believes that the subject's health is in jeopardy if rescue therapy is not administered.

Rescue therapy is defined in the protocol as follows: Use of PE or IVIg will be allowed for subjects who experience a Clinical Deterioration as defined by this protocol. The rescue therapy used for a particular subject is at the discretion of the treating physician

If PE is administered as a rescue therapy, supplemental IP (2 vials) are administered within 60 minutes after the end of each PE session. Routine (per protocol schedule) IP administration is continued per the specified dose-administration schedule for the subject. If the subject is scheduled to receive the protocol-scheduled dose on the day of a PE session, then the scheduled dose is administered within 60 minutes after the end of the PE session.

The total numbers of patients who experienced clinical deterioration during the protocol were as is shown below in Table 16.

The primary and secondary endpoints as described above were used as shown below:

Primary Endpoint:

- Change from baseline in MG-ADL Total Score at Week 26

Secondary Endpoints (hierarchal):

- Change from baseline in QMG Total Score at Week 26

- Proportion of subjects with > 3 -point reduction in MG-ADL Total Score from baseline to Week 26 and without rescue therapy

- Proportion of subjects with > 5-point reduction in QMG Total Score from baseline to Week 26 and without rescue therapy

- Change from baseline in the Myasthenia Gravis Composite (MGC) Total Score at Week 26

- Change from baseline in MG-QoL15 at Week 26 One primary endpoint in the MG-ADL score at week 26. The score ranges from 0-24 and contains 3 bulbar items, 1 respiratory item, 2 gross motor or limb items, and 2 ocular items. A clinically meaningful improvement in MG-ADL is defined as a 3 points or greater reduction. See Table 1.

The results from the patients who finished the entire protocol are shown in Table 18. Therefore, as shown in Table 20 the median value for the eculizumab group showed a -4 reduction in MG-ADL. This result demonstrates eculizumab produced a clinically meaningful improvement in MG patients as measured by their MG-ADL score. The data were analyzed in multiple ways for statistical purposes as shown in Tables 18, 19, 20, and 21, but in each case the eculizumab group produced clinically meaningful improvement in MG-ADL and the placebo group failed to produce clinically meaningful improvement in MG-ADL. See Tables 18-21.

Refractory gMG is an ultra-rare segment of MG— a debilitating, complement-mediated neuromuscular disease— in which patients have largely exhausted conventional therapy and continue to suffer profound muscle weakness throughout the body, resulting in slurred speech, impaired swallowing and choking, double vision, upper and lower extremity weakness, disabling fatigue, shortness of breath due to respiratory muscle weakness, and episodes of respiratory failure. In the study, the primary efficacy endpoint of change from baseline in Myasthenia Gravis- Activities of Daily Living Profile (MG-ADL) total score, a patient-reported assessment, at week 26, did not reach statistical significance (p=0.0698) as measured by a worst-rank analysis. Next the QMG scores were evaluated for all study participants. The current QMG scoring system consists of 13 items: ocular (2 items), facial (1 item), bulbar (2 items), gross motor (6 items), axial (1 item) and respiratory (1 item); each graded 0 to 3, with 3 being the most severe (see Table 2). The range of total QMG score is 0 - 39. The QMG scoring system is considered to be an objective evaluation of therapy for MG and is based on quantitative testing of sentinel muscle groups. The MGFA task force has recommended that the QMG score be used in prospective studies of therapy for MG. A clinically meaningful improvement in a patient's QMG would be a 5 point or greater reduction in score after 26 weeks of treatment.

The QMG score for the full data set was -5 in the eculizumab treated group and therefore resulted in a clinically significant improvement for all patients not needing rescue or dropping out of the study. See Table 22 below and Figure 11 for the results.

Next, the MGC score was evaluated for all study participants over time. The MGC is a validated assessment tool for measuring clinical status of subjects with MG (16). The MGC assesses 10 important functional areas most frequently affected by MG and the scales are weighted for clinical significance that incorporate subject-reported outcomes (see Table 3). MGC will be administered at Screening, Day 1, Weeks 1-4, 8, 12, 16, 20, and 26 or ET (Visits 1-6, 8, 10, 12, 14, and 17 or ET). Total scores range from 0-50. A clinically meaningful improvement in a patient's MGC would be a 3 point or greater reduction in score after 26 weeks of treatment.

The MGC score for the full data set was (-10) in the eculizumab treated group and therefore resulted in a clinically significant improvement for all patients not needing rescue or dropping out of the study. See Table 23 above for the results.

The 15-item Myasthenia Gravis Qualify of Life scale (MG-QOL 15) is a health-related quality of life evaluative instrument specific to subjects with MG. See Table 4. MG-QOL15 was designed to provide information about subjects' perception of impairment and disability and the degree to which disease manifestations are tolerated and to be easy to administer and interpret. The MG-QOL 15 is completed by the subject. Total scores range from 0 to 60 and higher scores indicate greater extent of and dissatisfaction with MG-related dysfunction. A clinically meaningful improvement in a patient's MGQOL would be a decrease in score after 26 weeks of treatment.

The MG-QOL 15 median score for the full data set was (-11.5) in the eculizumab treated group and therefore resulted in a clinically significant improvement for all patients not needing rescue or dropping out of the study. See Table 24 below for the results.

The Neuro-QOL Fatigue is a reliable and validated brief 19-item survey of fatigue completed by the subject. Higher scores indicate greater fatigue and greater impact of MG on activities (see Table 5). A clinically meaningful improvement in a patient's Neuro-QQL Fatigue score would be reflected in a decrease in score after 26 weeks of treatment.

As shown in Table 25 below, the eculizumab treated group realized a clinically meaningful improvement (reduction) in their Neuro-QQL Fatigue score after 26 weeks of treatment.

Discussion of the Significance of the REGAIN Study

The first prospectively defined secondary efficacy endpoint of change from baseline in Quantitative Myasthenia Gravis (QMG) total score, a physician-administered assessment of MG clinical severity, with eculizumab treatment compared to placebo at week 26, achieved a p-value of 0.0129 as measured by a worst-rank analysis. In addition, the second and third prospectively defined secondary efficacy endpoints of responder status in MG-ADL and QMG achieved p-values of <0.05: the proportion of patients with at least a 3 -point reduction in MG- ADL total score and no rescue therapy from baseline to week 26 with eculizumab treatment, compared to placebo, achieved a p-value of 0.0229, and the proportion of patients with at least a 5-point reduction in QMG total score and no rescue therapy from baseline to week 26 with eculizumab treatment compared to placebo achieved a p-value of 0.0018.

It is encouraging that the REGAIN study achieved clinically meaningful improvements in MG-ADL and QMG measures in patients treated with eculizumab compared with placebo. The magnitude of effect on QMG observed in this large, prospective registration trial is

unprecedented in more than 30 years of clinical investigation of refractory MG patients. There is an urgent need in the MG community for a therapy with the potential to dramatically improve the lives of patients with refractory gMG, who continue to experience profound complement- mediated muscle weakness that makes it difficult or impossible to perform simple daily activities, including walking, talking, swallowing, and even breathing normally.

Pre-specified sensitivity analyses were prospectively defined to validate results for the primary and first secondary endpoints. Three of the four prospectively defined MG-ADL sensitivity analyses achieved p-values <0.05, including the sensitivity analysis around the primary endpoint for change from baseline in MG-ADL using repeated measures, which showed a mean change with eculizumab treatment at week 26 of -4.2 versus a mean change with placebo at week 26 of -2.3 and achieved a p-value of 0.0058. Additionally, all four prospectively defined QMG sensitivity analyses achieved p-values <0.05, including the sensitivity analysis around the first secondary endpoint for change from baseline in QMG using repeated measures, which showed a mean change with eculizumab treatment at week 26 of -4.6 versus a mean change with placebo at week 26 of -1.6 and achieved a p-value of

0.0006.

The findings from this study underscore the pivotal role of complement inhibition in addressing the underlying pathophysiology of refractory gMG. Importantly, the totality of data including the first three secondary endpoints and a series of prospectively defined sensitivity analyses, shows early and sustained substantial improvements over 26 weeks for patients treated with eculizumab compared to placebo

Example 4: Anti-C5 Antibodies for Use in Treating Refractory Myasthenia Gravis

Table 27 below contains sequences of anti-complement protein C5 specific humanized antibodies that can be used in treating refractory MG. The antibody was an anti-C5 antibody such as eculizumab having three heavy chain complementarity determining regions (CDRs) as set forth in Table 27 using the Kabat definitions of CDRs as heavy chain CDRl in SEQ ID NO:

1, heavy chain CDR2 in SEQ ID NO: 2, and heavy chain CDR3 in SEQ ID NO: 3. The eculizumab light chain CDRs are set forth below as as light chain CDR1 in SEQ ID NO: 4, light chain CDR2 in SEQ ID NO: 5 and light chain CDR3 in SEQ ID NO: 6. The heavy chain variable region of eculizumab is set forth in SEQ ID NO: 7 and the light chain variable region of eculizumab is set forth in SEQ ID NO: 8. The complete heavy chain of eculizumab is set forth below as SEQ ID NO: 10 and the light chain is set forth below as SEQ ID NO: 11

The antibody may be an eculizumab variant known as BNJ441 and having selected mutations in the CDR regions combined with mutations in the Fc region to increase the Tl/2 of the antibody in the patient. The BNJ441 antibody has heavy chain variable region as set forth in SEQ ID NO: 12 and the light chain variable region of BNJ441 is set forth in SEQ ID NO: 8. The complete heavy chain of BNJ441 is set forth below as SEQ ID NO: 14 and the light chain is set forth below as SEQ ID NO: 11

The antibody may be an anti-C5 antibody unrelated to eculizumab such as the 7086 antibody and having three heavy chain complementarity determining regions (CDRs) as set forth in Table Table 27 using the Kabat definitions of CDRs as heavy chain CDR1 in SEQ ID NO: 21, heavy chain CDR2 in SEQ ID NO: 22, and heavy chain CDR3 in SEQ ID NO: 23. The 7086 antibody light chain CDRs are set forth below as light chain CDR1 in SEQ ID NO: 24, light chain CDR2 in SEQ ID NO: 25 and light chain CDR3 in SEQ ID NO: 26. The heavy chain variable region of 7086 is set forth in SEQ ID NO: 27 and the light chain variable region of 7086 is set forth in SEQ ID NO: 28.

The antibody may be an anti-C5 antibody unrelated to eculizumab such as the 8110 antibody and having three heavy chain complementarity determining regions (CDRs) as set forth in Table 27 using the Kabat definitions of CDRs as heavy chain CDR1 in SEQ ID NO: 29, heavy chain CDR2 in SEQ ID NO: 30, and heavy chain CDR3 in SEQ ID NO: 31. The 7086 antibody light chain CDRs are set forth below as light chain CDR1 in SEQ ID NO: 32, light chain CDR2 in SEQ ID NO: 33 and light chain CDR3 in SEQ ID NO: 34. The heavy chain variable region of 8110 is set forth in SEQ ID NO: 35 and the light chain variable region of 8110 is set forth in SEQ ID NO: 36.

The antibody may be an anti-C5 antibody or antigen binding fragment thereof comprising a heavy chain variable region amino acid sequence according to SEQ ID NO: 37 and a light chain variable region amino acid sequence according to SEQ ID NO: 38. Example 5: Dual Responder Analyses of Both Muscle Strength and Activities of Daily Living, Eculizumab Versus Placebo, in Refractory Generalized Myasthenia Gravis (gMG) Patients: Results from the REGAIN Study

The objective of the example was to assess the time course of response in patients who demonstrated a clinically meaningful response to eculizumab and the proportion of patients who had clinically meaningful relevant responses on both the MG-ADL and the QMG. Patients with refractory gMG continued to receive stable doses of ISTs (including corticosteroids) throughout the study; patients were randomized to receive blinded eculizumab 900 mg weekly for 4 weeks, 1200 mg on the fifth week, and then 1200 mg every 2 weeks thereafter (n = 62) or blinded placebo (n = 63) (Figure 12).

The Myasthenia Gravis Activities of Daily Living (MG-ADL) is a physician-directed, patient-reported measure of symptom severity related to MG-specific ADLs (Muppidi, Ann. N. Y. Acad. Sci. 1274: 114-19 (2012)), and the Quantitative Myasthenia Gravis (QMG) tool is a clinician-reported measure of muscle strength (Barohn et al., Ann. N. Y. Acad. Sci. 841 : 1 '69-72 (1998)). Pre-specified responder analyses included the proportion of patients who responded with >3 -point improvement in MG-ADL total score with no rescue; and the proportion of patients with >5-point improvement in QMG total score with no rescue. In an ad hoc dual responder analysis, response was defined as an improvement of >3 points from baseline in the MG-ADL total score and improvement of >5 points from baseline in the QMG total score, with no rescue therapy. In addition to the prespecified responder thresholds {i.e., >3-point improvement for MG-ADL and >5-point improvement for QMG), thresholds of >4, 5, 6, 7, and 8 for MG-ADL and >6, 7, 8, 9, and 10 for QMG were also examined. P values from a Cochran- Mantel-Haenszel (CMH) test were provided for the more stringent criteria to aid interpretation.

More patients receiving eculizumab than those who received placebo experienced clinically meaningful responses as defined above, and also clinically meaningful relevant responses based on the more stringent thresholds for both MG-ADL and QMG total scores (Figure 13). MG-ADL responder analyses conducted at each assessment date over the 26-week study are shown in Figure 14 (the proportion of patients with a >3, 5, or 8 point change in the MG-ADL). QMG responder analyses conducted at each assessment date over the 26-week study are shown in Figure 15 (the proportion of patients with a greater than 5, 7, or 10 point change in the QMG). There was a substantial overlap of patients who achieved a clinically meaningful response in both the MG-ADL total score and QMG total score (Figure 16). For each of the categorical thresholds of response, a >3-fold increase was seen in the proportion of improved patients in the eculizumab group compared with those in the placebo group (Figure 16). More patients receiving eculizumab versus placebo achieved clinically meaningful responses at week 26 in both the MG-ADL and QMG scores (week 26: eculizumab 40% vs placebo 13%; nominal P < 0.001) (Figure 16). The benefit of eculizumab treatment was apparent within the first 2 weeks (week 2: eculizumab 19% vs placebo 6% were dual responders; nominal P = 0.0297) and was sustained through week 26 (all P<0.05) (Figure 17).

Three times as many patients with refractory gMG who were treated with eculizumab experienced clinically meaningful improvements in both muscle strength and ADLs compared with the placebo group by week 26. An increased proportion of individual assessment responders (on both the MG-ADL and the QMG) as well as dual responders occurred in the eculizumab-treated patient group compared with the placebo group which was observed early and generally maintained over the course of the study.

As shown in Figure 18, the response rate was substantially higher in eculizumab-treated patients (40.3%) than in placebo-treated patients (12.7%), showing a clinically significant response by both patient- and physician-assessed outcome measures in patients treated with eculizumab. With increasingly stringent response criteria, the superiority of response to eculizumab over placebo becomes more pronounced, with odds ratios exceeding 10.

Example 6: Efficacy of Eculizumab is Maintained Beyond 26 Weeks in Patients with AChR+ Refractory Generalized Myasthenia Gravis (gMG)

Patients who completed REGAIN were allowed to continue into an open-label extension study known as ECU-MG-302. Each patient enrolled in the extension trial underwent an initial 4-week blinded induction before receiving open-label eculizumab maintenance treatment (1200 mg every 2 weeks). MG-ADL, QMG, MGC, and MG-QOL15 scores and safety were assessed.

In contrast with Study ECU-MG-301, in which patients were required to maintain stable MG therapy throughout the 26-week study period, adjustment of background immunosuppressant therapy (1ST), including corticosteroids and acetylcholinesterase inhibitors (AChI), was permitted in Study ECU-MG-302. Investigators could change dosing of an existing IST/AChI, discontinue an existing IST/AChI, or add a new IST/AChI.

The MG-ADL total score in eculizumab/eculizumab patients (n=56) was unchanged from open-label baseline through week 52. In the placebo/eculizumab patients (n=60), rapid improvement in MG-ADL total score from open-label baseline was demonstrated with a change from ECU-MG-302 baseline in MG-ADL total score observed as early as week 1 (-1.6

[-2.28, -0.89]; p<0.0001). The majority of the overall treatment effect was achieved by week 4 (- 2.4 [-3.19, -1.71]; pO.0001) during the blind induction phase, and was sustained through week 52 (-2.7 [-3.73, -1.63]; pO.0001). Changes in QMG, MGC, and MG-QOL15 total scores followed a pattern similar to that of the MG-ADL (QMG: -4.6; <.0001; MGC: -5.1; <.0001; and MG-QOL15: -5.7; .Ρ= 005 at week 52). Similar patterns of response were seen on the respiratory, bulbar, limb, and ocular MG-ADL domains. The safety profile of eculizumab remained unchanged throughout the open-label extension study and was consistent with the known profile.

Overall, 65 (55.6%) patients reported a change in their 1ST usage during the study. Greater proportions of patients had dose reductions or stopped >1 1ST than those who had dose increases or started >1 1ST (Table 26). 55 (47.0%) patients decreased their daily dose of 1 1ST and 2 (1.7%) patients decreased the daily dose of >1 1ST; 29 (24.8%) patients increased their daily dose of 1 1ST, and none increased their dose of >1 1ST. 19 (16.2%) patients stopped an existing 1ST; 5 (4.3%) patients started a new 1ST. The most common reason for change in 1ST therapy was improvement in MG symptoms, with 42 (35.9%) patients reporting improvement in MG symptoms as the reason for changing 1ST therapy. In comparison, 21 (17.9%) patients reported worsening of MG symptoms as the primary reason for changing 1ST therapy. Side- effects/intolerance to an 1ST was reported as the reason for change in 1ST therapy in 13 (11.1%) patients.

Overall, the extension study demonstrated that patients who received eculizumab in Study ECU-MG-301 sustained their improvements through 52 weeks of additional eculizumab treatment in Study ECU-MG-302. For patients who received placebo in Study ECU-MG-301, an improvement occurred rapidly after starting eculizumab treatment and was maintained through 52 weeks of Study ECU-MG-302, similar to the effect observed in eculizumab-treated patients in Study ECU-MG-301.

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The following references are hereby incorporated by reference in their entirety:

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