Docket No. 2208204-WOO

METHODS OF TREATING ALZHEIMER'S DISEASE WITH

(+)-ISOPROPYL 2-METHOXYETHYL 4-(2-CHLORO-3-C YANO-PHEN YL)- 1,4-

DIHYDRO-I ₅ O-DIMETHYL-PYRIDINE-S ₅ S-DICARBOXYLATE

AND A CHOLINESTERASE INHIBITOR

This application claims benefit of priority to U.S. Provisional Application No. 60/980,095, filed October 15, 2007, the entire contents of which is incorporated by reference in its entirety.

FIELD OF THE INVENTION

[01] The present invention relates to methods of treating Alzheimer's disease by administering (+)-isopropyl 2-methoxyethyl 4-(2-chloro-3-cyano-phenyl)-l,4-dihydro-2,6- dimethyl-pyridine-3,5-dicarboxylate and a cholinesterase inhibitor, such as donepezil, rivastigimine, or galantamine.

BACKGROUND OF THE INVENTION

[02] Alzheimer's disease (AD) is the leading cause of dementia and one of the most common diseases of the aging population. It is a chronic brain disease that involves gradual memory loss, decline in the ability to perform routine tasks, disorientation, difficulty in learning, loss of language skills, impairment of judgment, and personality changes in affected individuals. The neurodegenerative nature of the disease eventually leads to the failure of other organ systems and death. Consequently, AD often results in excessive caregiver burden, high costs of care, and institutionalization. The Alzheimer's Association

estimates that in the United States (US), 10% of the population over age 65, and 50% of the population over age 85 suffer from this disease. Although the etiology of AD is not fully understood, great strides have been made in understanding the risk factors, genetics, and pathophysiology of AD.

[03] Perturbations in calcium homeostasis in the central nervous system (CNS), such as those associated with AD and aging as well as stroke and head trauma can result in an increase in intracellular levels of calcium (Ca ⁺ ) (LaFerla, Nat Rev Neurosci. 2002 Nov;3(l l):862-72; Gibson and Peterson, Neurobiol Aging 1987 Jul-Aug;8(4):329-43; Kobayashi and Mori, Eur J Pharmacol. 1998 Dec 11;363(1):1-15). Increased levels of Ca ²⁺ may lead to cellular dysregulation and cell death (Choi, Trends Neurosci. 1995 Feb 18(2):58- 60). The role of calcium in these neurodegenerative processes led to the hypothesis that controlling calcium levels may be beneficial. See LaFerla, Nat Rev Neurosci. 2002 Nov;3(l l):862-72; Yagami et al, Biochem Pharmacol. 2004 Mar 15;67(6):1153-65; Weiss et al, J Neurochem. 1994 Jan;62(l):372-5; Harkany et al, Neuroscience 2000;101(l):101-14; Pierrot et al, J Neurochem. 2004 Mar;88(5):l 140-50.

[04] U.S. Patent No. 5,665,740 discloses racemic and optically pure isomers of isopropyl 2-methoxyethyl 4-(2-chloro-3-cyano-phenyl)- 1 ,4-dihydro-2,6-dimethyl-pyridine- 3,5-dicarboxylate (shown below) and their use for the treatment of cerebral and neuronal disorders.

[05] International Publication No. WO 05/051389 ("WO '389") discloses, inter alia, a method of treating mild memory and/or cognitive impairment with isopropyl 2- methoxyethyl 4-(2-chloro-3-cyano-phenyl)-l,4-dihydro-2,6-dimethylpyridine -3,5- dicarboxylate (including optically pure isomers and racemic and non-racemic mixtures of the compound) alone or in combination with certain other pharmaceutical agents.

[06] U.S. Patent Publication No. 2005/0153953 discloses compositions for treating memory and/or cognitive impairment comprising a L-type calcium channel blocker, such as (+)-isopropyl 2-methoxyethyl 4-(2-chloro-3-cyano-phenyl)- 1 ,4-dihydro-2,6- dimethylpyridine-3,5-dicarboxylate, and a cholinesterase inhibitor.

[07] There is a continuing need for new treatments for Alzheimer's disease.

SUMMARY OF THE INVENTION

[08] The present invention is a method of treating or preventing Alzheimer's disease (AD) in a patient in need thereof by administering a therapeutically effective amount of (+)-isopropyl 2-methoxyethyl 4-(2-chloro-3-cyano-phenyl)-l,4-dihydro-2,6-dimethyl- pyridine-3,5-dicarboxylate (referred to as "MEM- 1003" hereafter) and a cholinesterase inhibitor. The method of the present invention is, for example, effective in patients with mild to moderate Alzheimer's disease including, but not limited to, those with (a) a standardized MMSE Score of 10 to 24 points, (b) a diagnosis of Probable AD using National Institute of Neurological and Communicative Diseases and Stroke (NINCDS) and Alzheimer's Disease and Related Disorders Association (ADRDA) criteria, (c) magnetic resonance imaging or computed tomography examination within the past 1 year, performed after the onset of the cognitive impairment, compatible with AD, (d) or any combination thereof. The method of the present invention is also effective in the treatment of patients having moderate to severe

AD, or severe AD. The inventors have discovered that MEM- 1003 is surprisingly effective

in the treatment of Alzheimer's disease at low doses (e.g., at most 300 mg of MEM- 1003 per day) without the significant cardiovascular side effects which are commonly associated with other dihydropyridine calcium channel blockers. Furthermore, MEM- 1003 is surprisingly effective at increasing attention span in patients suffering from Alzheimer's disease. The inventors have also surprisingly discovered that daily adjunctive treatment with 60 mg of MEM- 1003 is more effective than with 180 mg of MEM- 1003. See Example 1 and Figure 1.

[09] Patients administered MEM- 1003 can be treated for Alzheimer's disease without inducing cardiovascular effects commonly associated with calcium channel blockers, such as for example, hypotension or myocardial infarction. Patients who do not have hypertension or other cardiovascular symptoms may therefore be treated without adverse side effects.

[10] According to one embodiment, from about 30 to about 300 mg of MEM-1003 is administered daily. According to another embodiment, from about 60 to about 180 mg of MEM-1003 is administered daily. According to yet another embodiment, from about 30 to about 90 mg of MEM-1003 is administered daily. According to a preferred embodiment, about 60 mg of MEM-1003 is administered per day (for example, 30 mg of MEM-1003 b.i.d.).

[11] In the treatment methods of the present invention, MEM-1003 can be administered twice daily or more frequently (for example, as an immediate release formulation). In one embodiment, about 15 to about 150 mg of MEM-1003 is administered twice daily to the patient. In another embodiment, about 60 to about 120 mg of MEM-1003 is administered twice daily to the patient. In yet another embodiment, about 30 to about 90 mg of MEM-1003 (e.g., about 30 to about 60 mg) is administered twice daily to a patient in need of treatment. According to one embodiment, about 15 mg of MEM-1003 is administered at least twice daily to the patient (and preferably twice daily). According to

another embodiment, about 30 mg of MEM- 1003 is administered at least twice daily to the patient (and preferably twice daily). According to yet another embodiment, about 60 mg of MEM- 1003 is administered at least twice daily to the patient (and preferably twice daily). According to yet another embodiment, about 90 mg of MEM- 1003 is administered at least twice daily to the patient (and preferably twice daily). According to yet another embodiment, about 120 mg of MEM- 1003 is administered at least twice daily to the patient (and preferably twice daily). The duration of the treatment is preferably at least 12 weeks. In all of these embodiments, the total amount of MEM-1003 administered is not greater than 300 mg per day

[12] According to one embodiment, about 15 mg MEM-1003 is administered in the form of one or more pharmaceutical compositions (e.g., oral dosage forms such as tablets or capsules) which provide an in vivo plasma profile in humans (not previously treated with MEM-1003) having at least one of: a mean C _max of more than about 8 ng/mL, a mean AUCo-t of less than about 20 ng h/ml (wherein t is the last time point with measurable concentrations), a mean T _max of more than about 0.7 hours, and a mean ty ₂ of more than 3.5 hours.

In one embodiment, the 15 mg MEM-1003 pharmaceutical composition provides an in vivo plasma profile in humans (not previously treated with MEM-1003) having at least one of: a mean C _max ranging from about 10 to about 18 ng/mL, a mean AUCo-t ranging from about 10 to about 20 ng h/ml (wherein t is the last time point with measurable concentrations), a mean T _max ranging from about 0.75 to about 0.9 hours, and a mean ty ₂ of ranging from about 4 to about 6 hours.

[13] According to another embodiment, about 30 mg MEM- 1003 is administered in the form of one or more pharmaceutical compositions which provide an in vivo plasma profile in humans (not previously treated with MEM- 1003) having at least one of: a mean C _max of more than about 8 ng/mL, a mean AUCo-t of less than about 30 ng h/ml (wherein t is the last time point with measurable concentrations), a mean T _max of more than about 0.7 hour, and a mean Xy ₂ of more than 6 hours.

In one embodiment, the 30 mg MEM- 1003 pharmaceutical composition provides an in vivo plasma profile in humans (not previously treated with MEM- 1003) having at least one of: a mean C _max ranging from about 10 to about 18 ng/mL, a mean AUCo-t ranging from about 20 to about 30 ng h/ml (wherein t is the last time point with measurable concentrations), a mean T _max ranging from about 0.75 to about 1.25 hours, and a mean ti _/2 of ranging from about 7 to about 9 hours.

[14] According to one embodiment, about 60 mg MEM- 1003 is administered in the form of one or more pharmaceutical compositions (e.g., oral dosage forms such as tablets or capsules) which provide an in vivo plasma profile in humans, after 7 days of twice daily dosing, having at least one of: a mean C _max of more than about 30 ng/mL, a mean AUCo-m of less than about 90 ng h/ml, a mean T _max of more than about 0.8 hours, and a mean ty ₂ of more than 6 hours. In one embodiment, the 60 mg MEM- 1003 pharmaceutical composition provides an in vivo plasma profile in humans, after 7 days of twice daily dosing, having at least one of:

a mean C _max ranging from about 30 to about 45 ng/mL, a mean AUCo-m ranging from about 55 to about 80 ng h/ml, a mean T _max ranging from about 0.8 to about 1.2 hours, and a mean ty ₂ of ranging from about 7 to about 9.5 hours.

[15] According to one embodiment, about 90 mg MEM- 1003 is administered in the form of one or more pharmaceutical compositions (e.g., oral dosage forms such as tablets or capsules) which provide an in vivo plasma profile in humans, after 7 days of twice daily dosing, having at least one of: a mean C _max of more than about 60 ng/mL, a mean AUCo-m of less than about 180 ng h/ml, a mean T _max of more than about 0.3 hours, and a mean ty ₂ of more than 6 hours.

In one embodiment, the 90 mg MEM- 1003 pharmaceutical composition provides an in vivo plasma profile in humans, after 7 days of twice daily dosing, having at least one of: a mean C _max ranging from about 60 to about 100 ng/mL, a mean AUCo-m ranging from about 100 to about 160 ng h/ml, a mean T _max ranging from about 0.4 to about 1.2 hours, and a mean ty ₂ of ranging from about 6 to about 10 hours.

[16] According to another embodiment, about 120 mg MEM- 1003 is administered in the form of one or more pharmaceutical compositions which provide an in vivo plasma profile in humans, after 10 days of twice daily dosing, having at least one of: a mean C _max of more than about 55 ng/mL, a mean AUCo-48h of less than about 200 ng h/ml, a mean T _max of more than about 0.4 hour, and a mean ty ₂ of more than 8 hours.

In one embodiment, the 120 mg MEM- 1003 pharmaceutical composition provides an in vivo plasma profile in humans, after 10 days of twice daily dosing, having at least one of: a mean C _max ranging from about 60 to about 100 ng/mL, a mean AUCo-48h ranging from about 130 to about 170 ng h/ml, a mean T _max ranging from about 0.6 to about 1.2 hours, and a mean ty ₂ of ranging from about 9 to about 15 hours.

[17] The cholinesterase inhibitor can be one or more acetylcholinesterase inhibitors. Suitable acetylcholinesterase inhibitors include, but are not limited to, donepezil (e.g., donepezil hydrochloride currently marketed as Aricept ^® by Eisai Inc. of Woodcliff Lake, NK and Pfizer Inc. of New York, NY), rivastigimine (e.g., rivastigimine tartrate currently marketed as Exelon ^R by Novartis Pharmaceuticals Corporation of East Hanover, NJ), galantamine (e.g., galantamine hydrobromide currently marketed as Razadyne ^R by Ortho-McNeil Neurologies, Inc. of Titusville, NJ), icopezil, pyridostigmine, edrophonium, neostigmine, physostigmine, Huperzine A, phenserine, tracine, pharmaceutically acceptable salts thereof, and any combination of any of the foregoing.

[18] MEM- 1003 and the cholinesterase inhibitor may be administered in combination with another Alzheimer's disease-treating agent such as ginkgo biloba, an NMDA receptor antagonist (e.g., memantine), xaliproden, tramiprosate, tarenflurbil, leuprolide, a statin (e.g., simvastatin, atorvastatin, or rosuvastatin), thiazolidinediones (e.g., pioglitazone), and vitamin E. This list of agents is not limiting.

[19] The MEM- 1003 and cholinesterase inhibitor can be administered by any route of administration known in the art. Oral administration is preferred.

BRIEF DESCRIPTION OF THE DRAWINGS

[20] Figure 1 shows the change in ADAS-cog in the patients receiving placebo (i.e., patients on acetylcholinesterase inhibitor only) or adjunctive therapy comprised of 30 or 90 mg of MEM- 1003 b.i.d. and an acetylcholinesterase inhibitor over 12 weeks according to the procedure described in Example 1.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

[21] MEM- 1003 as used herein refers to (+)-isopropyl 2-methoxyethyl 4-(2-chloro- 3-cyano-phenyl)-l,4-dihydro-2,6-dimethyl-pyridine-3,5-dicarb oxylate. The MEM-1003 is preferably administered in the form of the free base. Preferably, the (+)-isopropyl 2- methoxyethyl 4-(2-chloro-3-cyano-phenyl)-l,4-dihydro-2,6-dimethyl-pyridin e-3,5- dicarboxylate has an optical purity of at least 98, 98.5, 99, 99.1, 99.2, 99.3, 99.4, 99.5, 99.6, 99.7, 99.8, or 99.9% (by weight) (i.e., the weight percentage of (+)-isopropyl 2-methoxyethyl 4-(2-chloro-3-cyano-phenyl)-l,4-dihydro-2,6-dimethyl-pyridin e-3,5-dicarboxylate based on the total weight of (+) and (-) isopropyl 2-methoxyethyl 4-(2-chloro-3-cyano-phenyl)-l,4- dihydro-2,6-dimethyl-pyridine-3,5-dicarboxylate). MEM-1003 may be prepared by any method known in the art, such as that disclosed in U.S. Patent No. 5,665,740.

[22] As used herein, the term "patient" refers to a human, such as a man, woman, adult, or elderly person.

[23] As used herein, the term "treating" refers to (1) preventing or delaying the appearance of clinical symptoms of a disease or condition in a patient that may be afflicted with or predisposed to the disease or condition, but does not yet experience or display clinical or subclinical symptoms of the disease or condition; (2) relieving the disease or condition, i.e., causing regression of the disease or condition or at least one of its clinical or sub-clinical symptoms; and (3) inhibiting the progression of the disease or condition, i.e., arresting or

reducing its development or at least one clinical or sub-clinical symptom thereof. The benefit to a patient to be treated is either statistically significant or at least perceptible to the patient and/or the physician.

[24] As used herein, the terra ''Alzheimer's disease ^" ' and other clinical terms have the definitions provided for them in the Diagnostic and Statistical Manual of Mental Disorders, 4 ^th Ed., 2000 (DSM-IV-TR). According to the DSM-IV-TR, the criteria for Alzheimer's disease are as follows:

A. The development of multiple cognitive deficits manifested by both:

(1) memory impairment (impaired ability to learn new information or to recall previously learned information)

(2) one (or more) of the following cognitive disturbances:

(a) aphasia (language disturbance)

(b) apraxia (impaired ability to carry out motor activities despite intact motor function)

(c) agnosia (failure to recognize or identify objects despite intact sensory function)

(d) disturbance in executive functioning (i.e., planning, organizing, sequencing, abstracting)

B. The cognitive deficits in Criteria Al and A2 each cause significant impairment in social or occupational functioning and represent a significant decline from a previous level of functioning.

C. The course is characterized by gradual onset and continuing cognitive decline.

D. The cognitive deficits in Criteria Al and A2 are not due to any of the following:

(1) other central nervous system conditions that cause progressive deficits in memory and cognition (e.g., cerebrovascular disease, Parkinson's disease,

Huntington's disease, subdural hematoma, normal-pressure hydrocephalus, brain tumor)

(2) systemic conditions that are known to cause dementia (e.g., hypothyroidism, vitamin B12 or folic acid deficiency, niacin deficiency, hypercalcemia, neurosyphilis, HIV infection)

(3) substance-induced conditions

E. The deficits do not occur exclusively during the course of a delirium.

F. The disturbance is not better accounted for by another Axis I disorder (e.g,, major depressive disorder, schizophrenia).

[25] Subtypes of AD according to the DSM-IV-TR include (A) "With Early Onset," if the onset of the AD occurs in the patient at age 65 or earlier, and (B) "With Late Onset," if the onset of the AD is after age 65. Subtypes of AD according to the DSM-IV-TR also include (A) "Without Behavioral Disturbance," if the cognitive disturbance is not accompanied by any clinically significant behavioral disturbance and (B) "With Behavioral Disturbance," if the cognitive disturbance is accompanied by a clinically significant behavioral disturbance (e.g., wandering, agitation).

[26] The NINCDS-ADRDA (National Institute of Neurological and Communicative Diseases and Stroke and Alzheimer's Disease and Related Disorders Association) criteria for the clinical diagnosis of Probable Alzheimer's Disease include:

• dementia established by clinical examination and documented by the Mini-Mental

Test, Blessed Dementia Scale, or a similar examination, and confirmed by neuropsychologic tests;

• deficits in 2 or more areas of cognition;

• progressive worsening of memory and other cognitive functions;

• no disturbance of consciousness;

• onset between ages 40 and 90, most often after age 65;

• absence of systemic disorders or other brain diseases that in and of themselves could account for the progressive deficits in memory and cognition. [27] The NINCDS-ADRDA diagnosis of Probable AD is supported by:

• progressive deterioration of specific cognitive functions such as language (aphasia), motor skills (apraxia), and perception (agnosia);

• impaired activities of daily living and altered patterns of behavior;

• family history of similar disorders, particularly if confirmed neuropathologically; and

• laboratory results of:

• normal lumbar puncture as evaluated by standard techniques,

• normal pattern or nonspecific changes in EEG, such as increased slow-wave activity, and

• evidence of progressive cerebral atrophy on CT scan documented by serial observation.

[28] Other clinical features consistent with the NINCDS-ADRDA diagnosis of Probable AD, after exclusion of causes of dementia other than AD, include:

• plateaus in the course of progression of the illness;

• associated symptoms of depression, insomnia, incontinence, delusion, illusions, hallucination, catastrophic verbal, emotional, or physical outbursts, sexual disorders, and weight loss;

• other neurologic abnormalities in some patients especially with more advanced disease and including motor signs such as increased muscle tone, myoclonus, or gait disorder;

• seizures in advanced disease; and

• CT scan normal for age.

[29] Features that make the NINCDS-ADRDA diagnosis of Probable AD uncertain or unlikely include:

• sudden, apoplectic onset;

• focal neurologic findings such as hemiparesis, sensory loss, visual field deficits, and incoordination early in the course of the illness; and

• seizures or gait disturbances at the onset or very early in the course of the illness. See McKhann et al, Clinical diagnosis of Alzheimer's disease: report of the NINCDS- ADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer's Disease, Neurology 1984;34(7):939-44.

[30] The Alzheimer's Diseases Assessment Scale (ADAS) assesses major cognitive and behavioral symptoms associated with Alzheimer's disease. The test is devised to be sensitive to the cognitive and behavioral deterioration that occurs in patient's with AD. See Mohs, Neuropsychiatry Measures for Cognitive Disorders, p. 441 et seq. (Chapter 21) (1983).

[31] The ADAS-cog (Alzheimer's Disease Assessment Scale - Cognitive Subscale) is an instrument devised to assess the severity of cognitive impairment in patients with AD. The scale includes short neuropsychological tests in which the patient performs simple tasks such as word recall, word recognition, and constructional praxis. There are 11, 12, and 13 item versions of the ADAS-cog. Unless otherwise specified, the term "ADAS- cog" as used herein refers to the 12 item version with a maximum possible score of 80 (a

lower score reflecting improvement). The cognitive section of the ADAS consists of items which assess the following: memory, language (aphasia), and motor skills (praxis).

[32] The CIBIC-plus (Clinician Interview-Based Impression of Change with Caregiver Input) is not a single instrument and is not a standardized instrument like the ADAS-cog. Clinical trials for study medications have used a variety of CIBIC formats, each different in terms of depth and structure. As such, results from a CIBIC-plus reflect clinical experience from the trial or trials in which it was used and cannot be compared directly with the results of CIBIC-plus evaluations from other clinical trials. It represents the assessment of a skilled clinician based upon his/her observations at an interview with the patient, in combination with information supplied by a caregiver familiar with the behavior of the patient over the interval rated. The CIBIC-plus is scored as a 7-point categorical rating, ranging from a score of 1, indicating "markedly improved," to a score of 4, indicating "no change" to a score of 7, indicating "markedly worse."

[33] The MMSE (Mini-Mental State Examination) is a brief assessment instrument used to assess cognitive function in geriatric patients. The MMSE can be used to screen for cognitive impairment and as a measurement of cognition over time with or without pharmacologic treatment. The instrument is divided into 2 sections. The first section measures orientation, memory, and attention, while the second section tests the ability of the patient to name objects, follow verbal and written commands, write a sentence, and copy figures. The maximum score for the first section is 21 and the maximum score for the second section is 9. Scores for the MMSE range from 0 to 30 (o being worst). MMSE is available from Psychological Assessment Resources, Inc, of Lutz, Florida.

[34] The Neuropsychiatric Inventory Questionnaire (NPI-Q) is a rapidly administered instrument that provides an assessment of psychopathologic behaviors commonly observed in patients with dementia. The NPI-Q may be a useful tool for family

physicians because it assesses the severity of the symptom in the patient and the distress the symptom causes in the caregiver. The questions are answered based on the changes that have occurred since the patient first began to experience memory problems, and is rated "yes" only if the patient has had symptoms in the last month. For items marked "yes," the rater assesses the severity of the behavior and the distress caused by those behaviors to the caregiver on numerical scales (including frequency rated 1-4 and severity rated 1-3). The maximum total score is 120 with a decrease in score reflecting improvement. See Kaufer et al, J Am Geriatr Soc. 1998;46:210-5.

[35] The ADCS-ADL (Alzheimer's Disease Cooperative Study - Activities of Daily Living Scale) is a set of informant-based items describing performance of activities of daily living by patients with AD. Questions are asked of the caregiver and are given in the form of an interview. Each question relates to the activities of the subject in the past 4 weeks and is answerable with "yes," "no," or "don't know." If "yes," the caregiver is asked to rate the task proficiency on a numerical scale, with higher scores indicating higher functioning. The highest possible score is 78 (improvement is an increase in score). See Galasko et al, Alzheimer Dis Assoc Disord. 1997;l l:S33-9.

[36] The pharmacokinetic parameters described herein include area under the plasma concentration-time curve (AUCo-t), maximum plasma concentration (C _max ), time of maximum plasma concentration (T _max ), and terminal elimination half-life (T _1/2 ). The time of maximum concentration, T _max> is determined as the time corresponding to C _max . Area under the plasma concentration-time curve up to the time corresponding to the last measurable concentration (AUCo-t) is calculated by numerical integration using the linear trapezoidal rule as follows:

AUC ₀ _ _t = ∑0.5 (C ₁ + C _1-1 ) (Z ₁ -/,_,) Eq. 1

1=2

where C ₁ is the plasma concentrations at the corresponding sampling time point tj and n is the number of time points up to and including the last quantifiable concentration. The terminal half-life (Ty ₂ ) is calculated using the following equation: where λ _z is the terminal elimination rate constant.

Methods of Treatment

[37] In the methods described herein, MEM- 1003 is typically administered in an amount sufficient for the desired effect.

[38] MEM- 1003 may be administered by any route. For example, MEM- 1003 may be administered parenterally, such as by one or multiple injections. Preferably, MEM- 1003 is administered orally, such as in the form of a tablet or capsule. The oral dosage form can be formulated for immediate release or controlled release of the MEM- 1003.

[39] The cholinesterase inhibitor may also be administered by any route. Preferably, the cholinesterase inhibitor is administered by the oral route, for example, as a tablet, capsule, or solution. The oral dosage form can be formulated for immediate release or controlled release of the cholinesterase inhibitor.

[40] The cholinesterase inhibitor may be administered with the MEM- 1003 in a unitary dosage form (i.e., a dosage form containing both the MEM- 1003 and the cholinesterase inhibitor), or concurrently in separate dosage forms, which may be administered by the same or different routes of administration and at the same or different times of the day.

[41] According to one embodiment, the patient is treated with MEM- 1003 and the cholinesterase inhibitor donepezil (or a pharmaceutically acceptable salt thereof such as

donepezil hydrochloride). Preferably, from about 5 to about 10 mg of donepezil or a pharmaceutically acceptable salt thereof (based on the equivalent weight of donepezil hydrochloride) is administered once daily. Preferably, the donepezil is administered in the evening just prior to retiring. MEM- 1003 and donepezil may be taken with or without food. When the patient suffers from severe Alzheimer's disease, the patient is preferably administered MEM- 1003 and about 10 mg of donepezil or a pharmaceutically acceptable salt thereof. According to one embodiment, a patient is initially treated with 5 mg of donepezil or a pharmaceutically acceptable salt thereof daily. After at least 4 to 6 weeks of daily treatment with 5 mg of donepezil or a pharmaceutically acceptable salt thereof, the dose can be increased to 10 mg of donepezil or a pharmaceutically acceptable salt thereof daily.

[42] According to another embodiment, the patient is treated with MEM- 1003 and the cholinesterase inhibitor rivastigmine (or a pharmaceutically acceptable salt thereof such as rivastigmine tartrate). Preferably, from about 6 to about 12 mg of rivastigmine or a pharmaceutically acceptable salt thereof (based on the equivalent weight of rivastigmine base) is administered daily. The doses may be given twice a day. For example, the patient may be administered from about 3 to about 6 mg of rivastigmine or a pharmaceutically acceptable salt thereof twice daily. According to one embodiment, the starting dose of rivastigmine or a pharmaceutically acceptable salt is 1.5 mg twice a day. If the dose is well tolerated, after a minimum of 2 weeks of treatment, the dose may be increased to 3 mg b.i.d. Subsequent increases to 4.5 mg b.i.d. and 6 mg b.i.d. can be attempted after a minimum of 2 weeks at the previous dose.

[43] According to yet another embodiment, the patient is treated with MEM- 1003 and the cholinesterase inhibitor galantamine (or a pharmaceutically acceptable salt thereof such as galantamine hydrobromide). Preferably, from about 16 to about 32 mg of galantamine or a pharmaceutically acceptable salt thereof (based on the equivalent weight of

galantamine hydrobromide) is administered daily. According to a preferred embodiment, from about 16 to about 24 mg of galantamine or a pharmaceutically acceptable salt thereof is administered daily. Galantamine or a pharmaceutically acceptable salt thereof may be orally administered once daily as an extended release formulation or twice daily as an immediate release formulation. Desirably, the extended release formulation is administered in the morning (preferably with food). The starting initial dose of galantamine or a pharmaceutically acceptable salt thereof is preferably 8 mg per day, which can be increased after a minimum of 4 weeks of treatment.

[44] A third active ingredient useful in the treatment of Alzheimer's disease may also be administered. Such active ingredients include, but are not limited to, ginkgo biloba, an NMDA receptor antagonist (e.g., memantine), xaliproden, tramiprosate, tarenflurbil, leuprolide, a statin (e.g., simvastatin, atorvastatin, or rosuvastatin), thiazolidinediones (e.g., pioglitazone), and vitamin E. The third active ingredient may be administered with the MEM- 1003 and/or cholinesterase inhibitor in a unitary dosage form, or concurrently in separate dosage forms, which may be administered by the same or different routes of administration.

Formulations

[45] MEM- 1003 and optionally the cholinesterase inhibitor can be administered by any route including, but not limited to, orally, nasally, parenterally (subcutaneously, intraveneously, intramuscularly, intrasternally and by infusion), rectally, vaginally, topically and by ocular administration. MEM- 1003 and optionally the cholinesterase inhibitor can be incorporated into a dosage form, such as a solid or liquid oral dosage form, suppository, vaginal dosage form, and topical dosage form. Such dosage forms typically contain one or more pharmaceutically acceptable carriers, diluents, and/or excipients.

[46] Suitable solid oral dosage forms include, but are not limited to, tablets, gelcaps, capsules, caplets, granules, lozenges and bulk powders. MEM- 1003 can be incorporated into the dosage form alone or in combination with one or more pharmaceutically acceptable carriers, diluents (such as sucrose, mannitol, lactose, and starches) and excipients, including but not limited to, suspending agents, solubilizers, buffering agents, binders, disintegrants, preservatives, colorants, flavorants, and lubricants. The dosage form can provide controlled release of MEM- 1003 and optionally the cholinesterase inhibitor. For example, the dosage form can be a time release capsule, tablet or gel.

[47] Suitable liquid oral dosage forms include, but are not limited to, aqueous and non-aqueous solutions, emulsions, suspensions, syrups, and elixirs. Such dosage forms can also contain one or more suitable inert diluents, such as water, and excipients, such as preservatives, wetting agents, sweeteners, flavorants, and agents for emulsifying and/or suspending the MEM- 1003 and/or the cholinesterase inhibitor. The dosage form can be injected, for example, intravenously, in the form of an isotonic sterile solution.

[48] Suppositories for rectal administration of the MEM- 1003 and optionally the cholinesterase inhibitor can be prepared by mixing the MEM- 1003 and/or cholinesterase inhibitor with a suitable excipient, such as cocoa butter, salicylates or a polyethylene glycol. Formulations for vaginal administration can be in the form of a pessary, tampon, cream, gel, paste, foam, or spray formula containing the active ingredient(s) and one or more carriers.

[49] For topical administration the pharmaceutical composition can be in the form of creams, ointments, liniments, lotions, emulsions, suspensions, gels, solutions, pastes, powders, sprays, and drops suitable for administration to the skin, eye, ear or nose. The topical formulation may be in the form of a transdermal patch.

[50] The MEM- 1003 and/or cholinesterase inhibitor can be present in these preparations in a concentration of 0.1 to 99.5% by weight and preferably at 0.5 to 95% by

weight of the total formulation. In general, it has proven advantageous to administer MEM- 1003 in total amounts of about 0.01 to about 50 mg/kg, preferably in total amounts of about 0.1 mg/kg to 10 mg/kg of body weight every 24 hours, if appropriate in the form of several individual doses, to achieve the desired result. The amount of MEM- 1003 is provided in the equivalent weight of the free base.

[51] The following example illustrates the invention without limitation. All percentages are by weight unless otherwise indicated.

Example 1

[52] A 12 week multi-center, randomized, double blind, placebo-controlled, parallel-group study was conducted to evaluate the efficacy and safety of MEM- 1003 ((+)- isopropyl 2-methoxyethyl 4-(2-chloro-3-cyano-phenyl)- 1 ,4-dihydro-2,6-dimethyl-pyridine- 3,5-dicarboxylate) for the treatment of patients with mild to moderate Alzheimer's disease. Primary outcome measures were the changes from baseline at Week 12 in the ADAS-cog (Alzheimer's Disease Assessment Scale - Cognitive Subscale). Secondary outcome measures were the ADAS-cog at Weeks 4, 8, and 16; the Alzheimer's Disease Cooperative Study - Activities of Daily Living Scale (ADCS-ADL) seal; Neuropsychiatric Inventory Questionnaire (NPI-Q); Clinician Interview-Based Impression of Change with Caregiver Input (CIBIC-plus); and the Mini-Mental State Examination (MMSE) at Weeks 4, 8, 12, and 16. Safety was assessed through self-reporting (patient and caregiver) of adverse events, concomitant medication use, clinical laboratory evaluations, vital signs, electrocardiogram findings, and physical examinations.

Methods

[53] The study involved 183 subjects with mild to moderate Alzheimer's disease at 41 centers in the U.S. The study consisted of a 12-week double-blind treatment phase followed by a 4-week, follow-up, single-blind, placebo treatment phase.

[54] The study had 3 treatment groups: placebo (n=60), 30 mg of oral MEM-1003 twice daily (n=62), and 90 mg of oral MEM-1003 twice daily (n=61). The MEM-1003 was provided in units of 30 mg in a hard capsule formulation.

[55] The entire study duration of approximately 18 weeks was divided into 3 phases as follows: (1) the Screening Phase (lasting approximately 2 weeks, from the time of the signing of the informed consent statement to the beginning of the double-blind treatment), (2) the 12-week treatment phase (first through last dose of blinded study medication), and (3) the follow-up phase (included 4 weeks of single-blind placebo dosing for all patients after completion of the last dose of blinded study medication and the time through the final follow- up study completion visit). The study site representative (study coordinator) called the patients or caregivers on the third day of the double-blind treatment phase to inquire about the occurrence of any adverse events (AEs) and to record the findings.

[56] The inclusion criteria for patients were (a) male or female patients 50 to 90 years of age, (b) standardized MMSE Score of 10 to 24 points at Screening and Baseline, (c) diagnosis of Probable AD using National Institute of Neurological and Communicative Diseases and Stroke and Alzheimer's Disease and Related Disorders Association criteria, (d) magnetic resonance imaging or computed tomography examination within the past 1 year, performed after the onset of the cognitive impairment, compatible with AD, (e) modified Hachinski Ischemia score of ≤4, and (f) current treatment with donepezil, rivastigmine, or galantamine is allowed providing: (1) the patient had been on the medication for the past 3 months, (2) the patient had been on a stable dose for the past 1 month, and (3) in the opinion

of the investigator, the patient either had not benefited from the treatment, had already achieved maximum benefits from the current treatment, or had shown signs of deterioration despite their current treatment. Subjects who entered the study while taking AD treatment (donepezil, rivastigmine, or galantamine) were required to remain on the same dose throughout the study. All other AD treatments were excluded.

[57] The exclusion criteria for patients were (a) resides in a secure behavioral management unit in any facility that provides intensive support for people with dementia (Residence in the general population of a long-term care facility is allowed as long as the subject has reliable support that will enable him or her to attend all study visits.), (b) patient's MMSE score at the Baseline Visit is 3 or more points higher than the Screening Visit MMSE score, (c) head injury associated with cognitive impairment, (d) history of vascular dementia stroke or transient cerebral ischemic episodes, (e) major depression, bipolar disorder, or psychotic disorder, (f) history of symptomatic postural hypotension, (g) current treatment with calcium channel blockers, (h) treatment with any investigational medications within the 30 days before the Screening Visit, (i) current treatment for AD except for treatment with donepezil, galantamine, or rivastigmine (as described in the inclusion criteria), and (j) treatment with memantine in the last 90 days.

[58] During the study, efforts were made to ensure that the same rater assessed each subject for each efficacy measurement throughout the entire study.

[59] For analysis purposes, the following populations were defined:

(a) Intent-to-Treat (ITT): includes all randomized patients who take at least 1 dose of double-blinded study medication and provide at least 1 postbaseline efficacy measurement.

(b) Safety population: includes all randomized patients who take at least 1 dose of double-blinded study medication.

[60] Five efficacy variables, ADAS-cog, MMSE, ADCS-ADL, NPI-Q, and CIBIC- plus were assessed at Baseline and Weeks 4, 8, 12, and 16. Change from baseline in these variables were analyzed for all but CIBIC-plus via an analysis of covariance model including treatment and center as fixed effects and baseline value as the covariate. The CIBIC-plus was analyzed via the Van Elteren Test. The primary efficacy variable was change from baseline in ADAS-cog. Week 12 was the primary time point. Ordered testing procedures were used to control the Type I error due to multiple comparisons.

Results

[61] As a monotherapy, MEM 1003 did not show an improvement in ADAS-cog compared to placebo. Notably, there was an unusually high placebo response of approximately 5 points on the ADAS-cog in the monotherapy group.

[62] In the adjunctive therapy group, the placebo sub-group showed a slight worsening in the ADAS-cog at week 12, while the 30 mg sub-group showed approximately a 2 point improvement and the 90 mg sub-group showed approximately a 1 point improvement at week 12. See Figure 1. In addition, both the 30 and 90 mg treatment groups showed consistent numerical improvements in MMSE, ADCS-ADL, NPI-Q, and CIBIC-plus.

[63] Although the invention herein has been described with reference to particular embodiments, these embodiments are merely illustrative of the principles and applications of the present invention. Therefore, numerous modifications may be made to the illustrative embodiments and other arrangements may be devised without departing from the spirit and scope of the present invention as described above.

[64] All publications, patents, and published patent applications cited herein are incorporated by reference to the same extent as if each individual publication, patent, or published patent application was specifically and individually indicated to be incorporated herein by reference.