METHODS OF TREATING SMALL CELL LUNG CANCER WITH LURBINECTEDIN

FORMULATIONS

FIELD OF THE INVENTION

[0001] Provided are methods for the treatment of SCLC patients by administering therapeutic amounts of lurbinectedin by intravenous infusion. Also provided are methods of treating cancer by administering lurbinectedin in combination with other anticancer drugs, in particular topoisomerase inhibitors. The invention further relates to the administration of lurbinectedin in combination with anti-emetic agents for effective control of symptoms related to nausea and vomiting, reduced lurbinectedin dosages to achieve a safer administration and an increase in the number of treatment cycles. Stable lyophilized formulations of lurbinectedin are also provided.

BACKGROUND TO THE INVENTION

[0002] Lung cancer is the leading cause of cancer death in both men and women in the United States. In 1998, an estimated 171 ,500 new cases were diagnosed, and about 160,100 deaths resulted from this disease. More women die from lung cancer than breast, ovarian, and uterine cancer combined, and 4 times as many men die from lung cancer than from prostate cancer.

[0003] Lung cancer is a disease in which malignant (cancer) cells form in the tissues of the lung. The two major types of lung cancer are small cell lung cancer (SCLC) and non small cell lung cancer (NSCLC). SCLC comprises only about 13-15% of all lung cancers at diagnosis; however, SCLC is the more aggressive form of lung cancer. With SCLC, the cancer cells tend to grow quickly and travel to other parts of the body, or metastasize, more easily. Its incidence is associated with smoking, almost two thirds of patients present with advanced disease, and although response rates to chemotherapy are high, the benefit is short-lived. The median survival of patients with untreated SCLC is two to four months (Clark, 1998; Glisson, 2003; Davies, 2004). The most common regimens include cisplatin or carboplatin and etoposide. Unfortunately, despite the 40-90% response rate to first-line chemotherapy, long-term survival is unusual because patients develop resistance to chemotherapy and relapse (Sundstrom, 2005; Jackman, 2005). The overall expected mean survival after disease relapse without treatment is two to four months (Huisman, 1999).

[0004] Treatment and survival have not changed substantially during the past two decades. Even limited-stage disease is rarely cured with radical local therapy (surgery or radiotherapy) and systemic chemotherapy (platinum plus etoposide) remains a cornerstone of first-line treatment in SCLC.

[0005] Topotecan is the only approved drug for second-line treatment of patients with a chemotherapy-free interval longer than 60 days. Topotecan monotherapy improves survival and quality of life, as well as cancer-related symptoms in the second-line setting. Alternatively, doxorubicin-based combination therapy can be administered with a similar outcome but a slightly lower rate of symptom control. In refractory patients no standard therapy exists. Amrubicin, a novel anthracyline, showed promising activity in refractory and relapsed patients. Phase III trials are ongoing. Other agents with activity include paclitaxel, docetaxel, gemcitabine, bendamustine and vinorelbine.

[0006] During the past few years, several clinical trials have evaluated the effect of addition of immunotherapy to conventional chemotherapy in patients with extensive SCLC. Checkpoint inhibitors are currently under investigation, especially the CTLA-4 and PD-1/PD-L1 inhibitors. Nivolumab and Pembrolizumab were the first immunotherapeutic agents to be approved by the FDA for patients with metastatic SCLC with disease progression on or after platinum-based chemotherapy and at least one other prior line of chemotherapy.

[0007] Lurbinectedin (PM01183) is a synthetic tetrahydropyrrolo [4, 3, 2-de]quinolin- 8(1 H)-one alkaloid analogue with antineoplastic activity. Lurbinectedin is a selective inhibitor of oncogenic transcription, induces DNA double-strand break generating apoptosis, and modulates the tumor microenvironment. For example, by inhibiting active transcription in tumor-associated macrophages, lurbinectedin downregulates IL-6, IL-8, CCL2, and VEGF.

[0008] Lurbinectedin has demonstrated a highly potent in vitro activity against solid and non-solid tumor cell lines as well as a significant in vivo activity in several xenografted human tumor cell lines in mice, such as those for breast, kidney and ovarian cancer. Preliminary clinical results have shown that lurbinectedin has activity as a second line therapeutic as a single agent in SCLC. There is a need for treatment for SCLC and other solid tumors.

SUMMARY OF THE INVENTION

[0009] Phase 2 clinical trial results demonstrate an at least 30% (35.2%) overall response rate for SCLC patients with lurbinectedin as a second line agent administered as single agent. Results from a phase 1 b-2 trial in solid tumor patients demonstrated activity of a combination of lurbinectedin and irinotecan, particularly in SCLC, endometrial carcinoma, soft tissue sarcoma and glioblastoma. Accordingly, provided herein are methods of treating SCLC in patients in need thereof, especially those patients whose SCLC has progressed after prior therapy, such as platinum-containing therapy or immunotherapy, including among others patients who have failed to respond or to respond adequately to prior treatment, those who may have responded to prior treatment but then experienced progression of the disease, and those who may have had such response followed by progression more than once. Also provided are methods of treating solid tumors, particularly SCLC, endometrial carcinoma, soft tissue sarcoma, and glioblastoma, in patients in need thereof administering lurbinectedin in combination with a topoisomerase inhibitor, particularly irinotecan or SN-38. Stable lyophilized formulations are further provided.

[0010] The methods provided herein involve administering to a patient suffering from SCLC, particularly an SCLC patient who has progressed after prior platinum-containing therapy, an effective amount of lurbinectedin by intravenous infusion. In certain embodiments, provided are methods of administering to a patient suffering from SCLC who has progressed after prior immunotherapy, particularly atezolizumab, including in combination with carboplatin and etoposide, or nivolumab, an effective amount of lurbinectedin by intravenous infusion. Lurbinectedin is preferably administered at a dose of 3.2 mg/m ² every 3 weeks, typically over a period of multiple months, and in most cases until disease progression and death or the patient experiences unacceptable toxicity, depending upon the patient’s response to the administration.

[0011] In certain embodiments, treatment effective amounts of lurbinectedin may be administered every 3 weeks to the patient as a 1-hour IV infusion using dosing levels of 3.2 mg/m ² , to achieve mean total plasma Cmax of about 85.6 μg/L to 133.75 μg/L, preferably 107 μg/L, and mean AUC∞ of about 440.8 μg*h/Lto 688.75 μg*h/L, preferably 551 μg*h/L. Treatment results in an overall response rate of greater than 30%, progression free survival for a median 3.5 months, (a range of 2.6 months to 4.3 months), including a median of 2.6 months in resistant patient population (CFTI less than 90 days for prior chemotherapy treatment) and a median of 4.6 months in sensitive patient populations (CFTI greater than or equal to 90 days for prior chemotherapy treatment). Overall survival for a median of 9.3 months (resistant patient population of 5.0 months and sensitive patient population of 11.9 months) may be achieved according to the methods disclosed herein.

[0012] In an embodiment, provided is a method of managing hematological adverse events associated with lurbinectedin treatment regimen by dose reduction and/or administration of G-CSF. The method provided relates to administering to an SCLC patient a lurbinectedin formulation by IV infusion at a dose of 3.2 mg/m ² ; assessing, after administering the lurbinectedin, whether the patient experiences an adverse reaction associated with the lurbinectedin administration that is a ≥ Grade 3 (severe) non hematological toxicity, Grade 4 thrombocytopenia (Platelet count less than 25,000 cells/mm3), Grade 3 thrombocytopenia (Platelet count less than 50,000 cells/mm ³ ) with bleeding that requires transfusion, Grade 4 neutropenia (Neutrophil count less than 500 cells/mm ³ ), or any grade neutropenia (Neutrophil count < LLN) that is associated with infection/sepsis or any other of the adverse reactions. At the next scheduled dose, preferably 3 weeks after the prior dose, and once the patient’s neutrophil count is greater than 1500 cells/mm ³ ; platelet count is greater than about 100,000 mm ³ ; and hemoglobin levels are greater than about 9 g/d, (i) if the adverse reaction consists of an isolated Grade 4 neutropenia, then administering to the patient a dose of G-CSF and a dose of lurbinectedin that is the same as the previous dose, for example, 3.2 mg/m ² , or (ii) if the adverse reaction is a hematological abnormality that is not solely Grade 4 neutropenia, then administering a dose that is reduced compared to the prior dose, for example is 80 to 85% of the prior dose, for example, 2.6 mg/m ² if the prior dose is 3.2 mg/m ² . Optionally, the dose may be reduced if the adverse reaction is Grade 4 neutropenia. [0013] In the event that after receiving a reduced dosage of lurbinectedin, a patient experiences an adverse event that is a ≥Grade 3 (severe) non hematological toxicity, Grade 4 thrombocytopenia (Platelet count less than 25,000 cells/mm3), Grade 3 thrombocytopenia (Platelet count less than 50,000 cells/mm3) with bleeding that requires transfusion), or any grade neutropenia (Neutrophil count < LLN) that is associated with infection/sepsis or any other of the adverse reactions (but, in certain embodiments, not solely isolated Grade 4 neutropenia), then at the next scheduled dosage, preferably 3 weeks after the prior dose, and once the patient’s neutrophil count is greater than 1500 cells/mm ³ ; platelet count is greater than about 100,000 mm ³ ; and hemoglobin levels are greater than about 9 g/d, administering a second reduced dosage to the patient which is 60 to 65% of the first, unreduced dose, particularly 2.0 mg/m ² (60-65% of the 3.2 mg/m ² dosage).

[0014] Also provided are embodiments in which an antiemetic is prophylactically administered prior to administration of lurbinectedin associated (acute and delayed- phase) nausea and/or vomiting comprising administering an antiemetic prophylaxis on the day of and prior to administering a dose of 2 to 3.2 mg/m ² lurbinectedin to the patient, particularly where the antiemetic agents comprise a corticosteroid and a serotonin antagonist. In certain embodiments, the corticosteroid is dexamethasone, preferably a dose of 8 mg administered intravenously, or a dose of a corticosteroid that is equivalent to 8 mg dexamethasone intravenously and where the serotonin antagonist is ondansetron, preferably a dose of 8 mg administered intravenously, or a dose of serotonin antagonist that is equivalent to 8 mg ondansetron administered intravenously. In certain embodiments, antiemetic therapy is administered post-infusion on the day of, or for 2, 3, or 4 days after administration of lurbinectedin, preferably comprising administering a corticosteroid, a serotonin antagonist and metoclopramide. In specific embodiments, the corticosteroid is dexamethasone administered orally at a dose of 4 mg, or a dose of corticosteroid equivalent to 4 mg oral dexamethasone; the serotonin antagonist is ondansetron administered orally at a dose of 8 mg, or a serotonin antagonist equivalent to 8 mg oral ondansetron; and metoclopramide is administered at a dose of 10 mg either intravenously or orally, or the dose equivalent to oral or intravenous 10 mg metoclopramide, wherein the metoclopramide is administered every 8 hours.

[0015] One aspect of the invention is a method of treating patients with solid tumors in need thereof by administering lurbinectedin in combination with a topoisomerase inhibitor, particularly irinotecan. In particular embodiments, the solid tumor patient is treated with a treatment regimen in which lurbinectedin is administered at a dose of 1 to 2.5 mg/m ² on day 1 with a dose of 75 mg/m ² irinotecan administered on day 1 and day 8 of the treatment cycle, and the irinotecan is administered with G-CSF. In some embodiments, the solid cancer is selected from endometrial cancer, SCLC, soft tissue sarcoma, glioblastoma, pancreatic adenocarcinoma, mesothelioma, colorectal carcinoma, and epithelial ovarian cancer. In preferred embodiments, the solid tumor is endometrial cancer, SCLC, soft tissue sarcoma, or glioblastoma.

[0016] In one aspect, provided is a stable, lyophilized formulation of lurbinectedin comprising lurbinectedin, a buffer derived from an organic acid (such as lactate buffer) and a disaccharide which has a pH of 3.8 to 4.5 when reconstituted with 8 mL of water. The lyophilized composition comprises or consists of 4 mg lurbinectedin, 22.1 mg lactic acid, 5.1 mg sodium hydroxide and 800 mg sucrose (or comprises or consists of these ingredients in this ratio). The composition is preferably packaged in a 30 ml vial and may be reconstituted in 8 mL water, to yield a solution containing 0.5 mg/ml lurbinectedin. The lyophilized formulation may be stored for 24 months or 36 months or more at 5 ^e C ± 3 ^e C. After 24 months or 36 months of storage, the amount of Impurity D (lurbinectedin degradation product resulting from deacetylation of lurbinectedin) present in the composition is not more than 0.8% wt./wt. of the total lurbinectedin weight. Also provided are methods of storing the lurbinectedin lyophilized formulation and methods of treating SCLC and solid tumors by administration of a lurbinectedin infusion solution prepared from a stored, stable lyophilized lurbinectedin solution. [0017] The present invention identifies methods of treatment using lurbinectedin alone or in combination with further agents. Where reference is made to a method of treatment the present invention also encompasses lurbinectedin and/or said further agents in the manufacture of a medicament for the treatment of cancer and also lurbinectedin and/or said further agents for use in the treatment of cancers as disclosed herein.

DETAILED DESCRIPTION OF THE INVENTION

[0018] Provided herein are methods of for the efficacious treatment of small cell lung cancer (SCLC) based on the administration of lurbinectedin as monotherapy. Also provided are methods of treating solid tumors by administration of a combination of lurbinectedin and irinotecan. Such methods may be carried out by administration of lurbinectedin prepared from stable, lyophilized formulations disclosed herein. Lurbinectedin

[0019] Lurbinectedin is a synthetic alkaloid and an ecteinascidin analog having the following chemical structure:

It is described for example, in US Patent No. 7,763,615, incorporated by reference herein in its entirety. Lurbinectedin may be prepared according to methods known in the art, for example, the process disclosed in International Application Publication PCT WO 2003/014127, which is incorporated herein by reference. [0020] Any lurbinectedin compound referred to herein is intended to represent hydrates, solvates, amorphous and crystalline or partially crystalline forms, and mixtures thereof when such forms exist in the medium. In addition, lurbinectedin compounds referred to herein may exist in isotopically-labelled forms. All geometric hydrates, solvates, and isotopically labelled forms of the compounds referred to herein, and mixtures thereof, are considered within the scope of the formulations and methodologies of this invention. [0021] In the present application, by "cancer" it is meant to include tumors, neoplasias, and any other malignant disease having as cause malignant tissue or cells.

[0022] The term "treating", as used herein, unless otherwise indicated, means reversing, alleviating, or inhibiting the progress of the disease or condition to which such term applies, or one or more symptoms of such disorder or condition. The term "treatment", as used herein, unless otherwise indicated, refers to the act of treating as "treating" is defined immediately above. In particular, the methods of “treatment” or “treating” herein may be used for alleviating one or more symptoms of solid tumors, delaying progression of solid tumors, shrinking tumor size in a solid tumor patient, inhibiting solid tumor growth, prolonging overall survival, prolonging progression free survival, preventing or delaying solid tumor metastasis, reducing (such as eradicating) preexisting solid tumor metastasis, reducing incidence or burden of preexisting solid tumor metastasis, or preventing recurrence of solid tumors.

[0023] The term “immunotherapy,” as used herein, means therapy that modulates the immune response, including promoting an immune response or blocking inhibition of an immune response, to cancer cells, for example, but not limited to, antibodies, proteins or other agents that bind to a checkpoint inhibitor, such as, CTLA-4, PD-1 , PD-L1 and others with like activity that promote immune response to cancer cells. Examples of immunotherapies include, but are not limited to, atezolizumab, nivolumab, pembrolizumab, ipilimumab, cemiplimab, durvalumab, avelumab and the like. Treatment of SCLC

[0024] Embodiments of this invention include methods of treating SCLC in a patient suffering therefrom by administering to the patient a therapeutically effective amount of lurbinectedin according to dosing regimen of one or more treatment cycles using pharmaceutical formulations of lurbinectedin described herein. Lurbinectedin therapy, in certain embodiments, is second line therapy, such that patients have previously been administered and disease has progressed in response to, therapies such as platinum- containing therapy and/or immune-oncology therapy. Such treatment regimens are preferably administering to the SCLC patient a dose of 2.0 to 3.2 mg/m ² lurbinectedin, in preferred embodiments at least for an initial dose, 3.2 mg/m ² , by intravenous infusion, preferably over 1 hour, every three weeks, provided that dose may be reduced and/or delayed depending upon the occurrence of adverse events, particularly hematological abnormalities as disclosed herein. In some embodiments, the SCLC patient is administered 3.2 mg/m ² by intravenous infusion over 60 minutes repeated every 3 weeks until disease progression or unacceptable toxicity. In aspects of the invention, treatment results in an overall response rate of greater than 30%, including greater than 35% or 35.2%; progression free survival for a median of 3.5 months, including 2.6 to 4.6 months, or 2.6 months (in resistant patient population (CTFI less than 90 days)) to 4.6 months (in sensitive patient populations (CTFI greater than or equal to 90 days)); and overall survival for a median of 9.3 months (resistant patient population (CTFI less than 90 days) of 5.0 months and sensitive patient population (CTFI greater than or equal to 90 days) at 11.9 months).

[0025] In various embodiments, the invention provides methods for treating small cell lung cancer (SCLC) in a patient in need thereof, especially those whose SCLC has progressed after prior therapy such as platinum-containing therapy, immunotherapy, or both, including among others patients who have failed to respond or to respond adequately to prior treatment, those who may have responded to prior treatment but then experienced progression of the disease, and those who may have had such response followed by progression more than once.

SCLC Patients

[0026] Patients with SCLC who fail to respond or progress through first-line platinum containing chemotherapy and/or immunotherapy are considered to be "refractory." Patients who initially respond to initial or "first-line" chemotherapy comprising platinum agents and then relapse/progress within 90 days (3 months) are considered to be "resistant." Patients who respond to initial treatment but then relapse or whose tumors progress within about 91 to 180 days (3-6 months) after the cessation of first-line therapy with platinum agents are considered sensitive and considered herein to have a "91 to 180 day progressive" SCLC. Patients who respond to initial relapse or whose tumors progress after 180 days are “sensitive”

[0027] The lurbinectedin therapy can be second-line therapy wherein the SCLC patient has been previously treated with one or more other chemotherapeutic agents such as carboplatin or cisplatin and etoposide. In particular, the treatments are suited for SCLC patients who are relapsing or refractory to previous chemotherapy. In some embodiments, the SCLC patient ceased to respond or ceased to respond adequately to prior platinum-containing therapy or had no response to prior platinum-containing therapy. More specifically, lurbinectedin therapy can be used when a SCLC patient is refractory, resistant, or relapsed/progressive, including in certain embodiments, within 0 to 90 days, or within 91 to 180 days, after cessation of first-line platinum-containing chemotherapy, and optionally radiation treatment. SCLC patients that progress within 0 to 90 days or within the 91 to 180 day period after cessation of the first-line therapy, as well as patients whose SCLC is refractory to treatment and progress, including within 90 days, 180 days or at any time, or whose SCLC responds to initial treatment and then progresses within 90 days, 180 days or at any time of cessation of initial treatment, can advantageously be treated with lurbinectedin so as to increase one or more of their progression-free survival, overall survival, or duration of response. In some embodiments, the SCLC patient had a chemotherapy-free interval of at least 90 days, at least 120 days, at least 150 days, or at least 180 days after prior administration of the prior platinum containing therapy. In specific embodiments, the patient had not received platinum-containing therapy in at least 30 days or at least 60 days or at least 90 days prior to administration of lurbinectedin. In some embodiments, the present disclosure provides methods of treating patients with SCLC who have progressed after prior platinum-containing therapy.

[0028] The lurbinectedin therapy can also be administered following first-line platinum- containing chemotherapy, such as carboplatin or cisplatin and etoposide, in combination with checkpoint inhibitors, such as atezolizumab, pembrolizumab, ipilimumb, durvalumab, or a combination thereof, or following second-line therapy with nivolumab or other immunotherapy, such as atezolizumab, pembrolizumab, ipilimumab or durvalumab. In particular, the treatments are suited for SCLC patients who are relapsing or refractory to prior immunotherapy. For example, in some embodiments, lurbinectedin treatment are suited for SCLC patients who are relapsing or refractory to prior first-line carboplatin/etoposide/atezolizumab combination therapy or second-line immunotherapy with nivolumab. In some embodiments, the SCLC patient ceased to respond or ceased to respond adequately to prior immunotherapy or had no response to prior immunotherapy. More specifically, lurbinectedin therapy can be used when a SCLC patient is refractory, resistant, sensitive or relapsed/progressive within 91 to 180 days, after cessation of first-line platinum-containing chemotherapy in combination with immunotherapy or second-line nivolumab, and, in certain embodiments, the patient has received radiation treatment. SCLC patients that progress after cessation of the first-line immunotherapy (in combination with platinum-containing therapy) or second-line immunotherapy at any time after therapy (including in certain embodiments within 90 days or within 180 days of treatment), as well as patients whose SCLC is refractory to treatment (has a chemotherapy free interval less than 90 days) and progresses within 180 days, or whose SCLC responds to initial treatment and then progresses within 180 days of cessation of initial treatment, can advantageously be treated with lurbinectedin so as to increase one or more of their progression-free survival, overall survival, or duration of response. In some embodiments, the SCLC patient had, with respect to prior treatment, a chemotherapy-free interval, including immunotherapy, of less than 90 days, and in other embodiments, the SCLC had a chemotherapy-free interval of at least 90 days, at least 120 days, at least 150 days, or at least 180 days, but in certain embodiments, no more than 120 days, 150 days or 180 days. In specific embodiments, the patient had not received first-line immunotherapy (in combination with platinum- containing therapy) or second-line immunotherapy in at least 30 days or at least 60 days or at least 90 days prior to administration of lurbinectedin.

[0029] It is expected that when a treatment of this invention is administered to a SCLC patient in need of such treatment, said treatment will produce an effect as measured by the extent of the anticancer effect, the (overall) response rate, the time to disease progression, or the survival rate. In one embodiment, the overall response rate is at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, or at least 60%. In some embodiments, the overall response rate is at least 11% or at least 20% for patients with a chemotherapy-free interval of less than 90 days or wherein the overall response rate is at least 30% or at least 40% for patients with a chemotherapy-free interval of at least 90 days. In some embodiments, the duration of response is at least 5.3 months or at least 4.7 months for the resistant patient (chemotherapy-free interval of less than 90 days) or wherein the duration of response is at least 6.2 months for the sensitive patient with a chemotherapy-free interval of at least 90 days.

[0030] Alternatively, the treatment can be a second-line therapy for SCLC with extensive or limited disease that is refractory to initial chemotherapy or progressive within less than 90 days (3 months) of completing first line, platinum-containing therapy. SCLC patients that progress after cessation of the first-line therapy (including within 30 to 90 days of treatment, but may be at anytime), as well as patients whose SCLC is refractory to treatment and progress within 90 days, or whose SCLC responds to initial treatment and then progress within 90 days of cessation of initial treatment, can advantageously be treated with lurbinectedin so as to increase one or more of their progression-free survival, overall survival, or duration of response. In some embodiments, the SCLC patient had a chemotherapy-free interval for the prior treatment of less than 90 days, such as less than 30 days, less than 60 days, or less than 90 days.

[0031] In various embodiments, the SCLC patient is first treated with platinum- containing therapy and immunotherapy, wherein the platinum-containing therapy and the immunotherapy were either given concurrently or consecutively, followed by administering to the patient an effective amount of lurbinectedin. For example, in some embodiments, a SCLC patient had received prior immunotherapy comprising administering antibodies targeting PD-L1 , CTLA-4, or PD-1 , wherein the antibodies are selected from atezolizumab, nivolumab, pembrolizumab, ipilimumb, durvalumab, or a combination thereof. In some embodiments, atezolizumab is administered in combination with platinum-containing therapy and etoposide. In some embodiments, the patient has received nivolumab treatment.

Treatment Cycles

[0032] Administration of the pharmaceutical compositions comprising lurbinectedin is preferably by intravenous infusion. Infusion times of up to 72 hours can be used, but are preferably between 1 and 24 hours, and generally about 1 hour. Short infusion times which allow treatment to be carried out without an overnight stay in hospital are especially desirable. In a preferred embodiment, lurbinectedin is administered by infusion over 1 hour.

[0033] Preferably, the administration of lurbinectedin is performed in cycles. In a preferred administration schedule an intravenous infusion of lurbinectedin is given to the patients the first day of each cycle and the patients are allowed to recover for the remainder of the cycle. The preferred duration of each cycle is 3 weeks. The treatment cycle can, however, be increased or decreased, for example by 1 to 6 days, one week, or two weeks, depending on patient response to the treatment. Administration of lurbinectedin by intravenous infusion during about 1 hour once every 3 weeks is the most preferred administration schedule, although other protocols can be devised as variations. Multiple cycles can be given as needed. Over the course of treatment of SCLC, 1 to 24 doses of lurbinectedin can be administered, with 4 to 8 doses being typically administered, at intervals of about 21 days (three weeks). Intervals of up to six weeks, e.g., 3 to 4 weeks, can be employed if, for example, it is necessary to modify the treatment schedule to reduce or manage side-effects (as discussed in detail below). Over the course of treatment of the cancer, 1 to 24 treatments of lurbinectedin can be administered, with 4 to 8 treatments being typically administered, at intervals of about 21 days (three weeks). In some embodiments, one dose of lurbinectedin is administered per treatment cycle and the patient undergoes 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, or 24 treatment cycles.

[0034] Bioavailability of a drug is defined as the proportion of a drug or other substance that enters the circulation when introduced into the body and so is able to have an active effect. Measures of bioavailability well known in the art include the area under the plasma concentration-time curve (AUC) and the concentration maximum (Cmax). Cmax is the maximum plasma concentration achieved after drug administration.

[0035] Provided herein are methods for lurbinectedin dosing by one or more pharmacokinetic parameters, wherein administration of said dosage is effective to treat resistant, refractory or progressive SCLC. In exemplary embodiments, the one or more pharmacokinetic parameters is peak concentration (Cmax) or area-under-the-curve (AUC). In one embodiment, 3.2 mg/m ² of lurbinectedin is administered to a SCLC patient in need thereof as a 1 -hour infusion, to achieve mean total plasma Cmax within 80% to 125% of about 107 μg/L and mean AUC ^∞ within 80% to 125% of about 551 μg*h/L. In some embodiments, lurbinectedin is administered to a SCLC patient on a 1 day on and 20 days off cycle (1/20 cycle). In one embodiment, the administration cycle is a 1/20 cycle and the target mean AUC ^∞ is about 551 μg*h/L. In one embodiment, the administration cycle is a 1/20 cycle and the target mean AUC ⁰⁰ is about 551 μg*h/L±5%, about 551 μg*h/L±10%, about 551 μg*h/L±20%, or about 551 μg*h/L±25%. In a preferred embodiments, the administration cycle is a 1/20 cycle and the target mean AUC ⁰⁰ is within 80% to 125% of about 551 μg*h/L. In one embodiment, the administration cycle is a 1/20 cycle and the mean target Cmax is about 107 μg/L. In one embodiment, the administration cycle is a 1/20 cycle and the mean target Cmax is about 107 μg/L±5%, about 107 μg/L±10%, about 107 μg/L±20%, or about 107 μg/L±25%. In a preferred embodiments, the administration cycle is a 1/20 cycle and the mean target Cmax is within 80% to 125% of about 107 μg/L.

[0036] Renal, hepatic, and hematologic impairment need to be ruled out prior to administration lurbinectedin to a patient afflicted with SCLC. In one embodiment of the present invention a patient afflicted with SCLC, determined to have a neutrophil count of at least 1.5 cells/mm ³ , a platelet count of at least 100,000/mm ³ , and hemoglobin levels of at least 9 g/dL (with transfusion if necessary), a first dose of about 3.2 mg/m ² lurbinectedin is administered. In another embodiment of the present invention a patient afflicted with SCLC, determined to have a calculated hepatic clearance of greater than 30 mL/min and an AST or ALT less than 3xULN or bilirubin less than 1.5xULN, and a calculated creatinine clearance greater than 30 mL/min, a first dose of about 3.2 mg/m ² lurbinectedin is administered. A second dose of 3.2 mg/m ² lurbinectedin is administered to the patient about 21 days after the first dose, and further dosing at this level is continued if hematological, renal, and hepatic parameters remain stable. To achieve the preferred dosing, preferably about 3.2 mg/m ² of lurbinectedin is administered per dose, e.g., per intravenous infusion. Dosing of lurbinectedin can include about 3.2 mg/m ² lurbinectedin per dose, e.g., per intravenous infusion or a reduced dose thereof as discussed below.

Antiemetic Treatment

[0037] Best supportive care for SCLC comprises a number of palliative treatments. For example, in one embodiment of the invention, best supportive care includes one or more, and preferably all, administration of analgesics to control pain, management of constipation, and treatment of dyspnea and treatment of anemia, e.g., by transfusions, so as to maintain hemoglobin levels (i.e., >9 g/dL).

[0038] In other embodiments, therapies are administered to specifically prevent and treat or manage nausea and/or vomiting associated with lurbinectedin administration, are set forth below.

[0039] Chemotherapeutics differ in their emetogenicity. In the absence of antiemetic prophylaxis, agents associated with >90% risk of emesis are classified as highly emetogenic chemotherapy and those associated with 30%-90% risk of emesis classified as moderately emetogenic chemotherapy.

[0040] Aspects include methods of prevention and treatment of lurbinectedin-induced (acute and delayed-phase) nausea and/or vomiting, wherein an effective antiemetic amount of a serotonin antagonist or corticosteroid, or a combination thereof, are administered to the patient prior to administration of lurbinectedin, particularly immediately prior to lurbinectedin administration, in order to reduce the side effects of nausea and vomiting that can accompany administration of lurbinectedin. A preferred embodiment is the treatment of SCLC in a patient in need thereof comprising: (1 ) administering one or more antiemetic agents effective to reduce nausea associated with administration of lurbinectedin to the patient on the day of and prior to administration of lurbinectedin to the patient; and (2) administering lurbinectedin at a dose of 2 to 3.2 mg/m ² to the patient by intravenous infusion. In certain embodiments, the lurbinectedin is administered as a single agent chemotherapeutic agent and/or is not administered in combination with doxorubicin.

[0041] In some embodiments, antiemetic agents are given intravenously or orally. If the one or more antiemetic agents are given intravenously, the one or more agents are administered between 30 and 90 minutes before administration of lurbinectedin, or at about 30 minutes, about 45 minutes, about 60 minutes, about 75 minutes, or about 90 minutes, before administration of lurbinectedin, preferably 30 or 60 minutes. If the one or more antiemetic agents are given orally, the one or more agents are administered between 30 to 60 minutes before administration of lurbinectedin, about 3 hours and 9 hours before administration of lurbinectedin, or about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, or about 9 hours before administration of lurbinectedin. In some embodiments, the antiemetic agents consist of a corticosteroid and a serotonin antagonists, wherein the corticosteroid is selected from the group consisting of dexamethasone, hydrocortisone, or methylprednisolone and the serotonin antagonist is selected from a group consisting of ondansetron, granisetron, and palonosetron. The dose of the corticosteroid is or is equivalent to about 4 mg to 20 mg of dexamethasone delivered intravenously, preferably 8 mg delivered intravenously. The dose of the serotonin antagonist is or is equivalent to about 8 mg to 16 mg of ondansetron delivered intravenously, preferably 8 mg delivered intravenously. If given orally, the dose can be increased to a dose equivalent of up to 24 mg of ondansetron. In preferred embodiments, the prophylactic antiemetic agents comprise dexamethasone intravenously administered at 8 mg, ondansetron intravenously administered at 8 mg, or a combination thereof.

[0042] In some embodiments, the method further comprises administering one or more antiemetic agents within 2, 3, or 4 days after administration of lurbinectedin to the patient, for example, administered on the same day after lurbinectedin administration, for example, within 2, 3, 4, 5, 6, 7 or 8 hours of lurbinectedin administration and/or on day 1 , 2, 3, or 4 after lurbinectedin administration. The one or more antiemetic agents administered after lurbinectedin administration are selected from the group consisting of a corticosteroid, wherein the corticosteroid is selected from dexamethasone, hydrocortisone, and methylprednisolone, a serotonin antagonist, wherein the serotonin antagonist is selected from ondansetron, granisetron, and palonosetron, and metoclopramide. In preferred embodiments, the post-infusion antiemetic treatment is 4 mg dexamethasone (oral), 8 mg ondansetron (oral), or 10 mg metoclopramide (oral or as infusion), or a combination thereof. The metoclopramide may be administered at 8 hour intervals. In some embodiments, post-infusion antiemetic agents are administered intravenously. In some embodiments, the first dose of post-infusion antiemetic agents are given on the evening of, or 1 , 2, 3, 4, 5, 6, 7 or 8 hours after lurbinectedin administration and continued for up to 1 , 2, 3, or 4 days post infusion. In some embodiments, a corticosteroid, e.g. dexamethasone, is given at a dose equivalent to 4 mg of dexamethasone on the evening of, or 1 , 2, 3, 4, 5, 6, 7 or 8 hours after chemotherapy and then twice per day for up to 1 , 2, 3, or 4 days. In some embodiments, metoclopramide is administered at a dose of 10 to 20 mg, orally, every 8 hours post chemotherapy for up to 1 , 2, 3, or 4 days. In other embodiments, a serotonin antagonist, e.g. ondansetron, is given orally at a dose equivalent to 8 mg or 16 mg of ondansetron every 12 hours or 24 hours, respectively, for up to 1 , 2 or 3 days after lurbinectedin administration.

[0043] In some embodiments, the antiemetic prophylaxis and optionally the post infusion antiemetic treatment is administered to a SCLC patient who is given about 2.0 mg/m ² , about 2.6 mg/m ² , or about 3.2 mg/m ² of lurbinectedin by intravenous infusion. The antiemetic prophylaxis and optionally the post-infusion antiemetic treatment is administered to a solid tumor patient who is administered 1 .0 to 2.0 mg/m ² lurbinectedin in combination with irinotecan.

Dosage and Dose Reduction

[0044] Additional embodiments of the invention include a dose modification in the event of identifying a ≥ Grade 2 adverse event (AE) in a SCLC patient upon administration of a first dose of 3.2 mg/m ² of lurbinectedin to the patient by intravenous infusion which requires frequent or prolonged (>2 weeks) dose delays.

[0045] In some embodiments, a lower amount of lurbinectedin is used as compared to the amount generally used for individual therapy. In some embodiments, the same or greater therapeutic benefit is achieved using a smaller amount (e.g., a lower dose or a less frequent dosing schedule) of lurbinectedin than the amount generally used for individual therapy. For example, the use of a smaller amount of lurbinectedin may result in a reduction in the number, severity, frequency, or duration of one or more side-effects associated with lurbinectedin infusion. For example, in preferred embodiments, the first dose modification is a dose reduction from about 3.2 mg/m ² to about 2.6 mg/m ² of lurbinectedin and the second dose modification is a dose reduction from about 2.6 mg/m ² to about 2.0 mg/m ² of lurbinectedin. Adverse events which require frequent or prolonged (>2 weeks) dose delays include, but are not limited to, any hematologic toxicity that is Grade 3 or Grade 4, or any Grade 3 or Grade 4 non-hematologic toxicity. In the event of non-hematologic toxicities of Grade 3 or Grade 4, the following cycle is delayed until non- hematologic parameters have improved to Grade 1 or 0. Administration of two doses of lurbinectedin are always spaced apart by at least 21 days. [0046] In the event of hematologic toxicities of Grade 3 or Grade 4, the following cycle is delayed until hematologic parameters, such as neutrophil count, platelet count, and hemoglobin level have improved. For example, at first occurrence of Grade 4 thrombocytopenia (platelet count less than 25,000 cells/mm ³ ), Grade 3 thrombocytopenia (platelet count less than 50,000 cells/mm ³ ) with bleeding that requires transfusion, Grade 4 neutropenia (neutrophil count less than 500 cells/mm ³ ), or of any grade neutropenia (neutrophil count < LLN), the lurbinectedin dose is reduced from 3.2 mg/m ² to 2.6 mg/m ² and the next cycle is delayed until the patient’s neutrophil count is greater than 1500 cells/mm ³ ; platelet count is greater than about 100,000/mm ³ ; and hemoglobin levels are greater than about 9 g/dL. In a certain embodiment, if the identified adverse event consists of isolated Grade 4 neutropenia, the method comprises administration to the patient a dose of G-CSF (“secondary G-CSF prophylaxis”) as prophylaxis to manage the isolated Grade 4 neutropenia and then a dose of lurbinectedin that is equal to the previous dose rather than reducing the lurbinectedin dose.

[0047] If the identified adverse reaction is not solely isolated Grade 4 neutropenia, the method comprises administering to the patient a reduced dose of lurbinectedin. Administration of two doses of lurbinectedin must be spaced apart by at least 21 days regardless of the dose of lurbinectedin.

[0048] A preferred embodiment is the treatment of small cell lung cancer (SCLC) in a patient in need thereof, comprising: (1) administering a first dose of 3.2 mg/m ² of lurbinectedin to the patient by intravenous infusion; (2) identifying an adverse reaction in the patient, wherein the adverse reaction is selected from the group consisting of: ≥Grade 3 (severe) non hematological toxicity, Grade 4 thrombocytopenia (Platelet count less than 25,000 cells/mm ³ ), Grade 3 thrombocytopenia (Platelet count less than 50,000 cells/mm ³ ) with bleeding that requires transfusion, Grade 4 neutropenia (Neutrophil count less than 500 cells/mm ³ ), or any grade neutropenia (Neutrophil count < LLN) that is associated with infection/sepsis or any other of the adverse reactions; and (3) after the adverse reaction is identified and after the patient’s neutrophil count is greater than 1500 cells/mm ³ ; platelet count is greater than about 100,000/mm ³ ; and hemoglobin levels are greater than about 9 g/dL: (i) if the identified adverse reaction consists of isolated Grade 4 neutropenia (Neutrophil count less than 500 cells/mm ³ ), administering to the patient a dose of G-CSF and a dose of lurbinectedin that is equal to the previous dose; or (ii) if the identified adverse reaction is not solely isolated Grade 4 neutropenia, administering to the patient a reduced dose of lurbinectedin, wherein administration of two doses of lurbinectedin are spaced apart by 21 days or 20 to 23 days or at least 18, 19, 20, 21 , 22, or 23 days.

[0049] In some embodiments, the first dose reduction is 80 to 85% of the first dose after first occurrence of the adverse reaction that it not solely isolated Grade 4 neutropenia or wherein a first reduced dose is 2.6 mg/m ² after a first occurrence of the adverse reaction that is not solely isolated Grade 4 neutropenia. In some embodiments, a second reduced dose is 60-65% of the first dose after a second occurrence of the adverse reaction that is not solely isolated Grade 4 neutropenia or wherein a second reduced dose is to 2.0 mg/m ² after a second occurrence of the adverse reaction that is not solely isolated Grade 4 neutropenia, wherein the second reduced is administered to the patient. Administration of lurbinectedin is discontinued after identification of the adverse reaction after administration of the second reduced dose.

Combination Therapy

[0050] In other embodiments, the invention is directed to the combination of lurbinectedin with a topoisomerase I and/or II inhibitor in the treatment of cancer, and more particularly in the treatment of endometrial cancer, SCLC, soft tissue sarcoma, glioblastoma, pancreatic adenocarcinoma, mesothelioma, colorectal carcinoma, and epithelial ovarian cancer. In preferred embodiments, the solid tumor is endometrial cancer, SCLC, soft tissue sarcoma or glioblastoma. In some embodiments, the method of treating patients with solid tumors comprises administering lurbinectedin at a dose of 1 to 2.5 mg/m ² in combination with other anticancer agents, such as a topoisomerase inhibitor selected from SN-38 or irinotecan, wherein the lurbinectedin is administered at a dose of 1 to 2.5 mg/m ² and wherein the topoisomerase inhibitor is administered at a dose equivalent to 50 to 75 mg of irinotecan/m ² . The chemotherapeutic group of topoisomerase I and/or II inhibitors includes, but is not limited to topotecan, SN-38, irinotecan, camptothecin, rubitecan, etoposide, amsacrine and teniposide. Particularly preferred is the combination of lurbinectedin with irinotecan in the treatment of cancer, and more particularly in the treatment of endometrial cancer, SCLC, soft tissue sarcoma, glioblastoma, pancreatic adenocarcinoma, mesothelioma, colorectal carcinoma, and epithelial ovarian cancer.

[0051] In some embodiments, lurbinectedin is administered at a dose of 1 , 1 .5, 2, or 2.4 mg/m ² and the topoisomerase inhibitor is administered at a dose equivalent to 50 to 75 mg/m ² of irinotecan. In preferred embodiments, lurbinectedin is administered at a dose of 2 mg/m ² and irinotecan is administered at a dose of 75 mg/m ² . G-CSF is administered to the patient with the combination. [0052] In some embodiments, the topoisomerase inhibitor is administered on day one of a treatment cycle. In some embodiments, the method further comprises administering G-CSF on the same day as the administration of the topoisomerase inhibitor. In another embodiment, the topoisomerase inhibitor is further administered to the patient on day 7, 8, 9, or 10 of the treatment cycle. In some embodiments, the treatment cycle is a 18, 19, 20, 21 , 22, 23, 24, or 25 day cycle. In one embodiment, the method further comprises administering one or more antiemetic agents on day one of a treatment cycle (as described in detail above).

Pharmaceutical Compositions and Methods of Preparation

[0053] Pharmaceutical compositions of lurbinectedin that can be used include solutions, lyophilized compositions, etc., with suitable excipients for intravenous administration. Preferably, lurbinectedin may be supplied and stored as a sterile lyophilized product, comprising lurbinectedin, a buffer derived from an organic acid an organic carboxylic acid buffer, for example, a buffer derived from lactic acid, butyric acid, propionic acid, acetic acid, succinic acid, citric acid, ascorbic acid, tartaric acid, malic acid, maleic acid, fumaric acid, and glutamic acid , aspartic acid, gluconic acid, a-ketoglutaric, particularly, lactic acid or succinic acid; a disaccharide, for example, sucrose, trehalose or lactose, or a combination thereof, and a sufficient base to provide an appropriate pH, particularly, when reconstituted, a pH of around 4, including of 3.5 to 4.5 or, more preferably, a pH of 3.8 to 4.1 . In certain embodiments, the buffer is not a phosphate buffer.

[0054] The lurbinectedin-containing formulations of this invention can be made by freeze-drying a composition of this invention in the form of a buffered bulk solution including lurbinectedin, a buffer derived from an organic acid, such as a lactate buffer or a succinate buffer, and a disaccharide. The disaccharide is preferably sucrose. Usually the bulk solution will be buffered, for example to a pH of about 3.5 to 4.5, more preferably pH 3.8 to 4.1. The preferred buffering agent is a sodium lactate buffer. In preferred embodiments, the lactate buffer comprises lactic acid and a base, preferably an inorganic, pharmaceutically accepted base such as sodium hydroxide.

[0055] As explained herein, lurbinectedin has limited aqueous solubility. It was found that lurbinectedin solubility is improved in the bulk solution by first forming a concentrated pre-solution of the lurbinectedin in a buffer derived from an organic acid, for example lactic acid, succinic acid, citric acid, or acetic acid which is further diluted with water for injection. A disaccharide is then dissolved in an aqueous solution containing a basic ingredient, for example an aqueous sodium hydroxide solution, and upon adjusting the pH to a set value, the pre-solution of the lurbinectedin and the buffer solution containing a disaccharide are mixed to obtain the lurbinectedin bulk solution in an organic buffer, pH=4 containing a disaccharide (for example, sucrose). Following this three-step process, this pre-dissolution the lurbinectedin concentration in the bulk solution and the vial can be increased and the fill volume in the vials can be reduced. In these embodiments of the present invention, the fill volume is usually reduced by about 80% with respect to that of the conventional fill volume. By way of illustration, but not as a limitation, embodiments of this invention provide a fill volume of 10 ml for a vial containing 1 mg lurbinectedin, and 30 ml for a vial containing 4 mg lurbinectedin. The fill volume can optionally be reduced further in other embodiments of this invention by increasing the lurbinectedin concentration.

[0056] Provided are processes useful for improving the solubility of lurbinectedin in the bulking solution that comprise dissolving lurbinectedin in lactic acid, for example 0.31 M lactic acid (25 mg/ml_), and subsequent dilution of the solution with water for injection to yield a lurbinectedin concentrated solution in 0.1 M lactic acid, mixing the solution containing pre-dissolved lurbinectedin with a buffer salt solution comprising sodium lactate buffer and a disaccharide, and, optionally, adjusting the pH. In some illustrative, but not limiting, embodiments of this invention, pH adjustment is accomplished with a lactate buffer.

[0057] Illustrative embodiments of bulk solution for freeze drying according to the present invention are provided by a solution of lurbinectedin buffered at pH 4 with sodium hydroxide and lactic acid with sucrose as bulking agent.

[0058] An illustrative embodiment of the methodology according to this invention provides as follows: lurbinectedin is dissolved in 0.31 M lactic acid, pH ~3 and subsequently diluted with water for injection to yield a lurbinectedin concentrated solution of 8.3 mg/ml_ lurbinectedin in 0.1 M lactic acid, pH ~3. Sodium lactate buffer salt solution is prepared by mixing 0.31 M lactic acid solution with 0.01 M sodium hydroxide solution to create a 0.05M lactate buffer salt solution. Sucrose is then added to the sodium lactate buffer salt solution. The 0.05M lactate buffer salt solution containing sucrose is diluted with water for injection to yield a 0.04M sodium lactate buffer, pH~4.2 containing 17% sucrose. Both solutions, 8.3 mg/ml_ lurbinectedin in 0.1 M lactic acid, pH ~3 and 0.04M sodium lactate buffer, pH~4.2 containing 17% sucrose are then mixed. Dissolution is visually checked at all steps before continuing, and dissolution is considered complete when it is so appreciated visually The pH of the solution is checked and adjusted to a value in the range from about 1 to about 5, more preferably in the range from about 2 to about 4.5, even more preferably in the range from about 3 to about 4.5, and most preferably to a pH of about 4.0 by slow addition of a suitable acid or base. A preferred embodiment of such acid is lactic acid, in which case a preferred concentration is about 0.1 M. A suitable base is optionally added for pH control. A preferred embodiment of such base is sodium hydroxide, preferably in solution, in which case a preferred concentration is about 0.1 M. The volume is finally adjusted by addition of a suitable, biocompatible fluid, preferably water for injection. The resulting bulk solution preferably comprises 0.5 mg lurbinectedin in 0.03M sodium lactate buffer, pH=4, with 10% (w/v) sucrose. The bulk solution is then filled in vials according to the desired dose.

[0059] In one embodiment, the lyophilized composition comprises or consists of 4 mg of lurbinectedin, 800 mg of sucrose, 22.1 mg of lactic acid and 5.1 mg of sodium hydroxide. In some embodiments, the weight ratio in the lyophilized composition is between 0.4% and 0.6% (w/w) of active compound, 96% to 98% (w/w) of sucrose, 2% to 3% (w/w) of lactic acid, and 0.5% to 0.7% (w/w) sodium hydroxide. In preferred embodiments, the weight ratio in the lyophilized composition is 0.5% (w/w) active compound, 96.2% (w/w) sucrose, 2.7% (w/w) lactic acid, and 0.6% (w/w) sodium hydroxide. The lyophilized formulation contains about 0.25 mmol of lactate ion for 4 mg of lurbinectedin. When reconstituted to 8 ml in the vial, the resulting solution is 0.5 mg/ml lurbinectedin, 0.03M sodium lactate buffer, 10% w/v sucrose at about pH 4.0 (range of pH 3.5 to 4.5, preferably 3.8 to 4.5).

[0060] The lyophilized material is usually present in a vial which contains a specified amount of lurbinectedin. Preferably the lyophilized composition of lurbinectedin is provided in a 30 ml. vial. The specified amount of lurbinectedin in a lyophilized composition can be from between 0.2 to 5 mg, or about 1 mg, about 2 mg, about 3 mg, or about 4 mg. The specified amount of lurbinectedin in a lyophilized composition is preferably 4 mg. In lyophilized embodiments, the composition contains between 0.4% and 0.6% by weight of lurbinectedin, preferably it is 0.5%.

Storage and Use of Pharmaceutical Lurbinectedin Formulations [0061] Embodiments of this invention also provide a method of storing a lyophilized lurbinectedin composition. The lurbinectedin lyophilized formulations are storage stable such that after prolonged storage at the lurbinectedin retains its therapeutic activity and exhibits minimal degradation. In one aspect, the amount of a lurbinectedin degradation product resulting from deacetylation of lurbinectedin (“Impurity D”) (having a relative retention time of 0.87 to 0.88 by commercial HPLC assay) is minimized, for example being less than 0.3%, 0.4%, 0.5%, 0.6%, 0.7% or 0.5% wt/wt of the weight of lurbinectedin in the formulation. Impurity D has the following structure:

[0062] In a preferred embodiment the method of storing a lyophilized lurbinectedin composition comprises storing a lyophilized composition comprising 4 mg lurbinectedin; lactate buffer; and a disaccharide at a temperature of for at least 24 months, wherein the lyophilized composition is formulated such that reconstitution with 8 ml. of water will yield a solution having a pH of 3.5 to 4.5 and a lurbinectedin concentration of 0.5 mg/ml and wherein after the at least 24 months storage, the amount of Impurity D present in the composition is not more than 0.8% wt./wt. of the total lurbinectedin weight. In some embodiments, the lyophilized lurbinectedin composition is stored at a temperature of C for, or for at least, 24 months, 30 months, 36 months, 42 months, 48 months or 60 months, wherein after 24 months, 30 months, 36 months, 42 months, 48 months or 60 months of storage, the amount of a lurbinectedin degradation product Impurity D present in the composition is not more than 0.8% wt./wt. of the total lurbinectedin weight. In some embodiments, the amount of Impurity D present in the composition after storage at about for 60 months is not more than 0.8% wt./wt, or is less than 0.7% wt./wt., less than 0.6% wt./wt., less than 0.5% wt./wt., or less than 0.4% wt./wt. of the total lurbinectedin weight. In one embodiment, the amount of lurbinectedin degradation product Impurity D present in the composition is not more than 0.8% wt./wt. of the total lurbinectedin weight after at least 36 months of storage. In some embodiments, the total % impurities and degradation products (as % area) after storage at about for 24 months, 30 months or 36 months is not more than 0.6 %, 0.7%, 0.8% 0.9% or 1 .0% (% area). In some embodiments, the initial amount of Impurity D present in the composition (i.e., one day of lyophilization) is less than 0.4% wt./wt. of the total lurbinectedin weight. In some embodiments, the initial amount of Impurity D present in the composition is at least 0.5 % wt./wt. or at least 0.1% wt./wt. of the total lurbinectedin weight. In some embodiments, after storage at about for 24 months, 30 months, 36 months, 48 months or 60 months the stable, lyophilized, lurbinectedin formulation shows negligible degradation of lurbinectedin, for example within 1 .0%, 0.5% or 0.2% decrease in the amount of lurbinectedin as compared to the amount of lurbinectedin present in the bulk solution from which the formulation is made. [0063] Accordingly, provided are stable, lyophilized lurbinectedin formulations comprising an a buffer derived from an organic acid, for example, succinate, citrate, acetate or lactate buffer at a molar ratio of buffer to lurbinectedin of about 48, including the molar ratio 52 to 46, 54 to 44, 50 to 48, 52 to 58, or the molar ratio 51 to 48, and sucrose as a bulking agent, which, when reconstituted in 8 mL of water has a pH of about 4.0, including pH 3.5-4.5 or pH 3.8-4.1 , which comprises Impurity D at no more than 0.8% wt/wt, or is less than 0.7% wt./wt., less than 0.6% wt./wt., less than 0.5% wt./wt., or less than 0.4% wt./wt of the total weight of lurbinectedin and, preferably, the Impurity D does not increase to more than 0.8% wt/wt. 1 .0% wt/wt or 1 .2% wt/wt after storage at 5°C ± 3 ^e C for 12 months, 24 months, 30 months, 36 months, 48 months or 60 months; or storage at 25°C/60%RH for 3 months, 6 months, 9 months, 12 months or 18 months; or 40°C/60% RH for 1 month, 3 months, 6 months or 12 months. In these embodiments, the lurbinectedin is 95 to 105%, or 97 to 103% of 4 mg lurbinectedin or of the amount of lurbinectedin by assay at day 1 .

[0064] Also provided are methods of reducing lurbinectedin degradation in a lyophilized formulation by incorporating a buffer derived from an organic acid, preferably a lactate or succinate buffer, in the lyophilized formulation with the lurbinectedin such that the Impurity D in the formulation does not exceed 0.5% wt/wt, 0.6% wt/wt, 0.7% wt/wt or 0.8% wt/wt of the total lurbinectedin weight after storage at for 12 months, 24 months, 30 months, 36 months, 48 months or 60 months; or storage at 25°C/60%RH for 3 months, 6 months, 9 months, 12 months or 18 months; or 40°C/60% RH for 1 month, 3 months, 6 months or 12 months, particularly when the amount of lurbinectedin is 95 to 105%, or 97 to 103% of 4 mg lurbinectedin or of the amount of lurbinectedin by assay at day 1.

[0065] Other impurities or degradation products that may be minimized in the storage of the stable, lyophilized lurbinectedin formulation may be the degradation products with the following relative retention time on the commercial HPLC method: rrt 0.68, rrt 0.80, rrt 1.11 (Impurity G), and rrt 1.12.

[0066] In some embodiments the method of treating SCLC in a patient in need therefore comprises: (1 ) administering to the patient lurbinectedin at a dose of 3.2 mg/m ² by intravenous infusion of a lurbinectedin infusion solution, wherein the lurbinectedin infusion solution administered to the patient is prepared from a lyophilized composition comprising 4 mg lurbinectedin, a lactate buffer, and a disaccharide reconstituted to form a reconstituted solution at a pH of 3.8 to 4.5. In preferred embodiments, the disaccharide is sucrose. In a preferred embodiment, the lyophilized composition comprises 4 mg lurbinectedin, a lactate buffer (preferably resulting from a solution comprising 22.1 mg lactic acid and 5.1 mg sodium hydroxide, including 0.25 mmol of lactate), and a disaccharide (preferably sucrose, particularly 800 mg sucrose), wherein reconstitution of the lyophilized composition in about 8 ml. of an aqueous solution provides a lurbinectedin solution at 0.5 mg/ml_ lurbinectedin having a pH of about 3.8 to about 4.5. In some embodiments, a lurbinectedin infusion solution is prepared by diluting the reconstituted solution with an isotonic solution, wherein the isotonic solution is a 0.9% sodium chloride solution or a 5% dextrose solution. In some embodiments, the reconstituted solution is diluted with at least 100 ml. or at least 250 ml. of the isotonic solution to prepare a lurbinectedin infusion solution. In some embodiments, after reconstitution or dilution, the solution can be stored for up to 24 hours following reconstitution, including infusion time, at either room temperature (i.e., about 23°C)/light or under refrigerated (5°C ±3°C) conditions. In particular embodiments, the % wt/wt of Impurity D relative to lurbinectedin does not increase by more than 0.1%, 0.2% or 0.3% wt/wt upon storage of the reconstituted or diluted solution for 24, 48 or 72 hours at either room temperature (i.e., about 23°C)/light or under refrigerated (5°C ±3°C) conditions.

[0067] Some embodiments provide a method of administering a pharmaceutical composition to a patient in need thereof, for example, a patient suffering from SCLC refractory to first line treatment, comprising (1) reconstituting a lyophilized pharmaceutical composition in a vial after the composition has been stored for 30 to 36 months, wherein the lyophilized pharmaceutical composition was prepared by lyophilizing a stock solution comprising lurbinectedin, lactic acid, sodium hydroxide, and sucrose at a ratio of 4 mg lurbinectedin: 22.1 mg lactic acid: 5.1 mg sodium hydroxide: 800 mg sucrose: 8 ml. water; and (2) administering the reconstituted solution to a patient, wherein the reconstituted solution may be diluted with an isotonic solution, such as a 0.9% sodium chloride solution or a 5% dextrose solution, from 100 ml to 250 ml volume for administration to the patient as an infusion solution.

[0068] Embodiments of this invention further provide a pharmaceutical product comprising a vial containing a lyophilized lurbinectedin composition. In a preferred embodiment, the pharmaceutical product comprises a vial containing a lyophilized composition consisting of 4 mg lurbinectedin; 22.1 mg lactic acid; 5.1 mg sodium hydroxide (or, including, 0.25 mmol lactate); and 800 mg sucrose; a label affixed to the vial comprising an expiration date that is at least 48 months from the date of manufacture. In some embodiments, the label affixed to the vial comprises an expiration date that is at least 24 months, at least 30 months, at least 36 months, at least 42 months, or at least 48 months from the date of manufacture. In some embodiments, the vial has a size of 30 ml. to 50 ml_, such as 30 ml_, 35 ml_, 40 ml_, 45 ml_, or 50 ml_. In a preferred embodiment, the vial is a 30 ml. vial.

[0069] The present invention identifies a number of methods of treatment using lurbinectedin alone or in combination with further agents. Where reference is made to a method of treatment the present invention also encompasses lurbinectedin and/or said further agents in the manufacture of a medicament for the treatment of cancer and also lurbinectedin and/or said further agents for use in the treatment of cancer.

[0070] In a further aspect, there is provided the use of lurbinectedin in the manufacture of a medicament for the treatment of small cell lung cancer (SCLC), wherein said treatment comprises:

(1) administering a prophylactic dose of a corticosteroid and a serotonin antagonist effective to reduce nausea associated with administration of lurbinectedin to the patient on the day of and prior to administration of lurbinectedin to the patient; and

(2) administering lurbinectedin at a dose of 2 to 3.2 mg/m ² to the patient by intravenous infusion.

[0071] In a further aspect, there is provided the use of corticosteroid in the manufacture of a medicament for the treatment of small cell lung cancer (SCLC), wherein said treatment comprises:

(1) administering a prophylactic dose of said corticosteroid and a serotonin antagonist effective to reduce nausea associated with administration of lurbinectedin to the patient on the day of and prior to administration of lurbinectedin to the patient; and

(2) administering lurbinectedin at a dose of 2 to 3.2 mg/m ² to the patient by intravenous infusion.

[0072] In a further aspect, there is provided the use of a serotonin antagonist in the manufacture of a medicament for the treatment of small cell lung cancer (SCLC), wherein said treatment comprises:

(1) administering a prophylactic dose of a corticosteroid and said serotonin antagonist effective to reduce nausea associated with administration of lurbinectedin to the patient on the day of and prior to administration of lurbinectedin to the patient; and (2) administering lurbinectedin at a dose of 2 to 3.2 mg/m ² to the patient by intravenous infusion.

[0073] In a further aspect, there is provided the use of lurbinectedin in the manufacture of a medicament for the treatment of small cell lung cancer (SCLC), wherein said method comprises:

(1) administering a first dose of 3.2 mg/m ² of lurbinectedin to the patient by intravenous infusion; and

(2) identifying an adverse reaction in the patient, wherein the adverse reaction is selected from the group consisting of: ≥Grade 3 (severe) non hematological toxicity, Grade 4 thrombocytopenia (Platelet count less than 25,000 cells/mm ³ ), Grade 3 thrombocytopenia (Platelet count less than 50,000 cells/mm ³ ) with bleeding that requires transfusion, Grade 4 neutropenia (Neutrophil count less than 500 cells/mm ³ ), or any grade neutropenia (Neutrophil count < LLN) that is associated with infection/sepsis or any other of the adverse reactions;

(3) after the adverse reaction is identified and after the patient’s neutrophil count is greater than 1500 cells/mm ³ ; platelet count is greater than about 100,000 mm ³ ; and hemoglobin levels are greater than about 9 g/dL:

(i) if the identified adverse reaction consists of Grade 4 neutropenia (Neutrophil count less than 500 cells/mm ³ ), administering to the patient a dose of G-CSF and a dose of lurbinectedin that is equal to the first dose; or

(ii) if the identified adverse reaction is not solely Grade 4 neutropenia, administering to the patient a reduced dose of lurbinectedin compared to the first dose, wherein administration of two doses of lurbinectedin are spaced apart by at least 21 days.

[0074] In a further aspect, there is provided the use of G-CSF in the manufacture of a medicament for the treatment of small cell lung cancer (SCLC), wherein said method comprises:

(1) administering a first dose of 3.2 mg/m ² of lurbinectedin to the patient by intravenous infusion; and

(2) identifying an adverse reaction in the patient, wherein the adverse reaction is selected from the group consisting of: ≥Grade 3 (severe) non hematological toxicity, Grade 4 thrombocytopenia (Platelet count less than 25,000 cells/mm ³ ), Grade 3 thrombocytopenia (Platelet count less than 50,000 cells/mm ³ ) with bleeding that requires transfusion, Grade 4 neutropenia (Neutrophil count less than 500 cells/mm ³ ), or any grade neutropenia (Neutrophil count < LLN) that is associated with infection/sepsis or any other of the adverse reactions;

(3) after the adverse reaction is identified and after the patient’s neutrophil count is greater than 1500 cells/mm ³ ; platelet count is greater than about 100,000 mm ³ ; and hemoglobin levels are greater than about 9 g/dL:

(i) if the identified adverse reaction consists of Grade 4 neutropenia (Neutrophil count less than 500 cells/mm ³ ), administering to the patient a dose of G-CSF and a dose of lurbinectedin that is equal to the first dose; or

(ii) if the identified adverse reaction is not solely Grade 4 neutropenia, administering to the patient a reduced dose of lurbinectedin compared to the first dose, wherein administration of two doses of lurbinectedin are spaced apart by at least 21 days.

[0075] In a further aspect, there is provided the use of lurbinectedin in the manufacture of a medicament for the treatment of small cell lung cancer (SCLC), wherein said method comprises: administering to the patient lurbinectedin at a dose of 3.2 mg/m ² by intravenous infusion of a lurbinectedin infusion solution, wherein the lurbinectedin infusion solution administered to the patient is prepared from a lyophilized composition comprising 4 mg lurbinectedin, an organic carboxylic acid, and a disaccharide reconstituted to form a reconstituted solution at a pH of 3.5 to 4.5.

[0076] In a further aspect, there is provided the use of lurbinectedin in the manufacture of a medicament for the treatment of endometrial cancer, SCLC, soft tissue sarcoma, glioblastoma, pancreatic adenocarcinoma, mesothelioma, colorectal carcinoma, or epithelial ovarian cancer, wherein said treatment comprises: administering to the patient lurbinectedin and a topoisomerase inhibitor selected from

SN-38 and irinotecan on day one of a treatment cycle; wherein the lurbinectedin is administered at a dose of 1 to 2.5 mg/m ² and wherein the topoisomerase inhibitor is administered at a dose equivalent to 50 to 75 mg of irinotecan/m ² .

[0077] In a further aspect, there is provided the use of a topoisomerase inhibitor selected from SN-38 and irinotecan in the manufacture of a medicament for the treatment of endometrial cancer, SCLC, soft tissue sarcoma, glioblastoma, pancreatic adenocarcinoma, mesothelioma, colorectal carcinoma, or epithelial ovarian cancer, wherein said treatment comprises: administering to the patient lurbinectedin and said topoisomerase inhibitor selected from

SN-38 and irinotecan on day one of a treatment cycle; wherein the lurbinectedin is administered at a dose of 1 to 2.5 mg/m ² and wherein the topoisomerase inhibitor is administered at a dose equivalent to 50 to 75 mg of irinotecan/m ² .

[0078] In a further aspect, there is provided the use of lurbinectedin in the manufacture of a medicament for the treatment of cancer, the treatment comprising reconstituting a lyophilized pharmaceutical composition in a vial after the composition has been stored for 30 to 60 months, wherein the lyophilized pharmaceutical composition was prepared by lyophilizing a stock solution comprising 4 mg of lurbinectedin, organic carboxylic acid, and sucrose, wherein the composition comprises lurbinectedin and disaccharide at a ratio of 1 mol lurbinectedin: 455 to 465 mol sucrose, wherein the lyophilized composition is formulated such that reconstitution with 8 ml. of water will yield a solution having a pH of 3.5 to 4.5; and administering the reconstituted solution to a patient.

[0079] In a further aspect, there is provided the use of lurbinectedin in the manufacture of a medicament for the treatment of small cell lung cancer (SCLC), wherein said treatment comprises: administering lurbinectedin at a dose of 2 to 3.2 mg/m ² to the patient by intravenous infusion; wherein the patient was administered an immunotherapeutic antibody for treating SCLC prior to beginning the treatment cycle and wherein the duration of response is at least 2 months, 3 months, 4 months, 5 months or 6 months or wherein the overall response rate is at least 40%.

In a further aspect, there is provided the use of lurbinectedin in the manufacture of a medicament for the treatment of small cell lung cancer (SCLC), wherein said treatment comprises: administering lurbinectedin at a dose of 2 to 3.2 mg/m2 to a patient by intravenous infusion every 3 weeks, wherein the lurbinectedin is provided in a lyophilized formulation comprising lurbinectedin, lactic acid, sucrose, wherein the ratio of lurbinectedin :lactic acid:sucrose is between 1 mol:46 mol:455 mol and 1 mol:50 mol:465 mol , wherein the formulation is stable at 5 degree C +- 3 degree C for at least 24 months or at least 36 months or at least 48 months or at least 60 months such that the lurbinectedin degradation product from deactylation does not exceed 0.8% wt./wt. of the total lurbinectedin weight.

[0080] In a further aspect, there is provided the use of lurbinectedin in the manufacture of a medicament for the treatment of small cell lung cancer (SCLC), wherein said treatment comprises:

1 ) dissolving a packaged, lyophilized composition comprising 4 mg lurbinectedin, a buffer derived from an organic acid and disaccharide in about 8 ml. of water to provide a lurbinectedin solution having a pH of about 3.5 to about 4.1 , and

2) administering about 2 to 3.2 mg/m ² of lurbinectedin to a patient whose SCLC has progressed after prior platinum-containing therapy by intravenous infusion every 3 weeks and wherein the lyophilized composition comprises less than about 0.3 % of Impurity D (w/w based on lurbinectedin) when the composition is packaged, and wherein upon storage at about 5 degrees C for about 24 months the composition comprises less than about 0.8% of Impurity D (w/w based on lurbinectedin).

[0081] In a further aspect, there is provided lurbinectedin for use in the treatment of small cell lung cancer (SCLC), wherein said treatment comprises:

(1) administering a prophylactic dose of a corticosteroid and a serotonin antagonist effective to reduce nausea associated with administration of lurbinectedin to the patient on the day of and prior to administration of lurbinectedin to the patient; and

(2) administering lurbinectedin at a dose of 2 to 3.2 mg/m ² to the patient by intravenous infusion.

[0082] In a further aspect, there is provided a corticosteroid for use in the treatment of small cell lung cancer (SCLC), wherein said treatment comprises:

(1) administering a prophylactic dose of said corticosteroid and a serotonin antagonist effective to reduce nausea associated with administration of lurbinectedin to the patient on the day of and prior to administration of lurbinectedin to the patient; and

(2) administering lurbinectedin at a dose of 2 to 3.2 mg/m ² to the patient by intravenous infusion.

[0083] In a further aspect, there is provided a serotonin antagonist for use in the treatment of small cell lung cancer (SCLC), wherein said treatment comprises:

(1) administering a prophylactic dose of a corticosteroid and said serotonin antagonist effective to reduce nausea associated with administration of lurbinectedin to the patient on the day of and prior to administration of lurbinectedin to the patient; and (2) administering lurbinectedin at a dose of 2 to 3.2 mg/m ² to the patient by intravenous infusion.

[0084] In a further aspect, there is provided lurbinectedin for use in the treatment of small cell lung cancer (SCLC), wherein said method comprises:

(1) administering a first dose of 3.2 mg/m ² of lurbinectedin to the patient by intravenous infusion; and

(2) identifying an adverse reaction in the patient, wherein the adverse reaction is selected from the group consisting of: ≥Grade 3 (severe) non hematological toxicity, Grade 4 thrombocytopenia (Platelet count less than 25,000 cells/mm ³ ), Grade 3 thrombocytopenia (Platelet count less than 50,000 cells/mm ³ ) with bleeding that requires transfusion, Grade 4 neutropenia (Neutrophil count less than 500 cells/mm ³ ), or any grade neutropenia (Neutrophil count < LLN) that is associated with infection/sepsis or any other of the adverse reactions;

(3) after the adverse reaction is identified and after the patient’s neutrophil count is greater than 1500 cells/mm ³ ; platelet count is greater than about 100,000 mm ³ ; and hemoglobin levels are greater than about 9 g/dL:

(i) if the identified adverse reaction consists of Grade 4 neutropenia (Neutrophil count less than 500 cells/mm ³ ), administering to the patient a dose of G-CSF and a dose of lurbinectedin that is equal to the first dose; or

(ii) if the identified adverse reaction is not solely Grade 4 neutropenia, administering to the patient a reduced dose of lurbinectedin compared to the first dose, wherein administration of two doses of lurbinectedin are spaced apart by at least 21 days.

[0085] In a further aspect, there is provided G-CSF for use in the treatment of small cell lung cancer (SCLC), wherein said method comprises:

(1) administering a first dose of 3.2 mg/m ² of lurbinectedin to the patient by intravenous infusion; and

(2) identifying an adverse reaction in the patient, wherein the adverse reaction is selected from the group consisting of: ≥Grade 3 (severe) non hematological toxicity, Grade 4 thrombocytopenia (Platelet count less than 25,000 cells/mm ³ ), Grade 3 thrombocytopenia (Platelet count less than 50,000 cells/mm ³ ) with bleeding that requires transfusion, Grade 4 neutropenia (Neutrophil count less than 500 cells/mm ³ ), or any grade neutropenia (Neutrophil count < LLN) that is associated with infection/sepsis or any other of the adverse reactions; (3) after the adverse reaction is identified and after the patient’s neutrophil count is greater than 1500 cells/mm ³ ; platelet count is greater than about 100,000 mm ³ ; and hemoglobin levels are greater than about 9 g/dL:

(i) if the identified adverse reaction consists of Grade 4 neutropenia (Neutrophil count less than 500 cells/mm ³ ), administering to the patient a dose of G-CSF and a dose of lurbinectedin that is equal to the first dose; or

(ii) if the identified adverse reaction is not solely Grade 4 neutropenia, administering to the patient a reduced dose of lurbinectedin compared to the first dose, wherein administration of two doses of lurbinectedin are spaced apart by at least 21 days.

[0086] In a further aspect, there is provided lurbinectedin for use in the treatment of small cell lung cancer (SCLC), wherein said method comprises: administering to the patient lurbinectedin at a dose of 3.2 mg/m ² by intravenous infusion of a lurbinectedin infusion solution, wherein the lurbinectedin infusion solution administered to the patient is prepared from a lyophilized composition comprising 4 mg lurbinectedin, an organic carboxylic acid, and a disaccharide reconstituted to form a reconstituted solution at a pH of 3.5 to 4.5.

[0087] In a further aspect, there is provided lurbinectedin for use in the treatment of endometrial cancer, SCLC, soft tissue sarcoma, glioblastoma, pancreatic adenocarcinoma, mesothelioma, colorectal carcinoma, or epithelial ovarian cancer, wherein said treatment comprises: administering to the patient lurbinectedin and a topoisomerase inhibitor selected from

SN-38 and irinotecan on day one of a treatment cycle; wherein the lurbinectedin is administered at a dose of 1 to 2.5 mg/m ² and wherein the topoisomerase inhibitor is administered at a dose equivalent to 50 to 75 mg of irinotecan/m ² .

[0088] In a further aspect, there is provided a topoisomerase inhibitor selected from SN- 38 and irinotecan for use in the treatment of endometrial cancer, SCLC, soft tissue sarcoma, glioblastoma, pancreatic adenocarcinoma, mesothelioma, colorectal carcinoma, or epithelial ovarian cancer, wherein said treatment comprises: administering to the patient lurbinectedin and said topoisomerase inhibitor selected from SN-38 and irinotecan on day one of a treatment cycle; wherein the lurbinectedin is administered at a dose of 1 to 2.5 mg/m ² and wherein the topoisomerase inhibitor is administered at a dose equivalent to 50 to 75 mg of irinotecan/m ² . [0089] In a further aspect, there is provided lurbinectedin for use in the treatment of cancer, the treatment comprising reconstituting a lyophilized pharmaceutical composition in a vial after the composition has been stored for 30 to 60 months, wherein the lyophilized pharmaceutical composition was prepared by lyophilizing a stock solution comprising 4 mg of lurbinectedin, organic carboxylic acid, and sucrose, wherein the composition comprises lurbinectedin and disaccharide at a ratio of 1 mol lurbinectedin: 455 to 465 mol sucrose, wherein the lyophilized composition is formulated such that reconstitution with 8 ml. of water will yield a solution having a pH of 3.5 to 4.5; and administering the reconstituted solution to a patient.

[0090] In a further aspect, there is provided lurbinectedin for use in the treatment of small cell lung cancer (SCLC), wherein said treatment comprises: administering lurbinectedin at a dose of 2 to 3.2 mg/m ² to the patient by intravenous infusion; wherein the patient was administered an immunotherapeutic antibody for treating SCLC prior to beginning the treatment cycle and wherein the duration of response is at least 2 months, 3 months, 4 months, 5 months or 6 months or wherein the overall response rate is at least 40%.

[0091] In a further aspect, there is provided lurbinectedin for use in the treatment of small cell lung cancer (SCLC), wherein said treatment comprises: administering lurbinectedin at a dose of 2 to 3.2 mg/m2 to a patient by intravenous infusion every 3 weeks, wherein the lurbinectedin is provided in a lyophilized formulation comprising lurbinectedin, lactic acid, sucrose, wherein the ratio of lurbinectedin :lactic acid:sucrose is between 1 mol:46 mol:455 mol and 1 mol:50 mol:465 mol , wherein the formulation is stable at 5 degree C +- 3 degree C for at least 24 months or at least 36 months or at least 48 months or at least 60 months such that the lurbinectedin degradation product from deactylation does not exceed 0.8% wt./wt. of the total lurbinectedin weight.

[0092] In a further aspect, there is provided lurbinectedin for use in the treatment of small cell lung cancer (SCLC), wherein said treatment comprises:

1 ) dissolving a packaged, lyophilized composition comprising 4 mg lurbinectedin, a buffer derived from an organic acid and disaccharide in about 8 mL of water to provide a lurbinectedin solution having a pH of about 3.5 to about 4.1 , and 2) administering about 2 to 3.2 mg/m ² of lurbinectedin to a patient whose SCLC has progressed after prior platinum-containing therapy by intravenous infusion every 3 weeks and wherein the lyophilized composition comprises less than about 0.3 % of Impurity D (w/w based on lurbinectedin) when the composition is packaged, and wherein upon storage at about 5 degrees C for about 24 months the composition comprises less than about 0.8% of Impurity D (w/w based on lurbinectedin).

Examples Example 1 : Preparation of Lurbinectedin in Different Buffers

[0093] A bulk lurbinectedin solution containing 0.5 mg/mL of was prepared in an acetate, citrate, lactate, and succinate buffered solution with the buffer concentrations of 0.02 to 0.05 M buffered to pH 3, 4, and 5 with sodium hydroxide. An example of a lurbinectedin formulation with lactate buffered to a pH=4 is provided in Table 1 below. Table 1 : Composition of lurbinectedin 4 mg reconstituted solution.

Concentration

Component Function

(mg/mL)

Lurbinectedin 0.5 Active ingredient

Sucrose 100 Bulking agent

Lactic acid 2.76 Buffering agent

Sodium hydroxide 0.64 Buffering agent

Example 2: Solubility of Lurbinectedin in Different Buffers

[0094] Bulk solutions of phosphate, acetate, citrate, lactate and succinate buffers were prepared to determine maximum solubility of lurbinectedin. Table 2 shows the maximum solubility of lurbinectedin in the 0.02M-0.05 M or 0.06-0.1 M buffers at pH=4. The results show that lurbinectedin was poorly solubilized in a phosphate buffer. The results also suggest that the molarity of the buffer does not have a significant impact on solubility. Table 2: Lurbinectedin maximum solubility in various buffers pH=4. Impact of buffer molarity.

Example 3: Stability of Lurbinectedin Formulations with Different Organic Carboxylic Buffers at Different pH Values

[0095] Stability and solubility studies were conducted to determine a pH wherein lurbinectedin exhibits good stability. Table 3 shows the solubility and the impurities and degradation products profile of lurbinectedin in the alternative 0.02M-0.05 M buffers at pH 3, pH 4 and pH 5. The solubility was similar for pH 3 and pH 4 and drastically decreased at pH 5. This decrease in solubility is accompanied by an increase in degradation products as the buffer pH increases.

Table 3: Solubility and degradation products profile of lurbinectedin in different organic carboxylic buffers in the pH range 3 to 5.

[0096] The stability of lurbinectedin in the different buffers was further evaluated at 14 days with 25 °C / 60% RH conditions. While lurbinectedin is relatively stable at pH 3 and 4, a significant decrease in assay and purity at pH = 5 is observed (Table 4).

Table 4: Effect of pH on the solubility and stability (25 ^e C / 60% RH 14 days) of lurbinectedin in different 0.02M-0.05M organic carboxylic buffers in the pH range 3 to 5.

[0097] These results showed that an organic carboxylic buffer with pH not more than pH 4.5 is the most adequate to increase the concentration of lurbinectedin in solution and to maintain an adequate stability. Sodium lactate and sodium citrate buffers were considered the most appropriate.

Example 4: Stability of Lyophilized Vials Formulated in Sodium Lactate and Sodium Citrate Buffers with pH = 4.0 under Stress Conditions

[0098] In order to determine which of the two buffers was the optimal for lurbinectedin, batches of lyophilized vials containing 1 mg lurbinectedin/vial were manufactured at a laboratory scale with lurbinectedin formulated at 0.5 mg/mL in 0.03M sodium lactate pH = 4 and 0.05M sodium citrate pH = 4. The pH 4 was chosen because of its greater physiological compatibility compared to pH 3. Sucrose was included as a bulking agent at 10% (w/v). The stability of the active principle in the lyophilized product under stress conditions of temperature (50° C) was evaluated. Freeze-dried vials formulated in 0.05M monopotassium phosphate buffer pH = 4 were also included in these studies for comparison. The stability results of lyophilized vials after 1 month at 50° C are shown in Table 5. Due to the large number of degradation products that appear under these conditions, only those with an area ≥ 0.20% are reported. [0099] The three formulations showed comparable characteristics at t=0. After storage at 50 °C for 1 month, quality attributes such as the appearance of the lyophilized solid, color and pH of the reconstituted solution and water content were not modified.

[0100] Lurbinectedin assay decreased significantly (between 11% and 17%) with respect to the initial content for the three compositions being the % degradation products the major differences observed. The vials formulated in sodium lactate buffer or monopotassium phosphate buffer showed very similar behavior, however sodium citrate buffer promoted larger degradation after storage for 1 month at 50°C. In all cases, the main degradation product was an impurity eluting at rrt 0.49-0.50 (HPLC Development method), being significantly higher in the lyophilized vial formulated in the sodium citrate buffer. Other degradation products that also appeared in very significant percentages were impurity D (rrt 0.73-0.74) and impurities with rrt 0.25, rrt 0.28 and rrt 1.09-1.10.

[0101] Based on the solubility and stability results, it was concluded that the most suitable dissolution medium for an optimized lurbinectedin formulation was 0.03M sodium lactate buffer pH 4.

Table 5: Stability under stress conditions ( ) of lurbinectedin freeze-dried vials formulated with 0.05M monopotassium phosphate buffer pH = 4, 0.05M sodium

citrate buffer pH = 4 or 0.03M sodium lactate buffer pH = 4 containing 10% (w/v) sucrose as bulking agent.

Example 5: Effect of Bulk Solution pH on Lyophilized Product Stability [0102] The stability of 4 mg of lyophilized product produced from various 0.03M sodium lactate buffer lurbinectedin bulk solutions was studied. The bulk solutions had a concentration of 0.5 mg lurbinectedin / ml. at pH 3.6, pH 4.0 and pH 4.5, using 10% sucrose (w/v) as bulking agent (8 ml. filling in 30 ml. glass vials). The stability of these batches was evaluated under 25°C / 60% RH to determine if small variations in pH could have a significant effect on the stability of the product. [0103] The stability results of lyophilized vials after 6 months at 25°C are shown in Table 6. All the batches showed similar behavior. Quality attributes such as the appearance of the lyophilized, appearance, color and pH of the reconstituted solution, water content (%) and assay were kept constant. Total degradation products did not undergo significant changes,

[0104] As conclusion and based on the solubility and stability data, the lurbinectedin solution and a freeze-dried presentation, 0.03M sodium lactate buffer pH 4.0 was selected as the most suitable dissolution medium for lurbinectedin presentations.

Table 6. Stability at 25°C / 60% RH of lurbinectedin 4 mg vial 30 ml. at different pH

Example 6: Bulking Agent Concentration [0105] The stability of 4 mg of lyophilized product produced from various 0.03M sodium lactate buffer lurbinectedin bulk solutions was studied. The bulk solutions had a concentration of 0.5 mg lurbinectedin / mL at pH 3.6, pH 4.0 and pH 4.5, using 10% sucrose (w/v) as bulking agent (8 mL filling in 30 mL glass vials). The stability of these batches was evaluated under 25°C / 60% RH to determine if small variations in pH could have a significant effect on the stability of the product.

[0106] Once the dissolution medium was selected, different bulking agents were screened at different concentrations: sucrose (5%, 7.5% and 10%), mannitol (5%), and combination of sucrose and mannitol (5% sucrose + 2.5% mannitol). [0107] For that purpose, several freeze-dried batches of lurbinectedin were manufactured with a strength of 4 mg/vial incorporating the different bulking agents at various concentrations. Lurbinectedin was dissolved at 0.5 mg / mL in 0.03M sodium lactate buffer pH 4. The batches composition is detailed in Table 7. Batches were characterized and their stability under stress conditions evaluated Table 7: Composition of batches of lurbinectedin 4 mg vial 30 mL manufactured with different contents of sucrose and mannitol

[0108] Table 8 below shows the stability results of lyophilized batches with the different bulking agents after 3 months stored at 40 ° C/75% RH. [0109] The batch formulated with 5% sucrose was stable, since it did not undergo changes in the appearance of the freeze-dried cake nor in the reconstituted solution, maintained the lurbinectedin assay, and only showed a slight increase in degradation products, being impurity D the main degradation product observed (rrt 0.88 HPLC commercial method).

[0110] However, batches formulated with sucrose and mannitol mixtures or only mannitol degraded significantly during storage at 40 °C. In both cases, the appearance of the freeze-dried cake differed from batches bearing only sucrose (5% or 10%). The formulation containing 5% mannitol suffered a very significant decrease in lurbinectedin assay (43% of the nominal target). In addition, the % degradation products increased in both formulations (up to 57% in the formulation containing 5% mannitol). The two major degradation products in formulations containing mannitol are those eluting at rrt 0.67- 0.68 and rrt 1.06).

Table 8. Stress stability of lurbinectedin batches containing different bulking agents.

[0111] Table 9 shows the results of stability of lyophilized vials formulated in 0.03M sodium lactate buffer pH = 4 with sucrose at different concentrations in the range 5% - 10% under stress conditions (40 ^e C / 75% RH)

[0112] Table 9. Stress stability of lurbinectedin freeze-dried vials formulated in 0.03M lactate buffer pH 4 with sucrose as bulking agent at different concentrations.

[0113] The batches containing sucrose at 3 different concentrations showed similar behavior and remained stable. They did not undergo significant changes in the appearance of the freeze-dried cake and lurbinectedin assay (%). A slight increase in the % degradation products was observed. In particular, Impurity D (rrt 0.88, HPLC commercial method) was the main degradation product. The percentage of sucrose does not significantly affect the stability of the product, although 10% sucrose showed the lowest degradation.

[0114] As a conclusion, sucrose showed a protective effect to prevent lurbinectedin degradation during storage at high temperature. Based on these results, sucrose was selected as the most appropriate bulking agent being the concentration of 10% (w/v) an optimal quantity for a suitable and stable lurbinectedin presentation.

Example 7: Stabilitv of Lurbinectedin at Lona-term Storaae Conditions [0115] The stability of lyophilized lurbinectedin composition (4 mg) at the conditions proposed for long-term storage (5°C ± 3°C) was evaluated during 36 months. A batch with high residual water content was chosen as it is considered as a worst case.

[0116] The product remained stable during the 36 months of the study (Table 10). None of the quality attribute underwent significant changes. The content of lurbinectedin suffered small variations attributed to the analytical variability during the first 24 months. The total degradation products did not change throughout the storage time. The related substance observed at reportable levels was Impurity D that remained constant and at the levels present in the active ingredient used to manufacture the batch.

Table 10. Stability Study of Lurbinectedin 4 mg at 5°C ± 3°C

Example 8: Clinical Study - Treatment of SCLC Patients with Lurbinectedin [0117] A clinical study of lurbinectedin monotherapy for patients collectively afflicted with

SCLC who have refractory or resistant disease, as defined herein, was carried out. In this clinical single-arm, multi-center, open-label, phase 2 trail, a cohort of 105 patients, who had measurable disease, including patients whose SCLC was unresponsive to first- line platinum-containing chemotherapy (cisplatin, carboplatin or oxaliplatin) (refractory) and patients whose SCLC recurred within or equal to 90 days after cessation of first-line therapy (resistant), were treated with lurbinectedin at a dosage of 3.2 mg/m ² given intravenously over a period of 1 hour every 21 days. Lurbinectedin was provided as a sterile isotonic aqueous solution for IV infusion as described below.

Study Population

[0118] Adult patients aged at least 18 years with a pathologically proven diagnosis of SCLC were included if they had: pre-treatment with only one previous chemotherapy- containing treatment line (immunotherapy was allowed, combined with chemotherapy or alone); measurable response as per the Response Criteria in Solid Tumors (RECIST version 1.1), and documented progression before study entry; and an Eastern Cooperative Oncology Group (ECOG) performance status of 2 or lower. Patients were required to have adequate bone marrow function (evaluated by laboratory tests for absolute neutrophil count, platelet count, and hemoglobin), kidneys (evaluated by serum creatinine and creatinine kinase), liver (evaluated by total bilirubin, albumin, and aminotransferases). The minimum interval between any previous treatment and study commencement had to be 3 weeks for chemotherapy, 4 weeks for immunotherapy or radiotherapy, and 2 weeks for any investigational or palliative therapy. Only patients with grade 1 or lower toxicities from any previous therapies were included, except for cases with alopecia and peripheral sensory neuropathy (both grade 2), which were also allowed. Women of child-bearing age had to receive adequate contraception during the study and for at least 3 months after study conclusion.

[0119] Patients were excluded if they have: previously received lurbinectedin or trabectedin; previous or concurrent malignant disease unless in complete remission for than 5 years; known CNS involvement (screening of CNS metastasis at baseline are mandatory); concomitant unstable or serious medical condition within the past year (history or presence of unstable angina, myocardial infarction, congestive heart failure, valvular heart disease, arrhythmia, severe dyspnoea, or active infection, such as hepatitis or HIV); impending need for radiotherapy; or inability or restricted ability to comply with the study protocol. More details on inclusion and exclusion criteria can be found in Table 11.

Study Drug Formulation - Preparation and Administration

[0120] Lurbinectedin was presented as lyophilized powder for concentration for solution for infusion in 4mg vials. Before use, the 4mg vials were reconstituted with 8 mL of water for injection to give a solution containing 0.5 mg/mL of lurbinectedin. For administration to patients as an i.v. infusion, reconstituted vials were diluted with glucose 50 mg/mL (5%) solution for infusion or sodium chloride 9 mg/mL (0.9%) solution for infusion. The full composition and the reconstituted solution per mL was as shown in Table 12.

Table 12. Composition of 4 mg lurbinectedin vials

Dosage and Administration

[0121] Lurbinectedin was administered over a minimum total volume of 100 ml. of solution for infusion (either on 5% glucose or 0.9% sodium chloride), through a central catheter, or over a minimum total volume of 250 ml. if administered through a peripheral line, always over one hour at a fixed infusion rate.

[0122] Starting dose was 3.2 mg/m ² . Dose was capped at body surface area of 2.0 mg/m ² (e.g. dose not allowed to exceed 6.4 mg). Patients received lurbinectedin i.v. as a one-hour infusion on Day 1 every three weeks until disease progression or unacceptable toxicity. Three weeks was defined as one treatment cycle.

Premedication

[0123] All patients received antiemetic prophylaxis before each treatment infusion. The i.v. formulations of these agents were used in this setting: Corticosteroid (dexamethasone 8 mg or equivalent), serotonin antagonists (ondansetron 8 mg or equivalent), extended treatment with oral serotonin antagonists, and oral dexamethasone for two consecutive days. If necessary, and in addition to the above, administration of 10 mg of oral or i.v. metoclopramide (or equivalent) every 8 hours. Aprepitant and equivalent agents were forbidden in patients treated with lurbinectedin. Criteria for Treatment Continuation

[0124] Further treatment cycles were administered q3wk (± 48 hours) if the patient fulfilled all the treatment criteria described in Table 13.

AE(s), adverse event(s); ANC, absolute neutrophil count; AP, alkaline phosphatase; AST/ALT, aspartate aminotransferase/alanine aminotransferase; CPK, creatinine phosphokinase; ECOG, Eastern Cooperative Oncology Group; GGT, gamma- glutamyltransferase; PS, performance status; ULN, upper limit of normal.

[0125] Patients received packed red blood cells transfusion and/or erythropoietin treatment, if clinically indicated, to increase/maintain adequate hemoglobin levels. If a patient did not meet the requirements for re-treatment on Day 1 of any following cycle, regardless of the reason, reassessments were performed at least every 48-72 hours. T reatment was then withheld, up to a maximum of three weeks beyond its due date, until appropriate recovery. Patients not meeting re-treatment criteria after a maximum 3-week delay had to withdraw from trial. For any delay due to treatment-related adverse events lasting for more than one week, a dose reduction was implemented upon recovery, following the rules explained in the next section.

Dose Modifications for Adverse Reactions

[0126] Patients continued the treatment if they presented with any of the following: (1 ) Grade ≥ 3 treatment-related non-hematological toxicity. Exceptions were: Grade ≥ 3 nausea and/or vomiting not optimally treated, grade 3 asthenia lasting ≤ 3 days, grade 3 diarrhea lasting ≤ 2 days or not optimally treated, grade 3 transient ALT/AST elevations which are rapidly reversible and not leading to subsequent delays, and non-clinically relevant biochemical abnormalities. (2) Grade 4 thrombocytopenia or Grade 3 thrombocytopenia concomitantly with grade ≥ 3 3leeding. (3) Grade 4 neutropenia, any grade febrile neutropenia or neutropenia associated with infection/sepsis. (4) Frequent of prolonged (> 1 week) dose delays due to treatment-related adverse events. Patients who experienced Grade 3 or 4 hypersensitivity reactions were discontinued from study treatment.

[0127] Previous analysis with lurbinectedin administered following a dose based on body surface area showed that the incidence of febrile neutropenia with lurbinectedin use was lower than 10%. Therefore, according to guidelines from the American Society of Clinical Oncology and European Society for Medical Oncology, primary prophylaxis with granulocyte colony-stimulating factors (G-CSF) was not allowed (secondary prophylaxis with G-CSF for neutropenia was allowed).

[0128] Dose reduction levels are shown in Table 14 below:

Table 14. Dose Modification

Lurbinectedin Dose (mg/m2)

Dose Reduction

1 (starting dose) 3.2 ^**

-1 2.6

-2 2.0

^** Dose will be capped at BSA of 2.0m2 (i.e. dose will not exceed 6.4 mg) BSA, body surface area.

[0129] Up to 2 dose reductions were allowed per patient. Patients who continued to experience treatment-related toxicity and/or frequent dose delays after permitted dose reductions were withdrawn from the study. They could continue receiving the study medication if objective clinical benefit is adequately documented. Once a dose had been reduced for an individual patient, the dose was not re-escalated under any circumstances.

Efficacy Evaluations

[0130] The primary objective of this study was to assess the antitumor activity of lurbinectedin in terms of overall response rate (ORR) as primary endpoint and supported by duration of response (DOR) as secondary endpoint. ORR was assessed using RECIST v1.1. on a set of measurable lesions identified at baseline as target lesions or as non-target lesions (if any), and followed until disease progression (PD) by an appropriate method.

[0131] Radiological tumor assessment (CT scan or MRI) was performed at baseline, and every 6 weeks from the onset of the study treatment until cycle 6 or evidence of PD, and every 9 weeks thereafter. If an objective response was observed, according to RECIST v1 .1 ., it had to be confirmed by the same method at least four weeks after the date of the first documentation of response.

[0132] ORR was defined as the percentage of evaluable patients with a confirmed response, either complete (CR) or partial response (PR), from the start of treatment to the date of progression or the start of a subsequent therapy or end of patients follow-up according to RECIST v1.1. DOR was calculated from the date of first documented PD, recurrence, or death due to any cause in the responder patients. The date of response, the date of radiological or clinical PD, according to the investigator assessment and the independent assessment by an independent review committee (IRC), and the date of death was registered and documented, as appropriate. The IRC determined the patient’s best response and assigned the date of first documentation of response and progression/censoring according to RECIST v1.1.

[0133] Counts and percentages, with their corresponding exact 95% confidence intervals were calculated for the binominal endpoints (i.e. ORR, clinical benefit). Time- to-event variables (OS, PFS, and DOR) and their set time estimates (i.e. PFS4/6 and OS6/12) were analyzed according to Kaplan-Meier method. The evaluation of the efficacy endpoints evaluated by I A and IRC were analyzed and compared.

Pharmacokinetic Evaluations [0134] The plasma PK of lurbinectedin was evaluated during Cycles 1 and 2 in all treated patients. The sampling schedule is shown in Table 15 and Table 16, respectively.

[0135] PK analysis of plasma-concentration-time data of lurbinectedin was performed using non-linear mixed-effects modeling and/or non-compartment analysis.

Table 15. Blood samples from PK evaluations - Cycle 1

Table 16. Blood samples from PK evaluations - Cycle 2

Safety Evaluation [0136] Patients were evaluated for safety if they had received any partial or complete infusion of lurbinectedin. All adverse events were graded according to the National Cancer Institute-Common Toxicity Criteria for Adverse Events (NCI-CTCAE, v4). The safety profile of patients was monitored throughout the treatment and up to 30 days after the last lurbinectedin infusion (end of treatment), or until the patient started a new antitumor therapy or until the date of death, whichever occurred first. T reatment delays, dose reduction requirements, transfusions, and reason for treatment discontinuation was monitored throughout the study. Any treatment-related adverse events were followed until recovery to at least grade 1 or stabilization of symptoms or until the start of a new anti-tumor therapy, whichever occurred first.

Study Endpoints

Primary Endpoint

Overall Response Rate (ORR) ORR is defined as the percentage of patients with a confirmed response, either complete (CR) or partial (PR), according to the RECIST (v. 1.1).

Secondary Endpoints

Duration of Response (DR) DR is defined as the time between the date when the response criteria (PR or CR, whichever one is first reached) are fulfilled to the first date when PD, recurrence or death is documented.

Clinical Benefit Clinical Benefit is defined as ORR or stable disease lasting over four months (SD > 4 months)

Progression-free Survival (PFS) PSF is defined as the period of time from the date of first infusion to the date of PD, death (of any cause), or last tumor evaluation.

PFS4/PFS6 PFS4/PFS6 is defined as the Kaplan-Meier estimates of the probability of being free from progression and death after the first infusion at these time points (4 and 6 months).

Overall Survival (SO) OS is defined as the period of time from the date of first infusion to the date of death or last contact in case of patients lost to follow-up or alive at the clinical cut-off established for the cohort.

OS6/OS12 OS6/OS12 is defined as the Kaplan-Meier estimates of the probability of being alive after the first infusion at these time points (6 and 12 months)

Plasma Pharmacokinetics (PK) Non-compartmental (NCA) PK parameters: area under the curve (AUC), cmax, clearance (CL) and half-life (t1/2). Population PK parameters of the compartment model to be developed (initially based on Volumes and Clearance), and PK/PD correlation parameters, if applicable.

Safety Profile • Clinical examinations.

• Clinical assessment of AEs and serious adverse events (SAEs).

• Changes in laboratory parameters (hematological and biochemical, including liver function tests).

• Reasons for treatment discontinuations.

• Reasons for dose reduction and treatment delays.

Statistical Methods [0137] This phase II trial was designed to assess the antitumor activity of lurbinectedin in terms of ORR according to the RECIST v.1 .1 assessed by IA and tumor evaluation was also done by IRC.

[0138] Up to 100 evaluable patients were recruited to test the null hypothesis that 15% or less patients get a response (p < 0.15) versus the alternative hypothesis that 30% or more patients get a response (p ≥ 0.30). The variance of the standardized test was based on the null hypothesis. The type I error (alpha) associated with this one-sided test is 0.025 and the type II error (beta) is 0.051 (normal approximation; -0.05 if exact binomial distribution); hence, statistical power is 95% (normal approximation; -95% if exact binomial distribution). With these assumptions, if the number of patients who achieved a confirmed response is ≥ 23, then this would allow the rejection of the null hypothesis. The judgement of patient’s evaluability and replacement of non-evaluable patients in each cohort for the interim analyses was guided by the investigator assessment.

Duration of Study Period

[0139] Patients were evaluated at scheduled visits within three study periods: (1) Pre- treatment: from signature of IC to the first infusion of the study treatment; (2) Treatment: from the first infusion of the study treatment to the end of treatment; and (3) Follow-up: after end of treatment; patients were followed-up every 4 weeks until resolution or stabilization of all drug-related adverse events, if any, or until start of new anti-tumor therapy. Patients were followed up for at least 1 year after their first lurbinectedin infusion. Patients who finished treatment without PD were followed every 2 months during the first six months and every 3 months thereafter until PD, start of a new antitumor therapy, death, or until end of study date.

Results

[0140] 105 SCLC patients were enrolled into the study. All 105 patients were treated and included in the analysis for the primary endpoint. Of the 105 treated patients, 60% were male, 75% were white, 92% had ECOG PS 0 or 1 , and the median age was 60 years (range, 40-83 years; 35.2% were ≥ 65 years old). Two of the 105 treated patients (1.9%) had previously undergone surgery (curative resection in one patient). Prior radiotherapy had been administered to 75 patients (71.4%). The patients had received a median of one prior line of chemotherapy for advanced disease (range, 1-2 lines). The chemotherapy-free interval was less than 30 days in 21 (21%) patients, less than 90 days in 45 (43%) patients, and 90 days or longer in 60 (57%) patients. One patient with CNS metastases at baseline was included, and another patient had rechallenge with carboplatin plus etoposide and atezolizumab as previous line of therapy; these two cases were considered protocol deviations, but they were minor and were included in the primary analysis. [0141] 618 treatment cycles in total were administered, with a median of four cycles per patient, and 46 (44%) patients received six cycles or more. The median relative dose intensity of the study drug was 97.4% of the planned maximum dose. Dose administration was delayed in 23 (22%) patients and reduced in 28 (26%) because of treatment-related adverse events (neutropenia was the most common cause of both dose delays in 13 (12%) and reductions in 17 (16%) of patients).

Efficacy of Lurbinectedin in SCLC Patients

[0142] At data cutoff, median follow-up was 17.1 months. According to the investigator assessment of all treated patients, 37 (35.2%) had an overall response as shown in

Table 17.

0143] In the pre-planned analysis of overall response by chemotherapy-free interva (≥90 days vs <90 days) of 60 patients who had a chemotherapy-free interval of 90 days or longer (i.e., those with chemotherapy-sensitive disease), 27 (45.0%) had an overall response, with a median duration of response of 6.2 months, whereas in 45 patients who had a chemotherapy-free interval of less than 90 days (i.e., chemotherapy-resistant disease), ten (22.2%) had an overall response, with a median duration of response of 4.7 months.

Progression-Free Survival [0144] Investigator-assessed median progression-free survival was 3.5 months (95% Cl 2.6-4.3) in the overall population: 4.6 months in patients with a chemotherapy-free interval of 90 days or longer and 2.6 months in patients with chemotherapy-free interval of less than 90 days. Eight (9%) of 94 patients who discontinued lurbinectedin treatment had disease progression with new lesions in the CNS. No increased incidence of CNS metastases was therefore observed.

Overall Survival

[0145] With a censoring of 37.1% (39 of 105 patients alive at data cutoff), median overall survival was 9.3 months (95% Cl 6.3-11.8) in the overall population, 11.9 months (9.7- 16.2) in patients with a chemotherapy-free interval of 90 days or longer, and 5.0 months (4.1-6.3) in patients with chemotherapy-free interval of less than 90 days. Notably, 29 (48%) of 60 patients with a chemotherapy-free interval of 90 days or longer and seven (16%) of 45 patients with a chemotherapy-free interval of less than 90 days were alive at 1 year after the first dose administration.

[0146] In a post-hoc analysis, of the 37 patients who had an initial objective response, median overall survival exceeded 1 year in the overall population (12.6 months, 95% Cl 10.8-15.8) and in patients with sensitive disease (15.8 months, 10.2-not reached) and was 10.9 months in patients with resistant disease (10.9 months, 6.3-14.0).

Safety

[0147] All 105 treated patients were evaluable for safety (Table 18). The most common Grade 3-4 adverse events and laboratory abnormalities (in ≥ 2% of patients) were hematological disorders, including anemia (nine [9%] patients), leukopenia (30 [29%]), neutropenia (48 [46%]), thrombocytopenia (seven [7%]), and febrile neutropenia (five [5%]); of these, only febrile neutropenia was regarded as treatment related (Table 18). Notably, no cases of drug-induced liver injury were reported. 23 (22%) of 105 patients received G-CSF secondary prophylaxis or therapy for neutropenia. Serious treatment- related adverse events occurred in 11 (10%) of 105 patients; neutropenia and febrile neutropenia were the most common (five [5%] patients for each). Grade 3 pneumonia was reported in two (2%) patients; these episodes were associated with grade 3 febrile neutropenia and grade 4 neutropenia, lasted 3 days for one patient and 13 days for the other, and resolved with no clinical consequences. One patient had a grade 3 skin ulcer because of extravasation, with no clinical consequences. Only two (2%) patients discontinued lurbinectedin therapy because of treatment-related adverse events. No treatment-related deaths occurred, but 66 (63%) of 105 patients died from disease progression. Table 18.

Prior Immunotherapy

[0148] Post-hoc exploratory analysis was done on the response in patients who had previously received immunotherapy (n=8). Data from this group of patients showed a trend for a better response to single-agent lurbinectedin following first-line platinum- containing chemotherapy in combination with checkpoint inhibitors or second-line with nivolumab (Table 19). This is an important finding in light of the recent approval of atezolizumab in first-line SCLC in combination with carboplatin/etoposide; hence, lurbinectedin could provide a viable option for patients who progress on immunotherapy. Table 19.

Summary and Conclusions

[0149] 105 SCLC patients were enrolled and treated with lurbinectedin. Median follow up was 17.1 months (IQR 6.5-25.3). Overall response by investigator assessment was seen in 37 patients (35.2%; 95% Cl 26.2^5.2). The most common grade 3-4 adverse events (irrespective of causality) were hematological abnormalities — namely, anemia (in nine [9%] patients), leucopenia (30 [29%]), neutropenia (48 [46%]), and thrombocytopenia (seven [7%]). Serious treatment-related adverse events occurred in 11 (10%) patients, of which neutropenia and febrile neutropenia were the most common (five [5%] patients for each). No treatment-related deaths were reported. [0150] Lurbinectedin was active as second-line therapy for SCLC in terms of overall response and had an acceptable and manageable safety profile. Lurbinectedin could represent a potential new treatment for patients with SCLC, who have few options especially in the event of a relapse. Example 8: Clinical Study - Treatment of Solid Cancer Patients with Lurbinectedin and Irinotecan

[0151] A clinical study of lurbinectedin in combination with irinotecan for patients afflicted with solid tumors was carried out. A Phase 1 trial to evaluate escalating doses of lurbinectedin on Day (D) 1 plus a fixed dose of irinotecan 75mg/m ² on D1 and D8 every 3 weeks (q3w) in patients with advanced solid tumors. Patients were enrolled following a standard 3 + 3 dose escalation design. Phase Ib/ll expansion part at the recommended dose (RD) was performed to explore efficacy in indications where antitumor activity signal was observed. Study Population

[0152] Details on inclusion and exclusion criteria can be found in Table 20.

Inclusion Exclusion

Voluntarily signed and dated written Concomitant diseases/conditions:

History or presence of unstable angina, informed consent prior to any specific- myocardial infarction, congestive heart study procedure. failure, or clinically significant valvular heart disease within the previous year.

Age ≥ 18 years. Symptomatic arrhythmia or any uncontrolled arrhythmia requiring ongoing treatment.

Eastern Cooperative Oncology Group Myopathy or any clinical situation that (ECOG) performance status (PS) < 1. causes significant and persistent elevation of CPK (> 2.5 x ULN in two different

Life expectancy ≥ 3 months. determinations performed one week apart). Ongoing chronic alcohol consumption or

No more than two prior lines of cytotoxic- cirrhosis with Child-Pugh score B or C. containing chemotherapy regimens for Known Gilbert disease.

Active uncontrolled infection. advanced disease. There is no limit for Known human immunodeficiency virus (HIV) infection. Known human immunodeficiency prior targeted therapy, hormonal therapy virus (HIV) or known hepatitis C virus (HCV) and immunotherapy (such as nivolumab). infection or active hepatitis B.

Any past or present chronic inflammatory Histologically or cytologically confirmed colon and/or liver disease, past intestinal obstruction, pseudo or sub-occlusion or diagnosis of advanced disease of any of paralysis. the following tumor types: Evident symptomatic pulmonary fibrosis or interstitial pneumonitis, pleural or cardiac

Glioblastoma; Soft-tissue sarcoma effusion rapidly increasing and/or [excluding gastrointestinal stromal tumors necessitating prompt local treatment within seven days. (GIST)]; Endometrial carcinoma; Epithelial Any other major illness that, in the Investigator's judgment, will substantially ovarian carcinoma (including primary increase the risk associated with the peritoneal disease and/or fallopian tube patient's participation in this study.

Prior treatment with PM01183, trabectedin carcinomas and/or endometrial (Yondelis®) or topoisomerase I inhibitors (irinotecan, topotecan, etc.). Prior adenocarcinomas) regardless of platinum topoisomerase inhibitors (e.g., irinotecan) sensitivity; Mesothelioma; are only allowed in patients with colorectal carcinoma.

Gastroenteropancreatic neuroendocrine Prior bone marrow or stem cell transplantation, or radiation therapy in more tumors (GEP-NET); Small cell lung cancer than 35% of bone marrow. (SCLC); Pancreatic adenocarcinoma; Known brain metastases or leptomeningeal disease involvement. Glioblastoma lesions Gastric carcinoma; Colorectal carcinoma (primary or locally advanced) are eligible. In SCLC, patients with brain metastases or (CRC); leptomeningeal disease involvement are

Expansion phase: Tumor-specific eligible provided they are radiologically stable, i.e. without evidence of progression cohort(s) at the RD: for at least 4 weeks by repeat imaging (note that the repeat imaging should be performed during study screening), clinically stable and without requirement of steroid treatment (patients taking steroids in the process of Measurable disease according to already being tapered within two weeks prior to screening are allowed). Brain CT-scan or Response Evaluation Criteria in Solid MRI results must be provided at baseline. Tumors (RECIST) v.1.1. Women who are pregnant or breast feeding and fertile patients (men and women) who

For patients with glioblastoma: are not using an effective method of contraception. ( ^* ) Measurable disease according to RECIST Limitation of the patient's ability to comply v.1 .1 and RANO criteria. with the treatment or follow-up protocol.

Documented disease progression per RECIST v.1.1 during or immediately after last therapy according to any of the aforementioned criteria.

For patients with glioblastoma: Documented disease progression per RECIST v.1.1 and RANO criteria.

At least three weeks since the last anticancer therapy (excluding immunotherapy that must be at least two weeks, provided that is not combined with chemotherapy), including investigational drugs and radiotherapy, and at least six weeks since nitrosoureas and mitomycin C (systemic).

For patients with glioblastoma: at least 12 weeks since the end of radiotherapy, except if:

The patient has a new lesion outside of the radiotherapy field, or

The patient has undergone brain surgery to remove the tumor before study entry, and progressive disease has been confirmed histologically.

Adequate bone marrow, renal, hepatic, and metabolic function (assessed ≤ 7 days before inclusion in the study): Platelet counts 100 x 10 ^Λ 9/L, hemoglobin ≥ 9.0 g/dL and absolute neutrophil count (ANC) ≥ 2.0 x 10 ^Λ 9/L.

Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 3.0 x the upper limit of normal (ULN), even in the presence of liver metastases.

Alkaline phosphatase (ALP) ≤ 2.5 x ULN (≤ 5 x ULN if disease-related/in the case of liver metastases).

Total bilirubin ≤ 1.5 x ULN or direct bilirubin ≤ ULN.

International Normalized Ratio (INR) < 1 .5 (except if patient is on oral anticoagulation therapy).

Calculated creatinine clearance (CrCL) ≥

30 mL/minute (using Cockcroft-Gault formula).

Creatine phosphokinase (CPK) ≤ 2.5 x ULN.

Albumin ≥ 3.0 g/dL(*).

Recovery to grade ≤ 1 or to baseline from any adverse event (AE) derived from previous treatment (excluding alopecia and/or cutaneous toxicity and/or peripheral neuropathy and/or fatigue grade ≤ 2).

Study Drug Formulation - Preparation and Administration

[0153] Lurbinectedin was presented as lyophilized powder for concentration for solution for infusion in 4mg vials. Before use, the 4mg vials were reconstituted with 8 mL of water for injection to give a solution containing 0.5 mg/mL of lurbinectedin. For administration to patients as an i.v. infusion, reconstituted vials were diluted with glucose 50 mg/mL (5%) solution for infusion or sodium chloride 9 mg/mL (0.9%) solution for infusion. The full composition and the reconstituted solution per mL was as shown in Table 12 supra. [0154] Irinotecan was presented as lyophilized powder for concentration for solution for infusion in 40 mg, 100 mg, or 300 mg vials.

Dosage and Administration

[0155] Lurbinectedin was administered over a minimum total volume of 100 ml. of solution for infusion (either on 5% glucose or 0.9% sodium chloride), through a central catheter, or over a minimum total volume of 250 mL if administered through a peripheral line, always over one hour at a fixed infusion rate.

[0156] Dose levels in patients at the escalation phase (n=39) were as shown in Table 21. Patients received lurbinectedin i.v. as a one-hour infusion on Day 1 and irinotecan, i.v. as a 90-minute infusion at days 1 and 8 every three weeks. Three weeks was defined as one treatment cycle.

Table 21.

Outcome Measures

[0157] Primary outcome measures were (1) maximum tolerated dose (MTD) and (2) recommended dose (RD). MTD was defined as lowest dose explored during dose escalation which one third or more of evaluable patients develop DLT in Cycle 1 . RD was defined as highest dose level explored during dose escalation in which fewer than one third of evaluable patients develop DLT during Cycle 1.

[0158] Secondary outcome measures included safety evaluation, peak plasma concentration (Cmax), area-under-the plasma concentration versus time curve (AUC), volume of distribution based on the terminal half-life (Vz), volume of distribution at steady state (Vss), clearance (CL), half-life (t1/2), evaluation of antitumor response (RECIST v1 .1 , start of treatment until PD, other antitumor therapy, death or until 12 months after the inclusion of the last evaluable patient in the study (end of study), whichever occurs first), progression-free survival (from the date of first infusion of study treatment to the date of progression or death or until 12 months after end of study, whichever occurs first), and overall survival (from the date of first infusion to study treatment to the date or death or until 12 months after end of study, whichever occurs first).

Pharmacokinetic Evaluations

[0159] Patients underwent PK sampling for assessment of lurbinectedin, irinotecan, and SN38 (active metabolite of irinotecan), aimed at ruling out major drug-drug interactions.

Safety Evaluation

[0160] Patients were evaluated for safety if they had received any partial or complete infusion of lurbinectedin and irinotecan. All adverse events were graded according to the National Cancer Institute-Common Toxicity Criteria for Adverse Events (NCI-CTCAE, v4). The safety profile of patients was monitored throughout the treatment and up to 30 days after the last administration of study treatment (end of treatment), or until the patient started a new anti-tumor therapy or until the date of death, whichever occurred first. Treatment delays, dose reduction requirements, transfusions, and reason for treatment discontinuation was monitored throughout the study. Any treatment-related adverse events were followed until recovery to at least grade 1 or stabilization of symptoms or until the start of a new anti-tumor therapy, whichever occurred first.

Results

[0161] 39 patients were initially treated at 5 dose levels (DL, see Table 21 supra)·, 13 at the recommended dose (RD). 56% were females, 69% had ECOG PS = 1 ; median age was 58 years; median of 2 prior chemotherapy lines for advanced disease (range, 0 - 4) per pt. RD was defined as lurbinectedin 2.0 mg/m ² on D1 + irinotecan 75 mg/m ² on D1 and D8 q3w + G-CSF. Dose limiting toxicities in Cycle 1 were observed in 2/3 evaluable patients at the maximum tolerated dose (MTD) and in 3/13 evaluable patients at the RD. At the MTD and the RD, DLTs were skipping irinotecan D8 doses due to grade (G) 3-4 neutropenia (n = 3 patients) or G2-4 thrombocytopenia (n = 2). At the RD common G1/2 toxicities were nausea, vomiting, fatigue, diarrhea, anorexia and neuropathy; G3/4 hematological abnormalities comprised neutropenia (33%), but no thrombocytopenia.

Pharmacokinetics Data

[0162] Concentration-time data of lurbinectedin, irinotecan, and SN-38 are available from 39 patients. Mean (±SD) of main PK parameters are provided in the Table below, along with those reported elsewhere for lurbinectedin single agent, and irinotecan and SN-38 (Camptosar Label).

[0163] Based on the comparability with reference PK data, these PK results of the three analytes evaluated do not suggest any type of major drug-drug interactions, thus indicating that the drug combination of lurbinectedin and irinotecan can be administered safely from a PK standpoint.

Table 22. Compound Dose Level n Cmax CL (L/h) HL (h) Vz (L)

(mg/m2) (ug/L)

Lurbinectedin 1.0-2.4 39 9.9 (5.4) 44.2 (22.4) 580.9

(345.5)

3.2 (ref) 329 127.5 12.4 (7.6) 42.6 (38.4) 664.7

(100.2) (460.3)

Irinotecan 75 39 828.2 30.2 9.9 (4.3) 233.2

(174.7) (10.3) (83.3)

125 (label) 64 1660 (797) 22.6 11.7 (9) 187

(10.2) (82.5)

SN-38 39 18.1 (7.7) 810.3 18.6 (9.1 ) 18232.3

(574) (8208.4)

- (label) 64 26.3 (11.9) NA 21.0 (20) NA

Efficacy Data

[0164] Encouraging activity has been observed in patients with SCLC, including some cases as third line treatment. Signals of activity were also observed in endometrial carcinoma and soft tissue sarcoma (STS) and glioblastoma (GBM). Consequently, a Phase II expansion at the RD to further explore efficacy and safety in SCLC, GBM, STS, and endometrial carcinoma. A total of 59 patients were treated at the RD, including n=15 SCLC, n=11 endometrial cancer, n=10 STS, and n=20 GBM patients. Efficacy data per tumor type at all doses are shown in the table below.

Table 23.

Tumor Type SCLC Endometrial STS GBM

(No of evaluable patients) (n=13) (n=10) (n=10) (n=16) Median no. of cycles 8 (1 -12) 7 (2-37) 4 (2-15) 2 (1 -7)

(range)

ORR* (PR) [n(%)] 9 (69.2) 3 (30) 0 1 (6.3)

CBR (ORR + SD>4 mo) (%) 76.9 60 40 18.8

DCR (ORR + SD) (%) 84.6 100 80 43.8 Median PFS (mo) 4.3 7.1 2.6 1.4

Median DoR (mo) 4.6 4.6

PFS rate at 6 mo (%) 36.3 50 33.8 7.1

Safety

[0165] Two patients (3.4%) discontinued treatment due to a treatment-related adverse event (Bilirubin G2, weakness G3). 17 patients (28.8%) had dose reductions (76% of reductions were due to day 8 irinotecan omissions related to adverse events). 19.8% of day 8 irinotecan infusions were omitted at the RD (mostly due to hematological toxicity).

No treatment-related deaths occurred. A detailed description of adverse events and laboratory abnormalities observed in patients at RD is shown in Table 24. Table 24.

Adverse Events & Patients at RD Laboratory Abnormalities LUR + IRI (n=59)

G1-2 (%) G3-4 (%)

Treatment-related Fatigue 33 (55.9%) 5 (8.5%) adverse events Nausea 33 (55.9%) 1 (1 .7%)

Vomiting 15 (25.4%)

Diarrhea 25 (42.4%) 5 (8.5%)

Constipation 7 (11 .9%)

Abdominal Pain 6 (10.2%)

Anorexia 18 (30.5%)

Febrile Neutropenia 3 (5.1%)

Laboratory Anemia 46 (78%) 8 (13.6%) abnormalities Neutropenia 21 (35.6%) 29 (49.1%) Thrombocytopenia 30 (50.8%) 6 (10.1%) ALT increase 23 (39%) 3 (5.1%) AST increases 23 (39%) 2 (3.4%)

Summary and Conclusions [0166] The RD is lurbinectedin 2.0 mg/m ² on day 1 and irinotecan 75 mg/m ² on day 1 and day 8 q3wk, with GCS-F, in solid tumors. DLTs are mostly day 8 irinotecan omissions in cycle 1 due to hematological toxicity. Main toxicities observed were myelosuppression, gastrointestinal and fatigue. Gastrointestinal and myelosuppression were predictable and manageable. Promising activity has been observed in SCLC. Notable activity has been observed in endometrial carcinoma, and hints of activity have been found in STS (especially Ewing and synovial sarcoma). Modest activity has been observed in glioblastoma patients._Expansion cohorts in SCLC, endometrial carcinoma and STS patients are still ongoing, to enroll a total of 20 patients in each indication.

[0167] Although the invention is described in detail with reference to specific embodiments thereof, it will be understood that variations which are functionally equivalent are within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and accompanying drawings. Such modifications are intended to fall within the scope of the appended claims. Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims

[0168] All publications, patents and patent applications mentioned in this specification are herein incorporated by reference into the specification to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference in their entireties.