Eribulin

12.1 Mechanism of Action Eribulin inhibits the growth phase of microtubules without affecting the shortening phase and sequesters tubulin into nonproductive aggregates. Eribulin exerts its effects via a tubulin-based antimitotic mechanism leading to G 2 /M cell-cycle block, disruption of mitotic spindles, and, ultimately, apoptotic cell death after prolonged mitotic blockage. In addition, eribulin treatment of human breast cancer cells caused changes in morphology and gene expression as well as decreased migration and invasiveness in vitro . In mouse xenograft models of human breast cancer, eribulin treatment was associated with increased vascular perfusion and permeability in the tumor cores, resulting in reduced tumor hypoxia, and changes in the expression of genes in tumor specimens associated with a change in phenotype.

1 INDICATIONS AND USAGE Eribulin mesylate injection is a microtubule inhibitor indicated for the treatment of patients with: Metastatic breast cancer who have previously received at least two chemotherapeutic regimens for the treatment of metastatic disease. Prior therapy should have included an anthracycline and a taxane in either the adjuvant or metastatic setting. ( 1.1 ) Unresectable or metastatic liposarcoma who have received a prior anthracycline-containing regimen. ( 1.2 ) 1.1 Metastatic Breast Cancer Eribulin mesylate injection is indicated for the treatment of patients with metastatic breast cancer who have previously received at least two chemotherapeutic regimens for the treatment of metastatic disease. Prior therapy should have included an anthracycline and a taxane in either the adjuvant or metastatic setting [see Clinical Studies ( 14.1 )]. 1.2 Liposarcoma Eribulin mesylate injection is indicated for the treatment of patients with unresectable or metastatic liposarcoma who have received a prior anthracycline-containing regimen [see Clinical Studies ( 14.2 )] .

2 DOSAGE AND ADMINISTRATION Administer 1.4 mg/m 2 intravenously over 2 to 5 minutes on Days 1 and 8 of a 21-day cycle. ( 2.1 ) Reduce dose in patients with hepatic impairment or with moderate or severe renal impairment. ( 2.1 ) Do not mix with other drugs or administer with dextrose-containing solutions. ( 2.3 ) 2.1 Recommended Dose The recommended dose of eribulin mesylate injection is 1.4 mg/m 2 administered intravenously over 2 to 5 minutes on Days 1 and 8 of a 21-day cycle. The recommended dose of eribulin mesylate injection in patients with mild hepatic impairment (Child-Pugh A) is 1.1 mg/m 2 administered intravenously over 2 to 5 minutes on Days 1 and 8 of a 21-day cycle [see Use in Specific Populations ( 8.6 )] . The recommended dose of eribulin mesylate injection in patients with moderate hepatic impairment (Child-Pugh B) is 0.7 mg/m 2 administered intravenously over 2 to 5 minutes on Days 1 and 8 of a 21-day cycle [see Use in Specific Populations ( 8.6 )] . The recommended dose of eribulin mesylate injection in patients with moderate or severe renal impairment (creatinine clearance (CLcr) 15 to 49 mL/min) is 1.1 mg/m 2 administered intravenously over 2 to 5 minutes on Days 1 and 8 of a 21-day cycle [see Use in Specific Populations ( 8.7 )]. 2.2 Dose Modification Assess for peripheral neuropathy and obtain complete blood cell counts prior to each dose. Recommended dose delays • Do not administer eribulin mesylate injection on Day 1 or Day 8 for any of the following: - ANC < 1,000/mm 3 - Platelets < 75,000/mm 3 - Grade 3 or 4 non-hematological toxicities. • The Day 8 dose may be delayed for a maximum of 1 week. - If toxicities do not resolve or improve to ≤ Grade 2 severity by Day 15, omit the dose. - If toxicities resolve or improve to ≤ Grade 2 severity by Day 15, administer eribulin mesylate injection at a reduced dose and initiate the next cycle no sooner than 2 weeks later. Recommended dose reductions • If a dose has been delayed for toxicity and toxicities have recovered to Grade 2 severity or less, resume eribulin mesylate injection at a reduced dose as set out in Table 1. • Do not re-escalate eribulin mesylate injection dose after it has been reduced. Table 1: Recommended Dose Reductions Event Description Recommended Eribulin Mesylate Injection Dose Permanently reduce the 1.4 mg/m 2 eribulin mesylate injection dose for any of the following: 1.1 mg/m 2 ANC <500/mm 3 for >7 days ANC <1,000 /mm 3 with fever or infection Platelets <25,000/mm 3 Platelets <50,000/mm 3 requiring transfusion Non-hematologic Grade 3 or 4 toxicities Omission or delay of Day 8 eribulin mesylate injection dose in previous cycle for toxicity Occurrence of any event requiring permanent dose reduction while receiving 1.1 mg/m 2 0.7 mg/m 2 Occurrence of any event requiring permanent dose reduction while receiving 0.7 mg/m 2 Discontinue eribulin mesylate injection ANC = absolute neutrophil count. Toxicities graded in accordance with National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) version 3.0. 2.3 Instructions for Preparation and Administration Aseptically withdraw the required amount of eribulin mesylate injection from the single-dose vial and administer undiluted or diluted in 100 mL of 0.9% Sodium Chloride Injection, USP. Do not dilute in or administer through an intravenous line containing solutions with dextrose. Do not administer in the same intravenous line concurrent with the other medicinal products. Store undiluted eribulin mesylate injection in the syringe for up to 4 hours at room temperature or for up to 24 hours under refrigeration at 4°C (40°F). Store diluted solutions of eribulin mesylate injection for up to 4 hours at room temperature or up to 24 hours under refrigeration at 4°C (40°F). Discard unused portions of the vial.

6 ADVERSE REACTIONS The most common adverse reactions (≥25%) in metastatic breast cancer were neutropenia, anemia, asthenia/fatigue, alopecia, peripheral neuropathy, nausea, and constipation. ( 6.1 ) The most common adverse reactions (≥25%) in liposarcoma and leiomyosarcoma were fatigue, nausea, alopecia, constipation, peripheral neuropathy, abdominal pain, and pyrexia. The most common (≥5%) Grade 3 to 4 laboratory abnormalities in liposarcoma and leiomyosarcoma were neutropenia, hypokalemia, and hypocalcemia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Dr. Reddy’s Laboratories, Inc., at 1-888-375-3784 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, the adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in other clinical trials and may not reflect the rates observed in clinical practice. The following adverse reactions are discussed in detail in other sections of the labeling: Neutropenia [see Warnings and Precautions ( 5.1) ] Peripheral neuropathy [see Warnings and Precautions (5.2) ] QT prolongation [see Warnings and Precautions (5.4) ] In clinical trials, eribulin mesylate has been administered to 1,963 patients including 467 patients exposed to eribulin mesylate for 6 months or longer. The majority of the 1,963 patients were women (92%) with a median age of 55 years (range: 17 to 85 years). The racial and ethnic distribution was White (72%), Black (4%), Asian (9%), and other (3%). Metastatic Breast Cancer The most common adverse reactions (≥25%) reported in patients receiving eribulin mesylate were neutropenia, anemia, asthenia/fatigue, alopecia, peripheral neuropathy, nausea, and constipation. The most common serious adverse reactions reported in patients receiving eribulin mesylate were febrile neutropenia (4%) and neutropenia (2%). The most common adverse reaction resulting in discontinuation of eribulin mesylate was peripheral neuropathy (5%). The adverse reactions described in Table 2 were identified in 750 patients treated in Study 1 [see Clinical Studies ( 14.1 )] . In Study 1, patients were randomized (2:1) to receive either eribulin mesylate (1.4 mg/m 2 on Days 1 and 8 of a 21-day cycle) or single agent treatment chosen by their physician (control group). A total of 503 patients received eribulin mesylate and 247 patients in the control group received therapy consisting of chemotherapy [total 97% (anthracyclines 10%, capecitabine 18%, gemcitabine 19%, taxanes 15%, vinorelbine 25%, other chemotherapies 10%)] or hormonal therapy (3%). The median duration of exposure was 118 days for patients receiving eribulin mesylate and 63 days for patients receiving control therapy. Table 2 reports the most common adverse reactions occurring in at least 10% of patients in either group. Table 2: Adverse Reactions a with a Per-Patient Incidence of at Least 10% in Study 1 Adverse Reactions Eribulin Mesylate n=503 Control Group n=247 All Grades ≥ Grade 3 All Grades ≥ Grade 3 Blood and lymphatic system disorders b Neutropenia 82% 57% 53% 23% Anemia 58% 2% 55% 4% Nervous system disorders Peripheral neuropathy c 35% 8% 16% 2% Headache 19% <1% 12% <1% General disorders Asthenia/Fatigue 54% 10% 40% 11% Pyrexia 21% <1% 13% <1% Mucosalinflammation 9% 1% 10% 2% Gastrointestinal disorders Nausea 35% 1% 28% 3% Constipation 25% 1% 21% 1% Vomiting 18% 1% 18% 1% Diarrhea 18% 0 18% 0 Musculoskeletal and connective tissue disorders Arthralgia/Myalgia 22% <1% 12% 1% Back pain 16% 1% 7% 2% Bone pain 12% 2% 9% 2% Pain in extremity 11% 1% 10% 1% Metabolism and nutrition disorders Decreased weight 21% 1% 14% <1% Anorexia 20% 1% 13% 1% Respiratory, thoracic, and mediastinal disorders Dyspnea 16% 4% 13% 4% Cough 14% 0 9% 0 Skin and subcutaneous tissue disorders Alopecia 45% NA d 10% NA d Infections Urinary Tract Infection 10% 1% 5% 0 a. adverse reactions were graded per National Cancer Institute Criteria for Adverse Events version 4.0. b based upon laboratory data c includes peripheral neuropathy, peripheral sensorimotor neuropathy, peripheral motorneuropathy, polyneuropathy, peripheral sensory neuropathy, and paraesthesia. d not applicable; (grading system does not specify > Grade 2 for alopecia). Cytopenias: Grade 3 neutropenia occurred in 28% (143/503) of patients who received eribulin mesylate in Study 1, and 29% (144/503) of patients experienced Grade 4 neutropenia. Febrile neutropenia occurred in 5% (23/503) of patients; two patients (0.4%) died from complications of febrile neutropenia. Dose reduction due to neutropenia was required in 12% (62/503) of patients and discontinuation was required in <1% of patients. The mean time to nadir was 13 days and the mean time to recovery from severe neutropenia (<500/mm 3 ) was 8 days. Grade 3 or greater thrombocytopenia occurred in 1% (7/503) of patients. G-CSF (granulocyte colony-stimulating factor) or GM-CSF (granulocyte–m

7 DRUG INTERACTIONS 7.1 Effects of Other Drugs on Eribulin Mesylate No drug-drug interactions are expected with CYP3A4 inhibitors, CYP3A4 inducers or P‑glycoprotein (P-gp) inhibitors. Clinically meaningful differences in exposure (AUC) were not observed in patients with advanced solid tumors when eribulin mesylate was administered with or without ketoconazole (a strong inhibitor of CYP3A4 and a P-gp inhibitor) and when eribulin mesylate was administered with or without rifampin (a CYP3A4 inducer) [see Clinical Pharmacology ( 12.3 )]. 7.2 Effects of Eribulin Mesylate on Other Drugs Eribulin does not inhibit CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1 or CYP3A4 enzymes or induce CYP1A2, CYP2C9, CYP2C19 or CYP3A4 enzymes at relevant clinical concentrations. Eribulin is not expected to alter the plasma concentrations of drugs that are substrates of these enzymes [see Clinical Pharmacology ( 12.3 )].