Bortezomib

12.1 Mechanism of Action Bortezomib is a reversible inhibitor of the chymotrypsin-like activity of the 26S proteasome in mammalian cells. The 26S proteasome is a large protein complex that degrades ubiquitinated proteins. The ubiquitin-proteasome pathway plays an essential role in regulating the intracellular concentration of specific proteins, thereby maintaining homeostasis within cells. Inhibition of the 26S proteasome prevents this targeted proteolysis, which can affect multiple signaling cascades within the cell. This disruption of normal homeostatic mechanisms can lead to cell death. Experiments have demonstrated that bortezomib is cytotoxic to a variety of cancer cell types in vitro . Bortezomib causes a delay in tumor growth in vivo in nonclinical tumor models, including multiple myeloma.

1 INDICATIONS AND USAGE Bortezomib for injection is a proteasome inhibitor indicated for: • treatment of adult patients with multiple myeloma ( 1.1 ) • treatment of adult patients with mantle cell lymphoma ( 1.2 ) 1.1 Multiple Myeloma Bortezomib for injection is indicated for the treatment of adult patients with multiple myeloma. 1.2 Mantle Cell Lymphoma Bortezomib for injection is indicated for the treatment of adult patients with mantle cell lymphoma.

2 DOSAGE AND ADMINISTRATION • For subcutaneous or intravenous use only. Each route of administration has a different reconstituted concentration. Exercise caution when calculating the volume to be administered. ( 2.1 , 2.10 ) • The recommended starting dose of bortezomib for injection is 1.3 mg/m 2 administered either as a 3 to 5 second bolus intravenous injection or subcutaneous injection. ( 2.2 , 2.4 , 2.6 ) • Retreatment for Multiple Myeloma: May retreat starting at the last tolerated dose. ( 2.6 ) • Hepatic Impairment: Use a lower starting dose for patients with moderate or severe hepatic impairment. ( 2.8 ) • Dose must be individualized to prevent overdose. ( 2.10 ) 2.1 Important Dosing Guidelines Bortezomib for injection is for intravenous or subcutaneous use only. Do not administer bortezomib for injection by any other route. Because each route of administration has a different reconstituted concentration, use caution when calculating the volume to be administered. The recommended starting dose of bortezomib for injection is 1.3 mg/m 2 . Bortezomib for injection is administered intravenously at a concentration of 1 mg/mL, or subcutaneously at a concentration of 2.5 mg/mL [see Dosage and Administration ( 2.10 )]. Bortezomib for injection retreatment may be considered for patients with multiple myeloma who had previously responded to treatment with bortezomib for injection and who have relapsed at least six months after completing prior bortezomib for injection treatment. Treatment may be started at the last tolerated dose [see Dosage and Administration ( 2.6 )]. When administered intravenously, administer bortezomib for injection as a 3 to 5 second bolus intravenous injection. 2.2 Dosage in Previously Untreated Multiple Myeloma Bortezomib for injection is administered in combination with oral melphalan and oral prednisone for 9, six week treatment cycles as shown in Table 1 . In Cycles 1 to 4, bortezomib for injection is administered twice weekly (Days 1, 4, 8, 11, 22, 25, 29 and 32). In Cycles 5 to 9, bortezomib for injection is administered once weekly (Days 1, 8, 22 and 29). At least 72 hours should elapse between consecutive doses of bortezomib for injection. Table 1: Dosage Regimen for Patients with Previously Untreated Multiple Myeloma Twice Weekly Bortezomib for Injection (Cycles 1 to 4) Week 1 2 3 4 5 6 Bortezomib for injection (1.3 mg/m 2 ) Day 1 -- -- Day 4 Day 8 Day 11 rest period Day 22 Day 25 Day 29 Day 32 rest period Melphalan (9 mg/m 2 ) Prednisone (60 mg/m 2 ) Day 1 Day 2 Day 3 Day 4 -- -- rest period -- -- -- -- rest period Once Weekly Bortezomib for Injection (Cycles 5 to 9 when used in combination with Melphalan and Prednisone) Week 1 2 3 4 5 6 Bortezomib for injection (1.3 mg/m 2 ) Day 1 -- -- Day 8 rest period Day 22 Day 29 rest period Melphalan (9 mg/m 2 ) Prednisone (60 mg/m 2 ) Day 1 Day 2 Day 3 Day 4 -- -- rest period -- -- -- -- rest period 2.3 Dose Modification Guidelines for Bortezomib for Injection When Given in Combination with Melphalan and Prednisone Prior to initiating any cycle of therapy with bortezomib for injection in combination with melphalan and prednisone: • Platelet count should be at least 70 x 10 9 /L and the absolute neutrophil count (ANC) should be at least 1 x 10 9 /L • Nonhematological toxicities should have resolved to Grade 1 or baseline Table 2: Dose Modifications During Cycles of Combination Bortezomib for Injection, Melphalan and Prednisone Therapy Toxicity Dose Moidification or Delay Hematological toxicity during a cycle: If prolonged Grade 4 neutropenia or thrombocytopenia, or thrombocytopenia with bleeding is observed in the previous cycle Consider reduction of the melphalan dose by 25% in the next cycle If platelet count is not above 30 x 10 9 /L or ANC is not above 0.75 x 10 9 /L on a bortezomib for injection dosing day (other than Day 1) Withhold bortezomib for injection dose If several bortezomib for injection doses in consecutive cycles are withheld due to toxicity Reduce bortezomib for injection dose by one dose level (from 1.3 mg/m 2 to 1 mg/m 2 , or from 1 mg/m 2 to 0.7 mg/m 2 ) Grade 3 or higher nonhematological toxicities Withhold bortezomib for injection therapy until symptoms of toxicity have resolved to Grade 1 or baseline. Then, bortezomib for injection may be reinitiated with one dose level reduction (from 1.3 mg/m 2 to 1 mg/m 2 , or from 1 mg/m 2 to 0.7 mg/m 2 ). For bortezomib for injection-related neuropathic pain and/or peripheral neuropathy, hold or modify bortezomib for injection as outlined in Table 5 . For information concerning melphalan and prednisone, see manufacturer's prescribing information. Dose modifications guidelines for peripheral neuropathy are provided [see Dosage and Administration ( 2.7 )]. 2.4 Dosage in Previously Untreated Mantle Cell Lymphoma Bortezomib for injection (1.3 mg/m 2 ) is administered intravenously in combination with intravenous rituximab, cyclophosphamide, doxorubicin and oral prednisone (VcR

6 ADVERSE REACTIONS The following clinically significant adverse reactions are also discussed in other sections of the labeling: • Peripheral Neuropathy [see Warnings and Precautions ( 5.1 )] • Hypotension [see Warnings and Precautions ( 5.2 )] • Cardiac Toxicity [see Warnings and Precautions ( 5.3 )] • Pulmonary Toxicity [see Warnings and Precautions ( 5.4 )] • Posterior Reversible Encephalopathy Syndrome (PRES) [see Warnings and Precautions ( 5.5 )] • Gastrointestinal Toxicity [see Warnings and Precautions ( 5.6 )] • Thrombocytopenia/Neutropenia [see Warnings and Precautions ( 5.7 )] • Tumor Lysis Syndrome [see Warnings and Precautions ( 5.8 )] • Hepatic Toxicity [see Warnings and Precautions ( 5.9 )] • Thrombotic Microangiopathy [see Warnings and Precautions ( 5.10 )] Most commonly reported adverse reactions (incidence ≥ 20%) in clinical studies include nausea, diarrhea, thrombocytopenia, neutropenia, peripheral neuropathy, fatigue, neuralgia, anemia, leukopenia, constipation, vomiting, lymphopenia, rash, pyrexia, and anorexia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Hetero Labs Limited at 1-866-495-1995 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, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. Summary of Clinical Trial in Patients with Previously Untreated Multiple Myeloma Table 9 describes safety data from 340 patients with previously untreated multiple myeloma who received bortezomib (1.3 mg/m 2 ) administered intravenously in combination with melphalan (9 mg/m 2 ) and prednisone (60 mg/m 2 ) in a prospective randomized study. The safety profile of bortezomib in combination with melphalan/prednisone is consistent with the known safety profiles of both bortezomib and melphalan/prednisone. Table 9: Most Commonly Reported Adverse Reactions (≥ 10% in the Bortezomib, Melphalan and Prednisone Arm) with Grades 3 and ≥ 4 Intensity in the Previously Untreated Multiple Myeloma Study Bortezomib, Melphalan and Prednisone Melphalan and Prednisone (n=340) ( n =337) Body System Total Toxicity Grade, n (%) Total Toxicity Grade, n (%) Adverse Reaction n (%) 3 ≥ 4 n (%) 3 ≥ 4 Blood and Lymphatic System Disorders Thrombocytopenia 164 (48) 60 (18) 57 (17) 140 (42) 48 (14) 39 (12) Neutropenia 160 (47) 101 (30) 33 (10) 143 (42) 77 (23) 42 (12) Anemia 109 (32) 41 (12) 4 (1) 156 (46) 61 (18) 18 (5) Leukopenia 108 (32) 64 (19) 8 (2) 93 (28) 53 (16) 11 (3) Lymphopenia 78 (23) 46 (14) 17 (5) 51 (15) 26 (8) 7 (2) Gastrointestinal Disorders Nausea 134 (39) 10 (3) 0 70 (21) 1 (< 1) 0 Diarrhea 119 (35) 19 (6) 2 (1) 20 (6) 1 (< 1) 0 Vomiting 87 (26) 13 (4) 0 41 (12) 2 (1) 0 Constipation 77 (23) 2 (1) 0 14 (4) 0 0 Abdominal pain upper 34 (10) 1 (< 1) 0 20 (6) 0 0 Nervous System Disorders Peripheral neuropathy * 156 (46) 42 (12) 2 (1) 4 (1) 0 0 Neuralgia 117 (34) 27 (8) 2 (1) 1 (< 1) 0 0 Paresthesia 42 (12) 6 (2) 0 4 (1) 0 0 General Disorders and Administration Site Conditions Fatigue 85 (25) 19 (6) 2 (1) 48 (14) 4 (1) 0 Asthenia 54 (16) 18 (5) 0 23 (7) 3 (1) 0 Pyrexia 53 (16) 4 (1) 0 19 (6) 1 (< 1) 1 (< 1) Infections and Infestations Herpes Zoster 39 (11) 11 (3) 0 9 (3) 4 (1) 0 Metabolism and Nutrition Disorders Anorexia 64 (19) 6 (2) 0 19 (6) 0 0 Skin and Subcutaneous Tissue Disorders Rash 38 (11) 2 (1) 0 7 (2) 0 0 Psychiatric Disorders Insomnia 35 (10) 1 (< 1) 0 21 (6) 0 0 * Represents High Level Term Peripheral Neuropathies NEC Relapsed Multiple Myeloma Randomized Study of Bortezomib vs Dexamethasone The safety data described below and in Table 10 reflect exposure to either bortezomib (n=331) or dexamethasone (n=332) in a study of patients with relapsed multiple myeloma. Bortezomib was administered intravenously at doses of 1.3 mg/m 2 twice weekly for two out of three weeks (21 day cycle). After eight, 21 day cycles patients continued therapy for three, 35 day cycles on a weekly schedule. Duration of treatment was up to 11 cycles (nine months) with a median duration of six cycles (4.1 months). For inclusion in the trial, patients must have had measurable disease and one to three prior therapies. There was no upper age limit for entry. Creatinine clearance could be as low as 20 mL/min and bilirubin levels as high as 1.5 times the upper limit of normal. The overall frequency of adverse reactions was similar in men and women, and in patients < 65 and ≥ 65 years of age. Most patients were Caucasian [see Clinical Studies ( 14.1 )]. Among the 331 bortezomib-treated patients, the most commonly reported (> 20%) adverse reactions overall were nausea (52%), diarrhea (52%), fatigue (39%), peripheral neuropathies (35%), thrombocytopenia (33%), constipation (30%), vomiting (29%), and anorexia (21%). The most commonly reported (> 20%) adverse reaction reported among the 33

7 DRUG INTERACTIONS • Strong CYP3A4 Inhibitors: Closely monitor patients with concomitant use. ( 7.1 ) • Strong CYP3A4 Inducers: Avoid concomitant use. (7.3) 7.1 Effects of Other Drugs on Bortezomib Strong CYP3A4 Inducers Coadministration with a strong CYP3A4 inducer decreases the exposure of bortezomib [see Clinical Pharmacology ( 12.3 )] which may decrease bortezomib efficacy. Avoid coadministration with strong CYP3A4 inducers. Strong CYP3A4 Inhibitors Coadministration with a strong CYP3A4 inhibitor increases the exposure of bortezomib [see Clinical Pharmacology ( 12.3 )] which may increase the risk of bortezomib toxicities. Monitor patients for signs of bortezomib toxicity and consider a bortezomib dose reduction if bortezomib must be given in combination with strong CYP3A4 inhibitors. 7.2 Drugs Without Clinically Significant Interactions with Bortezomib No clinically significant drug interactions have been observed when bortezomib was coadministered with dexamethasone, omeprazole, or melphalan in combination with prednisone [see Clinical Pharmacology ( 12.3 )].