Bicalutamide

12.1 Mechanism of Action Bicalutamide is a non-steroidal androgen receptor inhibitor. It competitively inhibits the action of androgens by binding to cytosol androgen receptors in the target tissue. Prostatic carcinoma is known to be androgen sensitive and responds to treatment that counteracts the effect of androgen and/or removes the source of androgen. When bicalutamide is combined with LHRH analog therapy, the suppression of serum testosterone induced by the LHRH analog is not affected. However, in clinical trials with bicalutamide as a single agent for prostate cancer, rises in serum testosterone and estradiol have been noted. In a subset of patients who have been treated with bicalutamide and an LHRH agonist, and who discontinue bicalutamide therapy due to progressive advanced prostate cancer, a reduction in Prostate Specific Antigen (PSA) and/or clinical improvement (antiandrogen withdrawal phenomenon) may be observed.

1 INDICATIONS AND USAGE Bicalutamide tablets, USP 50 mg daily are indicated for use in combination therapy with a luteinizing hormone-releasing hormone (LHRH) analog for the treatment of Stage D 2 metastatic carcinoma of the prostate. Bicalutamide tablets, USP 150 mg daily are not approved for use alone or with other treatments [see Clinical Studies (14.2)]. • Bicalutamide tablet 50 mg is an androgen receptor inhibitor indicated for use in combination therapy with a luteinizing hormone-releasing hormone (LHRH) analog for the treatment of Stage D 2 metastatic carcinoma of the prostate. (1) • Bicalutamide tablet 150 mg daily is not approved for use alone or with other treatments. (1)

2 DOSAGE AND ADMINISTRATION The recommended dose for bicalutamide tablets therapy in combination with an LHRH analog is one 50 mg tablet once daily (morning or evening). (2) 2.1 Recommended Dose and Schedule The recommended dose for bicalutamide tablets therapy in combination with an LHRH analog is one 50 mg tablet once daily (morning or evening), with or without food. It is recommended that bicalutamide tablets be taken at the same time each day. Treatment with bicalutamide tablets should be started at the same time as treatment with an LHRH analog. If a dose of bicalutamide tablets is missed, take the next dose at the scheduled time. Do not take the missed dose and do not double the next dose. 2.2 Dosage Adjustment in Renal Impairment No dosage adjustment is necessary for patients with renal impairment [see Use in Specific Populations (8.7)]. 2.3 Dosage Adjustment in Hepatic Impairment No dosage adjustment is necessary for patients with mild to moderate hepatic impairment. In patients with severe liver impairment (n=4), although there was a 76% increase in the half-life (5.9 and 10.4 days for normal and impaired patients, respectively) of the active enantiomer of bicalutamide, no dosage adjustment is necessary [see Use in Specific Populations (8.6)].

6 ADVERSE REACTIONS 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 practice. Adverse reactions that occurred in more than 10% of patients receiving bicalutamide plus an LHRH-A were: hot flashes, pain (including general, back, pelvic and abdominal), asthenia, constipation, infection, nausea, peripheral edema, dyspnea, diarrhea, hematuria, nocturia, and anemia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Sun Pharmaceutical Industries, Inc. at 1-800-818-4555 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience In patients with advanced prostate cancer treated with bicalutamide in combination with an LHRH analog, the most frequent adverse reaction was hot flashes (53%). In the multi-center, double-blind, controlled clinical trial comparing bicalutamide 50 mg once daily with flutamide 250 mg three times a day, each in combination with an LHRH analog, the following adverse reactions with an incidence of 5% or greater, regardless of causality, have been reported. Table 1 Incidence of Adverse Reactions (≥ 5% in Either Treatment Group) Regardless of Causality Body System Adverse Reaction Treatment Group Number of Patients (%) Bicalutamide Plus LHRH Analog (n=401) Flutamide Plus LHRH Analog (n=407) Body as a Whole Pain (General) 142 (35) 127 (31) Back Pain 102 (25) 105 (26) Asthenia 89 (22) 87 (21) Pelvic Pain 85 (21) 70 (17) Infection 71 (18) 57 (14) Abdominal Pain 46 (11) 46 (11) Chest Pain 34 (8) 34 (8) Headache 29 (7) 27 (7) Flu Syndrome 28 (7) 30 (7) Cardiovascular Hot Flashes 211 (53) 217 (53) Hypertension 34 (8) 29 (7) Digestive Constipation 87 (22) 69 (17) Nausea 62 (15) 58 (14) Diarrhea 49 (12) 107 (26) Increased Liver Enzyme Test 30 (7) 46 (11) Dyspepsia 30 (7) 23 (6) Flatulence 26 (6) 22 (5) Anorexia 25 (6) 29 (7) Vomiting 24 (6) 32 (8) Hemic and Lymphatic Anemia 45 (11) 53 (13) Metabolic and Nutritional Peripheral Edema 53 (13) 42 (10) Weight Loss 30 (7) 39 (10) Hyperglycemia 26 (6) 27 (7) Alkaline Phosphatase Increased 22 (5) 24 (6) Weight Gain 22 (5) 18 (4) Musculoskeletal Bone Pain 37 (9) 43 (11) Myasthenia 27 (7) 19 (5) Arthritis 21 (5) 29 (7) Pathological Fracture 17 (4) 32 (8) Nervous System Dizziness 41 (10) 35 (9) Paresthesia 31 (8) 40 (10) Insomnia 27 (7) 39 (10) Anxiety 20 (5) 9 (2) Depression 16 (4) 33 (8) Respiratory System Dyspnea 51 (13) 32 (8) Cough Increased 33 (8) 24 (6) Pharyngitis 32 (8) 23 (6) Bronchitis 24 (6) 22 (3) Pneumonia 18 (4) 19 (5) Rhinitis 15 (4) 22 (5) Skin and Appendages Rash 35 (9) 30 (7) Sweating 25 (6) 20 (5) Urogenital Nocturia 49 (12) 55 (14) Hematuria 48 (12) 26 (6) Urinary Tract Infection 35 (9) 36 (9) Gynecomastia 36 (9) 30 (7) Impotence 27 (7) 35 (9) Breast Pain 23 (6) 15 (4) Urinary Frequency 23 (6) 29 (7) Urinary Retention 20 (5) 14 (3) Urinary Impaired 19 (5) 15 (4) Urinary Incontinence 15 (4) 32 (8) Other adverse reactions (greater than or equal to 2%, but less than 5%) reported in the bicalutamide-LHRH analog treatment group are listed below by body system and are in order of decreasing frequency within each body system regardless of causality. Body as a Whole: Neoplasm; Neck Pain; Fever; Chills; Sepsis; Hernia; Cyst Cardiovascular: Angina Pectoris; Congestive Heart Failure; Myocardial Infarct; Heart Arrest; Coronary Artery Disorder; Syncope Digestive: Melena; Rectal Hemorrhage; Dry Mouth; Dysphagia; Gastrointestinal Disorder; Periodontal Abscess; Gastrointestinal Carcinoma Metabolic and Nutritional: Edema; BUN Increased; Creatinine Increased; Dehydration; Gout; Hypercholesteremia Musculoskeletal: Myalgia; Leg Cramps Nervous: Hypertonia; Confusion; Somnolence; Libido Decreased; Neuropathy; Nervousness Respiratory: Lung Disorder; Asthma; Epistaxis; Sinusitis Skin and Appendages: Dry Skin; Alopecia; Pruritus; Herpes Zoster; Skin Carcinoma; Skin Disorder Special Senses: Cataract Specified Urogenital: Dysuria; Urinary Urgency; Hydronephrosis; Urinary Tract Disorder Abnormal Laboratory Test Values: Laboratory abnormalities including: elevated AST, ALT, bilirubin, BUN, and creatinine; and decreased hemoglobin and white cell count, have been reported in both bicalutamide-LHRH analog treated and flutamide-LHRH analog treated patients. 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of bicalutamide. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Respiratory disorders: Interstitial lung disease (some fatal) including interstitial pneumonitis and pulmonary fibrosis, most often at doses greater than 50 mg. Hemorrhage: Increased PT/INR due to interaction between coumarin anticoagulants and bicalutamide. Serious bleeding

7 DRUG INTERACTIONS Clinical studies have not shown any drug interactions between bicalutamide and LHRH analogs (goserelin or leuprolide). There is no evidence that bicalutamide induces hepatic enzymes. In vitro studies have shown that R-bicalutamide is an inhibitor of CYP 3A4 with lesser inhibitory effects on CYP 2C9, 2C19 and 2D6 activity. Clinical studies have shown that with coadministration of bicalutamide, mean midazolam (a CYP 3A4 substrate) levels may be increased 1.5-fold (for C max ) and 1.9-fold (for AUC). Hence, caution should be exercised when bicalutamide is coadministered with CYP 3A4 substrates. In vitro protein-binding studies have shown that bicalutamide can displace coumarin anticoagulants from binding sites. PT/INR should be closely monitored in patients concomitantly receiving coumarin anticoagulants and bicalutamide. Adjustment of the anticoagulant dose may be necessary [see Warnings and Precautions (5.2) and Adverse Reactions (6.2)]. • R-bicalutamide is an inhibitor of CYP 3A4; therefore, caution should be used when bicalutamide is coadministered with CYP 3A4 substrates. (7) • PT/INR should be closely monitored in patients already receiving coumarin anticoagulants who are started on bicalutamide. (7)