Bicalutamide

No dosage adjustment is necessary for patients with renal impairment [see Use in Specific Populations (8.7)].

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)].

Bicalutamide tablets are contraindicated in any patient who has shown a hypersensitivity reaction to the drug or any of the tablet’s components. Hypersensitivity reactions including angioneurotic edema and urticaria have been reported [see Adverse Reactions (6.2)].

Bicalutamide tablets have no indication for women, and should not be used in this population.

Bicalutamide tablets may cause fetal harm when administered to a pregnant woman. Bicalutamide tablets are contraindicated in women, including those who are or may become pregnant. There are no studies in pregnant women using bicalutamide. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be appraised of the potential hazard to the fetus [see Use in Specific Populations (8.1)].

Rare cases of death or hospitalization due to severe liver injury have been reported postmarketing in association with the use of bicalutamide. Hepatotoxicity in these reports generally occurred within the first three to four months of treatment. Hepatitis or marked increases in liver enzymes leading to drug discontinuation occurred in approximately 1% of bicalutamide patients in controlled clinical trials.

Serum transaminase levels should be measured prior to starting treatment with bicalutamide, at regular intervals for the first four months of treatment, and periodically thereafter. If clinical symptoms or signs suggestive of liver dysfunction occur (e.g., nausea, vomiting, abdominal pain, fatigue, anorexia, “flu-like” symptoms, dark urine, jaundice, or right upper quadrant tenderness), the serum transaminases, in particular the serum ALT, should be measured immediately. If at any time a patient has jaundice, or their ALT rises above two times the upper limit of normal, bicalutamide should be immediately discontinued with close follow-up of liver function.

In clinical trials with bicalutamide 150 mg as a single agent for prostate cancer, gynecomastia and breast pain have been reported in up to 38% and 39% of patients, respectively.

A reduction in glucose tolerance has been observed in males receiving LHRH agonists. This may manifest as diabetes or loss of glycemic control in those with preexisting diabetes. Consideration should therefore be given to monitoring blood glucose in patients receiving bicalutamide in combination with LHRH agonists.

Regular assessments of serum Prostate Specific Antigen (PSA) may be helpful in monitoring the patient’s response. If PSA levels rise during bicalutamide therapy, the patient should be evaluated for clinical progression. For patients who have objective progression of disease together with an elevated PSA, a treatment-free period of antiandrogen, while continuing the LHRH analog, may be considered.

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 multicenter, 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.

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.

The following adverse reactions have been identified during postapproval 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.

Uncommon cases of hypersensitivity reactions, including angioneurotic edema and urticaria [see Contraindications (4.1)], and uncommon cases of interstitial lung disease, including interstitial pneumonitis and pulmonary fibrosis, have been reported with bicalutamide.

Reduction in glucose tolerance, manifesting as diabetes or a loss of glycemic control in those with preexisting diabetes, has been reported during treatment with LHRH agonists.

Bicalutamide is not indicated for use in women.

The safety and effectiveness of bicalutamide in pediatric patients have not been established.

Labeling describing pediatric clinical studies for bicalutamide is approved for AstraZeneca Pharmaceuticals LP’s bicalutamide tablet. However, due to AstraZeneca Pharmaceuticals LP’s marketing exclusivity rights, a description of those clinical studies is not approved for this bicalutamide labeling.

In two studies in patients given 50 or 150 mg daily, no significant relationship between age and steady-state levels of total bicalutamide or the active R-enantiomer has been shown.

Bicalutamide should be used with caution in patients with moderate-to-severe hepatic impairment. Bicalutamide is extensively metabolized by the liver. Limited data in subjects with severe hepatic impairment suggest that excretion of bicalutamide may be delayed and could lead to further accumulation. Periodic liver function tests should be considered for hepatic-impaired patients on long-term therapy [see Warnings and Precautions (5.1)].

No clinically significant difference in the pharmacokinetics of either enantiomer of bicalutamide was noted in patients with mild-to-moderate hepatic disease as compared to healthy controls. However, the half-life of the R-enantiomer was increased approximately 76% (5.9 and 10.4 days for normal and impaired patients, respectively) in patients with severe liver disease (n = 4).

Renal impairment (as measured by creatinine clearance) had no significant effect on the elimination of total bicalutamide or the active R-enantiomer.

Bicalutamide has not been studied in women.

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 luteinizing hormone-releasing hormone (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.

Absorption

Bicalutamide is well-absorbed following oral administration, although the absolute bioavailability is unknown. Coadministration of bicalutamide with food has no clinically significant effect on rate or extent of absorption.

Distribution

Bicalutamide is highly protein-bound (96%) [see Drug Interactions (7)].

Metabolism/Elimination

Bicalutamide undergoes stereospecific metabolism. The S (inactive) isomer is metabolized primarily by glucuronidation. The R (active) isomer also undergoes glucuronidation but is predominantly oxidized to an inactive metabolite followed by glucuronidation. Both the parent and metabolite glucuronides are eliminated in the urine and feces. The S-enantiomer is rapidly cleared relative to the R-enantiomer, with the R-enantiomer accounting for about 99% of total steady-state plasma levels.

Pharmacokinetics of the active enantiomer of bicalutamide in normal males and patients with prostate cancer are presented in Table 3.

Two-year oral carcinogenicity studies were conducted in both male and female rats and mice at doses of 5, 15 or 75 mg/kg/day of bicalutamide. A variety of tumor target organ effects were identified and were attributed to the antiandrogenicity of bicalutamide, namely, testicular benign interstitial (Leydig) cell tumors in male rats at all dose levels (the steady-state plasma concentration with the 5 mg/kg/day dose is approximately 2/3 human therapeutic concentrations^* ) and uterine adenocarcinoma in female rats at 75 mg/kg/day (approximately 1 1/2 times the human therapeutic concentrations^* ). There is no evidence of Leydig cell hyperplasia in patients; uterine tumors are not relevant to the indicated patient population.

A small increase in the incidence of hepatocellular carcinoma in male mice given 75 mg/kg/day of bicalutamide (approximately 4 times human therapeutic concentrations^* ) and an increased incidence of benign thyroid follicular cell adenomas in rats given 5 mg/kg/day (approximately 2/3 human therapeutic concentrations^* ) and above were recorded. These neoplastic changes were progressions of non-neoplastic changes related to hepatic enzyme induction observed in animal toxicity studies. Enzyme induction has not been observed following bicalutamide administration in man. There were no tumorigenic effects suggestive of genotoxic carcinogenesis.

A comprehensive battery of both in vitro and in vivo genotoxicity tests (yeast gene conversion, Ames, E. coli, CHO/HGPRT, human lymphocyte cytogenetic, mouse micronucleus, and rat bone marrow cytogenetic tests) has demonstrated that bicalutamide does not have genotoxic activity.

Administration of bicalutamide may lead to inhibition of spermatogenesis. The long-term effects of bicalutamide on male fertility have not been studied.

In male rats dosed at 250 mg/kg/day (approximately 2 times human therapeutic concentrations^* ), the precoital interval and time to successful mating were increased in the first pairing but no effects on fertility following successful mating were seen. These effects were reversed by 7 weeks after the end of an 11 week period of dosing.

No effects on female rats dosed at 10, 50 and 250 mg/kg/day (approximately 2/3, 1 and 2 times human therapeutic concentrations, respectively^* ) or their female offspring were observed. Administration of bicalutamide to pregnant females resulted in feminization of the male offspring leading to hypospadias at all dose levels. Affected male offspring were also impotent.

In a multicenter, double-blind, controlled clinical trial, 813 patients with previously untreated advanced prostate cancer were randomized to receive bicalutamide 50 mg once daily (404 patients) or flutamide 250 mg (409 patients) three times a day, each in combination with LHRH analogs (either goserelin acetate implant or leuprolide acetate depot).

In an analysis conducted after a median follow-up of 160 weeks was reached, 213 (52.7%) patients treated with bicalutamide-LHRH analog therapy and 235 (57.5%) patients treated with flutamide-LHRH analog therapy had died. There was no significant difference in survival between treatment groups (see Figure 1). The hazard ratio for time to death (survival) was 0.87 (95% confidence interval 0.72 to 1.05).

There was no significant difference in time to objective tumor progression between treatment groups (see Figure 2). Objective tumor progression was defined as the appearance of any bone metastases or the worsening of any existing bone metastases on bone scan attributable to metastatic disease, or an increase by 25% or more of any existing measurable extraskeletal metastases. The hazard ratio for time to progression of bicalutamide plus LHRH analog to that of flutamide plus LHRH analog was 0.93 (95% confidence interval, 0.79 to 1.10).

Quality of life was assessed with self-administered patient questionnaires on pain, social functioning, emotional well being, vitality, activity limitation, bed disability, overall health, physical capacity, general symptoms, and treatment related symptoms. Assessment of the Quality of Life questionnaires did not indicate consistent significant differences between the two treatment groups.

Bicalutamide 150 mg is not approved for use either alone or with other treatments.

Two identical multicenter, randomized, open-label trials comparing bicalutamide 150 mg daily monotherapy to castration were conducted in patients that had locally advanced (T3-4, NX, MO) or metastatic (M1) prostate cancer.

Monotherapy — M1 Group

Bicalutamide 150 mg daily is not approved for use in patients with M1 cancer of the prostate. Based on an interim analysis of the two trials for survival, the Data Safety Monitoring Board recommended that bicalutamide treatment be discontinued in the M1 patients because the risk of death was 25% (HR 1.25, 95% CI 0.87 to 1.81) and 31% (HR 1.31, 95% CI 0.97 to 1.77) higher in the bicalutamide treated group compared to that in the castrated group, respectively.

Locally Advanced (T3-4, NX, MO) Group

Bicalutamide 150 mg daily is not approved for use in patients with locally advanced (T3-4, NX, MO) cancer of the prostate. Following discontinuation of all M1 patients, the trials continued with the T3-4, NX, MO patients until study completion. In the larger trial (N = 352), the risk of death was 25% (HR 1.25, 95% CI 0.92 to 1.71) higher in the bicalutamide group and in the smaller trial (N = 140), the risk of death was 36% (HR 0.64, 95% CI, 0.39 to 1.03) lower in the bicalutamide group.

In addition to the above two studies, there are three other on-going clinical studies that provide additional safety information for bicalutamide 150 mg, a dose that is not approved for use. These are three multicenter, randomized, double-blind, parallel group trials comparing bicalutamide 150 mg daily monotherapy (adjuvant to previous therapy or under watchful waiting) with placebo, for death or time to disease progression, in a population of 8113 patients with localized or locally advanced prostate cancer.

Bicalutamide 150 mg daily is not approved for use as therapy for patients with localized prostate cancer who are candidates for watchful waiting. Data from a planned subgroup analysis of two of these trials in 1627 patients with localized prostate cancer who were under watchful waiting, revealed a trend toward decreased survival in the bicalutamide arm after a median follow-up of 7.4 years. There were 294 (37.7%) deaths in the bicalutamide treated patients versus 279 (32.9%) deaths in the placebo treated patients (localized watchful waiting group) for a hazard ratio of 1.16 (95% CI 0.99 to 1.37).

Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature].

Dispense in a tight, light-resistant container as defined in the USP, with a child-resistant closure (as required).

BICALUTAMIDE

Tablets USP

50 mg

PHARMACIST: PLEASE DISPENSE WITH

ATTACHED PATIENT INFORMATION

LEAFLET

Rx only