Exemestane With or Without Bicalutamide in Treating Patients With Stage IV Prostate Cancer

OBJECTIVES:

• Compare the efficacy and tolerability of exemestane with or without bicalutamide as second-line therapy after failure of androgen suppression (luteinizing hormone-releasing hormone agonist or orchiectomy) in patients with stage IV prostate cancer.
• Determine the potential antagonistic effect of the weak androgen action of exemestane when combined with bicalutamide in these patients.
• Compare the quality of life (QOL) in patients treated with these regimens.
• Correlate prostate-specific antigen response and data of QOL, including scores for pain intensity and analgesic consumption, in patients treated with these regimens.

OUTLINE: This is a randomized, multicenter study. Patients are stratified according to performance status (0 vs 1-2), pain (none or mild vs moderate or severe), and participating center. Patients are randomized to 1 of 2 treatment arms.

• Arm I: Patients receive oral exemestane once daily.
• Arm II: Patients receive exemestane as in arm I and oral bicalutamide once daily.

Treatment in both arms continues every 4 weeks for a minimum of 2 courses in the absence of disease progression or unacceptable toxicity.

Quality of life and pain are assessed at baseline, on day 1 of course 2 and any subsequent courses, and at disease progression or treatment failure (if applicable).

Patients are followed monthly until disease progression.

PROJECTED ACCRUAL: A total of 20-62 patients (10-31 per treatment arm) will be accrued for this study.

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed stage IV adenocarcinoma of the prostate
• Documented disease progression based on prostate-specific antigen (PSA) progression during first-line androgen suppression (luteinizing hormone-releasing hormone agonist or orchiectomy)

• PSA progression is defined by the following:

• Interval of at least 1 week between reference value (time point value 1) and the next PSA level (time point value 2)
• PSA at time point value 3 is greater than PSA at time point value 2 OR
• PSA at time point value 3 is not greater than PSA at time point value 2, but PSA at time point value 4 is greater than PSA at time point value 2
• PSA at least 5 ng/mL
• Must continue primary androgen suppression if no prior surgical castration
• No known leptomeningeal or brain metastases

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• WHO 0-2

Life expectancy:

• Not specified

Hematopoietic:

• WBC at least 3,500/mm^3
• Neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3
• Hemoglobin at least 9 g/dL

Hepatic:

• Bilirubin no greater than 1.5 times upper limit of normal (ULN)
• AST and ALT no greater than 2.5 times ULN

Renal:

• Creatinine no greater than 1.5 times ULN

Other:

• No acute concurrent severe infection
• No other concurrent significant disease that would preclude study therapy
• No other malignancy within the past 5 years except curatively treated basal cell or squamous cell skin cancer

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No prior antibody or gene therapy

Chemotherapy:

• No prior cytostatic agents

Endocrine therapy:

• See Disease Characteristics
• No prior estramustine
• No prior antiandrogens (e.g., bicalutamide)
• No concurrent estrogen-containing medicine

Radiotherapy:

• More than 4 weeks since prior radiotherapy
• No concurrent radiotherapy to more than 1 field

Surgery:

• See Disease Characteristics

Other:

• At least 4 weeks since prior investigational drugs