A Phase II Study of Increased-Dose Abiraterone Acetate in Patients With Castration Resistant Prostate Cancer

This is an interventional treatment trial for Castration Resistant Prostate Cancer focused on measuring CRPC, Prostate, Cancer Read More

Inclusion Criteria:

• Have signed an informed consent document indicating that the subjects understands the purpose of and procedures required for the study and are willing to participate in the study
• Be willing/able to adhere to the prohibitions and restrictions specified in this protocol
• Written Authorization for Use and Release of Health and Research Study Information has been obtained
• Male aged 18 years and above
• Able to swallow the study drug whole as a tablet
• Willing to take abiraterone acetate on an empty stomach; no food should be consumed at least two hours before and for at least one hour after the dose of abiraterone acetate is taken
• Patients who have partners of childbearing potential must be willing to use a method of birth control with adequate barrier protection as determined to be acceptable by the principal investigator and sponsor during the study and for 1 week after last study drug administration.
• Have a baseline serum potassium of ≥ 3.5 milliequivalents per litre (mEq/L)
• Have aspartate aminotransferase (AST), alanine aminotransferase (ALT), and bilirubin levels < 1.5 x upper limit of normal (ULN)
• Have a serum albumin of ≥ 3.0 g/dL
• Total bilirubin ≤ 1.5 x ULN (In patients with known Gilbert Syndrome, a total bilirubin ≤ 3.0 x ULN, with direct bilirubin ≤ 1.5 x ULN is acceptable)
• Have a platelet count of ≥ 100,000/μL
• Have an absolute neutrophil count of > 1500 cell/mm3
• Have a calculated creatinine clearance ≥ 60 mL/min
• Have a hemoglobin of ≥ 9.0 g/dL
• Have histologically confirmed adenocarcinoma of the prostate.
• No prior therapy with chemotherapy for metastatic prostate cancer.
• Have metastatic disease based on a positive bone scan or objective imaging on CT scan.
• Have ongoing gonadal androgen deprivation therapy with Luteinizing hormone-releasing hormone (LHRH) analogues or orchiectomy. Patients who have not had an orchiectomy must be maintained on effective LHRH analogue therapy for the duration of the trial.
• Testosterone < 50 ng/dL.
• Progressive disease after androgen deprivation: PSA evidence for progressive prostate cancer consists of a PSA level of at least 2 ng/ml which has risen on at least 2 successive occasions, at least 2 weeks apart. If the confirmatory PSA value is less than the screening PSA value, then an additional test for rising PSA will be required to document progression.
• Antiandrogen Withdrawal (AAWD): Patients who are receiving an antiandrogen as part of primary androgen ablation must demonstrate disease progression following discontinuation of antiandrogen.
• Disease progression after antiandrogen withdrawal is defined as 2 consecutive rising PSA values, obtained at least 2 weeks apart, or documented osseous or soft tissue progression.
• For patients receiving flutamide, at least one of the PSA values must be obtained 4 weeks or more after flutamide discontinuation.
• For patients receiving bicalutamide or nilutamide, at least one of the PSA values must be obtained 6 weeks or more after antiandrogen discontinuation.
• No antiandrogen withdrawal response is expected in patients in whom antiandrogen therapy did NOT result in a decline in PSA or in those patients in whom the response to antiandrogens was < 3 months. Therefore, it is not necessary to wait for AAWD in patients without PSA decline on an anti-androgen or in those in whom a PSA response lasted < 3 months.
• Eastern Cooperative Oncology Group (ECOG) Performance Status 0-1
• Life expectancy of ≥ 12 weeks.

Exclusion Criteria:

• Active infection or other medical condition that would make prednisone/prednisolone (corticosteroid) use contraindicated
• Known brain metastasis
• Uncontrolled hypertension (systolic BP ≥ 160 mmHg or diastolic BP ≥ 95 mmHg) Patients with a history of hypertension are allowed provided blood pressure is controlled by anti-hypertensive treatment
• Active or symptomatic viral hepatitis or chronic liver disease
• History of pituitary or adrenal dysfunction
• Clinically significant heart disease as evidenced by myocardial infarction, or arterial thrombotic events in the past 6 months, severe or unstable angina, or New York Heart Association (NYHA) Class II-IV heart disease or cardiac ejection fraction measurement of < 50 % at baseline
• Atrial Fibrillation, or other cardiac arrhythmia requiring medical therapy
• Administration of an investigational therapeutic within 30 days of screening
• Have poorly controlled diabetes
• Have a history of gastrointestinal disorders (medical disorders or extensive surgery) that may interfere with the absorption of the study agents
• Have a pre-existing condition that warrants long-term corticosteroid use in excess of study dose
• Have known allergies, hypersensitivity, or intolerance to abiraterone acetate or prednisone or their excipients
• Any condition which, in the opinion of the investigator, would preclude participation in this trial.
• Pure small cell carcinoma of the prostate or any mixed histology cancer of the prostate (eg: neuroendocrine) which contains < 50% adenocarcinoma.
• Therapy with other hormonal therapy, including any dose of megestrol acetate (Megace), finasteride (Proscar), dutasteride (Avodart) any herbal product known to decrease PSA levels (e.g., Saw Palmetto and PC-SPES), or any systemic corticosteroid within 4 weeks prior to first dose of study drug.
• Prior therapy with Abiraterone Acetate or other CYP17 inhibitor(s) including TAK-700 or TOK-001, or investigational agent(s) targeting the androgen receptor for metastatic prostate cancer.
• Prior therapy with ketoconazole for > 2 weeks for prostate cancer.
• Therapy with supplements or complementary medicines/botanicals within 4 weeks of first dose of study drug, except for any combination of the following:
• Conventional multivitamin supplements
• Selenium
• Lycopene
• Soy supplements
• Prior radiation therapy completed < 4 weeks prior to enrollment
• Prior chemotherapy for castration resistant prostate cancer. Patients who have received chemotherapy for early stage prostate cancer (e.g. as part of a neoadjuvant or adjuvant trial) or for other malignancies are eligible provided that >1 year has passed since the administration of the last chemotherapy dose.
• Any "currently active" second malignancy, other than non-melanoma skin cancer. Patients are not considered to have a "currently active" malignancy, if they have completed therapy and are considered by their physician to be at least less than 30% risk of relapse over next year.
• Active psychiatric illnesses/social situations that would limit compliance with protocol requirements.
• Patients in whom urgent chemotherapy, in the opinion of the treating physician, is indicated should not be enrolled in this study.