This is an unblinded, randomized clinical study comparing the efficacy of DNA damaging chemotherapy using carboplatin, to standard of care therapy for patients who have metastatic castrate resistant prostate cancer. This trial will use olaparib or carboplatin as initial therapy with crossover to the alternate or second-line drug after first progression for patients with tumors containing BARD1, BRCA1, BRCA2, BRIP1, CHEK1, FANCL, PALB2, RAD51B, RAD51C, RAD51D, or RAD54L inactivating mutations.
Participants are randomized (1:1) and receive either carboplatin (AUC 5, IV) every 21 days, first or olaparib taken orally (300 mg), twice daily in 28 day cycles, until intolerance, complete response, or progression by Prostate Cancer Working Group 3 (PCWG3) criteria.
Participants then crossover from the first-line therapy to the second-line therapy with the opposite study medication and receive treatment to intolerance or progression (whichever is first). Enrolled participants will be allowed to crossover to second line therapy if they continue to meet initial eligibility criteria, and at least three weeks have elapsed since last administration of either carboplatin or olaparib. Throughout the study, safety and tolerability will be assessed. Progression will be evaluated with bone scan, CT of the abdomen/pelvis, or MRI and PSA as per PCWG3 criteria.
Signed study informed consent form (ICF) and HIPAA authorization form
Male age > 18 years
Diagnosis of prostate cancer (pure small-cell histology or pure high-grade neuroendocrine histology are excluded; neuroendocrine differentiation is allowed)
Ongoing gonadal androgen deprivation therapy with gonadotropin-releasing hormone (GnRH) analogues, antagonists or orchiectomy. Patients who have not had an orchiectomy must be maintained on effective GnRH analogue/antagonist therapy
Currently receiving active therapy for other neoplastic disorder(s)
Concurrent enrollment in another clinical investigational drug or device study
Histologic evidence of small cell carcinoma (morphology alone - immunohistochemical evidence of neuroendocrine differentiation without morphologic evidence is not exclusionary)
Prior treatment with platinum, mitoxantrone or PARP inhibitor for castration resistant prostate cancer