Olaparib Monotherapy or in Combination with Abiraterone for the Treatment of Patients with Metastatic Castration-Resistant Prostate Cancer (mCRPC) and a BRCA Mutation

Authored by Neal Shore, published on 2026-05-08 21:26:19.0

The algorithm is broadly aligned with current mCRPC practice in emphasizing PARP inhibition for BRCA1/2-altered disease and continuing therapy until progression/toxicity. The olaparib monotherapy pathway for BRCA-mutated mCRPC after ARPI (and post-taxane) is well supported by pivotal randomized evidence and incorporated into major guidelines. The preference for olaparib+abiraterone in BRCA-mutated mCRPC without prior taxane is directionally consistent with emerging/updated evidence for PARP+AR pathway combinations, but guideline positioning and regulatory labeling vary by region and biomarker definition (BRCA vs broader HRR) and should be verified locally.

  1. Treatment Algorithm for mCRPC with a BRCA Mutation
    Germline and/or Somatic Assess germline and somatic BRCA1/2 status Ensure continued ADT Consider bone health, symptom control, and supportive care throughout treatment
    • Patient Population
      Men with metastatic castration-resistant prostate cancer (mCRPC) and a BRCA1 or BRCA2 mutation
      • Prior Androgen Receptor Pathway Inhibitor (ARPI) in mCRPC?
        Abiraterone, enzalutamide, apalutamide, or darolutamide
        • No Prior ARPI in mCRPC
          Evidence: PROpel (Phase III) Olaparib + abiraterone vs abiraterone improved radiographic progression-free survival.
          • Recommended Approach
            Olaparib + abiraterone (with prednisone/prednisolone)
            • Assess Response and Tolerability
              Monitor PSA, imaging, symptoms, and adverse events
              • Continue
                Olaparib + abiraterone
              • Discontinue Current Regimen
                Consider alternative options (e.g., docetaxel, clinical trial, or other appropriate therapy)
        • Prior ARPI in mCRPC
          Progressed after prior abiraterone, enzalutamide, apalutamide, or darolutamide. Evidence: PROfound (Phase III) Olaparib monotherapy vs physician’s choice improved radiographic progression-free survival.
          • Recommended Approach
            Olaparib monotherapy
            • Assess Response and Tolerability
              Monitor PSA, imaging, symptoms, and adverse events
              • Continue
                Olaparib monotherapy
              • Discontinue Current Regimen
                Consider alternative options (e.g., docetaxel, clinical trial, or other appropriate therapy)
  2. Key Principles from the Study
    For men with mCRPC and a BRCA mutation who have NOT received prior ARPI in mCRPC, olaparib + abiraterone significantly improves radiographic progression–free survival compared with abiraterone alone. (PROpel: HR 0.53; p < 0.0001) In patients who have received prior ARPI in mCRPC, olaparib monotherapy is recommended after progression. (PROfound: HR 0.54 vs physician’s choice; p < 0.0001) Continue therapy until disease progression or unacceptable toxicity. Manage adverse events proactively and consider dose modifications as needed. Taxane exposure is not the primary decision point for PARP inhibitor sequencing in this algorithm, but may inform overall treatment planning and prognosis. Shared decision-making and individualization based on patient comorbidities, prior therapies, and preference are essential.
tosprivacyOlaparib Monotherapy or in Combination with Abiraterone for the Treatment of Patients with Metastatic Castration-Resistant Prostate Cancer (mCRPC) and a BRCA Mutation