The US Food and Drug Administration (FDA) has approved the combination treatment of olaparib with abiraterone and prednisone for patients with BRCA-mutated metastatic castration-resistant prostate cancer (BRCAm).
The combination showed strong efficacy in patients enrolled in the PROpel trial, which analyzed radiological progression-free survival (rPFS) as well as overall survival (OS) of the treatment.
A significant improvement in rPFS was seen in the intent-to-treat (ITT) population that received olaparib with abiraterone compared with placebo with abiraterone. An exploratory subgroup analysis of patients with BRCAm demonstrated a median rPFS that was not reached in the olaparib with abiraterone arm compared with 8 months for patients who received placebo with abiraterone.
The OS hazard ratio (HR) in these patients was 0.30; in the patient group without BRCAm, the rPFS HR was 0.77 and the OS HR was 0.92, suggesting that the improvement in rPFS observed in the ITT population was mainly attributable to patients with BRCAm.
The most common (≥10%) adverse reactions in patients receiving olaparib plus abiraterone included anemia, fatigue, nausea, diarrhea, decreased appetite, and lymphopenia.
Patients administered olaparib are recommended to take 300 mg orally twice daily with or without food. The recommended abiraterone dose is 1000 mg taken orally once daily. Abiraterone should be administered with prednisone or prednisolone 5 mg orally twice daily. Patients should also receive a GnRH analog concurrently or should have had a prior bilateral orchiectomy.
