Tolerability of Olaparib Combined with Abiraterone in Patients with Metastatic Castration-resistant Prostate Cancer:...

Area of Science:

• Oncology
• Pharmacology

Background:

• The PROpel study previously demonstrated a progression-free survival benefit for olaparib plus abiraterone in first-line metastatic castration-resistant prostate cancer (mCRPC).
• This benefit was observed irrespective of homologous recombination repair mutation status.

Purpose of the Study:

• To conduct additional safety analyses from the PROpel study.
• To enhance the clinical understanding of adverse event (AE) profiles for olaparib plus abiraterone versus placebo plus abiraterone.

Main Methods:

• A randomized, double-blind, placebo-controlled trial involving 126 centers in 17 countries.
• Patients with mCRPC and no prior systemic treatment received olaparib or placebo combined with abiraterone and prednisone/prednisolone.
• Safety was assessed via AE reporting using Common Terminology Criteria for Adverse Events v4.03 and analyzed descriptively.

Main Results:

• Common adverse events (all grades) for olaparib plus abiraterone included anemia (46.0%), nausea (28.1%), and fatigue (27.9%).
• Grade ≥3 anemia occurred in 15.1% of patients on olaparib plus abiraterone versus 3.3% on placebo.
• Venous thromboembolism events, particularly pulmonary embolism, were more frequent in the olaparib plus abiraterone arm (7.3% vs 3.3%).

Conclusions:

• Olaparib plus abiraterone demonstrates a manageable and predictable safety profile in the first-line mCRPC setting.
• Most common adverse events associated with olaparib plus abiraterone were manageable through dose modifications or standard medical care.
• Treatment discontinuation due to adverse events was higher in the olaparib plus abiraterone arm (13.8% vs 7.8%).