Evaluating the effects of olaparib plus abiraterone regarding patient-reported outcomes in patients with metastatic castration-resistant prostate cancer patients

This study compared the effects on patient-reported outcomes (PROs) of using olaparib (Lynparza) plus abiraterone (Zytiga) versus placebo plus abiraterone for the treatment of metastatic castration-resistant prostate cancer (mCRPC). The study found that adding olaparib to abiraterone in these patients did not significantly impact patient-reported pain and health-related quality of life (HRQOL) compared to abiraterone alone (plus placebo).

mCRPC is a type of prostate cancer that keeps spreading and growing even when the amount of testosterone in the body is cut down to very low levels. One treatment used for patients with mCRPC is abiraterone. This drug blocks the formation of testosterone. Although this treatment has proven effective, over time many patients develop resistance and need further treatments.

Olaparib is a targeted therapy called a PARP inhibitor. PARP is a protein that helps damaged cells repair themselves. Some types of cancer cells use the PARP protein to repair themselves and continue multiplying and spreading. Olaparib stops this, therefore, stopping cancer growth and spread. It has been shown that adding olaparib to abiraterone treatment improves the survival without cancer growing or spreading in men with mCRPC. However, adding another drug may add side effects and reduce the HRQOL of patients. It is important to evaluate whether adding olaparib to abiraterone therapy has an impact on HRQOL in patients with mCRPC. 

The study included 142 patients with mCRPC. They were randomly split into two equal groups. Group 1 received olaparib and abiraterone, and they were followed up for 15.9 months. Group 2 received a placebo and abiraterone, and they were followed up for  24.5 months. Both groups were also given oral prednisolone (Orapred; a steroid drug) as part of their treatment. Patients were asked to fill out questionnaires regarding their levels of bone pain and overall quality of life (QOL).

Overall, the pain remained stable for both groups at all follow-up visits. Time to worsening of pain was also similar between groups. Until the 48th week, the rates of pain and discomfort were getting better at the same rate between groups. After 48 weeks, more patients in the olaparib plus abiraterone group reported an improvement in pain levels compared to those in the placebo plus abiraterone group.

The study found that the combination of olaparib and abiraterone did not impact pain and HRQOL in patients with mCRPC compared to placebo and abiraterone. 

The study population and the study period were very small. Larger studies are needed to validate the findings. The study was funded by AstraZeneca, the manufacturer of olaparib.