Analysis of the PREVAIL Trial showed that Enzalutamide (Xtandi) significantly increased overall survival and radiographic progression-free survival compared with placebo in men with prostate cancer who were asymptomatic and minimally symptomatic, chemotherapy-naive and who had metastatic castration-resistant prostate cancer (mCRPC).

Now, an additional analysis of the data has shown the effect enzalutamide also has on health-related quality of life (HRQoL). These criteria include pain and skeletal-related events experienced during the trial.

The researchers utilized the Functional Assessment of Cancer Therapy-Prostate (FACT-P) and EQ-5D questionnaires to measure the participant’s reported HRQoL. Measurements were taken at baseline and during treatment. Pain status was also assessed at screening, baseline, week 13, and week 25 with the Brief Pain Inventory Short Form (BPI-SF).

Progression of pain at its worst was less common in the enzalutamide group than in the placebo group at week 13, but not at week 25.

However, in addition to improving overall survival relative to placebo, enzalutamide significantly improved patient-related outcomes and delayed the occurrence of first skeletal-related event in chemotherapy-naive men with metastatic castration-resistant prostate cancer.

 This trial, as well as the additional analysis was funded by Astellas Pharma and Medivation. In completely understanding research results it is always important to keep in mind that it is possible that funding might influence data collection and analysis. Do not misunderstand, I am not saying that the data from this study is not correct, but we must always bring a slightly cynical eye to the table.

Lancet Oncology; 2015 May;16(5):509-21. doi: 10.1016/S1470-2045(15)70113-0. Epub 2015 Apr 14. Loroit Y, Miller K, Sternberg C, etal.

Joel T. Nowak, M.A., M.S.W.