REGN2810 Followed by Chemoimmunotherapy for Newly Metastatic Hormone-sensitive Prostate Cancer

The slow progress for notable trials in metastatic, hormone-sensitive disease is attributed to the long duration of follow-up required, as well as the focus on time-to-event end points, i.e. overall survival, in clinical trial design. These landmark trials (CHAARTED, STAMPEDE, LATITUDE), which used overall survival as their endpoints, required, on average, 10 years from start of trial to first peer-reviewed publication. Given the challenge of using traditional measures of response (RECIST criteria) when designing prostate cancer clinical trials, the Prostate Cancer Working group 2 (PCWG2) made trial-design recommendations. One was to separate treatment outcomes into early measures of response and later time-to-event measures of progression. The goal is to shift the trial objective to capture and reflect the actual effect of the tested treatment and, in doing so, provide a more timely drug development milieu for the metastatic patient. These early measure of response end points, such as undetectable PSA with testosterone recovery, are now being actively integrated into clinical trial design.