Patient-Reported Outcomes in Clinical Trials Leading to Cancer Immunotherapy Drug Approvals From 2011 to 2018: A Systematic Review

Background Patient-reported outcomes (PROs) promote patient centeredness in clinical trials; however, in the field of rapidly emerging and clinically impressive immunotherapy, data on PROs are limited. Methods We systematically identified all immunotherapy approvals from 2011 through 2018 and assessed the analytic tools and reporting quality of associated PRO reports. For randomized clinical trials (RCTs), we developed a novel 24-point scoring scale: the PRO Endpoints Analysis Score based on 24 criteria derived from the recommendations of the Setting International Standards in Analyzing Patient-Reported Outcomes and Quality of Life Endpoints Data Consortium. Results We assessed 44 trial publications supporting 42 immunotherapy approvals. PROs were published for 21 of the 44 (47.7%) trial publications. Twenty-three trials (52.3%) were RCTs and 21 (47.7%) pertained to single-arm trials. The median time between primary clinical outcomes publications and their corresponding secondary PRO publications was 19 months (interquartile range = 9-29 months). Of the 21 PRO reports, 4 (19.0%) reported a specific hypothesis, and most (85.7%) used descriptive statistics. Three (3 of 21 [14.3%]) studies performed a control for type I error. As for RCTs, 14 of 23 (60.9%) published PRO data, including 13 (56.5%) that published a secondary dedicated manuscript. One-half of these 14 trials scored less than 13 points on the 24-point PRO Endpoints Analysis Score. The mean score was 12.71 (range = 5-17, SD = 3.71), and none met all the recommendations of the Setting International Standards in Analyzing Patient-Reported Outcomes and Quality of Life Endpoints Data Consortium. Conclusions Suboptimal reporting of PROs occurs regularly in cancer immunotherapy trials. Increased efforts are needed to maximize the value of these data in cancer immunotherapy development and approval.