Delays in the Publication of Important Clinical Trial Findings in Oncology.

Importance: The complete and timely dissemination of clinical trial data is essential to all fields of medicine, with delayed or incomplete data release having potentially deleterious effects on both patient care and scientific inquiry. While prior analyses have noted a substantial lag in the reporting of final clinical study results, we sought to refine these observations through use of a novel starting point for the measurement of dissemination delays: the date of a corporate press release regarding a phase 3 study's results.

Objective: To measure the length of time elapsed between when a sponsor had results of study findings they deemed important to announce, and when the medical community had access to them.

Design and Setting: Covering the years 2011 through 2016, we measured the delay from when 8 large pharmaceutical companies issued a press release announcing completed analyses of phase 3 clinical trials in oncology, and the public sharing of those results either on ClinicalTrials.gov or in a peer-reviewed biomedical journal as found via PubMed or Google Scholar. Press releases announcing regulatory steps and presentation schedules for conferences were excluded, as were those announcing results from preclinical trials, follow-up analyses, and studies of supportive care therapies or various modes of infusion for the same therapy.

Main Outcomes and Measures: Time to public dissemination of clinical trial data.

Results: Of the 100 press releases in our sample, 70 (70%) reported positive results, but only 31 (31%) included the magnitude of study findings. Through the end of follow-up, 99 (99%) of press releases had an associated peer-reviewed publication, complete data posting to ClinicalTrials.gov, or both, with a median time to reporting of 300 days (95% CI, 263-348 days). Positive findings were reported more quickly than negative ones (median of 272; 95% CI, 211-318 days vs 407; 95% CI, 298-705 days; log-rank P < .001).

Conclusions and Relevance: Even for the most pressing study findings, median publication delays approach 1 year. As publication delays hinder research progress and advancements in clinical care, policies that enable early preprint release or public posting of completed data analysis should be pursued.