Press releases of industry-sponsored clinical trials in oncology: Characteristics, timing and financial impact

Background: Press releases (PRs) anticipate the results of a clinical trial, possibly without providing detailed data. The purpose of this analysis was to describe the characteristics of PRs in oncology, delays in the availability of results and the impact on the financial market. Materials and methods: PRs published between 2018 and 2022 about solid tumors, archived on the websites of the top 20 oncology pharmaceutical companies, were screened. Information about PR content, time between PRs and scientific meeting, paper publication and approval by regulatory agencies were collected. Market reactions on the event days of the PRs were examined. Results: Out of 159 PRs, 157 were eligible. The most represented tumor was lung cancer (28 %). In most cases (117, 74.5 %), PRs announced that the study met its primary endpoint. Among these, 13 % of PRs included specific results, while the remaining 102 (87 %) contained only generic sentences. 85 % of PRs contained sentences supporting the clinical relevance of the results. Median time from PR to meeting presentation and full paper publication was 3.1 and 8 months, respectively. After a median follow-up of 48 months, 79 % were approved by FDA and 74 % by EMA. Median time from PR to approval by FDA and EMA was 10 and 15.9 months, respectively. Most events analyzed showed no statistically significant market reactions, with abnormal returns generally neutral or slightly positive. Conclusions: Most PRs announce firstly the positivity of a clinical trial, without detailed results. The market appears to absorb this information with minimal stock price adjustments.