Oncology clinical trial termination trends: Analysis across the prior 20 years.

e13602 Background: Terminations of oncology clinical trials are an unavoidable potential outcome when novel anti-cancer therapeutics are evaluated, yet are a significant burden on cancer patients, institutions, regulators and the industry as a whole. Overall, approximately 1 in 5 trials are terminated – the four main reasons are poor enrollment (PE), business decisions, lack of efficacy, and toxicity. The objective of our study is to describe trends in trial terminations. Methods: We searched Citeline® Trialtrove database for oncology, phase 1-3, industry sponsored trials, started 1Jan2000-31Dec2019 listed as completed or terminated. Data collection was performed in Jan2022. For analysis purposes, they were grouped based on start year into four 5-year periods: I-2000-2004, II-2005-2009, III-2010-2014, IV-2015-2019. Undetermined phase, phase 4 and non-oncology trials were excluded. Parameters collected: phase, reason for termination (more than one could be listed), sponsor (academic involvement; Top20 pharma as determined by Scrip 100 annually). Results: A total of 21,125 trials met search criteria, of which 4,596 (22%) were indicated as terminated. Termination rate increased from period I to II (17% to 24%) and remained at a steady 22% in periods III, IV. When evaluating the rate of termination according to phase, over periods I-II-III-IV we observed an increase in the rate of termination of phase 1/2 trials - 10%, 17%, 19% and 20% respectively. Across other phases, the change in termination rates was similar to change in their proportional representation per period. In terms of reason for termination, PE remained a major reason overall, 1275 trials (28%) were terminated due to poor enrollment with a low rate of 13% in period I, followed by 37%, 29%, 21% in periods II, III, IV. Of the trials that were terminated due to PE, 51% had academic, and 73% had Top20 involvement. This is a higher representation that their respective involvement in trials. Conclusions: According to the results of our analysis, the proportion of oncology industry-sponsored terminated trials remained high over the last 20 years, with early phases (1, 1/2 & 2) being the most affected. PE accounted for almost 1/3 of the overall terminations, with a possible trend of decrease. In terms sponsor type, there appeared to be a higher number of trials terminated due to PE with Top20, and with academic involvement, compared to their representation in the overall numbers. It is yet to be determined whether innovation in oncology early phase drug development, such as biomarker driven trials and seamless phase transitions will impact termination rates. Further analysis is ongoing focusing on early phase oncology trials.[Table: see text]