Evaluating the clinical benefits of anti-cancer drugs approved by Food and Drug Administration for gastrointestinal neoplasms for the past two decades.

820 Background: The number of FDA-approved anticancer drugs have increased in recent years with a more use of surrogate endpoints. However, it is unclear whether the same trend applies to GI cancers. Therefore, we aimed to evaluate the trend in FDA-approved GI cancer drugs over the past two decades and the associated clinical benefit. Methods: The FDA’s online database was searched for drugs approved for GI cancers from 2006 until 2024. Primary and secondary endpoints along with trial characteristics were extracted. ESMO Magnitude of Clinical Benefit Scale (ESMO-MCBS) was assessed by two blinded investigators with a third resolving disagreements. We divided the study into period A (01/2006-12/2014) and period B (01/2015-08/2024). Results: Since 2006, FDA approved 62 regimens for GI cancer based on 70 trials, mostly (n= 45;72.6%) in period B. Most trials (n=44) were phase III with only 26 phase II: 22 single arm, and 4 randomized. All the 22 single-arm phase II trials were approved in period B with two randomized phase II trials approved in each period. Approvals based on phase III trials dropped by 33.5% (from n=15 to n=29) between the two periods. Half (n=34) of the approvals were based on overall survival (OS) benefit, while the use of objective response rate (ORR) as an endpoint has increased from 11.8% (n=2) in period A to 45.3% (n=24) in period B. Quality of life (QoL) was assessed only in 27% of the studies and found benefit only in 22.7%. The mean gain in OS was similar across both periods; 2.3 months [1.2-4.7]. Out of the 19 accelerated approvals, 17 were in period B, of which 23% (4/17) were based on secondary endpoint, 18% (3/17) were withdrawn, and 59% (10/17) received full approval. Substantial clinical benefit (ESMO score 4-5) was seen in 11.8% of the trials in period A and 19.6% in period B, with 17.4% overall from 2006-2024. Conclusions: Despite rising FDA approvals for GI cancer drugs since 2006, only 17.4% demonstrated substantial clinical benefit based on ESMO-MCBS. Recent approvals rely more on single-arm phase II studies and ORR, often without OS or QoL benefit. These trends underscore the need for more rigorous clinical trials that prioritize meaningful endpoint to ensure that new therapies provide real clinical value to the patient.