Real-world data on efficacy and safety of trifluridine-tipiracil and bevacizumabin refractory metastatic colorectal cancer.

e15583 Background: Metastatic colorectal cancer (mCRC) has undergone significant improvements in its treatment, with new agents that have increased overall survival. Despite these advances, the development of resistance limits its efficacy. The combination of trifluridine/tipiracil with bevacizumab (TAS-Bev) is presented as a promising alternative, showing efficacy data in its phase 3 SUNLIGHT study (overall survival (OS) 10.8 vs. 7.5m, progression-free survival (PFS) 5.6 vs. 2.4), which places this combination as a choice for refractory patients, treated in third line or higher and without molecular selection, providing a very favorable toxicity profile. The aim of our study is to evaluate the efficacy and safety of TAS-Bev in real life in patients treated in our setting. Methods: This is a descriptive and observational study conducted in patients with advanced CRC who received TAS-Bev in third or successive lines every 28 days until toxicity or disease progression (PE), from 2021 to 2024 in the area of Huelva (Spain). SPSS Statistics 22 was used for data analysis. Results: 26 patients (Pts) were treated, median age 68 years and 64% male. ECOG PS 0-1 in 64%. According to tumor location 64% on the left side, 20% on the right and 16% rectal. Regarding RAS, 44% were mutated. 96% received Tas-Bev in 3ºL and 4% in posterior lines. 80.8% had initial liver metastases. In terms of efficacy: 26.9% of patients achieved disease stability and 3.8% achieved a partial response. Response was not evaluated in 27% because these patients maintained treatment. Median progression-free survival (PFS) was 3 months (m) (95% confidence interval (CI) 2.3 - 3.7) and median overall survival (OS) was 7m (95% CI 3.1-10.9). In both cases the results were not statistically significant. The most frequent adverse effects (AE) suffered by patients treated with TAS+Bev were, taking into account all grades: asthenia (65.4%), digestive toxicity (30%), anemia (53.8%) and neutropenia (46.2%). In the case of G3 toxicity, there were diarrhea (3.8%) and neutropenia (19.2%) with subsequent recovery, so treatment did not have to be interrupted. There were no cases of G4 toxicity. The addition of bevacizumab did not significantly increase serious adverse events. Conclusions: Our data are preliminary at the moment as 27% of the patients included are pending response evaluation. We can confirm that we consider it to be an effective therapeutic option (pending definitive results), with a very favorable safety profile, being an easily manageable combination that contributed to preserving the functional status of our patients.