Comparison of standard and biweekly trifluridine/tipiracil plus bevacizumab regimens in advanced or recurrent colorectal cancer: a retrospective study.

[BACKGROUND] Trifluridine/tipiracil (FTD/TPI) plus bevacizumab (BEV) is a standard third-line therapy for unresectable advanced or recurrent colorectal cancer. The standard dosing schedule (5 days of administration followed by 2 days off) is associated with a high incidence of severe neutropenia. Conversely, a biweekly dosing schedule (5 days of administration followed by 9 days off) reportedly reduces this incidence. However, no direct comparison of these regimens has been made. In this study, we retrospectively compared the efficacy and safety of these two dosing schedules.

[METHODS] We analyzed data from patients who received FTD/TPI + BEV treatment between June 2016 and January 2024 at three hospitals affiliated with Fujita Health University. The effects of the dosing schedules on hematological toxicity, overall survival (OS), and time to treatment failure (TTF) were assessed.

[RESULTS] Among the 125 patients, 26 and 99 were classified into the standard and biweekly groups, respectively. Grade ≥ 3 neutropenia occurred in 50.0% of patients in the standard group and 29.3% of those in the biweekly group (P = .062), with multivariable analysis confirming the dosing schedule impact (P = .048). Median TTF was 5.4 and 7.0 months, while median OS was 16.4 and 14.5 months (P = .908, 0.947) in the standard and biweekly groups, respectively.

[CONCLUSION] The biweekly regimen of FTD/TPI + BEV resulted in a lower tendency for severe neutropenia than that in the standard regimen, while maintaining comparable OS and TTF in patients with unresectable advanced or recurrent colorectal cancer.