Phase II Study of Irinotecan, Trifluridine/tipiracil (TAS-102) plus Bevacizumab as a Later-line Therapy for Patients with Metastatic Colorectal Cancer (mCRC): a prospective single-center explorative study.

Purpose: To explore the efficacy and safety of the combination of irinotecan, trifluridine/tipiracil (TAS-102), and bevacizumab in a later-line setting for metastatic colorectal cancer (mCRC) patients.

Patients and methods: This was a single-center, phase II trial. The mCRC patients who are refractory to standard first-line and second-line treatment are eligible. Patients who previously received irinotecan while progressing during maintenance therapy are also eligible. The primary endpoint was the objective response rate (ORR).

Results: Between August 1, 2022, and September 30, 2023, 35 patients were enrolled, and 31 of them were evaluable for efficacy. The ORR was 25.8% (8/31), and the disease control rate (DCR) was 93.5% (29/31). As of April 30, 2024, the median progression-free survival (PFS) was 9.2 months (95% CI 6.285-12.115), whereas the median overall survival (OS) was not reached with the 1-year OS rate of 73.5%. The most common grade 3/4 treatment-related adverse events were neutropenia (34.3%), anemia (17.1%), and thrombocytopenia (8.6%).

Conclusion: Irinotecan, TAS-102 plus bevacizumab regimen preliminarily demonstrated promising efficacy with tolerable toxicity for mCRC patients as later-line treatment. This regimen warrants further exploration in refractory mCRC patients.