Real-World Results of Raltitrexed Combined with S-1 and Bevacizumab in Heavily Pretreated Metastatic Colorectal Cancer.

PURPOSE

Treatment options for refractory metastatic colorectal cancer (CRC) are scarce. This retrospective study aimed to evaluate the efficacy and safety of raltitrexed combined with S-1 and bevacizumab in patients with heavily pretreated metastatic CRC in a clinical real-world setting.

PATIENTS AND METHODS

Records of patients with metastatic CRC refractory to standard therapies who initiated raltitrexed plus S-1 and bevacizumab from October 2017 to December 2021 were retrospectively reviewed at our institution. The study endpoints included median overall survival (OS), overall response rate (ORR), progression-free survival (PFS), disease control rate (DCR), and adverse events (AEs).

RESULTS

Forty-four patients with metastatic CRC, who had previously undergone standard chemotherapy received the regimen comprising raltitrexed plus S-1 and bevacizumab. As of March 2022, the median follow-up was 23.2 months (95% confidence interval 15.8-30.6). The median OS and median PFS were 13.5 (95% CI 9.9-17.1) and 4.7 months (95% CI 3.6-5.8), respectively, with a 16-week PFS rate of 60.9%. Among 43 patients with measurable lesions, the ORR and DCR were 7.0% (3/43) and 65.1% (28/43), respectively. Patients without peritoneal metastases (P = 0.003, hazard ratio 0.160, 95% CI 0.048-0.531), lower carcinoembryonic antigen level (≤42.8 ng/mL) (P = 0.039, HR 0.382, 95% CI 0.153-0.952), and no previous treatment with both vascular endothelial growth factor inhibitors (VEGF) and S-1 (P = 0.020, HR 0.215, 95% CI 0.059-0.785) had better OS. The incidence of any grade of treatment-related AEs was 88.6%, most of which were mild to moderate, and no treatment-related deaths occurred.

CONCLUSION

Raltitrexed combined with S-1 and bevacizumab shows promising antitumor activity and safety and could be an alternative for patients with metastatic CRC who are refractory or intolerant to standard therapy.