Comparison of the efficacy and safety of regorafenib monotherapy and regorafenib combination therapy in the third-line treatment of metastatic colorectal cancer: A real-world study.

e15529 Background: Regorafenib is a novel tyrosine kinase inhibitor (TKIs) approved in third-line of treatment for patients with metastatic colorectal cancer (mCRC). Methods: We retrospectively analyzed the efficacy and safety of patients with mCRC who received regorafenib as a third-line of treatment from September 2020 to September 2024 at China-Japan Friendship Hospital. Patients were grouped into 2 cohorts, namely, the monotherapy (regorafenib alone), combination therapy (regorafenib combined with trifluridine/tipiracil (TAS-102) or anti-PD-1). The clinical outcomes included progression-free survival (PFS), 1/2/3-year OS rates and safety data. Overall survival (OS) was not reach. Results: A total of 28 patients were enrolled with a median age of 66 (52-81) years. 15 patients received regorafenib monotherapy and 13 patients received regorafenib combination therapy. There were 17 (60.7%) males and 11 (39.3%) females. Most patients had left-sided cancer (60.7%). Before regorafenib, 18 patients (64.3%) had received bevacizumab treatment. The majority of patients had not been on frontline treatment for more than 18 months (53.6%). The median PFS of was 5.2 months, (95% CI, 4.37-NA). One-year, 2-year and 3-year overall survival rate of was 42.86%, 28.57% and 10.71%, respectively. In the meanwhile, compared with monotherapy group, the 3-year overall survival rate in the combination therapy group is higher (6.67% vs. 15.38%).The incidence of all grade treatment-related adverse events was higher in combination therapy (69.23%) vs. monotherapy (20.00%) group; P = 0.036. However, there was no significant difference in the incidence of grade 3/4 adverse events between the combination therapy and monotherapy groups (23.08% vs. 0%); P = 0.130. Conclusions: Regorafenib alone or in combination with TAS-102 or anti-PD-1 is safe and feasible for third-line treatment of mCRC. Additional prospective large-scale studies are required to explore combination therapy.