Efficacy and Safety of Regorafenib Monotherapy among Patients with Previously Treated Metastatic Colorectal Cancer in a Chinese Population: A Real-World Exploratory Study

Background: Present study was condeucted to investigate the efficacy and safety of regorafenib for patients with previously treated metastatic colorectal cancer (mCRC) in a Chinese population and the prognostic implications of adverse reactions. Methods: This retrospective study a total of 96 consecutive patients with mCRC who had failed standard chemotherapy regimens from June 2017 to December 2020. Patients received regorafenib at an initial dosage of 160 mg or 120 mg. The primary end point was progression-free survival (PFS), and secondary end points objective response rate (ORR), diseasecontrol rate (DCR), overall survival (OS), safety, and associations between prognosis and adverse-reaction status. Results: There were three patients with partial response, 49 with stable disease, and 44 with progressive disease. Consequently, the ORR and DCR of the 96 patients were 3.1% (95% CI 0.6%-8.9%) and 54.2% (95% CI 43.7-64.4%), respectively. Prognosis results showed that median PFS of the 96 patients was 2.5 (95% CI 1.98-3.02) months and median OS 9.8 (95% CI 7.02-12.59) months. Additionally, the most frequent adverse reactions during regorafenib treatment were hand-foot syndrome (HFS; 52.1%), hypertension (38.5%), and fatigue (33.3%). Interestingly, the relevance of prognosis to adverse-reaction status exhibited that median PFS of patients with HFS and patients without HFS was 3.3 months and 2.0 months, respectively (P=0.013). Similarly, median PFS of patients with hypertension and without hypertension was 3.6 months and 2.2 months, respectively (P=0.023). Conclusion: Potential clinical benefit of regorafenib monotherapy was observed for patients with mCRC who had failed standard chemotherapy regimens. Hypertension and HFS induced by regorafenib therapy could be used as valuable biomarkers to predict the prognosis of regorafenib.