Real-world experience of safety and effectiveness of regorafenib for treatment of metastatic colorectal cancer, advanced gastrointestinal stromal tumors, and hepatocellular carcinoma: a post-marketing surveillance study in Korea

Purpose: This regulatory post-marketing surveillance (PMS) study was performed to evaluate the safety and effectiveness of regorafenib on Korean patients with colorectal cancer (CRC), gastrointestinal stromal tumors (GIST), and hepatocellular carcinoma (HCC) in a real-world clinical setting. Methods: This PMS was conducted as a multi-center, prospective, observational study at 34 centers in Korea from August 2013 to August 2019. The primary objective was to evaluate the safety of regorafenib in real-world practice, with the secondary objective to investigate its effectiveness, including its overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). Results: In total, 301 patients were included in the analysis (254 patients with CRC, 14 patients with GIST, and 33 patients with HCC). The incidence rates of adverse events (AEs) were 85.0%, 78.6%, and 81.8% in patients with CRC, GIST, and HCC, respectively. The most frequent AE related to regorafenib in the three cancer types was palmar-plantar erythrodysesthesia syndrome (PPES). The ORRs of patients with CRC, GIST, and HCC were 4.7%, 0%, and 41.4%, respectively. The median PFS and OS were 2.1 and 6.1 months for CRC, respectively; 9.2 and 16.4 months for GIST, respectively; and 5.5 months and not estimated (NE) for HCC, respectively. Patients who experienced a dose modification or discontinuation of regorafenib showed significantly shorter median PFS and OS (2.2 vs. 2.6 months, respectively, P = 0.0335 for PFS; 5.3 vs. 8.5 months, respectively, P = 0.0010 for OS). Conclusion: This PMS study, which is the largest surveillance study of CRC in Korea, found no newly identified safety concerns for patients who received regorafenib in the real-world setting. Additionally, the results of this study were consisted with those previously reported in phase III trials.