Regorafenib in Refractory Metastatic Colorectal Cancer: A Multi-Center Retrospective Study.

Background: Regorafenib improves progression-free survival (PFS) and overall survival (OS) in patients with refractory metastatic colorectal cancer (mCRC). Here, we report the treatment patterns of regorafenib in the third- or late-line setting for mCRC in four centers in China. Patients and Methods: Patients with refractory mCRC in four centers in China administered regorafenib from February 1, 2018 to June 31, 2021 were enrolled. Patients were grouped into 3 cohorts, namely, the monotherapy (regorafenib alone), chemo (regorafenib plus chemotherapy), and immune [regorafenib plus anti-PD1 (programmed cell death 1) antibodies] groups. Demographic, clinical, survival and safety data were retrospectively analyzed. Results: A total of 177 patients were included in this study. Of them, 116 (65.5%) were treated with regorafenib alone, while 28 (15.9%) and 33 (18.6%) were administered regorafenib plus chemotherapy and anti-PD1 antibodies, respectively. The median followed-up time was 9.2 months. The disease control rate (DCR) was 40.7%. The median PFS (mPFS) was 2.43 months and the median OS (mOS) was 12.2 months. The immune group had longer median PFS (3.5 m vs. 2.2 m, p = 0.043) compared with the monotherapy group. Patients administered regorafenib plus chemotherapy had longer median OS (15.9 m vs. 8.4 m, p = 0.032) compared with the monotherapy group. Patients who began regorafenib treatment at 120 mg had longer median PFS and OS compared with those who began at 80 mg (PFS: 3.7 m vs. 2.0 m; p <0.001; OS: 13.4 m vs. 10.2 m; p = 0.005). Patients with a final dose of 120 mg had longer median PFS and OS compared with the 80 mg or less group (PFS: 5.0 m vs. 2.3 m; p = 0.045; OS: UR (unreach) vs. 10.9 m; p = 0.003). There were 87.0% (154/177) patients who experienced AEs. Three groups had similar rates of AEs (86.2% vs. 89.3% vs. 87.9%; p = 0.89). Conclusion: Patients administered regorafenib alone or regorafenib in combination with other agents were relieved to some extent, with a disease control rate of 40.7%. Regorafenib plus anti-PD1 antibodies showed better PFS, while regorafenib plus chemotherapy had the most benefit in OS. There was no significant difference among three groups in terms of AEs.