Efficacy and safety of regorafenib or fruquintinib plus camrelizumab in patients with microsatellite stable and/or proficient mismatch repair metastatic colorectal cancer: an observational pilot study.

This study was to investigate the efficacy and safety of regorafenib or fruquintinib combined with camrelizumab in patients with microsatellite stable (MSS) and/or proficient mismatch repair (pMMR) metastatic colorectal cancer (mCRC). Medical records of MSS/pMMR mCRC patients who received regorafenib (80 mg) or fruquintinib (3 mg) once a day (21 days on/7 days off) plus camrelizumab (200 mg) every three weeks in Yuhuangding Hospital between January 2020 and June 2020 were retrospectively collected. Follow-up data up to November 1st, 2020 was gathered. The primary endpoint was the objective response rate (ORR) and disease control rate (DCR). The safety profile was the secondary endpoint. A total of 16 patients were enrolled. The ORR was 25.0% (4/16) and the DCR was 62.5% (10/16). The main adverse events (AEs) included reactive cutaneous capillary endothelial proliferation (RCCEP) (81.3%), fatigue (43.8%), hypertension (37.5%), hand-foot skin reaction (25.0%), and thyroid dysfunction (25.0%). Most AEs were grade 1 or 2, with only 1 patient of grade 3 liver dysfunction. All the AEs were ameliorated by effective symptomatic treatment. Regorafenib or fruquintinib plus camrelizumab exhibited promising efficacy in patients with MSS/pMMR mCRC. The toxicity was moderate and manageable.