Retrospective pilot study of regorafenib combined with ICIs in the third-line treatment of advanced colorectal cancer.

Abstract

e15582 Background: An increasing number of patients with advanced colorectal cancer tend to receive third-line treatment. Although there are several treatment options, concerns about efficacy and adverse events still remained. Regorafenib seems to enhance the effect of immune checkpoint inhibitors (ICIs) by modulate tumor microenvironment. In the absence of stage III clinical trial data, the real-world study might show certain clinical value. Methods: From Aug 2019 to June 2020, 23 advanced MSS colorectal cancer patients underwent third-line treatment of regorafenib combined with ICI. All patients received regorafenib 80 mg QD for 21 days, as a 28-day cycle, combined with ICIs until disease progression or intolerable adverse events. We retrospectively collected the overall response data, survival data and adverse events data from these patients. Results: The characteristics of all 23 patients is shown in the table. All patients had received at least 2 lines of prior systemic chemotherapy, the median time from diagnosis to third-line treatment was 31 months. The overall response rate was 26% (6/23), including one complete response. Almost all the responders were male (5/6) and with pulmonary metastasis (5/6). The disease control rate was 60% (14/23). The progression free survival ranges from 0.69 month to 19.3 months (median 4.8 months), with 6 patients continued response and constantly treatment. Duration of response range from 6.4 months to 19.4 months. Serious adverse events were hepatitis occurred in two patients and lead to the termination of subsequent anticancer therapy, which was considered to be related to immunotherapy. Conclusions: Regorafenib combined with ICIs might favor a certain group of advanced colorectal cancer patients, with a acceptable response rate and comparatively long duration of response. Interestingly, this retrospective pilot study was in consistence with that of REGONIVO trials to some extent for that the male patients with pulmonary metastasis appeared to response better. Key words: colorectal cancer; regorafenib; immune check point inhibitors Clinical characteristics of 23 patients.[Table: see text]