A multicenter study evaluating efficacy of immune checkpoint inhibitors in advanced non-colorectal digestive cancers with microsatellite instability.

BACKGROUND: One randomized phase III trial comparing chemotherapy (CT) with immune checkpoint inhibitors (ICI) has demonstrated significant efficacy of ICI in deficient DNA mismatch repair system/microsatellite instability-high (dMMR/MSI-H) metastatic colorectal cancer. However, few studies have compared ICI with CT in other advanced dMMR/MSI-H digestive tumors. METHODS: In this multicenter study, we included patients with advanced dMMR/MSI-H non-colorectal digestive tumors treated with chemotherapy and/or ICIs. Patients were divided retrospectively into two groups, a CT group and an immunotherapy (IO) group. The primary endpoint was progression-free survival (PFS). A propensity score approach using the inverse probability of treatment weighting (IPTW) method was applied to deal with potential differences between the two groups. RESULTS: 133 patients (45.1/27.1/27.8% with gastric/small bowel/other carcinomas) were included. The majority of patients received ICI in 1st (29.1%) or 2nd line (44.4%). The 24-month PFS rates were 7.9% in the CT group and 71.2% in the IO group. Using the IPTW method, IO treatment was associated with better PFS (HR=0.227; 95% CI 0.147-0.351; p < 0.0001). The overall response rate was 26.3% in the CT group versus 60.7% in the IO group (p < 0.001) with prolonged duration of disease control in the IO group (p < 0.001). In multivariable analysis, predictive factors of PFS for patients treated with IO were good performance status, absence of liver metastasis and prior primary tumor resection, whereas no association was found for the site of the primary tumor. CONCLUSIONS: In the absence of randomized trials, our study highlights the superior efficacy of ICI compared with standard-of-care therapy in patients with unresectable or metastatic dMMR/MSI-H non-colorectal digestive cancer, regardless of tumor type, with acceptable toxicity.

Sequential Treatment With Trifluridine/Tipiracil and Regorafenib in Refractory Metastatic Colorectal Cancer Patients: An AGEO Prospective "Real-World Study".

INTRODUCTION: Regorafenib (R) and trifluridine/tipiracil (FTD/TPI) are of proven efficacy in metastatic colorectal cancer (mCRC) patient's refractory to standard therapies. However, it remains unclear which drug should be administered first. PATIENTS AND METHODS: This French observational study was prospectively conducted in 11 centers between June 2017 and September 2019. All consecutive patients with chemorefractory mCRC and receiving FTD/TPI and/or R were eligible. The aim was to evaluate the efficacy and tolerability of FTD/TPI and/or R in real-world setting with adjusted analysis. RESULTS: A total of 237 mCRC patients (25% R and 75% FTD/TPI) were enrolled. As compared to R, FTD/TPI patients were significantly older and with more metastatic sites. Median OS and PFS were respectively 6.2 and 2.4 months in the FTD/TPI and 6.6 and 2.1 months in the R group. After matching 46 paired patients according to a propensity score, a trend to a longer OS (P = .58), and a significantly longer PFS (P = .048) were observed in the FTD/TPI group. In the 24% of patients receiving the R/T or T/R sequence, median OS from first treatment was similar. Tolerability profiles were similar to published data and dose reductions were more frequent in the R group. CONCLUSION: Efficacy and safety results in this real-world prospective study are in line with phase III trials. In a matched population, PFS was significantly longer in the FTD/TPI group. Despite a limited number of patients, clinical outcomes seemed similar in patients treated with the T/R or R/T sequence.