Purpose: We evaluated the efficacy and safety of avelumab, an anti-PD-L1 antibody, in patients with metastatic or unresectable colorectal cancer (mCRC) with mismatch repair deficiency (dMMR)/microsatellite instability-high (MSI-H) or POLE mutations. VSports手机版.

Materials and methods: In this prospective, open-label, multicenter phase II study, 33 patients with mCRC harboring dMMR/MSI-H or POLE mutations after failure of ≥1st-line chemotherapy received avelumab 10 mg/kg every 2 weeks. dMMR/MSI-H was confirmed with immunohistochemical staining (IHC) by loss of expression of MMR proteins or polymerase chain reaction (PCR) for microsatellite sequences. POLE mutation was confirmed by next-generation sequencing (NGS). The primary endpoint was the objective response rate (ORR) by Response Evaluation Criteria in Solid Tumors ver. 1. 1. V体育安卓版.

Results: The median age was 60 years, and 78. 8% were male. Thirty patients were dMMR/MSI-H and three had POLE mutations. The ORR was 24. 2%, and all of the responders were dMMR/MSI-H. For 21 patients with MSI-H by PCR or NGS, the ORR was 28. 6%. At a median follow-up duration of 16 V体育ios版. 3 months, median progression-free survival and overall survival were 3. 9 and 13. 2 months in all patients, and 8. 1 months and not reached, respectively, in patients with MSI-H by PCR or NGS. Dose interruption and discontinuation due to treatment-related adverse events occurred in four and two patients, respectively, with no treatment-related deaths. .

Conclusion: Avelumab displayed antitumor activity with manageable toxicity in patients with previously treated mCRC harboring dMMR/MSI-H. Diagnosis of dMMR/MSI-H with PCR or NGS could be complementary to IHC to select patients who would benefit from immunotherapy. VSports最新版本.