Phase II Single-arm Study of Durvalumab and Tremelimumab with Concurrent Radiotherapy in Patients with Mismatch Repair–proficient Metastatic Colorectal Cancer

Abstract

This combination of radiotherapy plus ICI study did not meet the prespecified endpoint criteria to be considered worthwhile for further study. However, rare instances of systemic immune augmentation and regression in nonirradiated lesions were observed (an abscopal response). Combination durvalumab and tremelimumab plus radiotherapy is feasible in MMR-P mCRC with a manageable safety profile. Further studies of novel immunotherapy combinations, and identification of biomarkers predictive of abscopal response are warranted.