Neoadjuvant Pembrolizumab With a Watch-and-wait Strategy for dMMR/MSI-H Localized Colon Cancer: PREMICES Study.

The goal of this investigational, multicenter, open-label randomized, two-stage phase II study is to evaluate neoadjuvant pembrolizumab with a watch-and-wait approach in patients with localized deficient mismatch repair / high microsatellite instability (dMMR/MSI-H) colorectal cancer (CRC). The PREMICES trial is based on the hypothesis that non-operative management is effective for dMMR/MSI-H localized CRC when treated with neoadjuvant pembrolizumab. Eligible patients will be randomized in a 1:1 ratio to receive either pembrolizumab with a watch-and-wait approach (experimental arm A) or the standard strategy of surgical resection ± adjuvant chemotherapy (arm B).