Safety and Preliminary Efficacy of SAR445877 in Advanced Colorectal Cancer: Dose Optimization/Expansion of Phase 1/2 Trial

In this OncLive Rapid Readout, Dr. Aung Naing, MD, FACP, of The University of Texas MD Anderson Cancer Center, discusses findings from the dose-optimization and expansion cohorts of a phase 1/2 trial evaluating SAR445877, a novel bispecific PD-1 and IL-15 fusion protein, as monotherapy in patients with advanced microsatellite-stable (MSS) metastatic colorectal cancer. Presented at the ESMO 2026 Congress, the study evaluated preliminary antitumor activity, safety, and exploratory biomarkers. Dr. Naing reviews objective response rates across the 10-mg and 30-mg dose cohorts, responses in patients with liver metastases, treatment-related adverse events, and pharmacodynamic findings suggesting increased T-cell infiltration and expansion within the tumor microenvironment. The discussion highlights the potential of this immune-directed approach in a disease setting where conventional checkpoint inhibitor monotherapy has shown limited benefit, while emphasizing the need for further investigation to establish optimal dosing, characterize the benefit-risk profile, and identify patients most likely to benefit.