GlobeNewswire·Nov 6, 2026, 9:00 AM ET

Atebimetinib Combinations with Anti-PD1 Cured 50% of Mice in a RAS-Mutant Colorectal Cancer Model and Nearly Doubled Survival in a RAS-Mutant Lung Cancer Model; New Data Presented at SITC 2026

Durable complete regressions occurred in 50% of mice in a RAS-mutant colorectal cancer model treated with atebimetinib plus anti-PD-1, with no regrowth after dosing stopped
Median survival extended by 1.8-fold with atebimetinib plus anti-PD-1 & chemotherapy versus anti-PD-1 plus chemotherapy alone in a RAS-mutant lung cancer model
Pulsatile MEK inhibition reversed MAPK-driven immune suppression by lowering suppressive myeloid cells & regulatory T-cells while expanding NK cells
Phase 2 clinical trial of atebimetinib with anti-PD-1 & platinum-doublet chemotherapy in first-line RAS-mutant NSCLC is expected to dose the first patient by year-end
In the CT-26 colorectal model, atebimetinib plus anti-PD-1 groups achieved 6 of 12 complete tumor regressions per group without regrowth after treatment discontinuation
In the LL2 lung model, the triple combination of atebimetinib, anti-PD-1, carboplatin, & pemetrexed extended median survival to 25 days compared to 14 days for anti-PD-1 plus chemotherapy alone
Immuneering Corporation presented these preclinical data at the Society for Immunotherapy of Cancer 41st Annual Meeting in Phoenix, Arizona
Atebimetinib is a novel Deep Cyclic Inhibitor of MEK designed to shrink tumors durably, preserve body mass, & minimize side effects
Immuneering is also conducting the global randomized pivotal MAPKeeper 301 trial evaluating atebimetinib with chemotherapy in first-line pancreatic cancer patients

Company: Immuneering Corporation
Keywords: Nasdaq:IMRX, Immuneering Corporation, Immuneering, IMRX, atebimetinib, Atebi, anti-PD1, SITC, RAS, Colorectal Cancer, Lung Cancer