Immuneering’s Phase 2a trial of atebimetinib plus modified gemcitabine/nab-paclitaxel (mGnP) in first-line pancreatic cancer reported a 64% overall survival (OS) rate at 12 months, nearly doubling the 35% 12-month OS observed with mGnP alone. The analysis included 34 patients with a median follow-up of over 13 months. Cross-trial comparisons showing an OS decline from nine to twelve months are misleading, as Immuneering’s differentiated allosteric MEK inhibitor targets tumor resistance mechanisms that standard chemotherapy does not address.

As of the December 15, 2025 data cutoff, the atebimetinib (320 mg once daily) plus mGnP regimen demonstrated a tolerability profile comparable to chemotherapy alone, with only two Grade 3 adverse event categories occurring in more than 10% of patients. Median progression-free survival (PFS) reached 8.5 months versus 5.5 months for mGnP, and the confirmed overall response rate (ORR) was 39% at 12 months compared to 23% with chemotherapy, underscoring both efficacy and manageability of the combination.

Immuneering anticipates initiating its pivotal Phase 3 MAPKeeper-301 trial of atebimetinib plus mGnP in first-line pancreatic cancer in mid-2026, following regulatory guidance supporting accelerated pathways based on strong OS data. An expanded cohort update of 50 pancreatic cancer patients is expected in H1 2026. The company also plans to dose the first patient in a study combining atebimetinib with an anti-PD-1 therapy in non–small cell lung cancer during the second half of 2026. Cash reserves are sufficient to fund operations into 2029, positioning the company to sustain multiple late-stage programs without immediate dilution.