Immuneering (IMRX) Study update summary

Phase IIa efficacy

• Interim data for atebimetinib 320 mg QD + mGnP in 34 first-line metastatic pancreatic cancer patients: 6-month OS 94% (95% CI 77%–98%), 9-month OS 86% (66%–94%); median OS not reached at 9.0 months’ median follow-up.

• PFS was 70% at 6 months (95% CI 49%–83%) and 53% at 9 months (31%–71%); median PFS was 9.6 months.

• Versus reconstructed MPACT benchmarks, OS was 27 percentage points higher at 6 months and 39 points at 9 months; PFS was 26 and 24 points higher, respectively. Cross-trial comparisons are illustrative, not head-to-head.

Tumor response and safety

• Among 36 response-evaluable patients, ORR was 39% (14/36) and DCR was 81% (29/36), versus MPACT benchmarks of 23% and 48%.

• In 29 patients with tumor-response tracking, 20 had durable or deepening shrinkage; 11 of those 20 remained on treatment at data cutoff.

• Grade 3+ neutropenia occurred in 18% and anemia in 24%; these were the only adverse-event categories above 10%. No Grade 5 events or new safety signals were reported.

• Median age was 69 years, with 68% aged 65 or older; cited Phase 3 benchmarks had median ages of 61–64 and 28%–50% aged 65 or older.

• Atebimetinib’s Deep Cyclic Inhibitor approach pulses pathway inhibition to limit tumor adaptation while allowing healthy-cell signaling to recover; MEK is downstream in the MAPK pathway, activated in a majority of cancers and ~97% of pancreatic cancers.

Development plans and financing

• Planned global randomized Phase 3 trial in first-line metastatic PDAC: atebimetinib + mGnP versus gemcitabine/nab-paclitaxel, 180 patients per arm; OS primary, with PFS, ORR, DCR and quality of life secondary.

• Regulatory feedback and Phase 3 initiation were targeted for Q4 2025/by year-end, subject to feedback; first-patient dosing by mid-2026 and topline results by mid-2028.

• Further OS and PFS updates in the 34-patient cohort were planned, including a 2026 conference presentation; additional 2026 combination studies include NSCLC with LIBTAYO and olomorasib.

• A $175 million underwritten offering and $25 million private placement, including strategic investment from Sanofi, were expected to fund operations into 2029 and support Phase 3 and other programs.