NEW YORK — September 28, 2026
Immuneering Corporation presented new data at the 2026 AACR Conference on Pancreatic Cancer evaluating the potential relationship between tumor volume reduction, body mass preservation and overall survival in patients with first-line pancreatic cancer treated with atebimetinib plus modified gemcitabine/nab-paclitaxel (mGnP). The exploratory, post-hoc analysis used data from the single-arm Phase 2a study and examined the same April 24, 2026 data cutoff used for the company’s previous ASCO presentation. Among evaluable patients, 84% had stable or increased body weight at three months, while patients who maintained or gained weight had longer overall survival than those who experienced weight loss. The analysis also found comparable overall survival among patients with moderate and deeper tumor volume reductions. Immuneering said the findings support further investigation of atebimetinib’s potential effects on both tumor burden and cancer-associated weight loss.
Atebimetinib Analysis Links Weight Preservation With Survival
The AACR analysis examined body mass trajectories in pancreatic cancer patients receiving atebimetinib with mGnP, including a comparison with a published benchmark study. Among 23 patients evaluable for weight trajectory, the proportion with stable or increasing weight was approximately two times higher than in the benchmark population, according to Immuneering. Within the Phase 2a study, patients who maintained or increased their weight at three months had longer overall survival than patients who lost weight, with a reported hazard ratio of 3.13 and p=0.049. Median overall survival had not been reached in the weight-stable or weight-gain group after a median follow-up of 15.2 months. In addition, 66% of patients with low baseline scores on the FAACT-Anorexia Cachexia Subscale achieved at least a four-point improvement while receiving treatment. These findings are exploratory and do not establish a causal relationship between weight preservation and survival.
Tumor Volume Reduction Examined Across Response Depths
The analysis also evaluated whether the depth of tumor volume reduction was associated with overall survival. Patients with a reduction of at least 30% in the sum of longest tumor diameters had overall survival comparable with patients whose reductions were between 0% and 30%, with median overall survival not reached in either group. By comparison, median overall survival was reached among patients without a measured reduction in tumor diameter. Immuneering said the findings may indicate that achieving some degree of tumor volume reduction could be more relevant to survival than the magnitude of shrinkage alone. The analysis also suggests that potential clinical benefit could extend to patients whose tumor reduction does not meet the conventional RECIST partial-response threshold. However, the findings come from a single-arm study and post-hoc analyses, so they require confirmation in randomized clinical development.
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Immuneering Advances Atebimetinib Into Phase 3
Atebimetinib is an investigational oral, once-daily MEK inhibitor that Immuneering is developing as a Deep Cyclic Inhibitor for MAPK-driven cancers. The company is evaluating atebimetinib in combination with mGnP in the ongoing Phase 3 MAPKeeper 301 trial in patients with first-line pancreatic cancer. Immuneering’s development strategy is designed around three potential mechanisms: durable tumor reduction, preservation of body mass by addressing cancer-associated cachexia and maintenance of tolerability to support patient performance and combination treatment. The Phase 2a program previously reported a 17.3-month median overall survival in 55 first-line pancreatic cancer patients, according to the company. The AACR findings provide additional exploratory clinical observations for the program, while the randomized Phase 3 MAPKeeper 301 study is expected to provide more definitive evidence regarding atebimetinib’s efficacy and safety in first-line pancreatic cancer.
Source :Immuneering press release
