Immuneering Doses MAPKeeper 301 After ASCO Survival Data

The Tip Desk · August 5, 2026 · 3 min read

The company reported 17.3-month median overall survival in 55 first-line pancreatic cancer patients on atebimetinib plus mGnP, with cash of $182.7 million and runway still expected into 2029.

Immuneering Corporation (IMRX), a late-stage clinical oncology company, said it had dosed the first patient in MAPKeeper 301, its global randomized Phase 3 trial of atebimetinib plus modified gemcitabine/nab-paclitaxel (mGnP) in first-line metastatic pancreatic cancer, after presenting Phase 2a survival data at ASCO.

In June the company announced first-patient dosing in the pivotal study, which compares atebimetinib plus mGnP with mGnP alone. More than 30 study locations had been posted on clinicaltrials.gov. A quarter earlier the trial was recruiting, with first-patient dosing on track for mid-2026.

At the June 1 ASCO Annual Meeting, Immuneering reported 17.3-month median overall survival in 55 first-line pancreatic cancer patients treated with atebimetinib plus mGnP in a single-arm Phase 2a study, using an April 24, 2026 data cutoff. The company said 84% of evaluable patients were weight stable or had gained weight at three months, and that only two categories of treatment-related adverse events occurred at grade 3 or higher in at least 10% of patients. Chief Executive Officer Ben Zeskind said the survival figure “stands out as potentially best-in-class” and that the Phase 3 study “represents a compelling and differentiated option for first-line pancreatic cancer patients.”

In July the company published a Cancer Research article describing atebimetinib’s Deep Cyclic Inhibition, broad preclinical activity across RAS- and RAF-mutant tumors, resistance to RAF-mediated bypass signaling, and preservation of body mass in a cancer-cachexia model. In April it had presented circulating tumor DNA data from 123 atebimetinib-treated patients showing acquired MAPK pathway alterations were rarely seen.

Cash, cash equivalents and marketable securities were $182.7 million as of June 30, 2026, down from $217.0 million at year-end 2025. Based on that cash position and current operating plans, the company expects runway into 2029.

Research and development expenses for the second quarter were $14.0 million, compared with $10.5 million a year earlier. The company said the increase was primarily attributable to higher clinical costs on the lead atebimetinib program and other preclinical spend, partly offset by reduced envometinib spend. General and administrative expenses were $5.0 million, versus $4.3 million a year earlier, which the company attributed to employee-related costs and software.

Net loss attributable to common stockholders was $17.3 million, or $0.27 a share, versus $14.4 million, or $0.40 a share, a year earlier. Weighted-average shares outstanding more than doubled to 64.7 million from 36.0 million. Interest income was $1.08 million, and other income, net, was $0.65 million after none a year earlier.

In June the company appointed Andrew Gengos as Chief Financial Officer. He most recently served as chief financial officer and head of corporate development at Terns Pharmaceuticals.

Immuneering said it expects to dose the first patient in a Phase 2 trial of atebimetinib plus cemiplimab in non-small cell lung cancer in the second half of 2026, with a preliminary readout expected in late 2027. Additional preclinical combination data in that setting are anticipated in the fourth quarter of 2026. IND-enabling studies for a next Deep Cyclic Inhibitor candidate are planned for mid-2027, and topline data from MAPKeeper 301 are expected in mid-2028.