Immuneering CEO Touts 64% 12-Month Survival in Pancreatic Cancer; Phase 3 Launch Nears

Key Points

• Immuneering reported a 12‑month overall survival rate of 64% in a 34‑patient Phase II first‑line pancreatic cohort treated with atebimetinib plus chemotherapy (median OS not yet reached) and expects an updated readout in H1 from an expanded cohort of more than 50 patients.
• The company plans a pivotal Phase III MAPKeeper‑301 trial — a global randomized study of atebimetinib + modified GNP versus standard GNP with OS as the primary endpoint — that is fully funded, will enroll just over 500 patients, aims to dose the first patient mid‑year, and targets a top‑line readout about two years after dosing begins.
• Atebimetinib employs a novel "Deep Cyclic Inhibition" strategy (intense, intermittent MAPK suppression) that Immuneering says may reduce resistance and drive survival benefits through durable tumor control, body‑weight preservation, and improved tolerability, enabling combination with chemotherapy.

Immuneering NASDAQ: IMRX CEO Benjamin J. Zeskind told investors at a Needham conference session that 2026 has started with what he described as “extraordinary” early survival results for the company’s lead program, atebimetinib, in first-line pancreatic cancer, and outlined multiple upcoming clinical and regulatory milestones across pancreatic and lung cancer.

Phase II pancreatic cancer survival update and near-term catalysts

Zeskind said the company reported in January a 12-month overall survival (OS) rate of 64% in first-line pancreatic cancer patients treated with atebimetinib in combination with chemotherapy, with median OS not yet reached at the time of that cutoff. He said the dataset had a 13.4-month median follow-up and included 34 patients, exceeding the original enrollment goal of 30.

He also highlighted a cross-trial comparison against the pivotal MPACT study for gemcitabine/nab-paclitaxel (GNP), which he cited as having shown 35% 12-month OS. Zeskind emphasized that Immuneering’s survival curves “separate early” and remain separated at six, nine, and 12 months based on the company’s updates.

Looking ahead, Zeskind reiterated guidance for another survival update in the first half of the year based on an expanded cohort “of more than 50 patients,” describing it as the original 34 patients plus “another 20 or so.” He said the company previously indicated OS in the expanded cohort was “trending consistently” with the initial 34-patient cohort, while declining to provide additional specifics ahead of the planned update.

Beyond OS, he pointed to previously reported progression-free survival (PFS) of 8.5 months, which he said was “about three months better” than the standard-of-care benchmark, along with tolerability results. He said only two categories of grade 3 adverse events occurred in more than 10% of patients—neutropenia and anemia—which he associated with the chemotherapy backbone and said were not observed in monotherapy.

Zeskind also noted the phase II population skewed older than historical pivotal studies: he cited a median age of 69, with more than two-thirds of patients over 65.

Mechanism: “Deep Cyclic Inhibition” and a three-part survival thesis

Zeskind contrasted atebimetinib with traditional targeted therapies that aim for continuous pathway suppression, describing Immuneering’s approach as “Deep Cyclic Inhibition.” He said the company designed atebimetinib to deliver intense pulses of MAP kinase pathway inhibition—spiking rapidly to high concentration, shutting down signaling above the IC90, and then clearing quickly due to a short half-life—resulting in pathway “release” by the end of the day before the next dose.

He attributed this profile to novel chemistry that provides a “fast off rate” and supports once-daily oral dosing for patients. Conceptually, he said the intermittent pressure is intended to prevent the rapid selection of resistant cancer cell populations predicted by Darwinian models of tumor evolution, referencing work by Moffitt Cancer Center’s Robert Gatenby. Zeskind characterized the intended effect as keeping sensitive and resistant cells “fighting each other,” calling it a tumor “civil war.”

He said the company believes survival benefits may be driven by three mechanisms:

• Durable tumor control: long, slow, steady reductions rather than rapid shrinkage followed by resistance.
• Body mass preservation:
• Improved tolerability:

To support the importance of weight stability and tolerability, Zeskind cited literature-based hazard ratios, including 1.55 for patients who lose weight versus those stable or gaining, 1.48 when performance status declines to ECOG 2, and 1.51 for patients unable to receive second-line therapy.

Why first-line pancreatic cancer is the priority

In response to a question about differences between first-line and second-line activity, Zeskind said Immuneering has prioritized first-line pancreatic cancer because “that’s where the most patients are,” estimating there are twice as many patients in the first-line setting as in later lines and noting many do not reach later lines. He also pointed to the need to combine with chemotherapy in first line and said atebimetinib’s tolerability has enabled combination treatment.

He added that for first-line chemotherapies, the “primary resistance pathway is the MAP kinase pathway,” suggesting this biology may be relevant when thinking about line-of-therapy dynamics.

Phase III MAPKeeper-301: design, timing, and regulatory focus

Zeskind outlined Immuneering’s planned pivotal trial, MAPKeeper-301, calling it a “global randomized pivotal study” comparing atebimetinib plus modified GNP chemotherapy versus standard-of-care GNP, with OS as the primary endpoint. He said the trial will enroll “a little over 500 patients.”

He also referenced a December announcement of “regulatory alignment,” said the study is “fully funded,” and reiterated guidance to dose the first patient mid-year. On timing, he pushed back on discussing interim PFS timelines and said the company is guiding to a top-line readout “about two years after that first patient dose.”

On the chemotherapy landscape, Zeskind said use in the real world is “about 50/50” between gemcitabine-containing regimens and FOLFIRINOX/NALIRIFOX, describing gemcitabine regimens as better tolerated and the others as harsher but offering some survival advantage. He said Immuneering selected modified GNP (every-other-week dosing) based on work by Mayo Clinic investigators Daniel H. Ahn and Tanios Bekaii-Saab showing improved tolerability without a significant survival difference versus standard scheduling.

He added the company also has a phase II arm combining atebimetinib with FOLFIRINOX, and described a case discussed by Weill Cornell’s Allyson J. Ocean involving a “confirmed complete response,” while noting aggregate data have not yet been shared.

Competitive commentary and AACR ctDNA poster

Asked about competition, Zeskind discussed the company’s view of Revolution Medicines’ program and said Immuneering has urged the company to release additional first-line pancreatic cancer data—particularly overall survival and other endpoints—to allow more transparent comparisons, while acknowledging cross-trial caveats. Zeskind compared disclosed tolerability metrics, stating Immuneering’s reported adverse-event profile appears different from what Revolution has reported in first line, and argued that comparisons should use consistent denominators when assessing response rates.

Zeskind also previewed an upcoming AACR presentation focused on acquired alterations detected in circulating tumor DNA (ctDNA). He said Immuneering has previously observed “very few acquired alterations in the MAP kinase pathway” in phase I, which he believes supports the idea that atebimetinib may avoid driving common on-pathway resistance mechanisms seen with mutation-specific RAS inhibitors or pan-RAS approaches. He said the company’s AACR press release indicated a similar conclusion from the upcoming dataset.

About Immuneering NASDAQ: IMRX

Immuneering Nasdaq: IMRX is a clinical-stage biopharmaceutical company leveraging artificial intelligence and its proprietary RABIT (Repurposing and Accelerating Biotechnology Tools) platform to design and optimize small-molecule and peptide therapies. By analyzing large-scale biomedical datasets, Immuneering's machine learning algorithms identify novel drug–target interactions, repurpose existing drug scaffolds and accelerate lead candidate selection. The company's AI-driven approach aims to reduce development timelines and improve therapeutic profiles in areas of high unmet medical need.

The company's lead program, IRX-2, is a small-molecule candidate currently in Phase 2 clinical trials for the treatment of painful diabetic peripheral neuropathy.

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