NEW YORK, March 17, 2026 (GLOBE NEWSWIRE) -- Immuneering Corporation (NASDAQ:IMRX), a late-stage clinical oncology company focused on keeping cancer patients alive and helping them thrive, today announced it will present a poster on one of the three key mechanisms by which atebimetinib aims to improve overall survival: shrinking tumors durably. The poster will be presented at the American Association for Cancer Research (AACR) Annual Meeting taking place April 17-22, 2026 in San Diego, CA.

Inhibitors of RAS, RAF, or MEK often provide only temporary benefit due to resistance, as tumors acquire new mutations or mechanisms of escape within the MAPK pathway. Atebimetinib, a novel Deep Cyclic Inhibitor of MEK, is engineered to mitigate the selective pressure that typically drives these resistance mechanisms, with the goal of more durable anti-tumor activity. Immuneering will present an analysis of circulating tumor DNA (ctDNA) from ≥64 patients with RAS-mutant solid tumors treated with atebimetinib, showing that acquired MAPK pathway alterations are rarely seen in patients treated with atebimetinib. These findings suggest that Deep Cyclic Inhibitors have the potential to overcome the limitations of conventional MAPK inhibition and provide a more sustained clinical benefit for patients.

Poster Presentation Details:

Title: Atebimetinib's Deep Cyclic Inhibition of MEK Constrains MAPK-Axis Adaptive and Acquired Alterations in Patients with RAS-Mutant Tumors

Session Category: Experimental and Molecular Therapeutics

Session Title: Targeting Drug Resistance 2: RAS Signaling

Poster Number: 1873

Poster Board Number: 6

Session Date: April 20, 2026

Session Time: 9:00 AM – 12:00 PM ET

Location: Poster Section 19

The abstract will be available on the AACR website. Following presentation, the poster will be available on the publications section of Immuneering's website at https://immuneering.com/publications.

About Immuneering

Immuneering is a late-stage clinical oncology company focused on keeping cancer patients alive and helping them thrive. The Company is developing an entirely new category of cancer medicines, Deep Cyclic Inhibitors, designed to improve overall survival by three mechanisms: shrinking tumors durably with less resistance, preserving body mass by countering cachexia, and minimizing side effects to maximize performance status and combinability. Immuneering's lead product candidate, atebimetinib, is an oral, once-daily Deep Cyclic Inhibitor of MEK, designed to improve survival across many cancer indications, including MAPK pathway-driven tumors such as pancreatic cancer. The company expects to dose the first patient in mid-2026 in MAPKeeper 301, a globally randomized pivotal Phase 3 trial evaluating atebimetinib in combination with chemotherapy in first-line pancreatic cancer patients. The Company's development pipeline also includes additional combination opportunities and early-stage programs. For more information, please visit www.immuneering.com.

Forward-Looking Statements

This press release contains forward-looking statements, including within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including, without limitation, statements regarding: the treatment potential of atebimetinib, alone or in combination with other agents to treat cancer, including modified Gemcitabine/nab-paclitaxel (mGnP) in first-line pancreatic cancer and its potential to deliver overall survival with both durability and tolerability; the ability of the three design mechanisms of atebimetinib to shrink tumors durably, improve overall survival and overcome the limitations of conventional MAPK inhibition and provide a more sustained clinical benefit for patients.

These forward-looking statements are based on management's current expectations. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the following: the risks inherent in oncology drug research and development, including target discovery, target validation, lead compound identification, and lead compound optimization; we have incurred significant losses, are not currently profitable and may never become profitable; our projected cash runway; our need for additional funding; our unproven approach to therapeutic intervention; our ability to address regulatory questions and the uncertainties relating to regulatory filings, reviews and approvals; the lengthy, expensive, and uncertain process of clinical drug development, including potential delays in or failure to obtain regulatory approvals; our reliance on third parties and collaborators to conduct our clinical trials, manufacture our product candidates, and develop and commercialize our product candidates, if approved; failure to compete successfully against other drug companies; protection of our proprietary technology and the confidentiality of our trade secrets; potential lawsuits for, or claims of, infringement of third-party intellectual property or challenges to the ownership of our intellectual property; our patents being found invalid or unenforceable; costs and resources of operating as a public company; and unfavorable or no analyst research or reports.

These and other important factors discussed under the caption "Risk Factors" in our Annual Report on Form 10-K for the period ended December 31, 2025, and our other reports filed with the U.S. Securities and Exchange Commission, could cause actual results to differ materially from those indicated by the forward-looking statements made in this press release. Any such forward-looking statements represent management's estimates as of the date of this press release. While we may elect to update such forward-looking statements at some point in the future, except as required by law, we disclaim any obligation to do so, even if subsequent events cause our views to change. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date of this press release.

Investor Contact:

Courtney Dugan

Cdugan@immuneering.com

Media Contact:

Gina Nugent

Gina.nugent.external@immuneering.com

Immuneering to Present Molecular Data at 2026 AACR Annual Meeting from Atebimetinib-Treated Patients, Highlighting Mechanism Designed to Improve Durability and Survival