IMRX

EX-99.1

2 imrx-20260805xexx991.htm

EX-99.1

Document

Exhibit 99.1

Immuneering Reports Second Quarter 2026 Financial Results and Provides Business Updates

- 17.3 month median overall survival in 55 first-line pancreatic cancer patients treated with atebimetinib in combination with chemotherapy, reported in oral presentation at ASCO Annual Meeting on June 1 -

- Phase 3 MAPKeeper 301 trial is underway, with patients being dosed and over 30 study locations posted to date -

- Peer-reviewed publication in Cancer Research details atebimetinib’s broad, durable preclinical activity, and favorable tolerability across RAS- and RAF-mutant tumors, along with preservation of body mass -

- Ended Q2 2026 with $182.7 million in cash, cash equivalents and marketable securities with anticipated runway into 2029 -

NEW YORK, August 5, 2026 -- Immuneering Corporation (Nasdaq: IMRX), a late-stage clinical oncology company focused on keeping cancer patients alive and helping them thrive, today reported financial results for the second quarter ended June 30, 2026, and provided business updates.

“At a time when first-line pancreatic cancer patients finally have treatment options, the 17.3 month median overall survival reported at ASCO for atebimetinib in combination with modified gemcitabine/nab-paclitaxel (mGnP) in our single-arm Phase 2a study stands out as potentially best-in-class. Equally important in our Phase 2a data presented at ASCO is that 84% of evaluable patients treated with atebimetinib + mGnP were weight stable or gained weight at three months, and only two categories of treatment related adverse events occurred at a grade 3 or higher in at least 10% of patients. In other words, debilitating side effects may not have to be a given for patients. With over 30 study locations already posted on clinicaltrials.gov, and newly published preclinical data in the peer reviewed journal Cancer Research supporting atebimetinib’s unique mechanism of action, we believe our Phase 3 MAPKeeper 301 study represents a compelling and differentiated option for first-line pancreatic cancer patients.”

Recent Corporate Highlights:

•Dosing patients in the Company’s pivotal Phase 3 MAPKeeper 301 trial of atebimetinib + mGnP in first-line pancreatic cancer. In June, Immuneering announced it had dosed the first patient in MAPKeeper 301, a global, randomized, open-label pivotal Phase 3 clinical trial evaluating atebimetinib + mGnP in first-line metastatic pancreatic cancer patients.

•Presented compelling Phase 2a data at the ASCO 2026 Annual Meeting, demonstrating 17.3 month median overall survival and a favorable tolerability profile in 55 first-line pancreatic cancer patients, together with 84% of evaluable patients weight stable or gaining weight at 3 months. The Phase 2a trial is evaluating atebimetinib in combination with mGnP with results reported as of an April 24, 2026 data cutoff.

•Appointed Andrew Gengos as Chief Financial Officer. In June, Immuneering announced the appointment of Andrew Gengos as Chief Financial Officer. Mr. Gengos most recently served as Chief Financial Officer and Head of Corporate Development at Terns Pharmaceuticals, which Merck & Co., Inc. acquired for $6.7 billion. Mr. Gengos will oversee financial strategy, capital allocation, investor relations, business development, and corporate development activities.

•Published new findings in Cancer Research detailing atebimetinib’s broad, durable preclinical activity and favorable tolerability across RAS- and RAF-mutant tumors via Deep Cyclic Inhibition. In July, Immuneering announced the publication of an article in Cancer Research, a leading peer-reviewed journal of the American Association for Cancer Research, characterizing the differentiated mechanism and broad preclinical activity of atebimetinib. The article, “Dual-MEK Inhibitor Atebimetinib Displays Broad Activity in RAS- and RAF-Mutant Tumors via Deep Cyclic Inhibition and Resisting RAF-Bypass,” reports that atebimetinib demonstrated broad antitumor activity across RAS- and RAF-mutant models while resisting RAF-mediated bypass signaling, a key mechanism associated with resistance to other MEK inhibitors. Atebimetinib’s ability to preserve body mass in a preclinical model of cancer cachexia was also highlighted in the article.

•Presented Genetic Data at AACR demonstrating mechanism to improve durability and survival, supporting use of atebimetinib in first-line pancreatic cancer and beyond. In April, Immuneering presented new genetic data in a poster presentation demonstrating a key mechanism that may improve durability and survival, supporting the use of atebimetinib as a first-line treatment in pancreatic cancer and beyond. The circulating tumor DNA (ctDNA) data from 123 atebimetinib-treated patients showed that acquired MAPK pathway alterations were rarely seen. These findings suggest that Deep Cyclic Inhibitors have the potential to overcome the limitations of conventional MAPK inhibition and p

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imrx-202603060001790340FALSE00017903402026-03-062026-03-06

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 6, 2026

Immuneering Corporation (Exact name of Registrant as Specified in Its Charter)

Delaware001-4067526-1976972 (State or Other Jurisdiction of Incorporation)(Commission File Number)(IRS Employer Identification No.)

245 Main St. Second Floor Cambridge, MA 02142 (Address of principal executive offices) (Zip Code) (617) 500-8080 (Registrant’s telephone number, include area code) N/A (Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each classTrading Symbol(s)Name of each exchange on which registered Class A common stock, par value $0.001 per shareIMRXThe Nasdaq Global Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☒ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02. Results of Operations and Financial Condition. On March 6, 2026, Immuneering Corporation (the “Company”) announced its financial results for the quarter and the full-year ended December 31, 2025 and provided operational updates. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K (the “Current Report”). The information in this Item 2.02 of this Current Report, including Exhibit 99.1, is intended to be furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly provided by specific reference in such a filing.

Item 9.01. Financial Statements and Exhibits. (d)Exhibits The following exhibits relate to Item 2.02, which shall be deemed to be furnished, and not filed:

Exhibit No.Description 99.1Press Release issued on March 6, 2026

104Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

IMMUNEERING CORPORATION

Date: March 6, 2026 By: /s/ Benjamin J. Zeskind Name: Benjamin J. Zeskind, Ph.D. Title: Co-Founder, President, Chief Executive Officer and Director (Principal Executive Officer)