Phase 2a data for Immuneering (NASDAQ: IMRX) show 64% 12-month OS

Rhea-AI Filing Summary

Immuneering Corporation reported updated interim results from its ongoing Phase 2a trial of atebimetinib, an oral MEK inhibitor, combined with modified gemcitabine/nab-paclitaxel (mGnP) in first-line pancreatic cancer. In the initial intent-to-treat group of 34 patients treated at 320 mg once daily, 12‑month overall survival was 64% as of a December 15, 2025 cutoff, compared with 35% reported for standard of care in the MPACT trial. Median overall survival has not yet been reached, and median progression-free survival was 8.5 months.

Six‑ and nine‑month overall survival in this group was 94% and 83%, respectively, versus 67% at six months and an estimated ~47% at nine months for standard of care, based on MPACT data and company extrapolations. The combination was generally well tolerated, with Grade ≥3 treatment-emergent adverse events of anemia and neutropenia each in 18% of patients, no Grade 5 events, and no new safety signals. Immuneering outlined plans in 2026 to present additional circulating tumor DNA data, provide updated survival data from over 50 first-line pancreatic cancer patients, start a pivotal Phase 3 trial in first-line pancreatic cancer, and begin a trial with atebimetinib plus Libtayo in non-small cell lung cancer.

Positive

• Encouraging survival signals: In 34 first-line pancreatic cancer patients at 320 mg, atebimetinib plus mGnP showed 64% 12‑month overall survival versus 35% reported for standard of care in the MPACT trial, with median overall survival not yet reached and median progression-free survival of 8.5 months.
• Manageable safety profile: The combination remained generally well tolerated, with Grade ≥3 anemia and neutropenia each in 18% of patients, no Grade 5 events, and no new safety signals identified.
• Clear clinical development path: The company plans in 2026 to present additional biomarker data, expand survival data to over 50 first-line pancreatic cancer patients, initiate a pivotal Phase 3 trial in first-line pancreatic cancer, and start a trial with atebimetinib plus Libtayo in non-small cell lung cancer.

Negative

• None.

Insights

Oncology and biotech clinical development analyst

Early pancreatic cancer data look encouraging and are driving pivotal trial plans for atebimetinib.

The disclosure centers on interim Phase 2a data for atebimetinib plus mGnP in first-line pancreatic cancer. In 34 patients at the 320 mg dose, the regimen showed a 64% overall survival rate at 12 months versus 35% reported for gemcitabine/nab-paclitaxel in the MPACT trial, with median overall survival not yet reached and progression-free survival of 8.5 months. Six‑ and nine‑month survival of 94% and 83%, respectively, also compare favorably to MPACT-derived benchmarks.

Tolerability appears manageable, with Grade ≥3 anemia and neutropenia each in 18% of patients, and no Grade 5 events or new safety signals in this cohort. The company explicitly cautions that its trial is single-arm and that comparisons use historical MPACT data, including extrapolated estimates at nine months, so outcomes across trials may differ for reasons unrelated to drug effect.

Strategically, the company lays out a clear 2026 roadmap: presenting additional circulating tumor DNA data in Q2 2026, releasing updated survival data from over 50 first-line patients in the first half of 2026, initiating a pivotal Phase 3 pancreatic cancer trial in mid‑2026, and starting a trial in non-small cell lung cancer with atebimetinib plus Libtayo in the second half of 2026. These milestones, if executed, could substantially expand the clinical evidence base around atebimetinib.

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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): January 7, 2026

__________________________________

Immuneering Corporation

(Exact name of Registrant as Specified in Its Charter)

__________________________________

Delaware			001-40675			26-1976972
(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 class

Trading Symbol(s)

Name of each exchange on which registered

Class A common stock, par value $0.001 per share

IMRX

The 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 8.01 Other Events.

On January 7, 2026, Immuneering Corporation (the "Company") announced updated interim data from its ongoing Phase 2a clinical trial evaluating atebimetinib (formerly known as IMM-1-104), a once-daily oral mitogen-activated protein kinase kinase (or MEK) inhibitor, in combination with modified Gemcitabine/nab-Paclitaxel (“mGnP”) in first-line pancreatic cancer patients.

The Company announced that, as of a cutoff date of December 15, 2025 (the “Cutoff Date”), 64% overall survival (“OS”) at 12 months (with median follow-up time of 13.4 months) was observed in the initial intent-to-treat population of 34 patients dosed at the 320 mg once-daily dose level of atebimetinib in combination with mGnP (the “320 mg ITT Population”). The standard of care (described below) reported a 35% OS at twelve months. As of the Cutoff Date, the median OS of the 320 mg ITT Population had not been reached and the median progression free survival ("PFS") was 8.5 months.

As of the Cutoff Date, 94% OS and 83% OS were observed in the 320 mg ITT Population at six months and at nine months, respectively. The standard of care (described below) reported a 67% OS at six months; estimates of standard of care (described below) suggest a ~47% OS at nine months.

All data reported by the Company were from the same patient cohort (N=34) as the Company previously reported in September 2025.

The estimates of (and other references to) standard of care set forth above with respect to the six month and twelve month follow-up data were reported out directly from the publicly available third-party MPACT pivotal trial data for gemcitabine/nab-paclitaxel. The estimates of (and other references to) standard of care set forth above with respect to the nine month follow-up data were extrapolated and reconstructed by the Company based on the publicly available third-party MPACT pivotal trial data for gemcitabine/nab-paclitaxel. The Company’s Phase 1/2a clinical trial of atebimetinib does not include a head-to-head comparison against any other agents, and caution should be exercised when comparing data across trials.

The Company also announced that, as of the Cutoff Date, atebimetinib in combination with mGnP continued to be generally well tolerated. As of the Cutoff Date, Grade ≥ 3 treatment-emergent adverse events (“TEAEs”) observed in 10% or greater of patients in the 320 mg ITT Population consisted of Anemia (six patients or 18%) and Neutropenia (six patients or 18%). Grade ≥ 3 TEAEs observed in less than 10% of patients in the 320 mg ITT Population included Fatigue (6%), Leukopenia (3%), Vomiting (3%), Febrile Neutropenia (3%), Hypokalemia (3%) and Nausea (3%). No Grade 5 TEAEs were observed in this patient population and no new safety signals were identified.

The Company expects the following near-term anticipated milestones related to atebimetinib:

•Presenting further updated circulating tumor DNA data on acquired alterations from cancer patients treated with atebimetinib at a major scientific meeting, in the second quarter of 2026.

•Announcing further updated survival data from over 50 first-line pancreatic cancer patients treated with atebimetinib in combination with mGnP in the Company’s ongoing Phase 1/2a clinical trial, in the first half of 2026.

•Dosing the first patient in a pivotal Phase 3 clinical trial of atebimetinib in combination with mGnP in first-line pancreatic cancer patients, in mid-2026.

•Dosing the first patient in a clinical trial of atebimetinib in combination with Libtayo® in non-small cell lung cancer patients, in the second half of 2026.

Forward-Looking Statements

This Current Report on Form 8-K (this "Current Report") contains forward-looking statements, including within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this Current Report that do not relate to matters of historical fact should be considered forward-looking statements, including, without limitation, statements regarding: the Company’s plans to develop, manufacture and commercialize its product candidates; the treatment potential of atebimetinib, alone or in combination with other agents, including with mGnP in first-line pancreatic cancer and with Libtayo in non-small cell lung cancer; the timing of the Company's planned clinical trials (including a pivotal trial evaluating atebimetinib) and related patient dosing; and the timing, venue and content of the Company's future data releases and presentations.

These forward-looking statements are based only on the Company’s current expectations and are subject to inherent uncertainties, risks and assumptions that are difficult to predict. Factors that could cause actual results to differ include, but are not limited to, the important factors discussed under the caption “Risk Factors” in the Company’s Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2025, filed with the U.S. Securities and Exchange Commission (the “SEC”) on November 12, 2025, as such factors may be updated from time to time in the Company’s filings with the SEC, which could cause actual results to differ materially from those indicated by the forward-looking statements made in this Current Report. Any such forward-looking statements represent management’s estimates as of the date of this Current Report. While the Company may elect to update such forward-looking statements at some point in the future, except as required by law, it disclaims any obligation to do so, even if subsequent events cause the Company’s views to change. These forward-looking statements should not be relied upon as representing the Company’s views as of any date subsequent to the date of this Current Report.

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: January 7, 2026			By:			/s/ Michael D. Bookman
						Name: Michael D. Bookman
						Title: Chief Legal Officer and Secretary

FAQ

What clinical results did Immuneering (IMRX) report for atebimetinib in pancreatic cancer?

Immuneering reported updated interim Phase 2a data for atebimetinib plus modified gemcitabine/nab-paclitaxel in first-line pancreatic cancer. In 34 patients at 320 mg once daily, 12‑month overall survival was 64%, median overall survival had not been reached, and median progression-free survival was 8.5 months as of the December 15, 2025 cutoff.

How do atebimetinib survival rates compare to standard of care in the MPACT trial for IMRX?

Immuneering compared its results to gemcitabine/nab-paclitaxel data from the MPACT trial. Standard of care reported 35% overall survival at 12 months and 67% at six months, with the company estimating about 47% at nine months. The 320 mg intent-to-treat group showed 64% at 12 months, 94% at six months, and 83% at nine months, noting that these are cross-trial comparisons and should be interpreted with caution.

What safety profile was reported for atebimetinib plus mGnP in the IMRX trial?

The combination of atebimetinib and mGnP was described as generally well tolerated. Grade ≥3 treatment-emergent adverse events in at least 10% of patients were anemia and neutropenia, each occurring in 18% of the 34 patients. Less frequent Grade ≥3 events included fatigue, leukopenia, vomiting, febrile neutropenia, hypokalemia, and nausea, and no Grade 5 events or new safety signals were observed.

What near-term clinical milestones did Immuneering (IMRX) outline for atebimetinib?

Immuneering plans several milestones in 2026 for atebimetinib: presenting additional circulating tumor DNA data from treated cancer patients at a major scientific meeting in the second quarter, sharing updated survival data from over 50 first-line pancreatic cancer patients in the first half of the year, dosing the first patient in a pivotal Phase 3 pancreatic cancer trial in mid‑2026, and starting a trial in non-small cell lung cancer with atebimetinib plus Libtayo in the second half of 2026.

Does Immuneerings atebimetinib trial include a head-to-head comparison against another treatment?

No. The Phase 1/2a clinical trial of atebimetinib does not include a head-to-head comparison against other agents. The company states that its standard-of-care benchmarks are drawn from, or extrapolated from, publicly available MPACT trial data, and advises that caution should be exercised when comparing results across different trials.

What indications is Immuneering (IMRX) pursuing with atebimetinib based on this update?

Based on the current program, Immuneering is pursuing first-line pancreatic cancer using atebimetinib in combination with mGnP, with plans to initiate a pivotal Phase 3 trial, and is also preparing a trial of atebimetinib combined with Libtayo in non-small cell lung cancer in the second half of 2026.