Immuneering Reports Third Quarter 2022 Financial Results and Recent Business Highlights Recruiting has Commenced for Phase 1/2a Clinical Trial of IMM-1-104 in Advanced Solid Tumors with RAS Mutations ( NCT05585320), with

Immuneering Reports Third Quarter 2022 Financial Results and Recent Business Highlights

Recruiting has Commenced for Phase 1/2a Clinical Trial of IMM-1-104 in Advanced Solid Tumors with RAS Mutations (NCT05585320), with the First Patient Expected to be Dosed this Quarter

Shares Promising Preclinical Data on Second Program IMM-6-415 at the 37th Annual Meeting of SITC, Demonstrating Preclinical Single Agent Activity in RAF and RAS Mutant Tumors and Enhancement of PD1 and CTLA4 Checkpoint Blockade

Cash, Cash Equivalents and Marketable Securities of $117.2M is Expected to Provide Cash Runway into Q3 2024

CAMBRIDGE, Mass., November 10, 2022- Immuneering Corporation (Nasdaq: IMRX), a biopharmaceutical company that aims to create medicines for all patients with solid tumors driven by RAS mutations and other MAPK pathway activation events, today reported financial results for the third quarter ended September 30, 2022, and provided recent business highlights.

"The third quarter was a turning point for Immuneering as we submitted and cleared our first IND. Our Phase 1/2a trial for IMM-1-104 is now recruiting in what we believe is the first all-comers RAS clinical trial conducted to date," said Ben Zeskind, Chief Executive Officer of Immuneering Corporation. "Cancer patients need new treatment options, regardless of the specific mutations in KRAS, NRAS, or HRAS that might be driving their tumors. IMM-1-104 has shown pan-RAS activity in preclinical studies with good tolerability. The conventional wisdom has been that a pan-RAS approach makes it difficult to avoid hitting wild-type RAS in healthy cells, but IMM-1-104's novel deep cyclic inhibition mechanism aims to focus the therapeutic activity against RAS-driven malignant cells with the goal of largely sparing healthy cells."

Dr. Zeskind continued, "Today, we also shared promising preclinical data on our second program IMM-6-415 at the 37th Annual Meeting of SITC. IMM-6-415 is designed to target RAF and RAS mutant tumors as monotherapy and enhance therapeutic activity in select drug-drug combinations, including checkpoint inhibitors. We are very encouraged by this data and look forward to completing ongoing IND-enabling studies and expect to submit an IND for IMM-6-415 in Q4 2023."

Corporate Highlights

Key Development Highlights

Third Quarter 2022 Financial Highlights

2022 Financial Guidance

About Immuneering Corporation

Immuneering aims to create medicines for all patients with solid tumors driven by RAS mutations and other MAPK pathway activation events. Immuneering has more than a decade of experience applying translational bioinformatics to generate insights into drug mechanism of action and patient treatment response. Building on this experience, Immuneering's disease-agnostic discovery platform enables the company to create product candidates based on 1) biological insights that are both counterintuitive and deeply rooted in data, and 2) novel chemistry. Immuneering's lead product candidate, IMM-1-104, aims to achieve pan-RAS activity that selectively impacts cancer cells to a greater extent than healthy cells. IMM-1-104 is designed to be a highly selective third generation dual MEK inhibitor that modulates the signaling dynamics of the MAPK pathway by driving deep cyclic inhibition that deprives tumor cells of the sustained proliferative signaling required for rapid growth, while providing a cadenced, normalized level of signaling designed to spare healthy cells. IMM-1-104 is being developed to treat advanced solid tumors in patients harboring RAS mutations, and is translationally guided by Immuneering's proprietary, human-aligned 3D tumor modeling platform combined with patient-aligned bioinformatics. In addition to IMM-1-104, Immuneering is currently evaluating IMM-6-415 in IND-enabling studies. The earlier Immuneering drug discovery pipeline includes five additional oncology programs as well as two neuroscience programs.

Forward-Looking Statements

This press release includes certain disclosures that contain "forward-looking statements," including, without limitation, statements regarding Immuneering's expectations regarding the treatment potential of IMM-1-104 and IMM-6-415, the timing of enrollment and dosing of the first patient in the Phase 1/2a clinical trial for IMM-1-104, the design, enrollment criteria and conduct of the Phase 1/2a clinical trial, the timing of submission of the IND and commencement of clinical trials for IMM-6-415, that the Phase 1/2a trial of IMM-1-104 is believed to be the first all-comers RAS trial conducted to date, statements regarding Immuneering's financial guidance and Immuneering's ability to advance its pipeline and further diversify its portfolio and make progress towards its longstanding goal of creating better medicines for cancer patients. Forward-looking statements are based on Immuneering'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 risks inherent in oncology and neuroscience drug research and development, including target discovery, target validation, lead compound identification, lead compound optimization, preclinical studies and clinical trials. These and other risks and uncertainties are described more fully in the section titled "Risk Factors" in Immuneering's most recent Form 10-Q filed with the U.S. Securities and Exchange Commission. Forward-looking statements contained in this announcement are made as of this date, and Immuneering undertakes no duty to update such information except as required under applicable law.

Rebecca Kusko, Ph.D.

Immuneering Corporation

S.A. Noonan Communications

IMMUNEERING CORPORATION

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