Immuneering (IMRX) investor relations material

Current clinical progress and pipeline

• Phase III trial of third-generation MEK inhibitor atebimetinib is underway in first-line pancreatic cancer, with over 40 sites active and top-line readout expected mid-2028.

• Multiple ongoing studies include a phase II lung cancer trial in combination with cemiplimab, with first patient dosing expected by year-end and top-line results by end of next year.

• Phase II data in pancreatic cancer showed 84% of evaluable patients were weight stable or gained weight at three months.

• Additional phase II arms are ongoing, including combinations with standard-of-care regimens like FOLFIRINOX.

• Funding is secured through the anticipated phase III readout.

Differentiation and mechanism of atebimetinib

• Atebimetinib is a third-generation MEK inhibitor designed to address toxicity issues seen in earlier generations.

• Utilizes Deep Cyclic Inhibition technology, providing pulsed pathway inhibition for improved tolerability.

• Demonstrates efficacy in RAS mutant disease by blocking the CRAF bypass, a key resistance mechanism.

• Monotherapy data show significant reductions in rash and diarrhea compared to previous MEK inhibitors.

• Mechanistically distinct from first- and second-generation MEK inhibitors, offering a unique clinical profile.

Key clinical data and patient outcomes

• Phase II trial in first-line pancreatic cancer reported a median overall survival (OS) of 17.3 months, a result not achieved by any RAS inhibitor in this setting.

• Only two Grade 3 treatment-related adverse events (anemia and neutropenia) occurred in more than 10% of patients, both linked to chemotherapy.

• 60% of patients were able to proceed to second-line treatment, compared to 40% in the standard-of-care MPACT study.

• 84% of patients maintained or gained weight, supporting better quality of life and survival.

• Improved tolerability profile is expected to help patients maintain performance status and access subsequent therapies.