Immuneering (IMRX) Study Update summary

Study background and design

• IMM-1-104 is a MEK inhibitor targeting the MAP kinase pathway, tested in combination with modified gemcitabine and nab-paclitaxel in first-line pancreatic cancer patients.

• The Phase II-A/2a study includes multiple arms, each enrolling 30 patients, with initial data from the combination arm presented.

• Modified chemotherapy regimen is less intensive and better tolerated than the standard, with historical response rates around 18.6%.

• Three arms focus on pancreatic cancer, with others targeting RAS mutant melanoma and non-small cell lung cancer.

• IMM-1-104 received FDA Fast Track designation for first- and second-line pancreatic cancer.

Initial efficacy results

• Among the first five evaluable patients, one achieved a complete response and another had an unconfirmed partial response with a 40% reduction in lesions; the complete response patient remained on therapy for over six months.

• Initial overall response rate is 40% and disease control rate is 80%, both exceeding historical benchmarks for gemcitabine/nab-paclitaxel alone.

• The remaining three patients showed stable disease or equivocal progressive disease, but all remain on treatment.

• CA19-9 tumor marker levels dropped significantly in two patients, supporting observed clinical responses.

• Preclinical data suggested synergy between IMM-1-104 and chemotherapy, leading to deeper responses than either agent alone.

Safety and tolerability

• The combination has been well-tolerated, consistent with the safety profiles of the individual agents.

• No unexpected safety signals or significant adverse events reported at the 240 mg dose; higher dose (320 mg) now approved for use, and additional patients have been dosed at this level.