Preliminary blinded data from ongoing Phase 1 trial demonstrated mean weight loss of 7% (range 0-16%) at 8 weeks in first MAD Part B cohort (n=8, including 2 placebo)

MBX 4291 generally well tolerated, only one event of diarrhea, nausea or vomiting through 8 weeks in first MAD Part B cohort

MBX 4291 12-week Phase 1 MAD Part C data remain on track for Q4 2026

MBX 5765 nominated as amycretin prodrug development candidate, a novel GLP-1 / GIP / glucagon / DACRA agonist designed for once-monthly dosing, superior efficacy and improved tolerability

Imapextide Phase 2a STEADI™ trial results demonstrate positive proof of concept in post-bariatric hypoglycemia (PBH)

Company to host in-person and virtual Obesity Day today at 10:30 a.m. ET

CARMEL, Ind. and BURLINGTON, Mass., May 11, 2026 (GLOBE NEWSWIRE) -- MBX Biosciences, Inc. (NASDAQ:MBX), a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel precision peptide therapies for the treatment of endocrine and metabolic disorders, today announced multiple updates on its obesity portfolio. Preliminary blinded Phase 1 data for MBX 4291, a GLP-1/GIP co-agonist prodrug for obesity, demonstrate a pharmacokinetic profile supporting the potential for once-monthly dosing and competitive weight loss in the first multiple ascending dose (MAD) cohort. These results, along with additional pipeline updates, will be discussed at the Company's Obesity Day presentation today at 10:30 a.m. ET.