Clinical TrialMay 11, 2026, 07:07 AM
MBX Biosciences MBX 4291 Phase 1 Data Shows 7% Weight Loss, Monthly Dosing
AI Summary
MBX Biosciences provided an update on its obesity portfolio, including initial Phase 1 data for MBX 4291, a GLP-1/GIP co-agonist prodrug. The preliminary blinded data showed a mean weight loss of 7% at 8 weeks and a pharmacokinetic profile supportive of once-monthly dosing with good tolerability. The company also nominated MBX 5765 as its lead amycretin prodrug candidate and announced proof of concept for imapextide in post-bariatric hypoglycemia, though further investment in imapextide's Phase 2b will be deprioritized to focus on other programs.
Key Highlights
- MBX 4291 Phase 1 data showed mean weight loss of 7% (range 0-16%) at 8 weeks in first MAD Part B cohort (n=8).
- MBX 4291 demonstrated a T1/2Cmax of approximately 26 days, supporting potential once-monthly dosing.
- MBX 4291 was generally well tolerated, with only one subject experiencing GI-related adverse events through 8 weeks in first MAD Part B cohort.
- MBX 5765 was nominated as the lead amycretin prodrug candidate; IND-enabling studies expected in Q2 2026.
- Imapextide achieved proof of concept in PBH, with glucose nadir increases of 17-34% across doses.
- MBX 4291 12-week Phase 1 MAD Part C data remains on track for Q4 2026.
- Company expects to nominate its GLP-1/GIP/GCG receptor prodrug candidate in Q3 2026.
- MBX Biosciences has $440 million in cash, providing runway into 2029.
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