MBX Biosciences (MBX) Barclays 28th Annual Global Healthcare Conference summary

Platform technology and clinical pipeline

• Precision endocrine peptides (PEPs) platform enables extended and controlled peptide drug exposure for endocrine and metabolic diseases.

• Cleared a key regulatory milestone with FDA for hypoparathyroidism, advancing to phase III in Q3 with a once-weekly PTH replacement therapy.

• Obesity portfolio includes MBX 4291 (GLP-1/GIP co-agonist prodrug) targeting once-monthly dosing and improved tolerability, with a 12-week multiple ascending dose readout in Q4.

• Additional obesity candidates include single and triple agonists, with candidate selection and development milestones in Q2 and Q3.

• Cash runway supports operations into 2029, providing flexibility for advancing programs.

Hypoparathyroidism program and phase III design

• Phase III will be a six-month, placebo-controlled study with a primary composite responder endpoint and a key secondary endpoint of urine calcium normalization.

• Open-label extension will follow for 78 weeks, with FDA agreement on study design and endpoints.

• Differentiation from competitors centers on pre-specified urine calcium endpoint, which could support label claims.

• Once-weekly dosing addresses significant patient burden and unmet need, with strong support from patients and endocrinologists.

• Market research indicates 80% of endocrinologists would switch patients from daily to weekly therapy if available.

Phase II data and upcoming milestones

• Avail phase II showed 63% response at 12 weeks and 79% at six months, with placebo rates comparable to competitors.

• Phase III will stratify for endogenous PTH to ensure balanced arms.

• One-year follow-up data from Avail phase II to be presented in Q2, including retention, response, biomarkers, urine calcium, bone mineral density, safety, and tolerability.

• Expectation is BMD will decrease but remain within normal range for the population.