MBX Biosciences (MBX) Piper Sandler 37th Annual Healthcare Conference summary

Key program updates and milestones

• Strong phase II AVAIL data for once-weekly canvuparatide in hypoparathyroidism, with 79% treatment response at six months and plans for end-of-phase I meetings with FDA and EMA in Q1, aiming to start global phase III in Q3 2024.

• Phase III will use a new single-use, patient-friendly injector device with a 1 mL volume and a starting dose between 400–600 mcg weekly, targeting a 24–26 week double-blind placebo-controlled design.

• 94% of AVAIL completers entered a two-year open-label extension; one-year data expected as a key catalyst in Q2 2026, focusing on efficacy, safety, urine calcium, bone biomarkers, and BMD.

• Regulatory pathways for FDA and EMA are aligned, with no anticipated differences in endpoints or process.

Market research and product differentiation

• Market research with 27 physicians and patient feedback indicate strong preference for once-weekly dosing due to convenience and comparable efficacy, with high enthusiasm from both prescribers and patients.

• Physicians indicated willingness to switch patients from once-daily to once-weekly therapy and to start new patients on the weekly option.

Pipeline progress and future catalysts

• GLP-1/GIP agonist (4291) leverages PEP technology for once-monthly dosing, aiming for improved GI tolerability and sustained weight loss; 12-week MAD data in 30 patients expected in Q4 2026.

• Phase I design includes SAD, MAD, and a 12-week cohort to assess PK, tolerability, and weight loss, with focus on achieving monthly dosing and steady-state tolerability.

• Multiple development and partnership options are being considered for advancing 4291 after proof-of-concept data.

• Third program, 1416, targets post-bariatric hypoglycemia with phase IIa data expected in Q2 2026; study will assess glucose nadir, insulin, and C-peptide changes in a 39-day, 10-patient trial.