Shares of MBX Biosciences Inc (NASDAQ:MBX) declined 8.3% in after-hours trading on Monday after the clinical-stage biopharmaceutical firm announced a shift in its executive leadership.
The company said Steve Hoerter, who has been serving as Executive Chairman of the board, will take on the combined roles of Chairman and Chief Executive Officer with immediate effect. He succeeds Kent Hawryluk, who stepped down from his positions as President and Chief Executive Officer and also left the board of directors.
Concurrently, MBX moved to formalize its finance leadership by appointing John Smither as permanent Chief Financial Officer. Smither had been serving as Interim Chief Financial Officer since March 2026.
Background on the incoming executives
Hoerter joined MBX's Board of Directors in April 2025 and was elevated to Executive Chairman in November 2025. His prior role was President and Chief Executive Officer at Deciphera Pharmaceuticals, where he oversaw the company's changeover to a commercial-stage business in the United States and Europe until its acquisition by Ono Pharmaceutical in 2024.
Smither brings over 25 years of industry experience to the permanent CFO role. His previous positions as Chief Financial Officer include Arcutis Biotherapeutics - where he led the company's initial public offering and four follow-on financings - and finance leadership roles at Sienna Biopharmaceutics, UNITY Biotechnology and Kythera Biopharmaceuticals.
Company programs and timeline
MBX reiterated that it is targeting three principal milestones in the second half of 2026:
- Initiation of the Phase 3 trial for canvuparatide in chronic hypoparathyroidism.
- Nomination of a GLP-1/GIP/GCGR triple agonist candidate for obesity.
- Release of 12-week multiple ascending dose data from MBX 4291.
The company develops precision peptide therapies for endocrine and metabolic disorders, leveraging its proprietary PEP platform.
Market response and context
The immediate market reaction was a decline in MBX shares during after-hours trading following the personnel announcements. The company, its pipeline activities and investor sentiment appear likely to remain focused on the upcoming program milestones and the execution under the newly confirmed leadership team.
MBX Biosciences said it remains on track to deliver the stated milestones in the latter half of 2026.