Also known as: UX 143, UX143
Setrusumab is an investigational anti-sclerostin monoclonal antibody being developed for osteogenesis imperfecta (OI). In June 2025, the FDA granted Breakthrough Therapy designation for setrusumab in children and adults with OI based on fracture risk reduction data from phase 2b and phase 3 studies. It is not yet approved for marketing.
Ultragenyx began a restructuring plan that includes a 10% workforce reduction and termination of UX143 manufacturing agreements. The company also faces a class action tied to setrusumab disclosures.
Class action lawsuits allege false statements about clinical trial results and regulatory prospects at Atara Biotherapeutics, Ultragenyx, Mereo BioPharma, and Vistagen Therapeutics. The complaints cite failed Phase 3 studies for setrusumab in Osteogenesis Imperfecta and fasedienol for social anxiety disorder, along with manufacturing issues affecting Atara's tabelecleucel application. Investors have deadlines ranging from April to May 2026 to seek lead plaintiff status.
Ultragenyx Pharmaceutical confronts multiple shareholder class action lawsuits over Phase III trial disclosures while reporting positive UX111 gene therapy data and implementing a 10% workforce reduction.
Ultragenyx Pharmaceutical faces federal securities class action lawsuits following the failure of Phase 3 Orbit and Cosmic studies for setrusumab in Osteogenesis Imperfecta, with stock falling over 42% after December 2025 results announcement.
| NCT ID | Title | Status | Phase |
|---|---|---|---|
| NCT06636071 |
Setrusumab in Pediatric Japanese Subjects With Osteogenesis Imperfecta |
ACTIVE_NOT_RECRUITING | PHASE3 |
| NCT05768854 |
Setrusumab vs Bisphosphonates in Pediatric Subjects With Osteogenesis Imperfecta |
ACTIVE_NOT_RECRUITING | PHASE3 |
| NCT05312697 |
Long-term Extension Study of Setrusumab in Adults With Type I, III, or IV Osteogenesis Imperfecta |
TERMINATED | PHASE2 |
| NCT05125809 |
Setrusumab vs Placebo for Osteogenesis Imperfecta |
ACTIVE_NOT_RECRUITING | PHASE2/PHASE3 |
| NCT03118570 |
A Study in Adult Patients With Type I, III or IV Osteogenesis Imperfecta Treated With BPS804 |
COMPLETED | PHASE2 |
