Mereo held $41.0 million cash at December 31, 2025, and reduced R&D expenses by $3.1 million, from $20.9 million to $17.8 million year-over-year. Cost-saving measures and delayed investments in manufacturing and pre-commercial activities for setrusumab extend the company’s operational runway into mid-2027 to support upcoming pipeline milestones.

Analyses from the Phase 3 Orbit and Cosmic trials of setrusumab (UX143) in osteogenesis imperfecta demonstrated statistically significant improvements in bone mineral density versus placebo or bisphosphonates and significant gains in patient-reported pain and daily activity outcomes. Although the primary endpoints of fracture rate reduction were not met, data showed reductions in vertebral fractures in pediatric and teenage subgroups, underpinning planned regulatory interactions.

Site feasibility has been completed for a single global Phase 3 pivotal study of alvelestat in alpha-1 antitrypsin deficiency lung disease, targeting approximately 220 early- and late-stage patients over an 18-month treatment period. The trial will use the St. George’s Respiratory Questionnaire Total Score as the U.S. primary endpoint and CT-measured lung density for European approval, while Mereo advances partnering discussions for development and commercialization.

Mereo outlicensed European rights to vantictumab for autosomal dominant osteopetrosis Type 2 to āshibio, which plans to initiate a Phase 2 study in the second half of 2026. Pre-clinical mouse data showed significant decreases in bone mineral density and rescue of the disease phenotype, targeting a rare disorder with no approved therapies and high unmet medical need.