On May 12, 2026 Mereo BioPharma Group plc (NASDAQ: MREO) ("Mereo" or the "Company"), a clinical-stage biopharmaceutical company focused on rare diseases, reported financial results for the first quarter ended March 31, 2026, and provided an update on recent corporate developments.
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"Based on extensive analysis of data across the two global Phase 3 studies of setrusumab in osteogenesis imperfecta in collaboration with our partner Ultragenyx, we believe there is basis to engage with the regulatory agencies to determine if there is a path forward in pediatric patients. These interactions have been initiated, and we plan to provide updates once we have some definitive feedback. We continue to believe that setrusumab has the potential to provide meaningful benefit for people living with OI, a condition with no FDA or EMA approved therapies," said Denise Scots-Knight, Chief Executive Officer of Mereo. "We are engaged with potential partners for alvelestat in AATD-LD and believe alvelestat can quickly enter Phase 3 development following closing of a partnership transaction. Our other partnered program, vantictumab, is continuing to move forward with āshibio, who plan to initiate a Phase 2 trial in osteopetrosis in the second half of 2026. We continue to expect that our cash position, which totaled $36.2 million as of March 31, will provide runway into mid-2027, through several key inflection points expected during the remainder of this year."
Recent Corporate Developments and Anticipated Milestones
Setrusumab (UX143)
Further analyses of the data from the Orbit and Cosmic Phase 3 studies, including patient subgroups, have been completed.
While neither study achieved statistical significance against the primary endpoints of reduction in annualized clinical fracture rate compared to placebo (Orbit) or bisphosphonates (Cosmic), both studies achieved high statistical significance against the key secondary endpoint of improvement in bone mineral density versus control as well as reductions in vertebral fractures and improvements in patient reported outcomes (PROs) associated with disease severity, pain / discomfort and daily activities, with these PRO improvements achieving statistical significance in the Orbit study.
The safety profile of setrusumab was consistent with that observed in prior studies.
Based on the Phase 3 data analysis from both global Phase 3 studies and the safety profile of setrusumab, Mereo and its partner Ultragenyx believe there is a basis to engage regulatory agencies to determine if there is a path forward for setrusumab in pediatric patients. These interactions have been initiated.
Alvelestat (MPH-966)
Mereo is actively engaged in discussions with potential partners for the Phase 3 development and commercialization of alvelestat.
Based on previous discussions with the FDA and EMA, Mereo anticipates a single Phase 3 trial enrolling approximately 220 early- and late-stage AATD-LD patients evaluating alvelestat over an 18-month treatment period will support regulatory submissions in both the U.S. and Europe.
The primary efficacy endpoint for potential U.S. approval will be the St. George’s Respiratory Questionnaire (SGRQ) Total Score, with lung density measured by CT scan serving as the primary endpoint for potential European regulatory approval. These are independent primary endpoints.
The Company believes initiation of the Phase 3 study could happen within 6 months of closing a potential partnership transaction.
Vantictumab (OMP18R5)
The Company’s development partner for vantictumab, āshibio, Inc., is continuing to advance toward initiation of a Phase 2 clinical trial in autosomal dominant osteopetrosis Type 2 (ADO2), which is expected to commence in the second half of 2026.
āshibio is responsible for funding the global clinical program and holds the right to commercialize vantictumab outside of Europe, where Mereo has retained commercial rights.
First Quarter 2026 Financial Results
Total research and development ("R&D") expenses increased by $0.8 million, from $3.9 million in the first quarter of 2025 to $4.7 million in the first quarter of 2026. The increase was primarily due to increases of $1.8 million in R&D expenses for setrusumab, partially offset by reductions of $0.9 million in R&D expenses for alvelestat. The increase in program expenses for setrusumab was primarily driven by recognition of a payable for our share of certain costs related to the cancellation of manufacturing slots by our partner, Ultragenyx, partially offset by reductions of, and delays to, investment in manufacturing and ongoing activities, including medical affairs activities in Europe during the first quarter of 2026. The decrease in program expenses for alvelestat was primarily due to completion of activities undertaken in preparation for the potential Phase 3 study in the first quarter of 2025.
General and administrative expenses decreased by $3.3 million, from $7.3 million in the first quarter of 2025 to $4.0 million in the first quarter of 2026. The decrease was primarily due to the recognition of a $1.9 million reduction in expenses in the first quarter of 2026 for amounts received from our depository to reimburse certain expenses incurred by us in respect of our ADR program, and a reduction of approximately $1.4 million driven by delays to investment in pre-commercial activities to lay the foundation for the potential commercial launch of setrusumab in Europe, if approved, and other realized cost savings.
Net loss for the first quarter of 2026 was $6.7 million, compared to $12.9 million for the first quarter of 2025, primarily reflecting an operating loss of $8.8 million and foreign currency transaction gain of $1.6 million.
As of March 31, 2026, the Company had cash and cash equivalents of $36.2 million, compared to $41.0 million as of December 31, 2025. The Company’s guidance remains unchanged, and it continues to expect, based on current operational plans, that its existing cash and cash equivalents balance will enable it to fund its currently committed clinical trials, operating expenses, and capital expenditure requirements into mid-2027. This guidance does not include any potential payments associated with business development activity around any of the Company’s programs.
Total ordinary shares issued as of March 31, 2026 were 798,078,829. Total ADS equivalents as of March 31, 2026 were 159,615,765, with each ADS representing five ordinary shares of the Company.
(Press release, Mereo BioPharma, MAY 12, 2026, View Source [SID1234665583])