Mereo BioPharma Group plc announced additional endpoint data from the Company's Phase 2b dose-ranging "ASTEROID" clinical study of setrusumab (BPS-804), an anti-sclerostin antibody, in adults with Type I, III or IV osteogenesis imperfecta. These additional prespecified endpoint data build upon the Company's 12-month topline data from the ASTEROID study announced in November 2019, which demonstrated a dose-dependent, statistically significant bone building effect of setrusumab at multiple anatomical sites in adult OI patients (irrespective of OI subtype). OI is a rare disorder characterized by fragile bones and reduced bone mass with no approved treatments. Additional Prespecified Efficacy Endpoint Results; The primary endpoint of the ASTEROID study was change in Trabecular Volumetric Bone Mineral Density (Tr. vBMD) of the radius (wrist) over baseline after 12 months of treatment as measured by High Resolution peripheral Quantitative Computed Tomography (HR-pQCT), followed by bone strength as calculated using FEA, a derived measurement of the mechanical strength gained by accumulated material in the bone. Setrusumab demonstrated a dose dependent increase in both failure load and stiffness at the radius at 12 months, achieving statistical significance in the high dose cohort across both of these parameters (p=0.037 for failure load and p=0.022 for stiffness). FEA is based on the totality of the bone compartments (trabecular and cortical bone) and these data demonstrate that treatment with high dose setrusumab results in a significant increase in bone strength at the peripheral bone sites, consistent with the previously reported statistically significant increases in total vBMD as measured by HRpQCT (a secondary endpoint of the study).