A securities class action has been filed against Mereo BioPharma Group plc (MREO) on behalf of all investors who purchased or otherwise acquired Mereo American Depositary Shares between June 5, 2023 through December 26, 2025. This case has been filed in the USDC – SDNY.
During pre-market hours on December 29, 2025, Mereo announced results from two Phase 3 studies for setrusumab, a treatment for conditions impacting bone metabolism. Neither study achieved statistical significance against the primary endpoints of reduction in annualized clinical fracture rate compared to placebo or bisphosphonates, respectively. Both studies achieved their secondary endpoints of improvements in bone mineral density against comparators (placebo and bisphosphonates) with strong statistical significance. There was no change in the safety profile observed.
On this news, Mereo’s stock price fell $2.02 per share, or 87.64%, to close at $0.28 per share on December 29, 2025.