SCHEDULE 13G/A

MEREO BIOPHARMA GROUP PLC

American Depositary Shares, each representing five ordinary shares, nominal value of (pound)0.003 per share · CUSIP: 589492107

Event date: 2025-09-30

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• Mangrove Partners IM, LLC

  Shares: 38,952,900.00 · Class: 4.9%

• Nathaniel August

  Shares: 38,952,900.00 · Class: 4.9%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.