X0206 3 2024-01-01 0 0001719714 Mereo Biopharma Group plc MREO 0001687318 Sermon Charles C/O MEREO BIOPHARMA GROUP PLC 4TH FLOOR, ONE CAVENDISH PLACE LONDON X0 W1G 0QF UNITED KINGDOM 0 1 0 0 General Counsel American Depositary Shares representing Ordinary Shares 132376 D Share Options (Right to buy) 8.63 2025-09-25 American Depositary Shares 154474 D Share Options (Right to buy) 5.40 2029-05-20 American Depositary Shares 27500 D Share Options (Right to buy) 3.00 2029-07-23 American Depositary Shares 27500 D Share Options (Right to buy) 1.84 2030-02-20 American Depositary Shares 85000 D Share Options (Right to buy) 2.72 2031-02-01 American Depositary Shares 150000 D Share Options (Right to buy) 1.40 2032-01-14 American Depositary Shares 275000 D Share Options (Right to buy) 1.01 2033-01-25 American Depositary Shares 400000 D Performance Based Restricted Stock Unit 2025-01-25 American Depositary Shares 164000 D Each American Depositary Share ("ADS") represents five ordinary shares, nominal value GBP 0.003 per ordinary share, of the Issuer. This award is fully vested and exercisable. 25% of the shares underlying this share option vested and became exercisable on February 20, 2021, with the remainder vesting in equal monthly installments for the three years thereafter. 25% of the shares underlying this share option vested and became exercisable on February 1, 2022, with the remainder vesting in equal monthly installments for the three years thereafter. 25% of the shares underlying this share option vested and became exercisable on January 14, 2023, with the remainder vesting in equal monthly installments for the three years thereafter. 25% of the shares underlying this share option will vest and become exercisable on January 25, 2024, with the remainder vesting in equal monthly installments for the three years thereafter. Each performance based restricted stock unit ("PSU") represents the conditional right to receive one ADS and shall vest upon satisfaction of four escalating ADS price threshold values over a two year performance period. The number included in column 3 of Table II reflects the number of PSUs eligible for vesting. If a minimum ADS price threshold is not met, such PSUs may vest at zero ADSs. Reporting Person also beneficially owns 4 ordinary shares, nominal value of GBP 0.003 per share, of the Issuer. /s/ Charles Sermon 2024-01-02