Exhibit 99.1 MEREO BIOPHARMA GROUP PLC Condensed Consolidated Statements of Comprehensive Loss (unaudited) Six months ended Six months ended June 30, June 30, 2023 2022 Notes £’000 £’000 Revenue 3 7,128 — Cost of revenue 3 (2,455) 352 Research and development expenses (7,898) (13,322) Administrative expenses (9,548) (8,840) Other operating income 3 2,864 — Operating loss (9,909 ) (21,810 ) Finance income 4 550 173 Finance costs 4 (1,498) (1,859) Changes in the fair value of financial instruments 4 365 1,210 ...