HUTCHMED Highlights Sovleplenib Phase III ESLIM-01 Study and Hematological Malignancy Programs Data to be Presented at the upcoming EHA2024 Congress Hong Kong, Shanghai & Florham Park, NJ - Friday , May 17

HUTCHMED Highlights Sovleplenib Phase III ESLIM-01 Study and Hematological Malignancy Programs Data to be Presented at the upcoming EHA2024 Congress

Hong Kong, Shanghai & Florham Park, NJ - Friday, May 17, 2024: HUTCHMED (China) Limited ("HUTCHMED") (Nasdaq/AIM:HCM; HKEX:13) today announces that topline and subgroup results from the ESLIM-01 Phase III study of sovleplenib, as well as new and updated data related to novel investigational hematological malignancy therapies HMPL-306, HMPL-760 and tazemetostat, will be presented at the upcoming European Hematology Association ("EHA") Hybrid Congress, taking place on June 13-16, 2024 in Madrid, Spain and online.

ESLIM-01 is a randomized, double-blinded, placebo-controlled Phase III trial in China of sovleplenib in adult patients with primary Immune Thrombocytopenia ("ITP") who have received at least one prior line of standard therapy (NCT05029635). In 188 patients randomized to receive oral sovleplenib or placebo, sovleplenib demonstrated a clinically meaningful early and sustained durable platelet response in patients with primary ITP with durable response rate of 48.4% compared to zero with placebo (p<0.0001). The median time to response was 1.1 weeks with sovleplenib. It demonstrated a tolerable safety profile with grade 3 or above treatment-emergent adverse events (TEAEs) in 25.4% of patients with sovleplenib and 24.2% with placebo. Sovleplenib also significantly improved quality of life in physical functioning and energy/fatigue (p<0.05).

Most patients were heavily pretreated with a median of four prior lines of ITP therapy and a majority (71.3%) of the patients had received prior TPO/TPO-RA1 treatment. Further post-hoc subgroup analysis of the study demonstrated consistent clinical benefits across ITP patients regardless of prior lines of ITP therapies or prior TPO/TPO-RA exposure, regardless of TPO/TPO-RA treatment types and number of prior regimens.

In addition to the promising data in ITP, results from Phase II part of the ongoing ESLIM-02 Phase II/III study (NCT05535933) of sovleplenib for warm antibody autoimmune hemolytic anemia (wAIHA) will also be presented at the congress demonstrating encouraging hemoglobin (Hb) benefit compared with placebo, with overall response rate of 43.8% vs. 0% in the first 8 weeks, and overall response rate of 66.7% during the 24 weeks of sovleplenib treatment (including patients that crossed over from placebo). A favorable safety profile was also demonstrated.

Details of the presentations are as follows:

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the "safe harbor" provisions of the U.S. Private Securities Litigation Reform Act of 1995. These forward-looking statements reflect HUTCHMED's current expectations regarding future events, including but not limited to its expectations regarding the therapeutic potential of sovleplenib, HMPL-306, HMPL-760 and tazemetostat, the further clinical development for sovleplenib, HMPL-306, HMPL-760, tazemetostat and amdizalisib, its expectations as to whether any studies on sovleplenib, HMPL-306, HMPL-760, tazemetostat and amdizalisib would meet their primary or secondary endpoints, and its expectations as to the timing of the completion and the release of results from such studies. Such risks and uncertainties include, among other things, assumptions regarding enrollment rates and the timing and availability of subjects meeting a study's inclusion and exclusion criteria; changes to clinical protocols or regulatory requirements; unexpected adverse events or safety issues; the ability of sovleplenib, HMPL-306, HMPL-760, tazemetostat and amdizalisib, including as combination therapies, to meet the primary or secondary endpoint of a study, to obtain regulatory approval in different jurisdictions and to gain commercial acceptance after obtaining regulatory approval; the potential markets of sovleplenib, HMPL-306, HMPL-760 and tazemetostat for a targeted indication, and the sufficiency of funding. Existing and prospective investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. For further discussion of these and other risks, see HUTCHMED's filings with the U.S. Securities and Exchange Commission, The Stock Exchange of Hong Kong Limited and on AIM. HUTCHMED undertakes no obligation to update or revise the information contained in this press release, whether as a result of new information, future events or circumstances or otherwise.

This press release contains information about products that may not be available in all countries, or may be available under different trademarks, for different indications, in different dosages, or in different strengths. Nothing contained herein should be considered a solicitation, promotion or advertisement for any prescription drugs including the ones under development.

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1 TPO = Thrombopoietin; TPO-RAs = Thrombopoietin receptor agonists.