The Phase III registration stage of the ESLIM-02 study evaluating the novel spleen tyrosine kinase (Syk) inhibitor sovleplenib in adult patients with warm antibody autoimmune hemolytic anemia (wAIHA) has met its primary endpoint of durable hemoglobin (Hb) response during weeks 5 to 24 of treatment.

ESLIM-02 is a randomized, double-blind, placebo-controlled Phase II/III clinical trial conducted in China involving adult patients with primary or secondary wAIHA who were relapsed or refractory after at least one prior standard therapy.

Results from the Phase II stage of the study were published in The Lancet Haematology in January 2025, demonstrating encouraging hemoglobin benefits for sovleplenib compared to placebo, with an overall response rate of 43.8% versus 0% in the first 8 weeks.

The overall response rate at 24 weeks, including patients who crossed over from placebo, was 66.7% for sovleplenib, with a favorable safety profile.

Further details of the study can be found on clinicaltrials.gov under the identifier NCT05535933.

Professor Zhang Fengkui from the Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences, one of the principal investigators of the ESLIM-02 study, stated, "wAIHA is a highly heterogeneous and often chronic relapsing disease."

"Patients frequently experience symptoms such as fatigue, which severely impacts their quality of life, and if not effectively controlled, the condition can be life-threatening in severe cases."

"The positive top-line results from the ESLIM-02 study highlight the potential of sovleplenib to provide rapid and durable hemoglobin responses for wAIHA patients with limited treatment options after standard therapy failure, potentially marking a significant advancement in the treatment of this challenging disease."

Professors Han Bing from Peking Union Medical College Hospital and Zhang Liansheng from The Second Hospital of Lanzhou University also served as co-principal investigators for the study.

The complete dataset from the ESLIM-02 study will be submitted for presentation at an upcoming scientific conference.

HUTCHMED plans to submit a New Drug Application for sovleplenib for the treatment of wAIHA to the China National Medical Products Administration (NMPA) in the first half of 2026.