Shares of HUTCHMED (NASDAQ:HCM) rose around 1.9% in premarket trading on Wednesday after the company reported positive Phase III results for sovleplenib in patients with warm antibody autoimmune hemolytic anemia (wAIHA).
The company said its pivotal ESLIM-02 study met the primary endpoint, with sovleplenib — a next-generation spleen tyrosine kinase (SYK) inhibitor — delivering a durable hemoglobin response during the treatment window from weeks 5 to 24 in adult wAIHA patients in China.
WAIHA is a rare autoimmune condition in which antibodies destroy red blood cells. It affects an estimated 17 out of every 100,000 adults and carries a mortality rate of roughly 8% to 11%. The disease represents around three-quarters of all adult cases of autoimmune hemolytic anemia.
The Phase III trial enrolled patients whose disease had relapsed or proved refractory after at least one standard line of therapy. Earlier Phase II data, published in The Lancet Haematology, showed an overall response rate of 43.8% versus 0% for placebo in the first eight weeks, rising to 66.7% over the full 24-week treatment period.
Commenting on the findings, Professor Fengkui Zhang of the Chinese Academy of Medical Sciences Blood Diseases Hospital, a principal investigator in the study, said: “The positive topline results from ESLIM-02 highlight sovleplenib’s potential to deliver rapid and durable hemoglobin responses in wAIHA patients who have limited options after failing standard therapies. This could represent a meaningful advancement for managing this challenging condition.”
Looking ahead, HUTCHMED said it plans to submit a New Drug Application for sovleplenib to China’s National Medical Products Administration in the first half of 2026. The company is also advancing development of the drug in immune thrombocytopenia, with an NDA resubmission targeted for the same period following encouraging Phase III results in that indication.