Hong Kong, Shanghai & Florham Park, N.J., June 12, 2026
HUTCHMED (China) Limited announced positive results from the Phase III portion of the ESLIM-02 study evaluating sovleplenib in patients with warm antibody autoimmune hemolytic anemia (wAIHA). The data, presented at the European Hematology Association (EHA) 2026 Congress in Stockholm, demonstrated that the investigational oral Syk inhibitor achieved rapid and durable hemoglobin responses while maintaining a favorable safety profile. The findings support sovleplenib’s potential to address a significant unmet medical need in wAIHA, a rare autoimmune blood disorder for which there are currently no approved targeted therapies. The results have already supported a New Drug Application (NDA) accepted for review with priority status by China’s National Medical Products Administration (NMPA).
Phase III Trial Achieves Primary Endpoint with Strong Response Rates
The randomized, double-blind, placebo-controlled ESLIM-02 Phase III study enrolled 90 patients with relapsed or refractory wAIHA who had failed at least one prior standard treatment. Patients received either sovleplenib 300 mg once daily or placebo for 24 weeks. The trial successfully met its primary endpoint, with 66% of patients receiving sovleplenib achieving a durable response between weeks 5 and 24 compared with 15% in the placebo arm (p<0.0001). The overall response rate also strongly favored sovleplenib, reaching 70% versus 22% with placebo. Patients treated with sovleplenib experienced a significantly shorter median time to response of 3.1 weeks, compared with 6.3 weeks for placebo, while maintaining a substantially longer cumulative duration of response. Importantly, the treatment demonstrated efficacy across all patient subgroups, including those previously treated with rituximab, highlighting its broad therapeutic potential.
Reduced Need for Rescue Therapy and Blood Transfusions
Beyond improving hemoglobin levels, sovleplenib significantly reduced disease burden and treatment dependency. Only 16% of patients receiving sovleplenib required rescue therapy, compared with 54% in the placebo group. The proportion of patients requiring red blood cell transfusions was also notably lower at 11% versus 43%, demonstrating meaningful control of hemolysis. Additionally, half of the patients treated with sovleplenib were able to taper or discontinue glucocorticoids or other baseline anti-wAIHA therapies, compared with only 15% of placebo-treated patients. Improvements in key hemolytic biomarkers further confirmed the therapy’s ability to alleviate ongoing red blood cell destruction, a hallmark of the disease. These findings suggest that sovleplenib may provide a more durable and targeted treatment approach while reducing reliance on chronic steroid use and supportive interventions.
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Favorable Safety Profile Supports Regulatory Advancement
Sovleplenib demonstrated a favorable safety profile throughout the study. Grade 3 or higher treatment-emergent adverse events occurred in 43% of patients receiving sovleplenib, compared with 59% of placebo-treated patients. The most common severe adverse events included worsening wAIHA and upper respiratory tract infections, both of which occurred less frequently in the sovleplenib arm. Notably, there were no treatment-related deaths or treatment discontinuations reported among patients receiving the investigational therapy. Based on these positive results, HUTCHMED has secured Breakthrough Therapy Designation and Priority Review from the NMPA for sovleplenib in wAIHA. The company is also advancing development of the therapy in immune thrombocytopenia (ITP), further expanding its potential role in treating autoimmune hematologic disorders. If approved, sovleplenib could become one of the first targeted therapies specifically developed for patients with warm autoimmune hemolytic anemia.
Source: HUTCHMED press release
