HUTCHMED’s sovleplenib delivers 66% durable hemoglobin response in Phase III warm AIHA trial; China NDA under priority review

HUTCHMED (China) Limited has released detailed Phase III data from the ESLIM-02 study evaluating sovleplenib in adults with warm antibody autoimmune hemolytic anemia (wAIHA) who relapsed after, or were refractory to, at least one prior glucocorticoid regimen. Results were presented on 11 June 2026 at the European Hematology Association (EHA) Congress in Stockholm.

The randomized, double-blind, placebo-controlled trial enrolled 90 patients in China, assigning sovleplenib 300 mg once daily (n=44) or placebo (n=46) for 24 weeks. Sovleplenib met the primary endpoint, achieving a 66% durable hemoglobin response during weeks 5–24 versus 15% for placebo (p<0.0001).

Key efficacy outcomes: • Overall response rate (Hb ≥100 g/L with ≥20 g/L rise from baseline, no rescue therapy): 70% with sovleplenib vs 22% with placebo (p<0.0001). • Median time to response: 3.1 weeks for sovleplenib vs 6.3 weeks for placebo. • Median cumulative duration of response: 16.1 weeks vs 6.1 weeks, respectively. • Use of protocol-defined rescue therapy: 16% vs 54% (p=0.0001). • Red-blood-cell transfusion requirement: 11% vs 43%. • Tapering or discontinuation of glucocorticoids/other baseline therapies: 50% vs 15% (p=0.003). • In patients previously treated with rituximab: durable response rate 69% vs 16% (p=0.0022).

Safety remained favorable. Grade ≥3 treatment-emergent adverse events occurred in 43% of sovleplenib recipients compared with 59% on placebo. The most frequent Grade ≥3 events were wAIHA (18% vs 43%) and upper respiratory tract infection (2% vs 11%). No treatment-related deaths or discontinuations were reported in the sovleplenib arm.

Regulatory progress is advancing rapidly. China’s National Medical Products Administration (NMPA) accepted the New Drug Application for sovleplenib in wAIHA with priority review in April 2026, following Breakthrough Therapy Designation granted in March 2026. The compound is also under priority review for immune thrombocytopenia (ITP) after positive Phase III data; China has an estimated 430,000 existing ITP patients and 41,000 new cases annually.

Sovleplenib is a selective oral Syk inhibitor designed to curb Fc-mediated red-blood-cell destruction and autoantibody production—mechanisms central to wAIHA pathology. HUTCHMED retains global rights to the asset.