Warm autoimmune hemolytic anemia is a rare and serious disorder with limited treatment options; RBC transfusions can provide short term relief but do not help correct the complicated pathogenesis. Autoantibodies coat RBCs marking them for macrophage phagocytosis shortening RBC lifespan and increasing RBC clearance. Several new drugs targeting the spleen tyrosine kinase, including sovleplenib, are under investigation since this kinase plays a crucial role in B cell activation for antibody production and phagocytosis of antibody-coated RBCs by macrophages. In a phase 2 double-blinded trial of sovleplenib conducted at 13 centers in China, 21 adult patients with warm autoimmune hemolytic anemia who had experienced glucocorticoid treatment failures were randomized 3:1 to receive 300 mg of oral sovleplenib once a day for eight weeks or placebo. Following the 8-week double-blind period, all patients received sovleplenib daily for at least 16 weeks. After the 8-week double-blind period, 44% (7/16) of patients on sovleplenib had a hemoglobin response of at least 100 g/L (10 g/dL) with an increase of at least 20 g/L from baseline compared to none (0/5) receiving placebo. After switching all patients to sovleplenib at week 8, the overall hemoglobin response rate was 67% (14/21) by week 24. Furthermore, patients receiving soveplenib had fewer RBC transfusions, and sovleplenib was safe. Larger studies are needed for sovleplenib and other drugs to treat autoimmune hemolytic anemia.
References:
- Berentsen, Sigbjørn. Expanding treatment options for warm autoimmune haemolytic anaemia. The Lancet Haematology 2025; 12(2); e84 – e85.
- Zhao X, Sun J, Zhang Z, Chen M, et al. Sovleplenib in patients with primary or secondary warm autoimmune haemolytic anaemia: results from phase 2 of a randomised, double-blind, placebo-controlled, phase 2/3 study. The Lancet Haematology 2025; 12(2); e97 – e108.
