Data presented at ISTH 2025 highlight potential for improved outcomes and quality of life in rare bleeding disorder

Takeda presented final results from a Phase 2 study evaluating mezagitamab (TAK-079), an anti-CD38 monoclonal antibody, in patients with persistent or chronic primary immune thrombocytopenia (ITP). The findings were shared at the International Society on Thrombosis and Haemostasis (ISTH) 2025 Congress in Washington, D.C.

The study enrolled 28 patients and demonstrated that treatment with mezagitamab led to a rapid and durable increase in platelet counts, along with improved health-related quality of life through week 16 compared with placebo.

Patients showed a platelet response as early as two days after the first dose, with duration of response increasing in a dose-dependent manner. The mean increase in platelet response duration compared with placebo was 4.9 weeks for the 100 mg dose, 6.9 weeks for 300 mg, and 9.6 weeks for 600 mg.

Health-related quality of life, measured by the ITP patient assessment questionnaire (ITP-PAQ), showed clinically meaningful improvements in patients treated with mezagitamab compared to placebo.

Mezagitamab met both primary and secondary endpoints, consistent with interim data reported at ISTH 2024. The incidence of treatment-emergent adverse events was similar between mezagitamab and placebo groups. At the highest dose tested (600 mg), 81.8% of patients achieved complete platelet response, 90.9% reached clinically meaningful platelet response, and all patients achieved a hemostatic platelet response.

“The significance of the TAK-079 trial is that it presents a new treatment option for ITP that is highly effective, works rapidly, and improves quality of life with minimal adverse effects,” said data presenter David Kuter, director of clinical hematology at Massachusetts General Hospital.

“These results in this very refractory, difficult to treat patient population are expected to be even more robust when administered to patients with earlier, more responsive disease. TAK-079 may ultimately provide long-term, treatment-free remission of this disorder,”  

These results follow positive 48-week data from a proof-of-concept trial of mezagitamab in primary immunoglobulin A nephropathy (IgAN), presented at the European Renal Association Congress in June. Takeda is in discussions with global regulators regarding Phase 3 plans for mezagitamab in IgAN.

Additionally, Takeda presented data from a Phase 3 trial evaluating recombinant von Willebrand factor in children with von Willebrand disease. These data support pending regulatory applications for the investigational on-demand treatment in paediatric patients.