Hemab Therapeutics Advances Bleeding Disorder Pipeline with Promising Clinical Data at ISTH 2025
Key Insights
Sutacimig (search) (formerly HMB-001) demonstrates promising interim Phase 2 safety and efficacy results for Glanzmann thrombasthenia (search), receiving WHO International Non-Proprietary Name designation.
HMB-002 shows initial proof of mechanism clinical data in Von Willebrand disease (search) patients through the ongoing VELORA Pioneer study, supported by comprehensive preclinical data.
Natural history studies reveal significant disease burden, with 88% of Glanzmann thrombasthenia (search) patients reporting at least one bleed weekly and 34% requiring medical treatment.
Hemab Therapeutics (search) announced significant progress across its bleeding disorder pipeline, with the company set to present 11 presentations at the upcoming International Society on Thrombosis and Haemostasis (ISTH) 2025 Congress in Washington, DC, on June 21-25, 2025. The clinical-stage biotechnology company, based in Cambridge, Massachusetts, and Copenhagen, Denmark, is developing novel prophylactic therapeutics for serious, underserved bleeding and thrombotic disorders.
The World Health Organization's Non-Proprietary Name Expert Committee has selected "sutacimig (search)" as the international nonproprietary name for the company's investigational drug previously known as HMB-001, designed for treating Glanzmann thrombasthenia (search) and Factor VII Deficiency (search).
Sutacimig Shows Promise in Glanzmann Thrombasthenia
Sutacimig (search) continues to demonstrate promising interim safety, pharmacokinetic, and efficacy results in Phase 2 studies for Glanzmann thrombasthenia (search). The subcutaneously administered bispecific antibody binds and stabilizes endogenous Factor VIIa with one antibody arm and binds to TLT-1 (search) on activated platelets with the other arm. This mechanism allows for the accumulation of endogenous Factor VIIa in the body and recruitment of Factor VIIa directly to the surface of activated platelets, where it facilitates hemostatic plug formation.
Interim efficacy data from the ongoing Phase 2 study demonstrated greater than 50% reduction in treated bleeds at all three tested dose cohorts. The study consists of a minimum 6-week prospective run-in period where participants record bleeds via an electronic diary, followed by 3 months of treatment with sutacimig (search).
"We're excited to attend ISTH 2025. Updated results from our sutacimig (search) Phase 2 study and late-breaking initial clinical data from our HMB-002 program demonstrate our commitment to developing transformative therapies for people living with underserved diseases like GT, Factor VII Deficiency (search), and Von Willebrand disease (search)," said Benny Sorensen, MD, PhD, CEO of Hemab.
The U.S. Food and Drug Administration has granted Fast Track Designation and Orphan Drug Designation to sutacimig (search) for the treatment of Glanzmann thrombasthenia (search), while the UK Medicines and Healthcare products Regulatory Agency has awarded it designation under the Innovative Licensing and Access Pathway.
HMB-002 Advances in Von Willebrand Disease
HMB-002, a monovalent human antibody developed as a first-in-class prophylactic treatment for Von Willebrand Disease (search), shows promise with initial proof of mechanism clinical data from patients in the ongoing VELORA Pioneer study. The therapy targets the underlying root cause of the disease by specifically targeting the C-terminal CK domain of Von Willebrand Factor, which is distinct from regions critical to its essential interactions. This approach shields the protein from degradation, boosting endogenous levels without compromising its function.
The first participant with Von Willebrand Disease (search) was dosed in the VELORA Pioneer Phase 1/2 clinical trial in February 2025. The study is designed to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy of HMB-002 in individuals with Von Willebrand Disease, with interim data anticipated later this year.
Preclinical data demonstrate that administration of HMB-002 to cynomolgus monkeys resulted in time-dependent accumulation of Von Willebrand Factor, a corresponding rise in Von Willebrand Factor activity, and an increase in Factor VIII (search) levels. The distribution of different sizes of Von Willebrand Factor molecules remained largely unchanged, suggesting consistent activity levels.
Significant Disease Burden Revealed
Natural history studies conducted by Hemab reveal the substantial burden of these bleeding disorders. Results from the international Glanzmann's 360 natural history study of 117 participants showed that 88% reported at least one bleed in the previous week, with 34% of those bleeds requiring medical treatment. These bleeding episodes significantly impact patients' mental health and quality of life, with 67% reporting low mood, 52% reporting emotional problems, and 46% experiencing social isolation. Additionally, 81% of participants reported missing school or work due to bruising or bleeding.
Von Willebrand Disease (search), the most common inherited bleeding disorder, is characterized by quantitative or qualitative defects in Von Willebrand Factor, often resulting in frequent mucocutaneous bleeding events and heavy menstrual bleeding in women. The severity of bleeding ranges from low-volume events to potentially life-threatening hemorrhages, with chronic blood loss frequently leading to iron deficiency anemia.
Conference Presentations
Hemab's presentations at ISTH 2025 will include interim data from the Phase 2 study of sutacimig (search) for prophylactic treatment in Glanzmann thrombasthenia (search), first-in-human safety and pharmacokinetic/pharmacodynamic data from the VELORA Pioneer study of HMB-002 in Type 1 Von Willebrand Disease (search), and comprehensive natural history insights from multiple bleeding disorder studies.
The company plans to complete Phase 2 study recruitment for sutacimig (search) in the first half of 2025, while actively enrolling participants in multiple studies for HMB-002, including the VELORA Discover prospective observational study for individuals with Type 1 Von Willebrand Disease (search).