Hemab Therapeutics Begins Phase 1 Trial for HMB-003 to Treat Heavy Menstrual Bleeding

Hemab Therapeutics, a clinical-stage biotechnology company based in Cambridge, Massachusetts, and Copenhagen, Denmark, has announced the dosing of the first participant in a Phase 1 clinical trial for HMB-003, an investigational therapy aimed at managing heavy menstrual bleeding. The trial, which is being conducted under the identifier NCT07798505, marks a significant step in the company’s efforts to develop non-hormonal, long-acting treatment options for women suffering from this common condition.

According to the American College of Obstetricians and Gynecologists, approximately one in three reproductive-aged women experience heavy menstrual bleeding, a condition that affects more than 23 million women in the United States annually. Heavy menstrual bleeding is not only a significant health issue but also a leading cause of iron deficiency and anemia, leading to fatigue, shortness of breath, and difficulty concentrating. It is also a primary factor driving hysterectomies in the U.S., with about 600,000 such procedures performed each year.

HMB-003 is a novel fatty-acid-conjugated peptide antifibrinolytic designed to stabilize clots and reduce bleeding. Engineered to directly inhibit plasmin at its active site, HMB-003 blocks fibrinolysis independently of the plasminogen activation pathway. In preclinical studies, the compound demonstrated greater activity over tranexamic acid in various models. In minipigs, a single subcutaneous dose achieved peak plasma levels within hours and sustained antifibrinolytic activity for approximately one week, supporting the potential for cycle-matched, once-per-cycle dosing.

Benny Sørensen, MD, PhD, CEO of Hemab, stated, "Millions of women and girls live with heavy menstrual bleeding and have no approved non-hormonal, long-acting treatment option. Dosing our first participant with HMB-003, purpose-built for the management of heavy menstrual bleeding, is the first step toward resetting the standard of care for these women. Beyond heavy menstrual bleeding, we believe HMB-003 has the potential to become a cornerstone therapy for underserved patients across several large indications."

The Phase 1 study is a randomized, placebo-controlled, single-ascending-dose escalation trial designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of HMB-003 in healthy adult volunteers. Results from this study are expected to inform dose selection and clinical development plans for HMB-003 across additional high-unmet-need bleeding conditions.

Heavy menstrual bleeding, often referred to as "The Missed Vital Sign," is a common condition characterized by excessive menstrual blood loss that disrupts a person's physical, emotional, social, and daily life. The condition is frequently associated with pain, iron-deficiency anemia, and fatigue, and carries a significant social burden, including stigma and substantial lost days from work and school. Current treatment options are limited, with tranexamic acid (TXA) being the primary non-hormonal therapy, but it requires frequent dosing throughout menstruation, limiting adherence. Hormonal therapies are not suitable or preferred for many women, and there remains no approved non-hormonal, customized hemostatic treatment option for heavy menstrual bleeding.

Hemab Therapeutics is developing a range of therapies to address critical gaps in the treatment of coagulation disorders. In addition to HMB-003, the company is also in the clinical development phase for sutacimig (HMB-001), a bispecific antibody for the prophylactic treatment of Glanzmann thrombasthenia and Factor VII deficiency, and HMB-002, a monovalent antibody for the prophylactic treatment of Von Willebrand Disease. The company's mission is to discover, develop, and commercialize innovative therapies for the millions of patients worldwide suffering from serious bleeding and thrombotic diseases.

The results of this Phase 1 trial are expected to be shared no later than the middle of 2027, providing insights into the potential of HMB-003 for heavy menstrual bleeding and other bleeding conditions. Hemab's ongoing research and development efforts aim to improve the lives of millions of women and girls by offering effective, non-hormonal, and long-acting treatment options for heavy menstrual bleeding.