Hemab Therapeutics (Nasdaq: COAG) has dosed the first healthy volunteer in a Phase I trial of HMB-003, a subcutaneous plasmin inhibitor designed ed to reduce menstrual blood loss with once-per-cycle dosing — a profile that would differentiate it from the only approved non-hormonal option in the space.
The first-in-human study is a randomized, placebo-controlled, single-ascending-dose escalation trial evaluating safety, tolerability, pharmacokinetics, and pharmacodynamics in healthy adults. No clinical data have been reported. Hemab said results will inform dose selection and broader development plans across bleeding indications, with a readout expected no later than mid-2027.
HMB-003 is a fatty-acid-conjugated peptide that directly inhibits plasmin at its active site, blocking fibrinolysis independently of the plasminogen activation pathway — a mechanism distinct from that of tranexamic acid (TXA), a short-acting antifibrinolytic. In preclinical models, Hemab said HMB-003 demonstrated greater antifibrinolytic activity than TXA.
TXA, approved by the FDA in 2009 for heavy menstrual bleeding (HMB), requires dosing throughout menstruation due to its short half-life. Bayer's hormonal IUD Mirena (levonorgestrel) is approved for HMB but is not suitable or preferred for many patients. No approved non-hormonal, long-acting hemostatic therapy exists for the indication, according to Hemab. The company introduced HMB-003 publicly at the ISTH 2026 Congress in July, when it also presented Phase I/II data from HMB-002 in Von Willebrand disease.