Wolfgang Miesbach: A Snake Venom-Derived Factor X Activator for Haemophilia with Inhibitors
Wolfgang Miesbach, Professor of Medicine at Frankfurt University Hospital, shared on LinkedIn about a recent article by Wei Liu et al, published in Blood Advances:
”A snake venom-derived Factor X activator for haemophilia with inhibitors.
Published in Blood Advances, this multicentre phase II trial from China (9 centres, Chinese Academy of Sciences) evaluates bemiltenase alfa, purified from Daboia russelii siamensis (Russell’s viper) venom, as an on-demand haemostatic treatment for patients with haemophilia A or B and inhibitors (HAwI/HBwI).
Inhibitors complicate care in up to 30% of severe HA and 5% of severe HB patients.
Existing bypassing agents show variable efficacy — and crucially, no current non-factor therapy (emicizumab, fitusiran, concizumab) can treat active bleeding.
The mechanism of bemiltenase alfa: It directly activates Factor X — independently of FVIII or FIX — triggering a rapid thrombin burst via the common coagulation pathway.
Results of the clinical study
- Phase IIa: 94.1% effective haemostasis across 135 bleeding episodes
- Phase IIb: 81.9% effective haemostasis across 144 bleeding episodes
- Median time to resolution: 5.5 h from first dose
- Approximately 77% of bleeds controlled with 1–2 doses only
- Rescue therapy required in just 1.4% of episodes
- No serious adverse events, no DIC, no drug-related thromboembolism
How to use it
- IV injection, 0.10 U/kg every 4 hours (up to 6 doses per bleed)
- Half-life ~8 h; onset of APTT reduction and thrombin generation improvement within 10 minutes
- Higher dose (0.16 U/kg) available as escalation for non-responders
- An 8-hour dosing interval is under investigation
FDA Orphan Drug Designation granted June 2024. Phase III trial (NCT06922045) ongoing.”
Title: A specific FX activator for bleeding treatment in hemophilia with inhibitors: multicenter, open-label, phase I/II trials
Authors: Wei Liu, Hu Zhou, Ruibin Huang, Xin Du, Panjing Wang, Zeping Zhou, Changcheng Zheng, Shifeng Lou, Jun Ma, Yanping Song, Xinyue Dai, Xiaomin Wang, Renchi Yang, Lei Zhang
Read the Full Article on Blood Advances
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