Hemophilia B, a serious inherited bleeding disorder caused by a deficiency of factor IX (FIX), has long required frequent intravenous infusions of clotting factors, placing a heavy physical, emotional, and financial burden on patients and their families. However, a promising gene therapy is transforming the treatment landscape.
BBM-H901, a gene therapy based on a recombinant adeno-associated virus (rAAV) vector, delivers an optimized human coagulation FIX gene directly into patients’ liver cells, enabling the continuous production and secretion of FIX to promote blood clotting naturally. According to Professor Zhang Lei, leading investigator of the registered clinical study at the Blood Disease Hospital, Chinese Academy of Medical Sciences, this one-time treatment can significantly reduce bleeding risks, prevent joint damage, and allow patients to return to a normal life — a breakthrough long awaited by China’s hemophilia community.
The clinical journey of BBM-H901 began with its first Investigator-Initiated Trial (IIT) in 2019. By 2022, results published in The Lancet-Hematology and The New England Journal of Medicine reported a mean FIX activity of 36.9 IU/dL among ten adult patients with moderate to severe hemophilia B, with no serious adverse events. Long-term follow-up data presented at the 2024 International Society on Thrombosis and Haemostasis (ISTH) Congress confirmed the stability of FIX activity over more than three years, with no drug-related safety concerns.
BBM-H901 has since received significant regulatory recognition, including Breakthrough Therapy Designation in China, Orphan Drug Designation (ODD) and Rare Pediatric Disease Designation (RPDD) from the U.S. FDA, and Advanced Therapy Medicinal Product (ATMP) status from the European Medicines Agency (EMA).
At the 66th Annual Meeting of the American Society of Hematology (ASH) in December 2024, BBM announced the positive results of its Phase III trial. After 52 weeks, participants had a mean annualized bleeding rate (ABR) of just 0.6, with FIX activity rising to an average of 55.08 IU/dL. Notably, 80.8% of participants experienced no bleeding events, and FIX infusions dropped from 58.2 times a year to just 2.9.
As follow-up continues, BBM-H901 represents a major step forward in hemophilia B treatment, offering lasting therapeutic effects and the potential for a better, more independent life for patients in China and beyond.
