Phase III Study to Assess Safety and Effectiveness of Single Intravenous ZS801 Infusion in Adult Men with Hemophilia B and Low Factor IX Levels

What this Trial Is About

Researchers are evaluating the safety, tolerability, kinetics, and effectiveness of a single intravenous infusion of ZS801 in adult males with hemophilia B who have low levels of endogenous factor IX FIX 642%. Hemophilia B is a genetic disorder that reduces the ability of blood to clot, leading to repeated bleeding events, chronic joint disease, and potential life-threatening complications. ZS801 is a gene therapy using an adeno-associated viral vector to promote the production of human FIX to help improve clotting function. The study includes a dose-escalation phase where 16 participants receive increasing doses of ZS801 every 3 weeks or more between cohorts, with doses ranging from 2.01012 to 1.01013 vector genomes per kilogram. Following this, a dose-expansion phase will enroll 5 additional patients to receive the therapy. Treatment consists of a single intravenous infusion of ZS801, with careful monitoring of patients throughout the study period. Participants will undergo screening up to 6 to 8 weeks before receiving the infusion and will be observed for safety and efficacy for 52 weeks after treatment. Assessments include monitoring for adverse events, changes in vital signs and physical exams, laboratory abnormalities, and immune responses to the viral vector. The study also measures factor IX activity and antigen levels, as well as vector shedding. This comprehensive follow-up aims to evaluate how the gene therapy performs and its safety profile over one year.

A Study to Evaluate the Safety and Efficacy of ZS801 in Adult Hemophilia B Patients