How do you approach deciding which patients with hemophilia B to recommend for gene therapy?

There is no standard protocol for who gene therapy is recommended for, but certainly, potential candidates must meet all criteria according to the manufacturer's recommendations. Gray areas may exist if there is some preexisting liver disease, where hepatology consultation is desired to help determine candidacy. After that, individual patient characteristics are taken into account (i.e., is this someone you think will be compliant with the rigorous post-infusion monitoring schedule). Lastly, it goes without saying that the patient himself must be interested and motivated to proceed with treatment.

Regarding referral, I think this is appropriate for interested patients. I would recommend that the referring site ensure the basic requirements ...

Those of us involved in the care of patients with hemophilia feel like” kids in a candy store” with all these new wonderful treatments, as just in the last year we’ve had 3 FDA approvals of rebalancing agents-fitusiran, concizumab, and marstacimab, and the FIX gene therapy product Hemgenix has been approved since 2022. The uptake has been relatively low in the United States due to the prohibitive cost of approximately $3 million, though obviously, if yearly prophylaxis is costing $600,000 a year, it will pay in time, but it’s hard to convince insurers. It seems to be an option that is here to stay, unlike the factor VIII product that had poor durability. Hemegenix seems durable with levels remaining in the ~35% of the normal range at five y...

As mentioned above, there is no standard protocol. However, an example criterion used by one center to help decide eligibility for HEMGENIX is listed below. These guidelines were based on the clinical criteria used in the HOPE-B trial and the FDA package insert for HEMGENIX.

Consider HEMGENIX for adults with hemophilia B who meet all the following criteria:

• Male, 18 years and older
• Diagnosis of moderate (1-5% FIX) to severe (≤1%) hemophilia B
• No factor IX inhibitors on initial testing and repeat testing if indicated (repeat titers only if initial test is positive)
• No active hepatitis B or C infection, uncontrolled HIV infection, or evidence of advanced liver fibrosis
• Patient on factor IX prophylaxis therapy for at least 2 months, has at le...