Gene therapy for hemophilia B: what to arrange before and after a single infusion

EastMedGo Nov 6, 2026

China first approved dalnacogene ponparvovec (Xinjiuning, BBM-H901) in April 2025 for adults with moderate to severe hemophilia B. Before deciding whether to travel abroad for an assessment, ask a hemophilia center in China and your local hematology team to confirm two things: whether you meet the screening criteria, and who can continue monitoring your liver function and factor IX activity after you return home.

Key points

This article covers only congenital factor IX deficiency.
Long-term follow-up is still needed after a single infusion, and the number of vials also varies with body weight.

What the hemophilia center will assess first

Gather records from the past year showing the number and sites of bleeds, emergency visits or surgery, the names of factor IX products used, preventive doses, and any additional doses given as needed. The center will also ask whether you have ever developed factor IX inhibitors and whether you have liver disease or viral hepatitis, and will test for antibodies related to the AAV vector according to the product requirements. Bring the original reports and details of the testing methods; antibody testing thresholds differ between products.

What a study of a single infusion can tell us

This therapy uses an adeno-associated virus vector to deliver the factor IX gene to liver cells. The pivotal phase III study in China was a single-arm study involving 26 people. At 52 weeks after infusion, the mean annualized number of bleeds was 0.60, with a 95% confidence interval of 0.18–1.99 bleeds. The study used a prespecified historical reference and had no concurrent randomized control group receiving factor replacement therapy. Bleeding may still occur after infusion, so arrangements for on-demand clotting factor replacement need to remain in place during follow-up. Hemgenix, which is approved in the United States, is a different product; eligibility, testing, and follow-up requirements must be checked against each product's own prescribing information.

How to estimate medication costs and your stay in China

The dose of dalnacogene ponparvovec is calculated by body weight, and each vial contains 2 mL. For example, for someone weighing 60 kg, a single dose is 75 mL, requiring 38 vials. Ask the center to list the number of vials, price per vial, and total medication cost based on your actual weight, and to quote separately for screening, observation during and after infusion, and repeat liver function and clotting factor tests.

Patients traveling from abroad should request a quote based on the actual amount they need. Before paying, ask the pharmacy to confirm in writing whether you qualify for free medication, and include hospital expenses and the number of days needed for local follow-up tests in your budget.

What to hand over to your hematology team before returning home

Obtain a record of the infusion date, product and batch number, baseline and recent liver function and factor IX activity results, monitoring frequency, and a plan for emergency factor replacement. Confirm whether your local laboratory can perform testing using a method accepted by the center, and who will contact the original treatment team if liver enzymes rise or new bleeding occurs. If you sustain a head injury or have severe bleeding, seek immediate care nearby according to your existing emergency plan.

Frequently asked questions

Can this also be used for hemophilia A?

The product's approved indication in China specifically covers hemophilia B. First check whether your medical records state factor VIII deficiency or factor IX deficiency.

Can adolescents book through the same process as adults?

This approval in China covers adults. Patients under the age of majority should be assessed by a pediatric hematology team based on their age and locally approved treatments.

What if I have a history of viral hepatitis?

Submit your hepatitis test results, treatment records, and liver function records together. The center will determine whether treatment is suitable and whether a liver specialist needs to be involved.

Can I discard my backup clotting factor after the infusion?

Keep access to emergency medication until your hematology team provides a written plan. You may still need factor replacement for bleeding, surgery, or injury.

What if the tests required by the center are unavailable locally?

Before booking treatment, confirm which laboratory can provide the reports, when samples can be sent for testing, and who will receive the reports. A single infusion cannot replace subsequent monitoring.