Lead-in Study of VGB-R04 Gene Therapy for Hemophilia B-- An Observational Survey Analysis Study

Inclusion Criteria:

1. Male ≥18 years and ≤65years of age;
2. Confirmed diagnosis of hemophilia B (baseline FIX activity ≤ 2% of normal);
3. At least 50 days exposure history to FIX;
4. Currently receiving FIX Prophylaxis therapy or on-demand treatment to prevent bleeding;

5. Have acceptable laboratory values:

   1. Hemoglobin ≥110 g/L;
   2. Platelets ≥100×109 /L;
   3. AST, ALT, alkaline phosphatase ≤2×upper limit of normal (ULN) at the testing laboratory;
   4. Bilirubin ≤3× ULN ;
   5. Creatinine ≤1.5× ULN.
6. No measurable factor IX inhibitor as assessed by the central laboratory and have no prior history of inhibitors to factor IX protein;

Exclusion Criteria:

1. Have significant underlying liver disease within the past 6 months prior to or at Screening, including but not limited to:

   1. Preexisting diagnosis of portal hypertension;
   2. Splenomegaly;
   3. Encephalopathy;
   4. Reduction of serum albumin;
   5. Evidence of significant liver fibrosis;
2. Have anti-VGB-R04 neutralizing antibody titers ≥1:5;
3. Evidence of severe infection disease, i.e., human immunodeficiency virus (HIV) infection, syphilis, tuberculosis, etc.;
4. Novel coronavirus infection occurred in the 6 weeks prior to entry into the group
5. Evidence of active hepatitis B virus infection (HBsAg positive) or hepatitis C virus infection (HCV-RNA positive);
6. Evidence of malignant tumours or those with a previous history of malignant tumours;
7. Have a history of chronic infection or other chronic diseases that the Investigator considers to constitute an unacceptable risk;
8. Any immunodeficiency;
9. planned surgery may be required within one year;
10. Past thromboembolic events (arterial or venous thromboembolic events);
11. Hypertensive patients with poor blood pressure control (systolic blood pressure ≥150 mmHg or diastolic blood pressure ≥90mmHg after antihypertensive drug treatment);