Fidanacogene elaparvovec-dzkt — Drug Monograph

Brand names: Beqvez

Drug class: Other

Mechanism of Action

Beqvez is a recombinant adeno-associated viral (AAV) gene therapy using a novel AAV serotype Rh74var (AAVRh74var) capsid — engineered for efficient liver hepatocyte transduction with reduced pre-existing immunity compared to AAV5 or AAV8. The vector delivers a codon-optimized transgene encoding the FIX-Padua variant (human coagulation factor IX with a gain-of-function R338L point mutation). After IV infusion, the vector transduces hepatocytes, where the FIX-Padua transgene undergoes episomal expression, producing circulating factor IX at levels approximately 5–8× higher per copy than…

FDA Indications

• Moderately severe to severe hemophilia B (congenital factor IX deficiency) — adults who currently use factor IX prophylaxis, or who have current/historical life-threatening hemorrhage, or who have repeated serious spontaneous bleeding episodes, and who do not have neutralizing antibodies to AAVRh74var capsid (FDA approved April 26, 2024)

Common Side Effects

• Fatigue
• ALT/AST elevation (expected; requires corticosteroid management)
• Infusion-related reactions (flushing, nausea)
• Headache
• Arthralgia

Clinical Pearl

Beqvez and Hemgenix represent the two approved AAV-based gene therapies for hemophilia B, each using a different AAV capsid and the same FIX-Padua gain-of-function variant. Beqvez uses AAVRh74var — a primate-derived capsid with lower seroprevalence than AAV5, potentially allowing more patients to qualify. In the pivotal BENEGENE-2 trial (n=45), mean annualized bleeding rate decreased 71% and mean FIX activity rose to ~22 IU/dL at 15 months. The key clinical decision: test for AAVRh74var…

Related Therapies & Mechanisms

• Etranacogene dezaparvovec-drlb (Hemgenix) — Other · Hemophilia
• Adagrasib (Krazati) — Other
• Arsenic Trioxide (Trisenox) — Other
• Asparaginase (L-asparaginase, E. coli) (Elspar) — Other