Please check your internet connection and try again.
# Durveqtix (fidanacogene elaparvovec)
## Overview
Durveqtix is an adeno-associated virus (AAV) vector-based gene therapy designed to deliver a functional copy of the human coagulation Factor IX (FIX) gene to the liver. It provides sustained endogenous production of FIX, potentially eliminating the need for routine prophylactic factor replacement in eligible patients.
## Primary Indications
Treatment of adults (18 years or older) with moderately severe to severe hemophilia B (congenital Factor IX deficiency) who do not have neutralizing antibodies to AAVRh74var.
## Adult Dosing
The recommended dose is **1.33 × 10¹³ vector genomes (vg) per kilogram** of body weight. It is administered as a single, one-time intravenous infusion.
## Pediatric Dosing
Safety and efficacy have not been established in patients younger than 18 years. **Not recommended for pediatric use.**
## Dose Adjustments
No dose adjustments are provided for renal or hepatic impairment. Dose modification is not applicable as this is a one-time gene therapy.
## Contraindications
* Known hypersensitivity to fidanacogene elaparvovec or any of its components.
* Presence of neutralizing antibodies to AAVRh74var (determined by a validated assay).
* Active, uncontrolled infections (acute or chronic).
## Adverse Effects
* **Common:** Increased liver enzymes (ALT/AST elevations), infusion-related reactions (nausea, fatigue, headache, fever), and increased creatine phosphokinase (CPK).
* **Serious:** Potential for hepatotoxicity and the development of neutralizing antibodies. Long-term risk of malignancy (theoretical risk of insertional mutagenesis) requires ongoing surveillance.
## Key Drug Interactions
* **Corticosteroids/Immunomodulators:** Systemic corticosteroids are typically required *before* and *after* administration (as part of a prophylactic tapering regimen) to manage potential immune responses and liver inflammation.
* **Hepatotoxic Agents:** Use with caution; monitor for additive liver stress.
## Monitoring
* **Liver Function:** Monitor ALT levels weekly for at least 3 months post-infusion to detect and manage potential immune-mediated hepatotoxicity.
* **Factor IX Levels:** Monitor FIX activity levels periodically to assess clinical response and therapeutic efficacy.
* **Safety:** Monitor for signs of infusion-related reactions during administration. Monitor for evidence of thrombotic events if FIX levels become supra-physiological.
## Clinical Pearls
* **Immunogenicity:** Pre-screening for AAVRh74var neutralizing antibodies is mandatory prior to infusion.
* **Management of ALT Elevation:** If ALT elevations occur, immediate initiation or intensification of corticosteroid therapy is indicated per clinical protocol to prevent loss of transgene expression.
* **Post-Therapy:** Patients may continue to require factor replacement therapy in the initial weeks post-infusion until stable endogenous FIX levels are achieved.
* **Reporting:** Patients should be enrolled in long-term observational registries due to the novel nature of this gene therapy.
***
**Disclaimer:** This information is for educational purposes for healthcare professionals. Clinical protocols, availability, and regulatory status may change. Always verify current prescribing information, institutional guidelines, and official FDA/EMA documentation before prescribing or administering therapy.
