Fidanacogene Elaparvovec

Fidanacogene Elaparvovec is a prescription medication indicated for the treatment of adults with moderate to severe hemophilia B (congenital factor IX deficiency) who:

• Currently use factor IX prophylaxis therapy, or
• Have current or historical life-threatening hemorrhage, or
• Have repeated, serious spontaneous bleeding episodes, and,
• Do not have neutralizing antibodies to adeno-associated virus serotype Rh74var (AAVRh74var) capsid as detected by an FDA-approved test.

Fidanacogene Elaparvovec is available under the following different brand names: Beqvez, fidanacogene Elaparvovec-dzkt.

Common side effects of Fidanacogene Elaparvovec include:

• increased liver enzymes (increase in transaminases)

Serious side effects of Fidanacogene Elaparvovec include:

• not available

Rare side effects of Fidanacogene Elaparvovec include:

• none 

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, coordination loss, unsteady, very stiff muscles, high fever, profuse sweating, or tremors.
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult dosage

Injection, suspension

• 1 x 1013 vector genomes/mL (1-mL vial)

Hemophilia B

Adult dosage

• 5 x 1011 vector genomes (vg)/kg
• Calculate the patient's dose weight
  • BMI less than or equal to 30 kg/m2: Use actual body weight
  • BMI more than 30 kg/m2: Dose weight (kg) = 30 kg/m2 x (height [m])2
• Calculate dose volume (mL)
  • Dose weight (kg) divided by 20 = dose in mL
  • Division factor 20 represents the amount of vg/mL in suspension – (1 x 1013 vg/mL) divided by the per kilogram dose (5 x 1011 vg/kg)

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Fidanacogene Elaparvovec has severe interactions with no other drugs
• Fidanacogene Elaparvovec has serious interactions with no other drugs
• Fidanacogene Elaparvovec has moderate interactions with no other drugs
• Fidanacogene Elaparvovec has minor interactions with no other drugs

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, health questions, or concerns.

Contraindications

• None

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Fidanacogene Elaparvovec?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Fidanacogene Elaparvovec?”

Cautions

• Hepatotoxicity
  • IV administration of a liver-directed AAV vector could lead to liver enzyme elevations, especially ALT elevation
  • Transaminase elevations, particularly when observed in the first 4 months after administration, are presumed to occur due to immune-mediated injury of transduced hepatocytes and may reduce the therapeutic efficacy of the AAV vector-based gene therapy
  • Monitor ALT, AST, and factor IX activity levels 1-2 times weekly for at least 4 months and institute corticosteroid treatment in response to transaminase elevation and/or decrease in FIX activity, as required
  • Monitor for and manage adverse reactions secondary to corticosteroid therapy
  • For the first year following administration, advise patients to limit alcohol consumption, since it may impact liver enzyme elevation and potentially reduce factor IX activity over time
• Infusion reactions
  • Infusion-related reactions, including hypersensitivity reactions and anaphylaxis, may occur
  • Symptoms include but are not limited to hypotension, pyrexia, palpitation, nausea, vomiting, chills, or headache
  • Monitor patients during and for at least 3 hours after completing infusion
  • If an infusion reaction occurs, slow or stop administration
  • Restart at a lower rate once the infusion reaction has resolved
  • Discontinue infusion for anaphylaxis
  • Consider management of an infusion reaction with a corticosteroid, antihistamine, and other measures
• Malignancy
  • Integration of liver-targeting AAV vector DNA into the genome may carry the theoretical risk of hepatocellular carcinoma development; integration of AAV vector DNA into the host cell DNA in other tissues may also occur
  • Monitor for hepatocellular malignancy in patients with risk factors for hepatocellular carcinoma (eg, hepatitis B or C, non-alcoholic fatty liver disease, chronic alcohol consumption, non-alcoholic steatohepatitis, advanced age) with regular ultrasound (eg, annually) and alpha-fetoprotein testing for 5 years after administration
  • If any malignancy occurs after treatment, contact t Pfizer Inc. at 1-800-438-1985 to obtain instructions on collecting patient samples for testing
• Monitoring laboratory tests
• Factor IX assays
  • When using an in vitro activated partial thromboplastin time (aPTT)-based one-stage clotting assay (OSA) for determining factor IX activity, plasma factor IX activity results can be affected by both the type of aPTT reagent and the reference standard used in the assay
  • Higher inter-laboratory and inter-reagent variability in OSA results observed at lower factor IX activity levels (0.025 IU/mL)
  • Consider this, particularly when changing laboratory and/or reagents used in the assay
  • Recommended to use the same laboratory (applicable to both, chromogenic or one-stage assays) for factor IX activity monitoring over time, particularly during the timeframe for corticosteroid treatment decision-making, to minimize the impact of inter-laboratory variability
• Factor IX inhibitors
  • Monitor patients through appropriate clinical observations and laboratory tests for the development of inhibitors to factor IX after Fidanacogene Elaparvovec administration
  • Perform an assay that detects factor IX inhibitors if bleeding is uncontrolled, or plasma factor IX activity levels decrease
• Drug interaction overview
  • Vaccinations
    • Do NOT administer live vaccines while on immunosuppressive therapy
    • Before infusion, ensure patients are up-to-date on their vaccinations
    • Consider adjusting individual vaccination schedules to accommodate concomitant immunosuppressive therapy

Pregnancy and Lactation

• Not intended for administration in women
• There are no data regarding use in pregnant women
• No animal reproductive studies have been conducted
• Contraception
  • Males
    • Vector DNA was shed in semen but declined to undetectable levels in semen within a mean of 1-4 months after infusion
    • Male patients should refrain from donating sperm, be abstinent, or use a male condom for up to 6 months after receiving Fidanacogene Elaparvovec
  • Fertility
    • No studies in animals or clinical studies have been performed to evaluate potential effects on fertility in humans
• Lactation
  • Not intended for administration in women.
  • Data are not available regarding the presence of Fidanacogene Elaparvovec in human milk, its effect on breastfed infants, and its effects on milk production