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nAbCyte™ Hemophilia B

Testing Program Provided by Labcorp

Neutralizing Antibody Testing Program

The nAbCyte™ Anti-AAVRh74var HB-FE Assay (nAbCyte Assay) is indicated as a qualitative in vitro companion diagnostic device intended for the detection of neutralizing antibodies to the AAVRh74var capsid in serum specimens from patients previously diagnosed with hemophilia B to determine eligibility for treatment with the Pfizer® hemophilia B gene therapy, BEQVEZ™ (fidanacogene elaparvovec).

Learn more about how to order testing below. 

Healthcare providers can order the nAbCyte AAVRh74var HB-FE Assay (nAbCyte Assay) for eligible patients from whom they intend to prescribe BEQVEZ (fidanacogene elaparvovec) using the following test number:

  • Canada 007213

Program Participation

Step 1: Register for the Program

To order testing, healthcare providers must first complete a one-time enrollment in the program. Register for the program online using the form below.

Step 2: Receive Welcome Package

Once registration is complete, a representative from the Labcorp Program team will provide you with program account setup and detailed instructions for test ordering.

Step 3: Order the Test

Complete the nAbCyte-specific test request form (TRF) provided in your Welcome Package. Collect the specimen. Shipping instructions will be provided in your Welcome Package.

Step 4: Receive Results

Test results will be sent to the ordering healthcare provider within approximately 7-10 days from the time the sample is received at the lab. 

Current Market Availability: 

This testing program is currently only available in Canada and the United States. This program will become available in other regions throughout 2024. Please contact for further details.

Collection Instructions

The nAbCyte Anti-AAVRh74var HB-FE Assay for BEQVEZ (fidanacogene elaparvovec).

Eligibility in moderate to severe Hemophilia B, or nAbCyte Anti-AAVRh74var HB-FE Assay, is a cell-based qualitative in vitro companion diagnostic device intended for the detection of neutralizing antibodies to the AAVRh74var capsid in serum specimens from adult patients previously diagnosed with moderate to severe hemophilia B to determine eligibility for treatment with the Pfizer® hemophilia B gene therapy, BEQVEZ. Patients who test positive for neutralizing antibodies to the AAVRh74var capsid are not eligible for treatment with BEQVEZ. Patients who test negative for neutralizing antibodies to the AAVRh74var capsid are eligible for treatment with BEQVEZ.

Patients must have a confirmed diagnosis of hemophilia B and conform to the drug label.

Collection tube Red-top tube (glass or plastic clot activator, silicone-coated plastic red-top tube). 
Do not use gel-barrier tubes.
Sample type/volumeSerum/1 mL (preferred)
0.2 mL minimum (does not allow for repeat testing)
Submission tubeScrew-cap polypropylene transport tube.
Do not use snap-cap or pop-top tubes.
Sample handlingThe collection tubes should be filled and thoroughly mixed by manual inversion to mix the blood with the clotting activation agent. After mixing, allow the whole blood to clot for 30 minutes with the tube standing upright before centrifugation. Centrifuge the tube at 1500-2000 g for 15 minutes to separate the clot from serum.
Transfer serum into a 1.5-2.5 mL screw-cap polypropylene transport tube within 6 hours of collection. Freeze serum at -20°C in a non-defrosting freezer. Do not flash freeze on dry ice. Do not thaw the sample after freezing.
Shipping preparationFreeze sample prior to Labcorp courier arrival. Sample will be shipped on dry ice by Labcorp’s courier service.
Sample stabilitySerum frozen at -20°C for 1 month
Serum refrigerated at 4°C for 3 days
Serum ambient for 20 hours

For questions related to disease management and the clinical impact of a test result, please refer to prescribing information. 

Adverse events suspected to be associated with BEQVEZ (fidanacogene elaparvovec) should be reported directly to Pfizer Pharmacovigilance at https://www.pfizersafetyreporting.com

Additional Information

Our dedicated Program team is available to answer your questions about the program and the process. 

Have questions or concerns about the program or nAbCyte Assay? Contact Labcorp at nAbCyteHemB@labcorp.com or call 844-294-7361.

Need to report a BEQVEZ (fidanacogene elaparvovec) adverse event? Contact Pfizer at: 
https://www.pfizersafetyreporting.com/

BEQVEZ is a trademark of Pfizer Inc. nAbCyte is a trademark of Labcorp. ©2024 Labcorp. All rights reserved.

Healthcare Provider Program Attestation Language

By submitting the test request form, the healthcare provider (“You” or “Your”) is responsible for ordering testing under this program in accordance with Your own medical judgment and applicable laws. You understand that Pfizer will cover the cost of testing and shipping for eligible patients, and the testing will be performed by Labcorp. You understand that Labcorp may share aggregated, deidentified metrics with Pfizer. You understand the eligibility criteria set forth above and have determined that the patient meets those criteria. The patient has been informed by you that Pfizer covers the cost of the testing, and the patient understands that they are under no obligation to purchase or use any Pfizer or Labcorp products or services.