Summary: The FDA approved Labcorp’s companion diagnostic test that is designed to determine eligibility for Pfizer’s BEQVEZ gene therapy for hemophilia B patients.
Takeaways:
- Labcorp’s nAbCyte Anti-AAVRh74var HB-FE assay is designed for pre-treatment screening to detect preexisting neutralizing antibodies in hemophilia B patients.
- The approval of Labcorp’s companion diagnostic test provides a critical tool for identifying the right patients for treatment with Pfizer’s BEQVEZ gene therapy.
- This screening from Labcorps CDx helps ensure that the gene therapy is safe and effective for the patient.
Labcorp announced the U.S. Food and Drug Administration (FDA) approved its nAbCyte Anti-AAVRh74var HB-FE Assay, a companion diagnostic (CDx) to determine patient eligibility for treatment with BEQVEZ (fidanacogene elaparvovec-dzkt), Pfizer’s recently FDA-approved hemophilia B gene therapy.
Considering the BEQVES Gene Therapy
The nAbCyte cell-based neutralizing antibody assay is a component of Pfizer’s program to target recombinant adeno-associated virus (rAAV)-based gene therapies to the appropriate patient population. Before infusion with BEQVEZ, patients will require testing for preexisting anti-AAVRh74var antibodies. Labcorp’s nAbCyte cell-based neutralizing antibody assay will allow for the accurate detection of preexisting neutralizing antibodies (nAbs), which could impact patient safety and/or efficacy of the one-time treatment.
“At Labcorp, we are committed to advancing cell and gene therapy and driving innovation that assists clinicians in making well-informed treatment decisions,” says Brian Caveney, MD, Labcorp’s president of early development research laboratories and chief medical and scientific officer. “Labcorp is proud to offer the first cell-based, companion diagnostic to receive FDA approval, which represents a pioneering breakthrough in the field of companion diagnostics and will help transform the therapeutic landscape and the lives of patients living with rare, genetically inherited conditions.”
Further reading: Labcorp’s New Blood Test Identifies Neurodegenerative Diseases and Brain Injuries
Impact of Hemophilia B
An estimated 6,000 people in the United States are living with hemophilia B, which is a rare inherited bleeding disorder that prevents normal blood clotting due to a deficiency in Factor IX (FIX), which causes those with the disease to bleed more frequently and longer than others. It is estimated that as many as 60% of the American population have preexisting anti-AAV antibodies, which could interfere with rAAV gene delivery, demonstrating the essential need for nAbCyte CDx testing prior to treatment with BEQVEZ.
“The approval of the nAbCyte companion diagnostic represents a first for a gene therapy that treats eligible patients with hemophilia B, helping to bring clarity to physicians and patients who are considering BEQVEZ as a treatment option,” says Sonal Bhatia, MD, head of U.S. Specialty Care Medical Affairs, Pfizer. “We believe this companion diagnostic is an important tool for evaluating patients who may be suitable for gene therapy as the treatment paradigm advances with the introduction of gene therapies like BEQVEZ.”
The results from the nAbCyte test will be reported qualitatively as negative (not detected) or positive (detected). A negative test result indicates that an individual with moderate to severe hemophilia B can be considered for BEQVEZ therapy.
The FDA approval of nAbCyte Anti-AAVRh74var HB-FE CDx builds on Labcorp’s comprehensive cell and gene therapy solutions, including specialized pre-clinical toxicology, biomarker and CDx development, and post-commercialization capabilities, the company says.
