The US Food and Drug Administration (FDA) has announced a de novo classification petition to Quest Diagnostics‘ STRATIFY JCV Antibody ELISA testing service.

STRATIFY JCV is an FDA market authorised antibody-based blood test to help stratify progressive multifocal leukoencephalopathy (PML) risk in multiple sclerosis patients.

The blood test will qualitatively detect antibodies to the polyomavirus JC virus (JCV) for stratifying risk for PML, an infrequent but serious brain infection, in patients with multiple sclerosis (MS) receiving TYSABRI.

The FDA has approved a product label change for TYSABRI that identifies JCV antibody status as a PML risk factor. Others include duration of treatment with TYSABRI and prior immunosuppressant therapy use.

STRATIFY JCV was developed under an exclusive collaboration for the US market with Biogen, co-manufacturer with Elan of natalizumab. The test leverages technology licensed from Biogen and is exclusively offered through Quest‘s Focus Diagnostics laboratory in the US.

Quest discovery and development senior vice president Kathy Ordonez said STRATIFY JCV is an example of the capacity of pharmaceutical and diagnostic companies to collaborate to bring medical innovations.

"The test marks a significant step forward in the personalization of clinical management of MS patients who may benefit from natalizumab," Ordonez added.

Approximately 50% to 60% of MS patients have been infected with JCV. MS is an immune disorder affecting the central nervous system, alternating between remission and relapse and often progressively worsening over time.

The STRATIFY JCV Antibody ELISA testing service provided by Focus Diagnostics is intended for the qualitative detection of antibodies to the John Cunningham Virus in human serum or plasma.

The assay is used in conjunction with other clinical data, in multiple sclerosis and Crohn’s disease patients receiving natalizumab therapy, as an aid in risk stratification for progressive multifocal leukoencephalopathy development.