This includes the recently FDA-approved Zepatier™, from Merck, and Daklinza™, from Bristol-Myers Squibb.
The new services enhance the ability of physicians to determine the type, dose or duration of treatment with direct acting antiviral agents (DAAs) therapies that inhibit the NS5A protein, which influences hepatitis C viral replication. The FDA has approved several DAA therapies that act by inhibiting NS5A, most recently Zepatier (elbasvir and grazoprevir) for the treatment of HCV in adults with genotypes 1 or 4 infections, in January 2016, and Daklinza™ (daclatasvir), in combination with sofosbuvir with or without ribavirin, for the treatment of patients with genotypes 1 or 3, in July 2015. The FDA approved an expanded indication for daclatasvir to include HCV patients with HIV-1 coinfection, advanced cirrhosis, or post-liver transplant recurrence of HCV in February 2016.
The hepatitis C virus is genetically diverse and can mutate, including during drug therapy, with genotypes 1 and 3 comprising most cases of HCV. Prescribing information for both Zepatier and Daklinza recommends laboratory testing to determine the presence of certain drug-resistance NS5A polymorphisms (genetic mutations) in patients with genotype 1a, a subtype of genotype 1. Guidelines updated in February 2016 from the American Association for the Study of Liver Diseases (AASLD) and Infectious Diseases Society of America (IDSA) recommend HCV genotype and subtype and quantitative HCV RNA (viral load) testing for all HCV patients prior to the initiation of antiviral therapies.
"These new Quest services underscore the value of diagnostics to advance precision medicine," said Rick L. Pesano, M.D., Ph.D., vice president, research and development, Quest Diagnostics. "Our new offerings can help improve health care quality and cost savings using specialty pharmaceuticals for an infectious disease, HCV, that is highly prevalent yet curable when treated appropriately. With insight into HCV NS5A status, the physician can better determine if the patient will not benefit from, or develops resistance to, an NS5A inhibitor, so an alternative treatment can be prescribed more quickly."