New combination therapy from Gilead demonstrates a 96% success rate in trials.
The FDA announced it has approved Gilead Science’s Vosevi to treat adults with chronic hepatitis C virus (HCV). Vosevi is an orally administered, fixed dose tablet that combines two approved drugs—sofosbuvir and velpatasvir with a new drug, voxilaprevir. According to the FDA, Vosevi is the first treatment for patients previously prescribed with direct-acting antiviral sofosbuvir, or similar drugs to treat HCV that inhibit the NS5A protein.
HCV is a viral disease that causes inflammation of the liver and can lead to its diminished function or failure. Citing CDC statistics, the FDA noted that as many as 3.9 million people in the US suffer from chronic HCV. “Direct-acting antiviral drugs prevent the virus from multiplying and often cure HCV,” said Edward Cox, Director of the Office of Antimicrobial Products in the FDA’s Center for Drug Evaluation and Research. “Vosevi provides a treatment option for some patients who were not successfully treated with other HCV drugs in the past.”
Six distinct HCV strains exist and knowing the particular strain can help guide the treatment. “Approximately 75 percent of Americans with HCV,” explains the announcement, “have genotype 1; 20-25 percent have genotypes 2 or 3; and a small number of patients are infected with genotypes 4, 5 or 6.”
To evaluate the safety and efficacy of Vosevi, the drug went through two Phase III clinical trials, in which approximately 750 adults with mild cirrhosis and without cirrhosis were evaluated. One trial compared Vosevi and a placebo for three months with genotype 1 (and previously failed using NS5A) patients. This trial prescribed Vosevi to patients with 2, 3, 4, 5 and 6 genotypes. The other trial compared the new drug with 12 weeks of treatment with sofosbuvir and velpatasvir in adults with 1, 2, or 3 genotypes or who had failed with sofosbuvir but not on NS5A inhibitors.
The results of both trials, said the FDA, demonstrated that 96-97 percent of patients treated with Vosevi had no virus to detect after treatment, which suggests that the patients’ infection had been cured.