US regulators have waved through Gilead’s Vosevi allowing the drug’s use to treat adults with chronic hepatitis C virus (HCV) genotypes 1-6 without cirrhosis (liver disease) or with mild cirrhosis.

Vosevi is a fixed-dose, combination tablet containing two previously approved drugs - sofosbuvir and velpatasvir - and new drug voxilaprevir.

It is the first treatment cleared by the US Food and Drug Administration for patients who have already received the direct-acting antiviral drug sofosbuvir or other NS5A inhibitors, providing a new option for those whose previous treatment has been unsuccessful.

“For patients who require re-treatment, there remains an unmet clinical need for an effective and well-tolerated option,” noted Ira Jacobson, chairman of the Department of Medicine at Mount Sinai Beth Israel, New York City and a principal investigator in the Vosevi clinical trials.

“Treatment with Vosevi resulted in high cure rates in clinical studies of patients who were not previously cured with several widely-prescribed DAA regimens and will provide physicians with an important new therapeutic option that could offer hope for their hardest-to-treat patients.”

The decision rides on the back of clinical data from two Phase III clinical trials involving around 750 HCV patients without cirrhosis or with mild cirrhosis. Both showed that 96-97 percent of those who received Vosevi had no virus detected in the blood 12 weeks post treatment.

On the safety side, the most common adverse reactions in patients taking the pill were headache, fatigue, diarrhoea and nausea, but the therapy also comes with a boxed warning in its product label regarding the risk of hepatitis B virus (HBV) reactivation in patients coinfected with HCV/HBV.

According to the US Centers for Disease Control and Prevention, an estimated 2.7 to 3.9 million people in the US have chronic HCV.

Vosevi is also currently under accelerated review in Europe, and recently won the support of the European Medicines Agency’s Committee for Medicinal Products for Human Use which backed its approval in June.