Advisers to the US Food and Drug Administration (FDA) have unanimously recommended approval of one of the first therapies to directly target the hepatitis C virus (HCV).
The Antiviral Drugs Advisory Committee voted 18 to 0 that Merck’s boceprevir should be approved for use in combination with the current standard therapy, the two antiviral drugs interferon and ribavirin. Later today, the same committee will vote on telaprevir, a similar drug produced by Vertex Pharmaceuticals in Cambridge, Massachusetts.
The FDA does not always follow the recommendations of its advisers, but it often does. Both drugs have long been expected to win approval.
The approvals would usher in a new generation of HCV treatments (see ‘New drug targets raise hopes for hepatitis C cure’). Pharmaceutical companies are racing to bring targeted HCV therapies to market. The need is high: about 3% of the world is infected, yet the current therapy benefits only about half of patients.
Meeting on 27 April, FDA advisers heaped praise on boceprevir which, like telaprevir, inhibits a critical HCV protein called a protease. One panel member said that to leap from 50% efficacy with standard therapy to an efficacy of about 70% with boceprevir “seems like a dream come true”.
But advisers were also cautious about the drug’s possible side-effects, particularly the risk of anaemia, and noted the need to educate physicians about those effects and how to treat them. “You need to be somewhat of a Talmudic scholar to prescribe this drug,” said Lawrence Friedman of the Massachusetts General Hospital in Boston. Several panelists also noted that the drug should be approved only for those infected with one of the eleven HCV genotypes, HCV genotype 1.
When asked what post-marketing studies they would recommend, panelists stressed the need for more data on how boceprevir may interact with other drugs. One called the lack of such information “shocking”, adding, “I know that there’s a race with all of these drugs, but I think it’s irresponsible that these studies haven’t been done before now.” In particular, panelists focused on the possible interaction between boceprevir and anti-depressants (a concern because one side effect of interferon can be depression), methadone, HIV therapies, and oral contraceptives.