An FDA panel's unanimous endorsement of HCV candidates Victrelis boceprevir from Merck & Co. Inc. and telaprevir from Vertex Pharmaceuticals Inc. last week was hardly a surprise. However, the panel's lukewarm reception for response-guided therapy with the protease inhibitors except in a subset of treatment-naïve patients means it could be another five years before the majority of patients can reduce or eliminate interferon-based treatment.
In two separate meetings last week, FDA's Antiviral Drugs Advisory Committee voted 18-0 to recommend approval of both boceprevir and telaprevir in combination with standard of care consisting of pegylated interferon and ribavirin.
Vertex and Merck each showed triple therapy with a thrice-daily oral HCV NS3/4A protease inhibitor and SOC allows more patients to achieve a cure.
Both companies proposed using response-guided therapy (RGT) to shorten treatment duration from 48 weeks with SOC to 24-32 weeks in patients who quickly reach undetectable levels of HCV RNA.
But neither company provided RGT data for all the populations it hopes to include on its label, and because of this, the panel fully endorsed RGT regimens only for treatment-naïve patients who are not black.
That wasn't the only lesson for companies working on the next generation of direct-acting antivirals. In response to an eleventh hour question from FDA, the panel also made it clear that any new HCV candidate must be compared with a new standard of care - either boceprevir or telaprevir plus pegylated IFN and ribavirin.
Clinicians contacted by BioCentury agreed the triple combination will quickly become standard of care. But they hope to see an all oral regimen within five years that could eliminate the use of IFN altogether (see "HCV: The Next Generation").
Both compounds improved sustained viral response (SVR) rate, or cure rate, compared with SOC. This is significant, because in historical studies,