Do Futility Rules for HCV Triple Therapy Work?

Although triple therapy with either telaprevir or boceprevir is more effective than combination therapy for hepatitis C virus (HCV) infection, it is associated with significantly higher incidence of adverse events and the development of resistant variants. Therefore, to minimize unnecessary drug exposure in triple-therapy regimens, the U.S. FDA implemented futility rules when approving their use. So, are the rules working?

To examine the validity of the current rule for the telaprevir-based regimen (to cease all therapy in treatment-naive or -experienced patients if HCV RNA level >1000 IU/mL at week 4 or 12 or detectable at week 24), investigators retrospectively analyzed data from the telaprevir phase 3 trials.

Patients with HCV RNA levels >…