HCAB Position Statement: Hepatitis C Drug Development and Drug-Drug Interaction Studies

February 2012 – The Hepatitis C Community Advisory Board (HCAB) recognizes the value of more effective and less toxic treatment for hepatitis C virus (HCV). We believe that sponsors can conduct key drug-drug interaction (DDI) studies with direct-acting antivirals (DAAs) and other candidates in development and medications commonly used by people with hepatitis C and those coinfected with HIV/HCV prior to their approval, without delaying development of these important therapies.

DAAs may share metabolic pathways with drugs that are commonly used by populations with a high prevalence of hepatitis C, such as hormonal contraceptives, methadone, buprenorphine, lipid lowering agents, immunosuppressive drugs, herbal remedies, and commonly prescribed psychiatric medications.

In recognition of the suboptimal efficacy and tolerability of peginterferon and ribavirin, rapid trajectory of liver disease progression and increasing mortality from HCV-related complications among HIV/HCV coinfected patients, regulators in the US and the EU encourage sponsors to conduct trials in HIV/HCV coinfected patients prior to approval for HCV monoinfection. Sponsors have already opened, or plan to launch these trials.

The recent discovery of drug-drug interactions between boceprevir and boosted HIV protease inhibitors underscores the importance of DDI studies with DAAs. Although we commend the sponsor, Merck, for opening one of the first coinfection trials with a DAA, we were outraged that Merck chose not to conduct DDIs with commonly used antiretroviral agents prior to launching the trial, and prior to gaining approval for boceprevir.  Vertex and Tibotec were able to bring telaprevir to market with a much fuller portfolio of DDI data, although both drugs were developed within the same timeframe.

HCAB asks FDA, EMA and pharmaceutical companies to work together to minimize potential harm to hepatitis C monoinfected and HIV/HCV coinfected patients from uncharacterized drug-drug interactions (DDIs). Furthermore, we call upon sponsors to perform DDI studies (as indicated by metabolic profile of their drug or drugs) with DHHS, EACS and WHO-recommended antiretroviral agents for first-line, and treatment-experienced HIV/HCV coinfected people prior to approval, and strongly encourage studies of hormonal contraceptives, methadone, buprenorphine, lipid lowering agents, immunosuppressive drugs, herbal remedies, and commonly prescribed psychiatric medications.