In December 2011, a group of Maryland physicians published provisional treatment guidelines for the use of protease inhibitors in patients co-infected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) in the online version of the journal Clinical Infectious Diseases. The lead author was David L. Thomas, MD, Chief, Division of Infectious Diseases, Johns Hopkins School of Medicine in Baltimore, MD.
Two protease inhibitors (PIs) were approved by the U.S. Food and Drug Administration (FDA) in May 2011 for use in HCV genotype 1 patients, which account for approximately 70% of patients. Merck’s boceprevir, brand name Victrelis™, and Vertex Pharmaceutical’s telaprevir, brand name Incivek™, augment the standard therapy, the combination of interferon and ribavirin.
PIs belong to a class of drugs called direct-acting antivirals, which prevent viral enzymes from replicating. Success is measured by patients’ ability to “clear” the virus by achieving a sustained virological response (SVR) for at least six months after completing therapy. The inclusion of a protease inhibitor increases the likelihood that a patient with HCV genotype 1 will reach SVR in up to half the time–24 weeks vs. 48 weeks.
Although the new PIs were not approved for use in co-infected patients, interim data showed that these patients have a higher virological response when a PI was added to peginterferon/ribavirin and that adverse events were no different than patients with HCV alone. The study physicians are interested in the possible off-label use of these drugs in co-infected patients because their liver disease progression is more accelerated, pegylated interferon/ribavirin is less effective for them and liver transplantation is neither highly successful nor widely available to them.
The impetus for the recommendations was to provide the Maryland AIDS Drug Assistance Program with a framework to help guide the use of HCV drugs in co-infected patients. Thomas and his colleagues recommend that HIV should be well controlled before HCV treatment is begun and that prescribing physicians continually monitor HCV PI package inserts for specific drug interactions, including antiretrovirals that should not be combined with either Victrelis or Incivek. The guidelines also include a list of specific recommendations for both PI products.
“Approvals of boceprevir and telaprevir for treatment of HCV infection are major advances for the care of persons with chronic genotype 1 HCV infection,” concluded the authors. “Although the medications are not approved by the U.S. Food and Drug Administration for treatment of HIV/HCV-coinfected persons, the benefits of including these medications will outweigh the risks for some individuals. In the future, HIV/HCV-coinfected persons should be included at earlier stages in drug development so that practice guidelines can be based more on data and less on expert opinion.”
The guidelines, “Provisional Guidance on the Use of Hepatitis C Virus Protease Inhibitors for Treatment of Hepatitis C in HIV-Infected Persons,” were published online December 14, 2011, in the journal Clinical Infectious Diseases.
Source: Aidsmed.com, January 3, 2012; hivandhepatitis.com, January 17, 2012