The government has approved a new indication for a well-known pegylated interferon currently used as hepatitis C therapy. Peginterferon alfa-2a, marketed as Pegasys, will soon be available for patients co-infected with hepatitis C and HIV, the virus that causes AIDS.
"Physicians can begin prescribing Pegasys for this indication now," said Pamela Van Houten, spokeswoman for drugmaker Hoffman La-Roche Pharmaceuticals.
"For the first time, the 300,000 Americans who are coinfected with hepatitis C and HIV have an FDA-approved hepatitis C treatment option," said Jeffrey Smith, director of Clinical Research at the American Foundation for AIDS Research (amfAR), in a statement. "Hepatitis C has become one of the leading killers of people with HIV because advances in HIV treatment are helping patients live longer and because hepatitis C progresses much more quickly to liver failure in people with HIV."
Pegasys was initially okayed by the government as a treatment for hepatitis C in 2002. It can be prescribed alone or in combination with Copegus (ribavirin) for the disease. It's now become the only treatment for hepatitis C in co-infected patients.
It will be up to individual physicians to determine when to treat coinfected patients, Van Houten explained. "But research suggests that as viral load becomes higher, liver damage increases, and the patient gets older, he or she is less likely to respond to hepatitis C treatment," she said. "So, these factors should be considered when making treatment decisions."
Basis for Government Approval
The FDA's approval hinged on a large clinical trial known as APRICOT evaluating the safety and efficacy of Pegasys in people coinfected with hepatitis C and HIV.1 In the trial of 868 patients, Pegasys was tested against the efficacy of interferon alfa-2a (Roferon-A), a form of standard interferon. Patients were assigned at random to one of 3 treatment groups: 180 micrograms (mcg) per week of Pegasys plus 800 milligrams (mg) daily of ribavirin, Pegasys monotherapy, or 3 million international units (IU) of Roferon-A three times per week plus ribavirin.
Patients underwent treatment for a total of 48 weeks, and investigators followed them for an additional 6 months. All patients were HCV positive, had compensated liver disease, and stable HIV disease, with or without antiretroviral therapy. At the end of the follow-up period, 40 percent of the patients taking Pegasys combination treatment achieved a sustained virologic response (SVR) compared to just 12 percent of those taking standard interferon plus ribavirin, and about one-fifth of those taking Pegasys alone.
A sustained virologic response is defined as the absence of detectable hepatitis virus for at least 6 months following the end of treatment.2
Side effects of treatment were generally the same as those seen in people with HCV alone, according to Hoffman LaRoche Pharmaceuticals, the manufacturer of Pegasys. Those included neutropenia, anemia, thrombocytopenia, weight loss and changes in mood.
"The safety and efficacy results from the APRICOT study and in our label can only be applied to Pegasys combination therapy," said Salvatore Badalamenti, MD, Roche's Medical Director.
Altered Disease Course in Coinfected Patients
In the United States, it's estimated that about 30 percent of people infected with HIV are also infected with hepatitis C. Approximately 50 to 90 percent of people who acquired HIV from injecting drugs are also infected with HCV. The natural infection of each viral disease is affected by the other one in co-infected people. For example, HIV causes liver disease to become worse, and boosts the risks of certain complications.3 According to Roche, HCV is more resistant to treatment in co-infected patients, as well.
Both the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH) recommended pegylated interferon combined with antiviral medication, ribavirin, as therapy for coinfected patients. "However, until now, no hepatitis C treatment had been FDA-approved specifically for HIV patients," Van Houten told Priority Healthcare.
1. Torriani FJ, Rodriguez-Torres M, Rockstroh JK et al. Peginterferon alfa-2a plus ribavirin for chronic hepatitis C virus infection in HIV-infected patients. N Engl J Med 2004 Jul 29;351(5):438-50.
2. Fried MW, Shiffman ML, Reddy KR et al. Peginterferon alfa-2a plus ribavirin for chronic hepatitis C virus infection. N Engl J Med 2002 Sep 26;347(13):975-82.
3. Tossing G. Treating hepatitis C in HIV-HCV coinfected patients. Infection 2002 Oct;30(5):329-31.
John Martin is a long-time health journalist and an editor for Priority Healthcare. His credits include coverage of health news for the website of Fox Television's The Health Network, and articles for the New York Post and other consumer and trade publications.
