A new drug combination that includes a chemically modified form of interferon is much more effective at treating hepatitis C in patients who also are infected with HIV than the standard HCV therapy, according to two studies in the July 29 issue of the New England Journal of Medicine. The first study, by researchers at Massachusetts General Hospital, found that treatment with peginterferon and ribavirin suppressed HCV in 27% of 66 HIV-HCV coinfected patients studied; standard treatment with interferon and ribavirin suppressed HCV in only 12% of 67 patients. A second study by University of California, San Diego, scientists conducted in 19 counties showed that 40% of those treated with peginterferon and ribavirin had suppressed HCV levels after 48 weeks of treatment compared with just 12% of those receiving standard HCV therapy. Both studies found that peginterferon remained active in the body longer than interferon. The studies also showed that hepatitis C treatment did not have any effect on HIV antiretroviral drug therapy. Peginterferon is sold under the brand name Pegasys; it was approved by the Food and Drug Administration in October 2002. About 300,000 HIV-positive people in the United States also have hepatitis C.