Pharmaceutical giant Roche on Thursday announced that it has filed an application with the Food and Drug Administration to market a combination hepatitis C treatment to patients also infected with HIV. The company has already received approval to market its anti-hepatitis C drugs Pegasys and Copegus as a combination therapy for HIV-negative adults, but Roche is seeking the new approval to met an "unmet medical need," according to company officials. About 300,000 HIV-positive Americans also are infected with HCV, according to Roche, and a recent study by the company showed Pegasys-Copegus treatment reduced hepatitis C viral loads to undetectable levels in 40% of HIV patients treated with the drugs. Only 12% of HIV-HCV coinfected patients taking only Copegus and an older form of the drug interferon achieved undetectable HCV viral levels. The FDA granted fast-track status for the new application; a decision will be issued by next March.