Schering-Plough has started a major new clinical trial to evaluate the use of a low dose of its long-acting interferon alfa drug PegIntron as a maintenance monotherapy in preventing or delaying hepatitis C disease progression in patients who also have HIV.

If effective as a maintenance treatment, PegIntron (peginterferon alfa-2b) could help reduce the occurrence of clinical events such as liver transplantation, liver cancer and death in cirrhotic patients with hepatitis C who are co-infected with HIV.

Known as the ENDURE study, the trial is targeted to enroll 448 patients at approximately 80 sites worldwide, including centers in the United States, Europe and Canada. Approximately one third of HIV patients, or about 10 million people worldwide, also have the hep C virus (HCV).

Liver disease caused by chronic hepatitis C is now a leading cause of morbidity and mortality among HIV-infected patients in the developed world. Furthermore, studies have shown that HCV can aggravate the course of HIV infection.

Schering-Plough’s arch rival in the long-acting interferon alfa maket, Roche, has already won approval in the USA for its Pegasys (peginterferon alfa-2a) and Copegus (ribavirin) drug in the combination treatment of HCV and HIV co-infection, based on the results of the APRICOT study.

S-P said in a statement there are some patients with HCV and HIV who are not eligible for combination treatment, including those with severe cirrhosis of the liver.