Ribavirin Therapy Shows Promise in Tests
Schering-Plough Corp.’s experimental hepatitis drug, Peg-Intron, is more effective than the standard treatment for chronic hepatitis C when the drug is combined with ICN Pharmaceuticals Inc.’s ribavirin, a study said.
Combining Peg-Intron with ribavirin reduced the virus to undetectable levels in 54% of patients, according to the study presented Tuesday. About 47% of patients on the standard treatment of Intron A and ribavirin, sold by Schering-Plough as Rebetron, had undetectable levels of the virus.
Schering-Plough, which is based in Madison, N.J., is in a race against Switzerland’s Roche Holding to market new hepatitis drugs. Both Roche’s Pegasys and Peg-Intron are improved versions of interferon, the standard treatment.
The combination of Peg-Intron and Costa Mesa-based ICN’s ribavirin “is a great improvement and an exciting step forward” in treating the disease, said John McHutchison, one of the study’s authors and medical director of liver transplantation at Scripps Clinic in La Jolla.
Ribavirin is available only in combination with Schering-Plough’s Intron A. Schering-Plough applied for Food and Drug Administration approval of Peg-Intron in January, and is likely to apply for FDA approval early next year to package it with ribavirin, the company said. Roche applied for FDA approval of Pegasys in May.
Schering-Plough’s Intron A is the world’s best-selling hepatitis drug.
Hepatitis C, a virus that can lead to cirrhosis and liver cancer, affects about 4 million people in the U.S. The virus is contracted mainly through infected blood and contaminated needles and is the leading cause of U.S. liver failures that require transplants.
Over 18 months, the Schering-Plough study looked at 1,529 patients with chronic hepatitis C, divided in three groups. One group received a standard combination of interferon and ribavirin, a second group received a low dose of Peg-Intron plus ribavirin and the third group received a higher dose of Peg-Intron plus ribavirin.
The group on the lower dose of Peg-Intron had about the same results as those receiving the standard treatment.
The third group had significantly better response rates. The virus was reduced to undetectable levels in 42% of patients with type I hepatitis C, the most widespread and difficult to treat type, compared with 33% of patients taking Intron A and ribavirin, the study said.
Peg-Intron and Pegasys were both designed to improve on standard Intron therapy. Both companies are expected to use studies such as the one presented Tuesday to try to persuade doctors to switch to the newer medications, if they are approved.
“There’s a huge marketing war going on. I think the two are going to be equivalent,” said McHutchison, who has also done research on Pegasys. “The issue is not going to be how effective they are by themselves, but how effective they are together with ribavirin.”
Roche presented 24-week results from an ongoing study showing Pegasys combined with amantadine, a generic drug for influenza, was more effective than standard interferon plus ribavirin or Pegasys plus amantadine and ribavirin, in patients who had not been treated before.
Amantadine causes less severe side effects than ribavirin, so the Pegasys-amantadine combination could rival any combination with ribavirin if final results back up the preliminary findings, said David Bernstein, director of hepatology at North Shore Hospital in New York and one of the study’s authors.
Roche medical director Chris Pappas said the company is conducting a study combining Pegasys and ribavirin, and expects results in May.
