InterMune Inc has presented interim findings from a retrospective clinical analysis done in collaboration with the New Jersey Medical Liver Center evaluating Infergen (interferon alfacon-1) plus Actimmune (interferon gamma-1b) combination therapy in patients chronically infected with hepatitis C virus (HCV) who have failed to respond to therapy with pegylated interferon alpha 2 plus ribavirin. These patients are referred to as nonresponders. The clinical analysis was presented at the Digestive Disease Week (DDW) 2004 meeting being held in New Orleans this week.
Approximately half of all patients treated with pegylated interferon alpha 2 plus ribavirin do not respond. There are approximately 150,000 nonresponders in the United States and the number is growing by an estimated 50,000 each year. Retreatment options for these patients are limited and generally provide very poor response rates.
"47 per cent of patients are HCV RNA negative at 24-weeks. Though early, this is very promising and may represent a significant improvement in treating this unmet medical need," said Carroll Leevy M.D., director of Clinical Affairs, The New Jersey Medical Liver Center and Sammy Davis Jr. National Liver Center, Newark, New Jersey. "I look forward to seeing the results of further investigations of this exciting interferon combination including InterMune's recently initiated Phase II study."
The results presented were a retrospective analysis conducted on 32 patients who had previously failed to show any significant reduction in viral load following 12 weeks of therapy with pegylated interferon alpha 2a plus ribavirin. This subpopulation of nonresponders is typically referred to as nullresponders and is considered to be one of the most difficult patient populations to treat. During the course of their clinical care, these patients were administered 15 micrograms of daily Infergen and 50 micrograms of Actimmune three times a week, and will be dosed for up to 48 weeks; ribavirin is not part of the regimen.
After 24 weeks of therapy with Infergen and Actimmune, 47 per cent (15/32) of patients had undetectable levels of HCV RNA in their blood. In addition, having received 12 weeks of pegylated interferon alpha 2a plus ribavirin therapy, all patients had depressed hemoglobin levels prior to receiving Infergen plus Actimmune therapy. During the course of therapy with Infergen and Actimmune, hemoglobin levels returned to normal without the addition of growth factors. No patients discontinued therapy. Eight patients received growth factor therapy for reductions in absolute neutrophil counts, a recognized side effect of alpha interferon therapy. Other side effects observed were consistent in incidence and severity with Infergen and Actimmune therapies.
There is a strong scientific rationale for combining Infergen and Actimmune for the treatment of hepatitis C nonresponders. Published clinical research has shown that endogenous levels of interferon gamma play an important role in the clearance of acute HCV infection from the blood. In addition, in vitro experiments undertaken at InterMune have demonstrated synergistic antiviral effects for a range of doses of Infergen and Actimmune in combination. Based upon this rationale and early clinical findings, InterMune recently initiated a Phase II clinical trial of the combination of daily Infergen plus Actimmune with or without ribavirin.
"Over the last year, InterMune's hepatology portfolio has risen to prominence as a major development opportunity for the Company," said Dan Welch, chief executive officer and president of InterMune. "The Company is currently conducting research to develop new treatment paradigms and expand the options for patients suffering from chronic hepatitis C, exemplified by this novel combination therapy which is now in a Phase II clinical study."