3.1.1f Beta Interferon, Recombinant (Betaseron, Avonex and Rebif)

Human interferon beta-1a has been approved in Europe, Canada, and Latin America for the treatment of multiple sclerosis.

According to a report in the Journal of Interferon and Cytokine Research 1997 Jan; 17(1):27-30, the intramuscular administration of interferon-beta (IFN-beta) at a dosage of 6 million units three times per week for 6 months was evaluated in 90 patients included in a multi-center, randomized, controlled trial for the treatment of chronic hepatitis C. At the end of the study, the researchers concluded that intramuscular IFN-beta, at the dosage used, has little efficacy in the treatment of chronic hepatitis C.

While the efficacy of beta-interferon has been proven to be ineffective when administered intramuscularly, a study reported at the 1996 Annual AASLD conference (“Therapy of Chronic Hepatitis C Non-Responders to Alpha-Interferon: A Preliminary Report of Intravenous Natural Beta-Interferon”) reports that beta-interferon has been proven to be efficacious when administered by intravenous infusion, and that intravenous beta-interferon can be a well tolerated effective treatment for patients with chronic hepatitis C non-responders to alpha-IFN.

Another study reported at the 1996 Annual AASLD conference (“Analysis of Amino Acid Residues 2209 to 2248 of NS5A of HCV-1b in Relation to the Response to Interferon Beta Therapy”), suggests that some HCV patients with genotype 1b who have a mutant type of the NS5A2209-2248 gene are sensitive to interferon beta therapy regardless of lower doses and shorter treatment periods compared to interferon alpha. HCV-1b patients with the intermediate or the wild type of the NS5A2209-2248 gene are resistant to interferon beta therapy.

Hepatogastroenterology 1999 Nov-Dec;46(30):3216-22 reports that beta-IFN therapy was not associated with a significant improvement either in biochemical or virological response in cirrhotic patients with chronic hepatitis C. No significant reduction of cirrhosis related clinical events was linked to treatment.

Clinical trials are still underway for the use of Rebif, Ares-Serono’s beta interferon, for hepatitis C, and are now in phase III trials in 250 Asian patients ( www.serono.com/pipeline/ 8/2003).