A pegylated interferon commonly prescribed as a therapy for hepatitis C has now won U.S. regulatory approval for treatment of hepatitis B. Hoffman-LaRoche Pharmaceuticals made the announcement about its HCV drug, peginterferon alfa-2a, branded as Pegasys, on May 13.
"Chronic hepatitis B infection is a serious disease that causes more than 5,000 deaths in the United States each year," said Roche's Medical Director, Salvatore Badalamenti, MD. "Pegasys now offers hepatitis B patients a treatment option that is taken for a fixed duration of 48 weeks with the goal of providing a lasting response after treatment is completed."
A First
The drug is approved as the first pegylated interferon for the treatment of hepatitis B, and is indicated for both variations of the virus: HBV e antigen positive (HBeAg+) and HBV e antigen negative (HBeAg-) chronic HBV. The latter is a mutant, or abnormal, form of the hepatitis B virus that has typically not responded as well to treatment compared to the more conventional form of the virus, HBeAg positive HBV.1
Peginterferon alfa-2a was initially approved in late 2002 as a treatment in combination with ribavirin for people diagnosed with chronic hepatitis C. The other pegylated interferon available as an HCV treatment is peginterferon alfa-2b, branded as PEG-Intron. Several months ago, Pegasys additionally received approval as a treatment for people with hepatitis C coinfected with HIV, the virus that causes AIDS, combined with ribavirin.
What Led to the Endorsement?
The latest FDA approval of Pegasys hinged on two multinational pivotal clinical trials involving more than 1,500 patients diagnosed with both HBeAg-positive and HBeAg-negative variations of chronic hepatitis B.2-4 In one study, presented at a medical meeting in mid-April, doctors tested the effectiveness of Pegasys plus placebo, Pegasys combined with lamivudine (Epivir-HBV) or lamivudine monotherapy. They found that those patients selected at random to receive one of the two Pegasys treatment plans had better response rates 1 year after treatment ended compared to those only taking lamivudine.
In a second study of HBeAg-positive hepatitis B patients released at the same medical conference, investigators also found more positive results in the groups of patients given Pegasys combined with Epivir-HBV than with Epivir-HBV alone.4
How Pegasys Works in HBV
Because of the study outcomes, lead investigators stated that Pegasys should become first-line treatment for both HBeAg-positive and HBeAg-negative chronic hepatitis B. Experts have found that Pegasys has two mechanisms of action against hepatitis B: it helps slow viral replication and also helps boost the immune response to the virus.
HBV Data
Hepatitis B is a form of liver disease caused by the hepatitis B virus, or HBV. It's estimated that more than 1 million people living in the United States are chronically infected with the virus, meaning they have it for the rest of their lives. Chronic infection boosts the risk of contracting liver cirrhosis or liver cancer, also known as hepatocellular carcinoma. Of those who do not develop chronic HBV infection, up to 95 percent clear the virus from their systems within a few months and develop an immunity. The virus is spread via one of several means:
• Sexual contact with an infected person.
• Use of illicit drugs.
• Vertical transmission (from mother to baby at birth)
• Living with a person infected with HBV
• Exposure to HBV-infected blood in a health care setting5
In addition to Pegasys, other medications commonly prescribed for HBV include Intron-A (interferon alfa-2b), Hepsera (adefovir dipivoxil), Epivir-HBV, and the recently approved Baraclude (entecavir).
1. Lagget M, Rizzetto M. Current pharmacotherapy for the treatment of chronic hepatitis B. Expert Opin Pharmacother 2003 Oct;4(10):1821-7.
2. Marcellin P, Lau GKK, Bonino F et al. Sustained response to peginterferon alfa-2a (Pegasys) in HBeAg-negative chronic hepatitis B. 1-year follow-up data from a large randomized multinational study. 40th Annual Meeting of the European Association for the Study of the Liver (EASL). 2005 Apr 13-17. Paris, France.
3. Marcellin P, Lau GKK, Bonino F et al. Peginterferon alfa-2a alone, lamivudine alone, and the two in combination in patients with HBeAg-Negative chronic hepatitis B. N Engl J Med 2004 Sep 16;351(12):1206-17.
4. Lau GKK, Piratvisuth T, Luo K-X et al. Peginterferon alfa-2a (Pegasys) versus peginterferon alfa-2a plus lamivudine versus lamivudine in HBeAg-positive chronic HBV: effect of previous treatment and drug exposure on sustained response. 40th Annual Meeting of the European Association for the Study of the Liver (EASL). 2005 Apr 13-17. Paris, France.
5. Centers for Disease Control and Prevention (CDC). Living With Chronic Hepatitis B. Available at: http://www.cdc.gov/ncidod/diseases/hepatitis/resource/PDFs/
Chronic_Hep_B_brochure.pdf. Accessed May 19, 2005.
John Martin is a long-time health journalist and an editor for Priority Healthcare. His credits include overseeing health news coverage for the website of Fox Television's The Health Network, and articles for the New York Post and other consumer and trade publications.
