Treating chronic hepatitis B (search) remains a challenge, but new research shows that a long-acting version of an old hepatitis drug works just as well as a combination approach.

A year of treatment with a long-acting interferon (search) called Peg-Intron (search) led to a sustained response in just over a third of patients. The response rate was higher than is typically reported with other treatments and was as effective as the combination of Peg-Intron and another hepatitis B drug, Epivir.

The findings are published in the Jan. 8 issue of the journal The Lancet.

“Patients on the combined therapy had a higher initial response rate, but the sustained responses were the same at (six months) follow-up,” lead researcher Harry Janssen, MD, tells WebMD.

International Study

Worldwide, more than 350 million people, including 1.25 million Americans, are chronically infected with hepatitis B. The virus is transmitted through body fluids and is 100 times more contagious than HIV. About 40 percent of chronically infected people who do not respond to treatment eventually develop potentially life-threatening liver disease. Symptoms typically do not occur until several decades after infection.

Recent research suggests that interferon in its longer-acting pegylated form is a more effective treatment for hepatitis B than the older, standard version of the drug. Two pegylated interferons are available, Pegasys and Peg-Intron. Peg-Intron’s manufacturer, Schering-Plough, partially funded the current study.

In this study, which included patients from 15 countries in Europe, East Asia, and North America, Janssen and colleagues treated 307 patients with Peg-Intron for one year. Some patients also received Epivir.

Patients in both treatment groups received 100 micrograms per week of Peg-Intron for eight months, followed by 50 micrograms per week for the remaining four months of treatment.

At the end of treatment 44 percent of the patients in the combination group had cleared the virus, compared with 29 percent treated with the interferon alone. Roughly six months later, however, sustained viral clearance was almost identical among the two groups -- 36 percent for those treated with interferon alone and 35 percent for those who received the combination treatment.

Virus Type Matters

The study by Janssen and colleagues is one of the first to suggest that the genetic makeup (genotype) of the virus helps predict treatment outcome. It’s well known that genotype affects hepatitis C treatment, but that has not been thought to be important in hepatitis B.

Response rates among patients with genotypes A and B averaged 45 percent, compared with about 27 percent among patients with genotypes C and D. The A and B genotypes are more common among whites, while C and D genotypes are more commonly seen in Asian populations.

“This is the first prospective evidence indicating that genotype is an important predictor of treatment response for hepatitis B in the same way that it is for hepatitis C,” Janssen says.

What the Experts Say

While the international study suggests that single-drug treatment with pegylated interferon is the most effective available treatment, two hepatitis B experts contacted by WebMD say it may not be the best choice for all patients.

Columbia University’s Howard Worman, MD, who has written several books on hepatitis treatment, says many patients are not able to tolerate the side effects of interferon treatment. Epivir and the similar hepatitis B drug Hepsera have few side effects and are taken by mouth instead of by injection.

“When you are considering individual patients you have to weigh response rates vs. the ability to tolerate interferon,” he says. “You can’t make a blanket statement that pegylated interferon is the best treatment for every patient.”

Eugene Schiff, MD, added that combination treatment with pegylated interferon and either Epivir or Hepsera might confer treatment advantages that were not evident in the study. Patients who got the combined therapy were taken off both pegylated interferon and Epivir after one year. Schiff says in clinical practice patients would probably be kept on Epivir if they were still responding to it.

“It is possible that the combined treatment group would have ended up with an ever-higher sustained response if they had been kept on [Epivir] or switched to [Hepsera] if resistance occurred,” he says.

But Schiff says the evidence is building that pegylated interferon will play a major role in the treatment of patients with chronic hepatitis B infection.

“If we continue to see data that is this persuasive, I think that even physicians who currently use other drugs to treat hepatitis B will be much more likely to use interferon,” he says.

By Salynn Boyles, reviewed by Michael W. Smith, MD

SOURCES: Janssen, H. The Lancet, Jan 8, 2005; vol 365: pp 123-129. Harry Janssen, MD, department of gastroenterology and hepatology, Erasmus University Medical Center, Rotterdam, Netherlands. Howard J. Worman, MD, associate professor of medicine, anatomy and cell biology, College of Physicians and Surgeons, Columbia University, New York. Eugene Schiff, MD, chief of the division of hepatology, University of Miami School of Medicine.