Newer Hepatitis B Drug Bests Standard Treatment
Entecavir more effective with less chance of resistance than lamivudine, studies find
WEDNESDAY, March 8, 2006 (HealthDay News) -- In a pair of studies on hepatitis B, researchers from around the world have found the medication entecavir is more effective than the commonly used drug lamivudine in managing the liver disease.
Additionally, the researchers found that no one developed resistance to entecavir (brand name Baraclude) after 12 months on the drug. Resistance to lamivudine is a concern when people have to be on it long-term, as is often the case with hepatitis B patients.
"Hepatitis B is not curable, but it is treatable. Entecavir represents a huge leap forward," said a researcher involved in both studies, Dr. Robert Gish, medical director of the liver transplant program at California Pacific Medical Center in San Francisco.
Results of these studies, both of which were at least partially sponsored by entecavir's manufacturer, Bristol Meyers Squibb, appear in the March 9 issue of the New England Journal of Medicine.
Throughout the world, as many as 400 million people are infected with hepatitis B, a viral infection that affects the liver. It is spread through blood and bodily fluids. Some common ways of acquiring the infection include having unprotected sex, sharing drug needles, or living with someone who has the infection and sharing personal hygiene items such as a razor or toothbrush. There is an effective vaccine available to protect against hepatitis B.
For most adults, the infection is acute and lasts no more than six months. But for about 10 percent of adults, up to half of all children and about 90 percent of babies infected with hepatitis B, the disease becomes chronic and can lead to scarring of the liver, liver cancer and liver failure.
Because some people recover from hepatitis B on their own, and some people with chronic infections don't develop liver problems, it can be difficult to know when someone should be treated. Medications for hepatitis B often must be taken long-term or the disease comes back even stronger. One indication that someone should be treated is a positive E-antigen test (HBeAg), which indicates a stronger infection, according to the Hepatitis B Foundation.
One of the new studies compared entecavir treatment to lamivudine in 715 randomly assigned HBeAg-positive patients. The researchers found that after 48 weeks, 72 percent of the entecavir group and 62 percent of the lamivudine group had improvements in their blood tests. However, many more people on entecavir (67 percent) had undetectable levels of hepatitis B DNA in their blood than those on lamivudine (36 percent).
The second study looked at people with HBeAg-negative hepatitis B. People in this group aren't always automatically referred for treatment. This trial included 648 people to randomly receive either entecavir or lamivudine.
After 48 weeks, 70 percent of the entecavir group and 61 percent of the lamivudine showed improvement, according to the study. But again, entecavir was much more effective at getting the DNA blood levels to undetectable amounts -- 90 percent vs. 72 percent.
"This level of suppression is unprecedented," said Gish, who added that he believed health-care practitioners will begin moving away from lamivudine as the standard treatment.
Neither drug had any serious side effects. No resistance developed to entecavir during the study period. And, according to Gish, these people have now been on treatment for two years and the resistance to entecavir is still zero. He said the only concern about entecavir resistance is for people who have already developed a resistance to lamivudine.
Dr. Tusar Desai, a gastroenterology and hepatology specialist at William Beaumont Hospital in Royal Oak, Mich., said, "Entecavir has a 10 percent advantage and no resistance, but it's three to four times as expensive as lamivudine."
He said if cost is an issue for a patient, he would still use lamivudine. However, he noted that he prescribes entecavir for anyone who shows signs of liver damage, such as cirrhosis, because they'll have to be treated for the rest of their lives and entecavir shows no signs of resistance.
Timothy Block, president of the Hepatitis B Foundation, added, "The number of options to treat Hepatitis B is growing. You're not stuck with one drug or one method of treatment. And, what's really exciting is the fact that you can use an antiviral and reverse some of the liver disease."
To learn more about hepatitis B, visit the Hepatitis B Foundation.