SOUTH LAKE TAHOE, CALIF. — Lamivudine and interferon alfa still have independent roles to play in treating some patients with chronic hepatitis B, Dr. Eddie C. Cheung said at an update in gastroenterology and hepatology sponsored by the University of California, Davis.
Lamivudine has shown consistent, rapid antiviral effects, but its role has diminished over time, primarily because of the high rate of drug resistance.
However, even without resistance being present, the drug's antiviral effects have been surpassed by those of entecavir, although lamivudine remains less expensive.
“Resistance is what killed this as a monotherapy,” said Dr. Cheung, chief of hepatology at the Veterans Affairs Northern California Health Care System, Martinez, Calif.
He is a speaker or adviser for GlaxoSmithKline, which makes lamivudine, and for Schering-Plough, which makes interferon alfa.
Lamivudine still is useful in at least three settings, he suggested. First, it can be a good and safe monotherapy if used for less than 6 months. “The resistance is really not an issue” with short-term treatment, he said.
Second, emerging data suggest that lamivudine is useful for treating pregnant women with chronic hepatitis B and a high viral load, to prevent vertical transmission. Treating with lamivudine 6 weeks before delivery can significantly reduce the chance of neonatal infection, Dr. Cheung said.
And third, all chronic hepatitis B carriers who are scheduled to undergo chemotherapy or immunotherapy should be started on prophylactic lamivudine to prevent a flare of their hepatitis B disease. “Please, if [the] oncologist forgets, make sure those patients are on prophylactic lamivudine, which is a good drug for that purpose,” he said.
Another drug that has fallen out of favor for treating hepatitis B—interferon alfa—similarly can be the right treatment for a specific patient. Interferon alfa generally has been replaced by peginterferon alfa.
Interferon alfa may be the treatment of choice for a young, highly motivated patient willing to withstand its significant side effects in order to undergo a relatively short course of therapy with a more durable response and a higher rate of hepatitis B surface antigen loss compared with oral adefovir or entecavir therapy. This treatment strategy carries a higher cost, but its duration is finite.
A young woman who wants to get rid of the virus and start a family, for example, may be a good candidate for interferon alfa monotherapy after counseling about efficacy and side effects.
“This is not an easy therapy to take, so it has to be a really motivated, well-informed patient,” Dr. Cheung said.
The drug is dangerous in patients with cirrhosis and is contraindicated in decompensated patients. For noncirrhotic patients, or those with cirrhosis who are clinically and biochemically compensated, a 16- to 24-week course of interferon alfa may produce hepatitis B e antigen (HBeAg) loss in 33% and HBeAg conversion in 18%. After 5 years, 11%–25% will have HBeAg loss.
No drug-resistant mutants have emerged from this treatment, a unique feature of interferon alfa among hepatitis B therapies.