Adefovir monotherapy not cost effective as treatment for HBV

Sequencing lamivudine (3TC) and adefovir provides cost-effective treatment for chronic hepatitis B virus, according to a study published in the May 17^th edition of the Annals of Internal Medicine. The investigators, from UCLA and Los Angeles Veterans Affairs also found that, particularly in resource limited settings, treatment with interferon, the oldest hepatitis B virus therapy, was cost-effective, especially in e-antigen negative individuals.

The investigators undertook their study as there is uncertainty about the cost-effectiveness of anti-hepatitis B virus treatment strategies. “We need to develop a more calculated approach and establish guidelines for the most cost-effective treatment,” said the lead author Dr Fasiha Kanwal.

Three drugs that are licensed for use against hepatitis B virus were included in their analysis: interferon, which has an unpleasant side-effect profile, lamivudine, which has a low barrier to resistance, and the more-expensive adefovir, which has been shown to be safe, generally well tolerated, and with a high barrier to resistance.

Five treatment strategies were compared for their cost-effectiveness. These were:

• No hepatitis B virus treatment.
• Interferon monotherapy.
• Lamivudine monotherapy.
• Adefovir monotherapy.
• Lamivudine with switch to adefovir after the development of resistance.

Data were obtained from a systematic review of MEDLINE between 1970 and 2005. Patients included in the investigators’ analysis had chronic hepatitis B virus infection with elevated aminotransferase levels but no cirrhosis.

The outcome was cost per quality-adjusted life year (QALY) gained. The general standard accepted for treating a chronic condition like hepatitis B virus is $50,000 or less per QALY gained.

Only two treatment strategies proved cost-effective.

Compared to doing nothing, treatment with interferon had an incremental cost of a little over $6300 per year to gain one additional QALY. Compared with interferon, initial monotherapy with lamivudine or adefovir was not cost-effective. Treatment with adefovir monotherapy would have cost $90,000 per QALY. However, they found that treatment with lamivudine and adefovir had an incremental cost of just under $8500 per QALY compared to interferon.

In further analysis, the investigators found that interferon provided the most cost-effective treatment in health care settings with limited resources and a high prevalence of e-antigen negative patients.

Study investigator Dr Brennan Spiegel also noted “the combined treatment strategy of lamivudine and adefovir is also a very viable option. This is part of a trend that we’re seeing in other areas of medicine as well – to use ‘hybrid’ treatments that reserve expensive yet effective drugs for specific patients who have shown no success with other treatments.”

The investigators emphasise that these findings only apply to patients with chronic hepatitis B virus infection, elevated aminotransferase levels, and no cirrhosis. “They do not apply to alternative populations,” they write.