Antiviral Response and Resistance Surveillance for HBeAg-negative Patients in a Study Evaluating Emtricitabine Plus Clevudine versus Emtricitabine Monotherapy

In the present study, researchers aimed to evaluate HBV viral load in nucleoside- naïve or experienced patients following 24 weeks of treatment with emtricitabine (FTC) [Emtriva] 200 mg plus the anti-HBV experimental nucleoside clevudine (CLV) 10 mg versus FTC monotherapy and to monitor for development of resistance.

Serum HBV DNA was monitored using a Real-Time PCR assay with a lower limit of detection (LOD) of 250 copies/mL (cp/mL). Genotypic analysis of the polymerase was performed at week 24 (W24) for viremic (>4700 cp/mL) patients.

Results

• Seventy-eight HBeAg- patients were enrolled; 38 (n=24 experienced and n=14 naïve) received FTC+CLV and 40 (n=28 experienced and n=12 naïve) received FTC monotherapy.
• The median baseline HBV DNA VL was 4 log10 cp/mL.
• At W24 a -1.6 log10 and -1.4 log10 reduction in serum HBV DNA was observed for experienced patients in the combination and monotherapy arms, respectively, and a - 1.9 log10 reduction was observed among naïve patients, regardless of treatment arm.
• Among experienced patients, 86% given FTC+CLV versus 63% given FTC had HBV DNA <250 cp/mL at W24, and among naïve patients, the proportions were 69% and 67%, respectively.
• The W24 prevalence of FTC associated mutations was 7% and 0% among experienced and naïve patients, respectively.

According to the study authors, “In this HBeAg- population, both emtricitabine plus clevudine and emtricitabine monotherapy produced a favorable antiviral response at week 24 as demonstrated by the median change from baseline in HBV DNA and by the proportion of patients with HBV DNA below the limit of detection.”

“At week 24 no naïve patient presented with FTC resistance mutations whereas the rate was 7% among FTC-experienced patients.”

11/21/05

Reference
A Snow and others. Antiviral response and resistance surveillance for HBeAg negative patients enrolled in a combination study evaluating emtricitabine plus clevudine versus emtricitabine monotherapy for the treatment of chronic hepatitis B infection. Abstract 989. Abstracts of the 56^th annual meeting of the American Association for the Study of Liver Diseases. November 11-15, 2005. San Francisco, CA.