Tenofovir disoproxil fumarate monotherapy improves virologic response in HBV patients
Monotherapy with tenofovir disoproxil fumarate (TDF) increases virologic response for up to 240 weeks in pretreated patients with hepatitis B virus infection (HBV) who are resistant to entecavir (ETV) and/or adefovir (ADV), a new study has found.
However, TDF produced poor serological responses and elicited drops in renal function and bone mineral density.
Researchers enrolled 192 HBV patients, of whom 90 were resistant to ETV but not ADV (mean age, 51±9 years; 75.6 percent male) while 102 had the inverse resistance profile (mean age, 50±10 years; 86.3 percent male).
After 240 weeks, 78.6 percent (n=151) had HBV DNA <15 IU/mL. This was significantly higher than the proportion of patients who showed the same response at week 48 (67.2 percent; p=0.003). There was no significant difference in this percentage between the ETV- and ADV-resistant patients (84.4 percent vs 73.5 percent; p=0.07).
Of the 176 patients who completed the 240-week treatment period, only 25 had serum HBV DNA ≥15 IU/mL; the median level was 41 IU/mL.
Despite the good virological response profile, TDF treatment did not result in the seroclearance of hepatitis B surface antigen (HBsAg) in any patient. The mean change in HBsAg from baseline was comparably low in the ETV- and ADV-resistant groups (–0.45log10 vs –0.42log10 IU/mL; p=0.33).
Similarly, the percentage of patients with decline in HBsAg ≥1log10 IU/mL from baseline was 16.7 percent and 11.8 percent in the ETV- and ADV-resistant groups, respectively (p=0.33).