[Resistance mutation patterns of hepatitis B virus in patients with suboptimal response to adefovir dipivoxil therapy after lamivudine resistance].

OBJECTIVE: To investigate the resistance mutation patterns of hepatitis B virus(HBV) during adefovir dipivoxil (ADV) monotherapy or combination therapy after lamivudine(LAM) resistance. METHODS: Serum samples from fifteen patients with suboptimal viral response to ADV therapy after LAM resistance were collected. The RT region of HBV P gene was PCR-applied, cloned and sequenced, and the mutation patterns in relation to resistance were analyzed. RESULTS: The ADV resistance mutation patterns of A181T+N236T, A181V, A181T were selected in ADV monotherapy group. The LAM resistance mutation patterns of M204V+L180M, M204V+L180M+L229V, M204I+L80I, M204V+L180M+V207I were detected in the combination therapy group. 20% of clones from three serum samples were detected double resistance to LAM and entecavir (ETV) in the combination therapy group, the resistance patterns were M204I+L80I+T184I (2/10), M204V+L180M+T184S (2/10), and M204V+L180M+G173L+S202G (2/10) respectively. I269L clones were detected in two serum samples from both two groups and P109S clones also detected in the one from monotherapy group. CONCLUSIONS: In the patients with suboptimal viral response to ADV therapy after LAM resistance, the ADV resistance mutation patterns of A181T+N236T, A181V and A181T could easily be selected during ADV monotherapy; while in the patients with combination therapy, the LAM resistance mutation patterns of M204V+L180M, M204V+L180M+L229V, M204I+L80I, and M204V+L180M+V207I were predominant, the ETV resistance mutation T184I/S and S202G could be selected. The mutation patterns of I269L and P109S may impact the responses to ADV therapy in some patients.

Structure-based design, synthesis, and biological evaluation of irreversible human rhinovirus 3C protease inhibitors. 8. Pharmacological optimization of orally bioavailable 2-pyridone-containing peptidomimetics.

The optimization of the pharmacokinetic performance of various 2-pyridone-containing human rhinovirus (HRV) 3C protease (3CP) inhibitors following oral administration to either beagle dogs or CM-monkeys is described. The molecules described in this work are composed of a 2-pyridone-containing peptidomimetic binding determinant and an alpha,beta-unsaturated ester Michael acceptor moiety which forms an irreversible covalent adduct with the active site cysteine residue of the 3C enzyme. Modification of the ester contained within these compounds is detailed along with alteration of the P(2) substituent present in the peptidomimetic portion of the inhibitors. The pharmacokinetics of several inhibitors in both dogs and monkeys are described (7 h plasma concentrations after oral administration) along with their human plasma stabilities, stabilities in incubations with human, dog, and monkey microsomes and hepatocytes, Caco-2 permeabilities, and aqueous solubilities. Compounds containing an alpha,beta-unsaturated ethyl ester fragment and either an ethyl or propargyl P(2) moiety displayed the most promising combination of 3C enzyme inhibition (k(obs)/[I] 170 000-223 000 M(-1) s(-1)), antiviral activity (EC(50) = 0.047-0.058 microM, mean vs seven HRV serotypes), and pharmacokinetics following oral administration (7 h dog plasma levels = 0.248-0.682 microM; 7 h CM-monkey plasma levels = 0.057-0.896 microM).