Meeting report: 30th International Conference on Antiviral Research, in Atlanta, GA, USA

Vere Hodge, R Anthony

D-FMAU was known to be very active against herpesviruses but it was highly toxic. Therefore, the enantiomer, L-FMAU was synthesised -the synthesis, starting from either L-xylose or L-arabinose, was shown. Although L-FMAU had only modest activity against EBV, it had good activity against HBV in cell culture assays (EC 50 , 0.1 mM) and did not inhibit cell replication at >100 mM. Against woodchuck hepatitis virus (WHV) in woodchucks (n ¼ 4/group), L-FMAU (clevudine) at various doses was administered for 28 days and the levels of serum WHV DNA (pg/ml) were followed for 16 weeks. Very quickly, the WHV DNA levels decreased to below the detection limit and remained so for the rest of the dosing period. Soon after dosing with nucleoside/tide analogues, it is usual for HBV DNA levels to return to baseline. With the lower doses of clevudine (0.3 and 1 mg/kg), there appeared to be a slow return to baseline levels. With the higher doses (3 and 10 mg/kg), WHV DNA remained undetectable to week 14, then low levels were detected at week 16.