2'-DEOXY-L-CYTIDINE

Description

Torcitabine (b-L-2u-deoxycytidine) (L-dC) is the b-L-enantiomer of the natural nucleoside D-cytidine. The drug is currently under development by Idenix as an antiviral agent for the treatment of chronic hepatitis B virus infection. Torcitabine has poor oral bioavailability, but its 3u,5u-divaline ester (val-L-dC) and the 3u-monovaline ester, valtorcitabine dihydrochloride, have excellent oral bioavailability and consequently the torcitabine prodrug, valtorcitabine, has replaced torcitabine in clinical development.

The Uses of 2'-DEOXY-L-CYTIDINE

Torcitabine and its prodrug, valtorcitabine, are investigational drugs being developed solely for the treatment of chronic HBV infection. Torcitabine itself has undergone preliminary phase I/II clinical trials in HBeAg-positive patients, initially as the 3u,5u-divalyl prodrug in escalating doses of 50, 100, 200, and 400 mg/day, but later as the more stable monovaline ester form, valtorcitabine dihydrochloride, and administered to four cohorts in doses of 300, 600, 900, and 1200 mg/ day for 28 days.