Triangle Pharmaceuticals Inc., of Durham, N.C., presented data on the antiviral activity and tolerability of Coviracil (emtricitabine) and clevudine (formerly L-FMAU), its compounds being tested separately for chronic hepatitis B.

The positive data were presented at the 52nd annual meeting of the American Association for the Study of Liver Diseases in Dallas.

Coviracil, a cytosine nucleoside analogue, in a Phase I, 48-week, double-blind, randomized study in patients with chronic hepatitis B infection called FTCB-102, doses of 25 mg, 100 mg and 200 mg once daily were tested in 95 patients. Coviracil was well tolerated at all doses. At 48 weeks, the median decrease in viral load from baseline was 2.59, 3.12 and 2.92 log¹⁰ copies/mL for the three dose groups, respectively. At 48 weeks, HBeAg loss occurred in 32 percent, 38 percent and 50 percent of HBe antigen-positive patients, respectively. Seroconversion to anti-HBe occurred in 23 percent of the patients across dosage groups.

Clevudine, a pyrimidine analogue, was studied in chronic HBV patients in a trial called L-FMAU-102. Data were available from four subjects in the 10-mg cohort, 10 subjects in the 50-mg cohort, and 10 in the 100-mg cohort who had completed the 28-day dosing period. The baseline median viral load was 7.13, 7.96 and 8.76 log¹⁰ in the three groups, respectively. At the end of a 28-day dosing period, the median reduction in serum HBV DNA was 2.48, 2.74 and 2.95 log¹⁰, respectively. Five months after treatment ended, the median decrease in HBV DNA was 1.9 log¹⁰ copies in the 10-mg cohort. In seven patients in the 50-mg cohort for which long-term data were available, the median decrease after 24 weeks was 2.07 log¹⁰. In the 100-mg cohort, five patients exhibited a decrease in HBV DNA of 3 log¹⁰ at one month post-treatment.

In other news from the meeting:

¿ Ribozyme Pharmaceuticals Inc., of Boulder, Colo., said five papers presented in the areas of hepatitis C and hepatitis B diagnosis and treatment highlighted the progress of the ribozyme technology platform for antiviral treatment and detection. Initially, RPI reported results of a Phase I study of Heptazyme. Results demonstrated that Heptazyme was well tolerated and was efficiently absorbed after subcutaneous administration. RPI also highlighted the results of research that describes a new, low-cost alternative ribozyme-based approach for detection of low-copy nucleic acids using hepatitis C virus as a model system. RPI scientists presented the results of its ongoing efforts in the field of hepatitis B research, highlighting the preclinical efficacy of its anti-HBV ribozyme drug candidate, HepBzyme.