Agouron Pharmaceuticals reported that the profound anti-HIV effects of its protease inhibitor nelfinavir(Drug information on nelfinavir) mesylate (Viracept), when taken in combination with other anti-HIV drugs, continue to be observed after 10 months of treatment. Nelfinavir was recently cleared for marketing by the FDA.
At the Tenth International Conference on Anti-viral Research (ICAR) meeting in Atlanta, Agouron senior clinical scientist Dr. Sharon Chapman provided an update on results from a key clinical trial of nelfinavir taken in combination with zidovudine (AZT [Retrovir]) and lamivudine(Drug information on lamivudine) (3TC).
After 10 months of treatment, HIV remained below the lower limit of sensitivity (1,200 viral copies per milliter) of the assay (bDNA) in the plasma of 87% of 74 patients receiving the recommended dose of nelfinavir (750 mg three times daily) for use in the three-drug combination. CD4+ T-cells continued to rise in these patients over the 10 months of treatment to a mean increase of 173 cells.
In a subgroup of 12 patients with advanced disease who had pretreatment CD4+ T-cell counts of 50 or below and who received the recommended dose of nelfinavir, mean reductions in plasma HIV were 2.2 log 10 (more than 99%), with HIV falling below the assay sensitivity limit (1,200 viral copies per milliliter) in 11 of 12 patients.
In clinical studies of nelfinavir, the most commonly observed adverse event of moderate or greater severity was diarrhea, which was generally controlled with over-the-counter medications.