Idenix to study novel NNRTI at lower doses on strong early data

The USA's Idenix Pharmaceuticals reported encouraging data on IDX899, its non-nucleoside reverse transcriptase inhibitor being developed for HIV. According to data presented at the 2008 Conference on Retroviruses and Opportunistic Infections, held in Boston, USA, in the first dosing cohort of an ongoing Phase I/II study, eight HIV-1 infected treatment-naive patients receiving 800mg of IDX899 once-daily achieved a mean reduction in virus level of 2.01 log10, or 99%, after seven days of treatment.

Six out of eight patients in the trial reached a 2 log10 or greater reduction in viral load with one patient achieving undetectable virus levels (under 50copies/mL). No serious adverse events were reported in this cohort and no patients discontinued the study, noted Idenix. Given the potent antiviral activity and favorable preliminary safety demonstrated at 800mg once-daily, the firm plans to explore sequential cohorts of 400mg once-daily followed by 200mg once-daily.

"We are pleased with the safety profile and potency observed with the 800mg dose of IDX899 in HIV-infected patients and, based on these data, we will continue to evaluate lower dosing regimens in order to optimize the role of IDX899 in HIV combination therapy," said Douglas Mayers, Idenix' chief medical officer.