PARIS ¿ Tibotec-Virco NV plans to embark on Phase I clinical trials of its anti-HIV drug candidate TMC125 in the U.S., following the completion of the FDA¿s review of its investigational new drug application.

TMC125 is a non-nucleoside reverse transcriptase inhibitor (NNRT1) that Tibotec already tested in Phase I and IIa clinical trials in Europe. The Phase IIa randomized, double-blind, placebo-controlled trial using TMC125 as a monotherapy in 18 previously untreated HIV-positive patients produced ¿significant reductions in viral load,¿ the company said.

The reductions ranged from a 1.1 log drop to a 3.4 log drop after seven days. Eight of the 12 subjects who received TMC125 had their viral loads reduced to less than 400 copies of HIV/ml, with two subjects below the 50-copy limit of a more sensitive test. TMC125 was well tolerated, with no apparent differences in side effects between it and placebo.

Earlier laboratory research demonstrated that TMC125 and other second-generation NNRTIs being developed by Tibotec were highly active against strains of HIV that are resistant to first-generation NNRTIs.

Tibotec-Virco, of Mechelen, Belgium, attributes its success in developing more effective HIV drugs to a ¿unique parallel drug profiling strategy¿ that accelerates drug discovery and development by rapidly identifying ¿new anti-HIV compounds which in vitro are highly active against both wild-type and resistant HIV.¿ In addition, TMC125 is a diaminopyrimidine compound, which Tibotec said is a highly flexible formulation that ¿results in favorable binding interactions with mutant HIV strains as well as the wild-type virus.¿

¿ James Etheridge