A new drug in development, apricitabine (ATC), may have moved another step closer toward inclusion in the arsenal of drugs approved to fight HIV. Data newly released by the drug’s Australian maker, Avexa, and reported by Business Wire, found that 70 percent of people who had a detectable viral load who switched to ATC from 3TC (Epivir)—both nucleoside reverse transcriptase inhibitors—were able to lower their HIV to undetectable levels for up to 24 weeks.

Researchers reported in March of this year on the first 21 days of the study (see our story), which included 52 treatment-experienced patients, recruited primarily in Argentina. After failing on a regimen including 3TC, a percentage of the trial participants were switched at the beginning of the study to ATC at a dose of either 600mg or 800mg twice a day. The new 24-week data demonstrated how many people on either dose of ATC achieved undetectable viral loads compared to those who stayed on 3TC. Also of interest were increases in CD4 cell counts and proof of safety and tolerability.

Researchers found that more than 80 percent of those switching to either dose of ATC from 3TC had virus levels under 400 copies per ml at 24 weeks, and more than 70 percent had less than 50 copies. Those switching also had CD4 increases averaging 150 cells. Thus far, ATC appears to be safe and has few side effects.