New Studies Bolster Truvada's Effectiveness in Preventing HIV

LOS ANGELES—Results from two new studies looking at the effectiveness of Truvada used in a pre-exposure prophylaxis (PrEP) regime as a way to reduce the risk of HIV infection have bolstered findings from previous studies that showed promising results from daily use of the drug. In fact, HealthDay reporter Alan Mozes writes that results from the new studies—"one from Britain and one jointly conducted in France and Canada."—indicate that even non-daily use of Truvada can prevent infection. "The British investigation, called PROUD, involved 500 gay men and seems to reconfirm the effectiveness of standard, once-a-day PrEP," reports Mozes. "That study found that this dosing strategy lowered HIV infection risk by 86 percent among gay men. "The French/Canadian investigation, called IPERGAY, looked at PrEP taken on a different schedule -- only around the days surrounding a sexual encounter," he added. "It found the same degree of protection -- an 86 percent lower risk for new infection -- among men who took two Truvada pills anytime between 2 and 24 hours prior to having sex with another man, followed by another two pills 24 and 48 hours after sex." Despite those results, which were presented Tuesday at the annual Conference on Retroviruses and Opportunistic Infections, the U.S. Centers for Disease Control and Prevention continues to recommend a conservative regime for the moment; specifically, the daily use of Truvada. Still, Dr. Jonathan Mermin, director of the CDC's National Center for HIV/AIDS, Viral Hepatitis, STD & TB Prevention, did say of the new results, "CDC welcomes the findings presented today by the IPERGAY and PROUD teams, which provide additional evidence of the power of PrEP to reduce the risk of HIV infection." Mozes added, "Mermin said it is not clear if the approach of only taking PrEP in the days before and after sex will work in all situations. He noted that the strategy was only tested in men who were having frequent sex (an average of 10 times per month, and eight partners every two months). "So, in reality," he continued, "that meant that some participants were taking as many as eight pills per week -- actually exceeding the older, once-per-day dosage." About Truvada's potential for other demographics, Mermin said, "There are also no data on how effective this regimen would be for heterosexual men and women and injection drug users, or on adherence to this relatively complex PrEP regimen outside a trial setting." While the results from the studies are still considered preliminary, and even though the CDC continues to recomment only daily use of Truvada, Mermin opined that the "IPERGAY findings, combined with other recent research, suggests that even with less than perfect daily adherence, PrEP may still offer substantial protection if taken consistently." Interestingly, those positive findings were "based on men who were having frequent sex," which pretty much defines the majority of adult performer sexual activity. It's a development that is sure to irk AIDS Healthcare Foundation's Michael Weinstein, a longtime critic of Truvada and wannabe Condom Czar.