Over 4,700 Kenyan and Ugandan heterosexual serodiscordant couples'in which one partner is HIV-positive and the other is negative'took part in a recent trial studying the effectiveness of pre-exposure prophylaxis, a.k.a. PrEP, the use of HIV medication by those who are not HIV-positive as a prevention measure.
One third of uninfected partners were given a placebo, another third the drug tenofovir (Viread), and the final third took Truvada, a pill that contains tenofovir and the drug emtricitabine. The results, released in July, were staggering: Compared to those on the placebo, those taking tenofovir had a 62% lower transmission rate, and the Truvada users had 73% fewer transmissions. Researchers behind the study, sponsored by the University of Washington, stopped the trial, declared the PrEP therapy an unequivocal benefit, and distributed the drugs to all participants. Another recent study, sponsored by the U.S. Centers for Disease Control and Prevention, distributed Truvada to certain high-risk heterosexual HIV-negative individuals in Botswana. Although that study had a smaller focus group of 1,200 participants, the numbers were still extremely encouraging, with 62% fewer new HIV cases among those receiving the drug than those given a placebo.
Back in America, many hope the results will eventually lead to Truvada distribution to all serodiscordant couples and other high-risk individuals. Recent studies have already shown that the PrEP therapy is effective in transgender women and men who have sex with men. But Mitchell Warren, the executive director of the New York'based AIDS Vaccine Advocacy Coalition, says widespread distribution of Truvada will likely happen overnight.
There are two reasons for restraint, according to Warren. First, the two successful studies follow a trial that was stopped for the complete opposite reason that the recent couples' trial was halted'the drug didn't seem to work with high-risk heterosexual African women. Second, budgets are an issue. As AIDS Drug Assistance Programs are cut across the country, it's hard to conceive of states having the money to distribute Truvada widely.
'There's a kind of champagne celebration on one hand and a hangover on the other, because there's a tremendous burden on our system on how to implement this,' Warren says.
The issue of cost is one that's already being addressed, according to a report from Project Inform, a San Francisco-based HIV organization. Following the successful trials featuring PrEP and gay men, the CDC began initiating discussions with insurers, some of which demonstrated 'a willingness to reimburse PrEP in the limited circumstances described by the CDC's interim guidance,' while Gilead, the maker of Truvada, has shown interest in implementing a patient assistance program akin to ADAPs, which are currently used by tens of thousands of people.
Lisa Sterman, a San Francisco'based physician and board member for the San Francisco AIDS Foundation, is convinced of Truvada's benefit and already prescribes it to high-risk patients. While she's careful to ask potential users about diabetes history and kidney problems'conditions she says can be exacerbated by Truvada'Sterman believes the drug is a no-brainer for those regularly exposed to HIV and that the unsuccessful PrEP trial likely failed because of spotty adherence.
'[PrEP] works if people comply with it,' she says. 'I think it works 99% of the time if used properly.'