June 28, 2013
Trial of PrEP in Drug Users Called Into Question
A collection of HIV advocacy groups has lambasted the recent Centers for Disease Control and Prevention–sponsored trial that found a 49 percent reduction in risk among Thai injection drug users (IDUs) taking an antiretroviral (ARV) to prevent HIV infection. This practice is known as pre-exposure prophylaxis, or PrEP, and until this trial IDUs represented the last major risk group to lack proof that PrEP could help curb the spread of HIV among them. In a scathing release, the Thai Drug Users Network (TDN), the Thai AIDS Treatment Action Group (TTAG) and Treatment Action Group (TAG) claimed the study was conducted unethically, that it cannot effectively differentiate whether the apparent risk reduction affected transmission routes through needles or through sex, and that its faulty design prevents applying the findings to real-world settings.
TDN, TTAG and TAG say that, during the study’s planning process and its initiation, the study’s organizers willfully ignored the expressed concerns of community stakeholders in Thailand, including TDN, TTAG and the Thai National Network of People Living With HIV (TNP+). These groups feel their demands for needle exchange programs to curb HIV’s spread went unheard, as did their worries that the clinic staff administering methadone to the drug users were also recruiting for the trial, possibly causing visitors to the clinic to feel coerced. The groups also complained that Thai community advocacy organizations were not given a place in the community relations for the study.
What’s more, the groups claim the trial failed to create a model for a real-world scenario because participants were reimbursed financially for participation and because over 85 percent received their ARV doses under observation.
In the release, Paisan Suwannawong, executive director of TTAG and cofounder of TDN, said, “While TTAG is glad for any evidence of reduced HIV transmission among people who inject drugs, this trial failed to promote basic ethical practices and patently ignored community concerns. In our opinion, the trial serves as a ‘worst practice’ example of community engagement, failing to ensure participant access to a comprehensive prevention package in a placebo trial, and ignoring other issues we tried to raise to researchers at the outset.”
The advocacy groups also claim that the trial cannot effectively differentiate between whether tenofovir, the drug used in PrEP, prevented HIV transmission through needles or sex. They note that, during the first three years of the trial, when needle use was the highest, PrEP demonstrated no efficacy among the participants. Only in the last four years of the trial, during which the number of participants declined and the use of needles and the sharing of needles also dropped to “very low levels,” was there a significant difference in HIV transmission rates between the arms of the study.
To read the release, click here.
Search: Thailand, injection drug users, pre-exposure prophylaxis, PrEP, Thai Drug Users Network, TDN, Thai AIDS Treatment Action Group, TTAG, Treatment Action Group, TAG, Thai National Network of People Living With HIV, TNP+, Paisan Suwannawong.
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