Cancelled trials

PrEP and the trials investigating it were at the forefront of intense controversy during 2004 and 2005. Two trials were stopped permanently, one cancelled two of its three sites (though following up those already recruited) and another, the Thailand trial in injecting drug users, went ahead in the face of bitter activist opposition.

Trials of tenofovir PrEP were prematurely halted at two sites, Cambodia and Cameroon, because activists were concerned that trial participants might not be offered antiretroviral therapy should they become infected during the study. Concerns were also raised about the provision of independent counselling on safer sex and injection practices and the availability of condoms and sterile needles.

Two other tenofovir trials were stopped on different grounds. In Nigeria, the sites were not able to comply with the appropriate laboratory and clinical conditions needed for the safe conduct of the trial, while in Malawi, there were broader concerns regarding the fact that tenofovir had become available as a treatment in the country and there were concerns about tenofovir resistance impairing the PrEP trial.