FHI Cancels Nigerian Arm of Clinical Trial Testing Tenofovir for HIV PreventionFamily Health International on Monday announced that it has cancelled the Nigerian arm of an ongoing clinical trial testing Gilead's antiretroviral drug Viread because of a failure of local researchers to reach "necessary scientific standards," the Financial Times reports (Jack/Peel, Financial Times, 3/15). The Bill & Melinda Gates Foundation last year awarded a $6.5 million grant to FHI to conduct a randomized, placebo-controlled clinical trial of Viread including 2,000 HIV-negative volunteers at sites in Nigeria, Cambodia, Ghana, Cameroon and Malawi. The drug, known generically as tenofovir, is being tested to determine its effectiveness in preventing HIV transmission. Tenofovir, which is FDA-approved for HIV treatment, has been shown to boost immune response and lower viral levels in the bloodstreams of patients who are resistant to other antiretrovirals (Kaiser Daily HIV/AIDS Report, 3/9). FHI cancelled the study because not all of the trial sites were able to comply with "rigorous internationally accepted standards," according to an FHI release. "The ability to meet these standards is critical for ensuring the safety of participants and the quality of the data from the study," according to the release. However, there is "no evidence" that any of the trial participants -- who were HIV-negative commercial sex workers -- "were harmed or put at risk as a result of the procedural problems at the Nigeria site" and there have been "no serious medical problems" related to tenofovir, according to FHI (FHI release, 3/11). Nigeria's Ministry of Health on Monday said that it was "disappointed" that the trial was cancelled but did not comment further, according to the Times.
FHI Trial Implications
Dr. Ward Cates, president of FHI's Institute for Family Health, said the cancellation of the Nigeria arm of the tenofovir trial could jeopardize the statistical significance of the entire trial because of the overall reduction in the study population, the Times reports. The Nigerian arm is the second in the trial to experience problems (Financial Times, 3/15). Cameroon's Ministry of Health last month announced it had suspended the trial, which involved HIV-negative commercial sex workers in the city of Douala, after ACT UP/Paris alleged that the trial violated ethical norms and called for its cancellation. The group claimed that the study recruited particularly vulnerable participants without providing HIV/AIDS prevention information or treatment. However, FHI denies ACT UP/Paris' claim that the study is unethical and is addressing all of the ministry's concerns and recommendations regarding the trial. The health ministry has agreed to allow the follow-up of participants already enrolled in the trial (Kaiser Daily HIV/AIDS Report, 3/14). FHI is considering increasing the number of patients enrolled in the Malawian and Ghanaian arms of the Viread trial, Cates said.
Other Tenofovir Trials
Similar controversy has surrounded other trials involving tenofovir, the Times reports (Financial Times, 3/15). Cambodian Prime Minister Hun Sen in August 2004 ordered an end to a planned trial of the drug in commercial sex workers because of the possible effects of the drug on trial participants. About 150 Cambodian members of the Women's Network for Unity had said they would not participate in the study unless they were provided with 30 years of health insurance to cover possible adverse reactions and side effects from taking the drug. In addition, HIV/AIDS advocates on Thursday raised questions about the safety and transparency of a CDC-funded, three-year clinical trial of tenofovir in Bangkok, Thailand, which is scheduled to begin next month (Kaiser Daily HIV/AIDS Report, 3/14).