AIDS-prevention experts have had their hopes dashed after National Institutes of Health panel ruled that there was not need to stop the two ongoing studies of male circumcision as a method of reducing risk of HIV infection.
Last year a South African medical committee halted a circumcision study after an early look at the data, which showed that circumcision reduced risk of HIV infection by at least 60 percent. Scientists finding that the protective effect was so beneficial, believed that it would be unethical to continue the experiment and withhold the findings.
French researcher Bertran Auvert and colleagues in Johannesburg and France conducted the South African study. 3,274 men participated as subjects for the study. Its results were published in January in the journal PLoS Medicine.
The NIH committee monitoring similar studies in Rakai, Uganda and Kisumu ,Kenya took a preliminary look at results of those two experiments on Tuesday and ruled that they should continue until the scheduled completion time next year.
The decision has however ensured that there will be no early release of the data for discussion at the 16th International AIDS Conference this August in Toronto, which otherwise would have led to circumcision being the big news of the global AIDS meeting.
According to Robert Bailey, the University of Illinois epidemiologist who is lead investigator of the Kenyan study, 'It doesn't mean we don't have a 60 percent figure, or better.' The interim results remain a secret, even to the investigators involved, because the trial is known as "blinded." This is to ensure the scientific integrity of the eventual findings.
Bailey also mentioned that there was a possibility that the monitoring board would look at the data once again in six to eight months to determine whether an early halt to the experiment was warranted.
The study involved 3,000 previously uncircumcised men in Kisumu where circumcision is not a traditional practice. Half have subsequently been circumcised, and the others have their foreskins intact. The trial is scheduled to end by September 2007, at which time researchers will tally up any HIV-positive and HIV-negative in both groups.
Researchers at Johns Hopkins University and Columbia are leading the Rakai study, which is slated for completion in July 2007 and has enrolled 5,000 men.
Auvert's study in South Africa was stopped because early view at the data showed 49 of the uncircumcised men had become HIV-positive, compared with 20 in the circumcised group. That showed a protective effect of 60 percent, and further analysis of the data suggests it might be as high as 76 percent.
Dr. John Krieger, a University of Washington urologist who has been tracking the safety of the Kenyan trial, said he is not concerned about the failure to end the study early which actually was designed from the start to go on until next year.