The CDC writes us this morning to note their response to the early halting of an African HIV PrEP study, which I mentioned yesterday. Pre-exposure prophylaxis (PrEP) involves taking an HIV medication as a preventive to infection. The CDC expresses disappointment with the cessation of the African study, as “this approach has already been shown to be effective in reducing HIV infection among men who have sex with men.”
While PrEP with FTC/TDF was not shown to be effective in preliminary analyses of these study results, it cannot yet be definitely determined whether this drug combination works, or does not work, to prevent HIV among women. FEM-PrEP study investigators will be conducting additional analyses in the coming months to better assess potential reasons for the results in this study – including examining factors such as adherence and differential risk behavior between the two trial arms — that may account for the lack of demonstrated efficacy in this trial. Investigators from other PrEP trials, including CDC, will be working closely with FHI to review all available data and determine any implications for ongoing research. Given today’s results, CDC cautions against women using PrEP for HIV prevention at this time. We will not know if PrEP is effective for women, couples, or injection drug users until the conclusive results of this and other trials are reported.