The Burrill Report


Researchers have halted a study of Truvada, Gilead Sciences’ combination therapy for HIV, to see if its use could prevent infection in healthy women. The global health and development organization Family Health International said it decided to terminate the study after a scheduled interim review concluded it was “highly unlikely” continuing the study would show it protected women in the group against infection.

The organization described the results as “surprising and disappointing” because earlier studies suggested that exposure to antiretrovirals such as Truvada could prevent healthy men who have sex with men at risk of HIV from becoming infected with the virus. Truvada is a combination of Gilead’s HIV drugs Viread and Emtriva.

AIDS organizations that have opposed an effort by Gilead to win fast track approval from the U.S. Food and Drug Administration for Truvada as a prophylaxis for people not yet exposed to the virus, seized on the FHI’s decision to halt the trail to renew a call to slow the company’s efforts.

“Clearly Gilead should take the news today of this failed study in women as well as the unacceptable study results in its previous [men who have sex with men] study to heart, delay seeking FDA-approval for use of Truvada as prevention and concentrate on further studies and clinical trials,” says Michael Weinstein, president of the AIDS Healthcare Foundation. “Relying on the one study conducted in [men who have sex with men] that showed marginal success is simply not acceptable or sufficient for extending the approved use of this drug.”

The organization said Gilead’s likely pursuit of FDA-approval for expanding the use of its best selling $35 per day AIDS drug to include use as a form of HIV prevention comes following a recent and widely-reported study of 2,500 high risk gay men using Truvada which showed a 44 percent effectiveness rate in preventing HIV transmission.

On the heels of the results from that study of gay men, Gilead at the beginning of 2011 initiated discussions with the FDA and said it intends to file for expanded approval of Truvada to prevent infection in gay men. Amy Flood, a spokeswoman for Gilead, said there are a number of other ongoing studies of Truvada as an HIV prophylaxis in various population groups and that the company will continue to support these studies.

FHI said it would initiate an orderly end of the study over the next few months. Because final analyses have not been made, the researchers said it was not possible to determine whether Truvada prevents HIV infection in women. FHI conducted the study in partnership with research centers in Africa and funding from the United States Agency for International Development. The Bill & Melinda Gates Foundation provided earlier funding for the work.

The researchers said a number of reasons could explain the findings, including participants failing to regularly take the drug as required, a true lack of effect of Truvada on women, or other factors yet to be determined. FHI says it will be conduct further analyses and will share additional findings in the coming months.

The study enrolled nearly 2,000 women in Kenya, South Africa and Tanzania. The rate of new HIV infections among trial participants was about 5 percent. A total of 56 new infections occurred with an equal number of participants assigned to Truvada and those assigned a placebo.

The use of Truvada was associated with some known side effects that researchers say were not serious. But study participants randomly assigned to the Truvada arm experienced pregnancy rates that were higher than among women assigned to the placebo arm. The researchers say this is unexpected and inconsistent with known drug interactions involving the drug and contraceptive hormones, and with known metabolic effects of the drug.



April 22, 2011
http://www.burrillreport.com/article-study_of_gilead_hiv_drug_to_prevent_infection_halted.html