Researchers at pharmaceutical company Gilead Sciences report that their recently approved nucleotide reverse transcriptase inhibitor Viread may be useful not only in treating HIV infections but also in helping to prevent infections in the first place, and as such, studies on using the drug as pre-exposure prophylaxis are under way at the National Institutes of Health and Family Health International. The NIH is currently conducting a Phase I trail to determine the safety of a Viread-based gel in blocking vaginal HIV transmissions.
The Bill and Melinda Gates Foundation is financing the FHI study of using standard Viread pills as an HIV preventative. The study will include more than 1,600 women worldwide who are at high risk for infection. Using anti-HIV drugs as part of HIV prevention is a relatively new concept in addressing infections in regions where condoms are not readily available or where women have difficulty negotiating condom use with their partners.
Previous studies that tested Viread's ability to prevent infection in monkeys, both before and after exposure, have been very encouraging, company officials say. Participants in FHI's study will be given one 300-milligram Viread pill daily. If Viread use is deemed effective in preventing HIV infections, Gilead will consider providing the drug at steep discounts or free in geographic areas where need for prevention is greatest. "We would be committed to making the drug available in those areas," said Gilead vice president of research Jim Rooney.