Scientists are taking the battle to prevent HIV to the next level with large-scale trials set to start using injections to protect vulnerable groups such as gay men and women in Africa for at least two months. Scientist is hoping to produce matchstick-sized implants containing slow-release drugs – similar to existing under-the-skin contraceptive devices – that could offer year-long protection. Companies with drugs involved include GlaxoSmithKline , Gilead Sciences and Merck. The initiatives build on the success of Gilead’s once-daily pill Truvada, which has proved remarkably effective at stopping HIV infection during sex.
Clinical studies show such pre-exposure prophylaxis, or PrEP, can cut the risk of catching the virus by more than 90 percent, as long as people take their pills regularly. The problem is many do not. Some women in trials in Africa, for example, said they were reluctant to have HIV tablets in the house for fear of what partners or neighbours would think. An injection given in a clinic, experts argue, would add privacy and ensure steady drug levels. An implant in the arm might even combine contraception and HIV protection in one go. “The more options there are the better and I think for some individuals injections will be great,” said Jean-Michel Molina, professor of infectious diseases at Hospital Saint-Louis in Paris. “Now that we know antiretrovirals have great potential to prevent HIV infections, it is time to really assess other ways to deliver these drugs.”
The United Nations AIDS programme warned last week that the problem now threatened progress in ending the global epidemic, while the World Health Organization has recommended PrEP for all groups at substantial risk of HIV infection. GlaxoSmithKline’s majority-owned ViiV Healthcare unit, working with U.S. government agencies and the Bill & Melinda Gates Foundation, hopes to add the first injectable PrEP. It plans to start a four-year trial as soon as next month testing its experimental drug cabotegravir in gay men in the Americas and Thailand, with a second trial next year assessing the medicine in African women.