The British government and the Bill & Melinda Gates Foundation recently awarded more than 90 million British pounds -- almost $130 million -- in grant money to continue development on microbicides for HIV prevention, London's Times reports. The grant follows the results from a clinical trial of an experimental microbicide, called PRO 2000 and developed by Indevus Pharmaceuticals (Lister, Times, 2/23). Research presented earlier this month suggests that the vaginal gel is 30% effective in preventing HIV infection, though the findings were not statistically significant. A second, larger clinical trial -- involving 9,000 women and led by teams in Tanzania, South Africa and Uganda -- is expected to finish in August, with results reported by November (Kaiser Daily HIV/AIDS Report, 2/10).
The grant money -- about 20 million pounds from the U.K.'s Department for International Development and 70 million pounds from the Gates Foundation -- will be given to the International Partnership for Microbicides, according to the Times. The funding will then be dispersed to several research teams, including those at Imperial College London, which is leading the second PRO 2000 trial; the University of London; St. George University; and the Medical Research Council. Ten new clinical trials will be supported over the next five years with the grant money to investigate new and more advanced versions of PRO 2000, including longer-lasting gels and those with specific antiretroviral drugs.
According to the Times, a microbicide gel "shares many of the same advantages of a vaccine," such as being undetectable when used by women who might be unable to persuade their partners to use condoms. However, one "problem" is that the toxicity in many chemicals that can kill HIV is "such that they risk causing tissue damage that actually hastens any infection," the Times reports.
Renee Ridzon, senior program officer in global health for the Gates Foundation, said that the foundation recognizes the potential contribution microbicides can make, especially the "next generation" of more targeted drugs. Zeda Rosenberg, the chief executive of the International Partnership for Microbicides, said the PRO 2000 trial is an "important milestone." She added that the support of the British government and the Gates Foundation adds "crucial momentum to delivering on the promise of microbicides." Sheena McCormack -- a clinical epidemiologist at MRC's Clinical Trials Unit, which coordinated the PRO 2000 trials -- said that researchers involved with microbicides "have come together as an international community in a more coherent way (recently) and we are starting to see the results," adding that the results "should now come in quick succession." McCormack said that researchers "have given PRO 2000 the best chance," adding that if the product works, "it will be statistically significant in our trial and obviously a very, very exciting development." U.K. International Development Minister Ivan Lewis said the increased funding for the research is crucial to ensure the greatest possibility of success and that new research is "vital" to curbing the HIV/AIDS pandemic. He said the development of an effective microbicide "will enable women to protect themselves against infection and could be available long before a vaccine for HIV is found" (Times, 2/23).
Related Opinion Piece
The "holy grail of AIDS research remains elusive" as almost 25 years of research still has not resulted in an HIV/AIDS vaccine, Sam Lister, health editor for the Times, writes in an opinion piece. "The world's leading scientists have stopped talking of vaccine targets, instead favoring terms such as 'incremental advances,'" Lister writes. The finding from the PRO 2000 trial "suggests that it may not be a conventional vaccine that provides a breakthrough in AIDS control," he writes, adding, "But that does not mean that the quest for a vaccine, and the funding it requires, should be diverted in any way."
Although microbicides could be the "key" in the fight against HIV/AIDS, "they will never have the blanket disease-eradication power of a vaccine," Lister writes. "A medication that relies on repeat applications by an individual remains open to considerable human error," while a vaccine can "generate herd immunity to the point where, with a single jab, whole populations can live free of the condition," he writes, concluding that is "may take another 20 years, but it will be worth the wait. Let us hope that, in the meantime, microbicides step up to the plate" (Lister, Times, 2/23).
Reprinted with permission from kaisernetwork.org.