Hopes of a breakthrough that would allow women to protect themselves from HIV have been dashed with today's revelation from a large, British-funded trial that a promising drug has turned out to be ineffective.
Britain's
Medical Research Council (MRC) and the
department for international development (DfID) had backed the
trial in four African countries, involving 9,385 women. But after four years and significant investment, scientists have been forced to conclude that the PRO 2000 gel does not prevent HIV/Aids. Dr Sheena McCormack of the MRC, chief investigator of the trial, said they were deeply disappointed, but that the search must go on.
A microbicide, in the form of a cream or gel that kills the virus, would give women in Africa and Asia the power to defend themselves against HIV given the refusal of many men to wear condoms. The trials in Africa showed that both men and women found its use acceptable.
Expectations were raised in March when a smaller US-led trial of PRO 2000, involving 3,099 women, found a 30% reduction in infections, but the actual numbers of people who became HIV positive were not large enough to give conclusive results.
"I have to say then we got quite excited," said McCormack. "But in a big trial you get closer to the truth, and unfortunately the truth is it didn't work. It is bitterly disappointing for us, but it will inform the way we go forward."
Half the participants were given PRO 2000 while the other half got an inactive gel. There were 130 infections among those who used the real thing and 123 among those who had the inactive gel. The UK Government £14m to the MRC, Imperial College and five African countries in 2002. The final cost to DfID of the PRO 2000 trial has been £40m, with £2m from the MRC – a substantial sum, but tiny compared with the cost of pharmaceutical company trials.
About 2.7 million people were infected with HIV last year. A number of African countries have run out of money to put newly diagnosed people on drugs to keep them alive and will struggle to continue to treat those already taking them if donations fall because of the economic crisis. There is a danger, said McCormack, that it is "going to go wrong again for Africa".
If PRO 2000 had worked, it could have been made available cheaply over the counter to any woman who wanted it.
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