A trial involving French and Canadian anti-HIV medication for people who are HIV negative said today that participants on the placebo arm of its study should be immediately offered the active drug because they had found ‘a very significant reduction in the risk of HIV infection in the on demand PrEP group’. This comes two weeks after the announcement by the PROUD trial in the UK that participants in the ‘deferred PrEP arm’ would be immediately offered PrEP because of the significant protective effect for those taking it.

The ANRS IPERGAY trial, which was offered across France and the French-speaking Québec region of Canada, was launched in 2012 to controversy: some commentators said that it was unethical to offer placebo medication to people at risk of HIV. But these objections were quickly overruled.

The ANRS IPERGAY trial is important because unlike the PROUD trial, which involved taking PrEP daily, involves taking Truvada only as needed – between two and 24 hours both before and after sexual intercourse. The HIV infection rate was reduced by 42 per cent among those using medication compared to those receiving a placebo

Yusef Azad, Director of Policy and Campaigns at the National AIDS Trust, said: ‘This announcement from the ANRS IPERGAY trial is another exciting piece of news in the growing and powerful evidence base on the effectiveness of PrEP. It is especially important if it suggests that PrEP might work well when taken only around the time of sex rather than daily – that could be good news for costs.

‘We will now need to look at how such “intermittent PrEP” works in a “real life” setting rather than a placebo-controlled trial. This news adds to the urgency of the NHS deciding how to introduce PrEP effectively to reduce the current record numbers of gay and bisexual men, and others at high risk, being diagnosed with HIV in the UK.’

More than 6,000 people discover their HIV status in France each year, with sexual transmission accounting for 99 per cent of these infections. The trial involves some 400 volunteers in France, none of whom knew until now whether they were being given the real drug or a placebo. The trial therefore also recommended all participants followed standard prevention measures, including using condoms and lube; regular testing and personalised counselling was also provided.