Good news on PrEP for gay men this morning from #CROI2015. Both the UK PROUD study and the French and Canadian IPERGAY study reported 86% reductions in risk of HIV infection among partipants using PrEP. Both are studies of real world effectiveness among gay men and they found that indeed men at high risk of HIV were the ones putting themselves forward for PrEP.
PROUD used a daily dosing schedule and showed that good adherence is possible. IPERGAY used an intermittent or on demand dosing regime of two pills before and two pills after each sex act. With an average of 16 pills used per month participants did dose intermittently. Other risk reduction strategies were employed when PrEP wasn't used.
Neither study found evidence of increased sexual risk taking, allaying concerns that PrEP may lead to risk compensation. Essentially when PrEP is properly targeted, people continue with whatever risk behaviors and risk reduction strategies they had prior to taking the drugs.
Sean has also posted a more detailed update on the ASHM live blog from CROI 2015:
PrEP for gay men, serodiscordant heterosexual couples and women
- CDC Statement on IPERGAY Trial of Pre-Exposure Prophylaxis (PrEP) for HIV Prevention among Men Who Have Sex with Men (25 February, Centers for Disease Control and Prevention (CDC) media statement).
- Pre-exposure prophylaxis (PrEP) stops 86% of HIV infections in PROUD study (24 February, aidsmap.com).
- Pre-exposure prophylaxis also stops 86% of HIV infections in Ipergay study (24 February, aidsmap.com).
- PrEP Proactive Responsible Empowered Pleasure (24 February, Living Positive Victoria media release).