A rather late (18:30-20:30) but very interesting session.
Richardo Garcia-Lema presented the findings of his study in macaques which investigated several different intermittent TDF/FTC schedules to cover teh vaginal exposure to SIV, including: two pills within 24 hours before and after exposure each; one pill 24 hours before and one pill 2-3 hours after exposure; one pill 2-3 hours before and one pill 24 hours after exposure; two pills each time within 24 hours before and 24 hours after exposure. While all schedules were protective, the latter was most effective. The study highlighted the importance of post-exposure dosing, which has to be taken as soon as possible after exposure.
Jean-Michel Molina summarized the key findings of the French-Canadian IPERGAY study:
- HIV incidence was above 6 per 100 person-years and was twice higher than expected;
- the risk of HIV was reduced by 86%, which is some of the highest (if not the highest) levels of protection from HIV observed in clinical trials;
- risk was reduced due to intermittent, not daily PrEP;
- intermittent PrEP is highly effective in gay men who are frequently exposed to HIV, and
- intermittent dosing includes an inherent recommendation of how to start and stop PrEP (two pills before first exposure, one pill daily during ongoing exposures and one pill per day for two days after the last exposure). On that point, Bob Grant commented that he still struggles with the recommendation (or rather the lack of one) on how to start and stop daily PrEP.
Intermittent PrEP is now recommended in France, UK, Europe, and is up to be recommended in the new Canadian guidelines (which are being finalized now).
The discussion returned quite a few times to the importance of adherence to daily PrEP or strategic use of intermittent PrEP (strategic use seems to appear a new term to indicate correct use of intermittent PrEP).
Another important point in the discussion was that appropriately conducted information and education of patients at the start of PrEP results in better adherence to PrEP and unilaterally in better prevention outcomes.