It’s truly a controversial issue: PrEP is a strategy that is able to polarize positions not only between clinicians but also in the community. During a crowded and hot plenary session in Marseille –during the ISHEID conference last May- Mark Weinberg in a nice duel against Mark Nelson supported the idea of PrEP. A that time we know that FDA expert panel had expressed a positive opinion about the approval of truvada in order to prevent HIV transmission. But more time it was expected to be needed in order to get the final decision. The session was really very excited.
In order to be interesting and useful to the audience, such duels on hot issues need open mind duelists, ability to synthesize his own position, no caution in speaking neither diplomacy and a lot of pleasantness. All tool that both Weinberg and Nelson were able to show. We will be back on PREP issue hosting comments and opinions, and the whole story of this strategy.
The following dialogue about me and Mark Weinberg took place in Marseille, at the end of May 2012.
The newest area that you are covering now is the non-conventional use of drugs: I’m referring to PREP…
Well, that’s correct, it’s a very hot area. I addressed this topic I think it’s extremely encouraging that we are now at the stage where we all think that we should be using antiretroviral drugs as part of preventive strategies in addition to using these same compounds as part of therapeutic strategies and you know I think we would all agree that one danger associated with some of these approaches is the potential development of drug resistance. We have to be very careful that we don’t try out these drugs in a preventive way in people who may be infected and don’t know it: for example somebody who is in acute infection. I think ideally we would want to subject people to viral load measurements to be sure that they are not in an acute phase of infection whereby they might be still antibody-negative and viremia-positive and there are tests that we can do to try to ensure that this is the case but one of the problems is that these tests are not easily going to be done in developing-country settings. There is going to be a greater risk that people in developing-country setting and sometimes in fact wind up getting treated with a preventive regimen that will be sub-standard or inadequate in regard to actual therapy and there is where the greatest danger would lie in regard to potential development of drug resistance. But at least we can establish the proof of principle which has already been done through a number of studies, such as the iPrEx study and the Partners PrEP study: antiretroviral drugs do and can play a role in prevention and it’s a fantastic achievement.
Do you can describe the ideal profile of a person that could be eligible for such use of drug?
I think there are a number of categories of individuals who could be ideal candidates for use of antiretroviral drugs in prophylaxis. I think one obvious candidate is the sex worker, someone who is having repeated relations without protection, without condoms with a lot of other people who they may not know very well, that’s I think a very easy example. And, of course, several of the studies that have been done and are being done in regard to pre-exposure prophylaxis are being conducted among gay men and these gay men have volunteered for these studies, they understand what’s at stake and they want to be part of helping to develop strategies that will safely use some of the antiretroviral drugs in prevention. Now, one issue that has come up, and I think it’s an important thing to underline, is that in some setting some people have said “Well, you know, we don’t have drugs available here for treatment, why are you giving people drugs for prevention when we can’t access the same drugs in treatment strategies?” and I think that is a fair point, so I think we should certainly ensure that anybody who needs antiretroviral drugs for treatment should have access and ensuring access should not be in contradiction to following through with prevention strategies.
So, at least you welcome the position from Panel of Food and Drug Administration regarding the use of PrEP?
Yes, I think the future approvation by the Food and Drug Administration of Truvada as a prevention modality is welcome, I think it’s a step in the right direction. You know, it doesn’t mean though that we shouldn’t keep doing studies and I think it’s still important that for certain types of studies that have not yet been validated we should continue to use placebo arms in order to definitely show that PrEP works. One such strategy, for example, would be the idea of intermittent PrEP where people would take pills for prevention in advance of sexual relations and not every day and I think this is an excellent concept that should reduce toxicities associated with drugs because people won’t be taking them every single day, it would also have important ramifications in regard to costs, but the concept needs to be validated in the context of a placebo-controlled trial.
So, at the end, once again we can suggest a combination approach, PrEP can reduce the virus running in the world and fully suppressed people are not infective?
Yes, I think that’s correct, PrEP should prevent new infections, which should over time lead to reduce the viral burden in terms of new infections on the planet and at the same time, of course ,the same drugs should be used as part of key strategies in regard to therapy. Using these drugs therapeutically, if they reduce viral load, the will also lead to diminished rates of transmission. We should look on this as a win-win situation that really will only be complicated in the event that drug resistance develops at far higher than expected levels, because of the potential problem of people going on PrEP without actually realizing that they are infected or not being adherent to a PrEP regimen and becoming infected and then staying on PrEP, because they don’t know that they did get infected by HIV, in which case they would also be very very susceptible to development of drug resistance.
Articolo presente in – HAART and correlated pathologies n. 15 –