ARV-Based Prevention

Perhaps foolishly I was hoping we might get more data from either the PROUD or IPERGAY studies into PrEP trials, both of which have recently offered participants in their placebo arms active drug. But we will have to wait perhaps until CROI. This morning's plenary did, however, address ARV-Based Prevention.

Stafano Vella provided an update on prevention targets and reflected on the challenges of 90:90:90. He pointed out that drug efficacy should make reaching 90% viral suppression for people on treatment the most achievable of the three. Linking the tested to treatment he saw as a significant challenge and, particularly in the global south, as a difficult goal. But the real challenge globally he saw as reaching the diagnosis of 90% of people living with HIV.

Unfortunately he did not have any magic bullet for reaching the untested and pointed out that the majority of infection occurs before people are aware they are themselves infected. No further light was shone on this issue in question time, although most of the questions did concentrate on PrEP.

Presented by Simon Collins of I-base, this discussion was a thorough recap of PrEP. There is no doubt, that if taken, PrEP offers protection from infection. Yet uptake remains low. Simon showed an interesting slide previously presented at CROI in 2013 by Bob Grant from the iPrEx group which showed the variable risk of HIV acquisition over their study. (If you have not seen it, it is slide 10 in this link www.iprexnews.com/content/croi2013/Grant-Gap-Seroconversion.pdf )

This really is important as much of the debate around PrEP seems to centre on it being a life-long issue. Clearly that is not the case, at least in iPrEx. Simon characterised PrEP as an option which men may want to access a times of particular risk. He also raised the issue of cost. Often PrEP is characterised as the use of drug which would otherwise be able to be directed to people already living with HIV and in need of treatment. There is the capacity to make more drug and generic formulations are also on the horizon. Interestingly the Simon suggested that the cost (using the Gates rate) would be less than $100 per annum, leaving room for a substantial mark-up.

Poster 199 was also mentioned. It describes two MSM on multi-year Tenofovir treatment for hepatitis B who, with high compliance and demonstrable drug on board, sero-converted to HIV following high risk exposure. Both were identified early and notwithstanding treatment both established HIV infection and their "PrEP" did not prevent the establishment of a significant viral reservoir. (Davies et.al).

There clearly remain reservations about PrEP, but it seems like the tide is turning.