It’s been quite the roller coaster in the PrEP world recently. On the downside, April saw the closure of the FEM-PrEP trial due to “futility” (read the Mapping Pathways blog posts on this here and here). On the upside, we received exciting news this month from the HPTN 052 study, which confirmed that treatment as prevention works (read the Mapping Pathways post here).
With all this news relating to various studies and trials, we thought to check in with Dr. Linda-Gail Bekker from the Desmond Tutu HIV Foundation (DTHF) in South Africa, a Mapping Pathways partner organization. Dr. Bekker is one of the foremost experts in the field of biomedical trials and research.
She, along with her colleagues, is currently finalizing preparations for a new PrEP trial slated to begin during the second half of this year. Unlike other similar trials underway (such as the VOICE trial), the ADAPT study will focus more on the behavioral aspects of intermittent PrEP in sites in Bangkok (men who have sex with men) and South Africa (women who have sex with men). Explains Dr. Bekker, “It’s a feasibility study, it’s not an efficacy study. It’s looking at dosing – intermittent PrEP vs. event-driven PrEP (time of sex) vs. daily PrEP. The question is really about what’s your preference?”
Determining this “preference” includes exploring questions like: how easy or difficult are the different dosing regimens of PrEP to follow; if given the choice, what would be a person’s preference for the frequency of dosage; and how adherent are people to PrEP depending on this frequency? Asks Dr. Bekker, “How do you get truthful information around sexual risk and practices, and how do you gain authentic information around adherence? There’s a huge amount of research to be done. We’ve tended to keep behavior at arm’s length … but how do you get to the heart of that?”
To put it simply, regardless of whether PrEP is effective or not, people need to adhere to it for it to work; just as, although it’s been proven that condoms are effective, people need to use them in the first place. The ADAPT study is trying to determine whether the frequency of PrEP dosage influences this adherence or not.
This is an interesting concept because it looks beyond the science of PrEP to the behavior of PrEP, and the complexities and nuances of human behavior are wild cards Dr. Bekker often encounters in her work.
Dr. Bekker, the principal investigator for the iPrEx study’s Cape Town site, says the only certainty in this field is that anything is possible. For instance, until the FEM-PrEP endpoint results and analyses are released, it’s anybody’s guess as to whether the trial was deemed futile due to adherence issues or whether it was efficacy issues. Says Dr. Bekker, “Wait for the evidence, I think that is the message. Extrapolate at your peril. We know only what we know, and we need to just work within that. I think whenever the field starts to go on emotion, we get into trouble.”
“Human behavior keeps messing up the plot,” she continues. “For example, if we could tell people to just use condoms 100% of the time or go with a ‘Here’s a pill, swallow it’ approach as we would with a mouse or an automot, it would all be much easier. But the fact is that behavior and biology crash in the middle, and it’s difficult then to tease out what the biology is doing because the behavior has quite an undefined, nebulous impact. So it makes the work so much harder.”
Dr. Bekker’s solution?
“We go at it with evidence we try and get as truthful information as we can, we understand as much as we can, we know as much as we can … and then I think we’ll do much better.”
Linda-Gail Bekker is deputy director of the Desmond Tutu HIV Centre at the Institute of Infectious Disease and Molecular Medicine, University of Cape Town. She also serves as the chief operating officer of the Desmond Tutu HIV Foundation, a Mapping Pathways partner organization. You can read more about Dr. Bekker’s views and her work at the following links:
The Lancet: Linda-Gail Bekker: confronting the TB/HIV co-infection epidemic
New Statesman: Linda-Gail Bekker Extended Interview
Allafrica.com: Linda-Gail Bekker scoops award for TB/HIV
[Content that is linked from other sources is for informational purposes and should not construe a Mapping Pathways position.]
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