TUAC0105LB - Oral Abstract Session
Results of the iPrEx open-label extension (iPrEx OLE) in men and transgender women who have sex with men: PrEP uptake, sexual practices, and HIV incidence
Presented by Robert M Grant (United States).
R.M. Grant1,2,3, P.L. Anderson4, V. McMahan1, A. Liu2,5, K.R. Amico6, M. Mehrotra1, C. Mosquera7, M. Casapia8, O. Montoya9, S. Buchbinder2,5, V.G. Veloso10, K. Mayer11, S. Chariyalertsak12, L.G. Bekker13, S. Hosek14, E.G. Kallas15, M. Schechter16, D. Glidden2, for the iPrEx study team
1Gladstone Institutes, San Francisco, United States, 2University of California, San Francisco, United States, 3San Francisco AIDS Foundation, San Francisco, United States, 4University of Colorado, Denver, United States, 5San Francisco Department of Public Health, San Francisco, United States, 6University of Connecticut, Storr, United States, 7INMENSA, Lima, Peru, 8ACSA, Iquitos, Peru, 9Equidad, Guayaquil, Ecuador, 10FIOCRUZ, Rio de Janeiro, Brazil, 11Fenway Health, Boston, United States, 12Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand, 13Desmond Tutu Health Foundation, Cape Town, South Africa, 14Stroger Hospital of Cook County/The CORE Center, Chicago, United States, 15University of Sao Paulo, Sao Paulo, Brazil, 16Praca Onze, Rio de Janeiro, Brazil
Background: The impact of HIV PrEP depends on drug uptake,
adherence, sexual practices, and interactions between these factors.
Methods: Participants in randomized placebo-controlled
iPrEx, ATN 089, or US PrEP Safety trials were enrolled in a 72-week open label
extension (iPrEx OLE). The study
provided services regardless of choice to receive oral FTC/TDF PrEP. Tenofovir-diphosphate (TFV-DP) was quantified
in dried blood spots (DBS) among seroconverters and a random sample of site and
visit matched seronegatives.
Results: 1603 HIV-uninfected persons enrolled, of whom
76% opted to receive PrEP. Non-condom receptive anal intercourse (ncRAI) was
associated with PrEP uptake (P=0.001).
The reasons for not requesting PrEP included concern about side effects
(49%), the inconvenience of a daily pill (24%), and preference for other
prevention methods (14%). Among those starting PrEP, HIV incidence was
1.83/100PY which was 49% (95% CI: -1 to 74%) lower than among those who did not
choose PrEP after adjusting for sexual behavior, 53% (95% CI: 26 to 70%) lower
than in the placebo arm of the randomized phase (3.93/100PY), and 51% (95% CI:
23% to 69%) lower than during the gap between the randomized phase and OLE
(3.81/100PY). Incidence was lower among those with higher drug exposure.
[HIV Incidence According to TFV-DP in DBS]
|TFV-DP in DBS (fmol/punch)||Est. dosing||% of follow-up||HIV incidence||95% CI|
|<2.5||None||26%||4.7/100 PY||2.8 to 7.2|
|2.5 to < 350||<2 tablets/wk||27%||2.2/100 PY||1.1 to 4.1|
|>=350 to < 700||2 to 3 tablets/wk||12%||0.6/100 PY||0.0 to 2.5|
|>=700 to 1249||4 to 6 tablets/wk||22%||0 /100 PY||0.0 to 0.6|
|>=1250||Daily||5%||0 /100 PY||0.0 to 1.1|
Effective PrEP use (≥4 tablets/week) was
associated with older age, more schooling, ncRAI, more sexual partners, and
syphilis or herpes. The proportion
reporting ncRAI decreased from 33% to 25% among PrEP recipients (P < 0.01)
and from 27% to 20% among non-recipients (P< 0.01).
Conclusions: PrEP was preferentially requested by those
reporting higher risk sexual practices; risk declined in the cohort, regardless
of PrEP receipt. The impact of oral PrEP
may be increased by these synergies and limited by non-adherence. DBS drug
concentrations are convenient and strong correlates of PrEP protection.
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