New HIV Rate High After iPrEx Men Stop Truvada PrEP (or Placebo): when taking Truvada PrEP it works

20th Conference on Retroviruses and Opportunistic Infections, March 3-6, 2013, Atlanta

Mark Mascolini

HIV incidence among gay/bisexual men taking tenofovir/emtricitabine (Truvada) preexposure prophylaxis (PrEP) during the iPrEx trial rebounded to high levels after they stopped daily dosing [1]. Post-trial incidence remained at the same high level in men randomized to placebo during the study.

But incidence “tended to be lower among the group formerly exposed to active PrEP,” the iPrEx investigators determined, “indicating that infections averted during PrEP use were not offset by excess infections after PrEP use ended.”

iPrEx randomized sexually active men and transgenders who have sex with men to daily Truvada or placebo and found an overall 43% reduction in adjusted HIV incidence with Truvada [2]. Protection from HIV reached 92% in participants with detectable study drug in plasma or blood cells.

To see if HIV incidence changed after the randomized phase of iPrEx stopped, researchers monitored 1529 HIV negative participants for 7 to 19 months, before they started the iPrEx off-label extension (OLE) study ( During that time participants had access to services at study sites but got no Truvada for PrEP. Taking active drug during iPrEx did not affect willingness to enroll in iPrEx OLE.
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