Phase:Open Label
Principal Investigator(s):Robert M Grant
Objective:Continuation of the iPrEx study designed to provide additional information about the safety of PrEP and the behavior of people taking PrEP over a longer term. iPrEx OLE was fully enrolled in July 2012 and every participant is being followed for 72 weeks. Key results: Enrollment in OLE was greater for non-condom users, those practicing recreational anal intercourse, those with herpes or syphilis. There was no difference in PrEP update by age, education, transgender identity, prior randomized group, or substance use (measured: alcohol, methamphetamine, cocaine). HIV incidence on PrEP in OLE was 1) 49% lower than off PrEP after adjusting for baseline sexual risk, 2) 53% lower than during the placebo arm of the randomized phase, 3) 51% lower than during the gap in study phases. Adherence was good, not perfect. Those who stayed on 2-3 tablets/ week experienced 84% risk reduction, while those who adhered to greater than 4/ week experienced 100% risk reduction. Last updated August 9, 2022
Prevention Option(s):PrEP
Study Design:
Arms and Assigned Interventions
Mode of DeliveryTablet
Official Code: IPrEx OLE
Trial Sponsors: DAIDS/NIH, Gladstone Institutes
Start Date
End Date
July 9, 2011
April 1, 2014
Age range: 18 Years ↔ any
Population:Gay and Bisexual Men Who Have Sex with Men