Randomized Controlled Trial of Daily Text Messages to Support Adherence to Preexposure Prophylaxis in Individuals at Risk for Human Immunodeficiency Virus: The TAPIR Study

Abstract

Background Adherence is critical for efficacy of tenofovir disoproxil fumarate/emtricitabine (FTC) as preexposure prophylaxis (PrEP). Methods Between February 2013 and February 2016, 398 men who have sex with men and transgender women were randomized 1:1 to receive individualized texting for adherence building (iTAB) or standard care (SoC) for 48 weeks. The primary endpoint was dried blood spot (DBS) tenofovir diphosphate (TFV-DP) concentrations at both week 12 and the last on-drug visit of >719 fmol/punch (ie, adequate adherence). Secondary outcomes included DBS TFV-DP concentrations of >1246 fmol/punch (ie, near-perfect adherence) and plasma FTC >350 ng/mL (consistent with dosing within the past 24 hours). Results Concentrations >719 fmol/punch of TFV-DP were found in 88.6% of participants at week 12 and 82.5% at week 48. For the primary endpoint, the study arms did not differ (72.0% in iTAB and 69.2% in SoC; P >.05). For the secondary composite endpoint of >1246 fmol/punch the iTAB arm was superior to SoC (33.5% vs 24.8%; P =.06), reaching statistical significance when adjusting for age (odds ratio, 1.56 [95% confidence interval, 1.00-2.42]; P.05). Conclusions Automated text messaging is a low-burden tool that improves durability of near-perfect PrEP adherence. Clinical Trials Registration NCT01761643.