CCTG 595: Text Messaging Intervention to Improve Adherence to PrEP in High-risk MSM

• Adherence to PrEP [ Time Frame: Baseline to Week 48 ]

  CCTG 595 will compare adherence to fixed dose TDF/FTC, between subjects randomized to receive SoC plus text message reminders versus SoC, when used for pre-exposure prophylaxis among MSM at high risk for HIV acquisition.

  The primary adherence endpoint will be a binary endpoint (Yes/No) based on DBS samples from two visits (week 12 visit and the last on-drug visit over the 48 weeks). Both visits should have a detectable TFV-DP level > 719 fmol/punch (consistent with taking four or more doses per week) to be considered adherent. If the last on-drug visit was at week 12 (i.e. the subject had only one DBS sample), adherence will only be determined by that sample. If a subject discontinued study before week 12 (i.e. had no DBS samples at all), the subject will be considered non-adherent.

  
  

• Factors associated with poor adherence [ Time Frame: Baseline to Week 48 ]
  Determine factors associated with poor adherence/lost to PrEP in study participants (outcomes of < 90% adherent on drug at 48 weeks by ACTG 4 day recall or discontinuation of drug). Factors associated with poor adherence to TDF/FTC will include demographics, ongoing substance use, untreated mental illness, socioeconomic status, low health/HIV and system literacy, fear of disclosure and non-English language.
  
  
• Rate of HIV seroconversion [ Time Frame: Baseline to Week 48, and up to 2.5 years follow up if subject desires to remain on study after reaching the primary endpoint ]
  Determine the rate of HIV seroconversion in PrEP users and compare the iTAB to SOC arms for number of new infections as a proportion at 48 weeks and end of study.
  
  
• Acquisition of other sexually transmitted infections [ Time Frame: Baseline to Week 48, and up to 2.5 years follow up if subject desires to remain on study after reaching the primary endpoint ]
  Measure acquisition of other sexually transmitted infections (STIs); the proportion of subjects with any new STI at any site will be compared between the iTAB to SOC arms at 48 weeks and through the end of the study.
  
  
• Changes in risk behavior [ Time Frame: Baseline until up to 2.5 years follow up ]
  Evaluate changes in risk behavior after initiation of PrEP (risk compensation) comparing baseline to subsequent visits for number of HIV positive/unknown status partners and any unprotected anal intercourse with an HIV positive/ unknown status partner.
  
  
• Safety and tolerability of daily TDF/FTC [ Time Frame: Baseline until up to 2.5 years of follow up ]
  Evaluate the safety and tolerability of daily TDF/FTC given for PrEP including discontinuation for any adverse event, serious adverse events and adverse events (grade 2 or higher).
  
  

A total of 400 HIV-uninfected men who have sex with men (MSM)and male to female (M to F) transgender individuals with recent high-risk transmission behavior will be enrolled into the study. Each subject will be followed for up to 48 weeks after enrollment of the last subject. The primary endpoint will be measured at 48 weeks.

All subjects will start PrEP with TDF + FTC fixed dose combination given once daily. Subjects will be randomized (1:1) to either the iTAB text messaging adherence reminder intervention with SoC or the SoC alone arm. Subjects placed into the iTAB intervention arm will receive a personalized, automated texting system to maintain adherence and retention. Both groups will receive access to PrEP in accordance with standardized comprehensive methods of prescribing, risk reduction counseling, adherence counseling, and clinical assessments that include safety monitoring, as well as HIV and STD screening.

TDF 300 mg + FTC 200 mg fixed dose combination will be given orally once daily starting at the baseline visit (month 0) and continued throughout the study.