About The Study

CTN 332 aimed to understand the preferences of gay, bisexual, and other men who have sex with men (GBM) and transgender women (TW) related to delivery of HIV pre-exposure prophylaxis (PrEP) care. Specifically, the study aimed to quantify the proportion of participants who prefer a web-based mobile health platform (Freddie™) to standard PrEP care. Freddie is an existing system that was designed specifically for providing convenient, remote PrEP care to GBM and TW in Canada.

About The Disease

PrEP, using regular oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) or tenofovir alafenamide/emtricitabine (TAF/FTC), is an effective and safe HIV prevention option. Despite awareness, willingness, and early uptake of PrEP in Canada, there are barriers to broader expansion of PrEP programs. In general, there is a need to simplify and streamline PrEP delivery to improve quality of care and patient and provider satisfaction. While the standard of care has shifted to telephone- and digital-based care during the pandemic, these formats require coordinated scheduling and are affected by missed calls and inadequate technology.

Freddie allows for asynchronous contact between patients and care providers, meaning that it does not require both groups to be connected in real time, instead allowing communication over a number of days. The platform also reminds users about necessary lab testing before appointments and includes clinical surveys to capture routine PrEP follow-up information. Prescriptions can also be electronically sent to pharmacies through the system. CTN 332 will assess whether these benefits make Freddie a preferred platform over the usual standard of care.

Study Approach

This study aimed to enrol 142 participants in Calgary, Toronto, Winnipeg, and Hamilton. CTN 332 used a crossover design, meaning that all participants received care using both Freddie and the standard approach. At the beginning of the study, participants were randomized to receive one type of care and, after completing the first 36 weeks of the study, crossed over to receive the other type of care for another 36 weeks (72 weeks total). All participants in the study received daily oral PrEP in the form of TAF/FTC 200/25 mg (Descovy®) tablets.

The study team aimed to quantify the proportion of participants who indicate a preference for the Freddie platform over the standard of care at the final week 72 visit. Throughout the study, participants completed questionnaires about their satisfaction with care and the degree to which they are adhering to PrEP. Adherence was also measured using a dried blood spot test. The preferences of care providers was also be assessed using questionnaires.


This study was terminated.

Eligibility Requirements


  1. Self-reported GBM (inclusive of transgender men) or TW
  2. Age ≥16
  3. HIV seronegative, as documented by a 4th generation HIV antigen/antibody combination test performed within 14 days of baseline
  4. No symptoms of acute HIV seroconversion (fever, myalgias, arthralgias, malaise, headache, rash, pharyngitis, and/or diarrhea that is otherwise unexplained)
  5. Meets clinical criteria for PrEP according to the prescribing clinician. Patients can be enrolled into the study regardless of whether they will be newly initiating PrEP, or are already receiving PrEP; those already receiving PrEP can be using any regimen (e.g., daily TDF/FTC, on-demand TDF/FTC, daily TAF/FTC) as long as they are willing to transition to the study regimen of daily, oral TAF/FTC
  6. Has adequate kidney function (eGFR >30 ml/min)
  7. Has adequate access to the internet to permit use of the mHealth platform
  8. Adequate facility in English to communicate with their provider

Not Allowed

  1. Known hypersensitivity/allergy to TAF/FTC
  2. Actively participating in another interventional trial related to the delivery of PrEP or sexual health-related care
  3. Being unwilling or unable to perform self-collected pharyngeal and/or rectal swabs as part of routine PrEP care
  4. Potential to become pregnant
  5. Currently living in, or planning to move to a location that would render standard of care or ad hoc in-person visits to the study site impractical during the study period

Additional Information

If you would like to take part in this study or want more information, please contact:

Reva Persaud
Clinical Research Coordinator
Options Lab, St. Michael’s Hospital
Email: reva.persaud@unityhealth.to
Tel: 416-864-6060 ext 77105

Principal Investigators

Here’s who is leading this study.

Can’t find what you’re looking for? Email ctninfo@hivnet.ubc.ca.

Participating Sites

Here’s where this study is being conducted.