Short-Term PrEP May Be Effective Alternative Method of HIV Prevention Among MSM

August 19, 2020

Gay, bisexual, and other men who have sex with other men (MSM) during episodes of high-risk behavior could benefit from short-term use of preexposure prophylaxis (PrEP) to lessen their chances of contracting HIV, a new study reports.

There may be another inroad to HIV prevention: Gay, bisexual, and other men who have sex with other men (MSM) during periods of high-risk behavior could benefit from short-term use of emtricitabine/tenofovir disoproxil fumarate as preexposure prophylaxis (PrEP) to lessen their chances of contracting the virus, a new study in Journal of Acquired Immune Deficiency Syndromes reported.

In addition, their short-term use during these periods (eg, travel, vacation, moving, after a break-up) could lead to habitual longer-term use of the medication, which the CDC reports is 99% effective when used correctly.

“We started this as a feasibility study to see if we could identify barriers to short-term PrEP use and make adjustments. But we were excited when we got the results and discovered that almost all the participants were adherent to the point of protection against HIV,” James Egan, PhD, MPH, of the University of Pittsburgh School of Public Health and lead study author, said in a statement.

Among the 54 cisgender MSM from Pittsburgh, Pennsylvania, and Boston, Massachusetts, who participated in the nonrandomized naturalistic study of a pilot program for 30-day fixed-interval episodic PrEP (Epi-PrEP) use before, during, and after vacation, these barriers to long-term adherence included episodic risk, cost, and the medication’s adverse effects. Their mean (interquartile range [IQR]) age was 39 (IQR, 24-64) years.

The primary study outcome was adherence via self-reporting and plasma tenofovir concentrations. Enrollment included a preliminary medical evaluation for PrEP suitability 2 weeks before vacation and instructions to take the medication for at least 3 weeks: the week before, for the entire trip, and the week after.

Results revealed that upon return from vacation, 91.5% of the men had tenofovir plasma concentrations that indicated their daily use of PrEP while on vacation (>35.5 ng/mL, at a 90% sensitivity threshold). In addition, 93.6% produced drug levels that indicated consistent protection (4.2-35.4 ng/mL, or 4 pills/week). These results were seen as great positives, especially when considering that three-fourths and one-third, respectively, reporting condomless sex and recreational drug use.

During the 3-month follow-up, just 1 enrollee contracted the virus due to an inability to continually access PrEP, 48 were able to make the postvacation visit, and 42 completed the 3-month follow-up.

To qualify for the study, the men had to be at least 18 years old, have an upcoming episodic-risk period (eg, vacation) of 5 to 14 days, and provide consent, among other criteria. They could not be HIV-positive or have taken PrEP in the previous 3 months. A phone screening determined initial eligibility between January 2016 and April 2017.

For the self-reported PrEP adherence results:

  • 95.8% said they had an excellent or very good ability to adhere to daily PrEP use
  • 85.4% said they didn’t miss any doses
  • 66.7% said it wasn’t difficult to take PrEP
  • 6 MSM missed 2 or fewer doses
  • 1 participant missed 6 doses
  • 71.4% are likely to remain on PrEP
  • 48.7% would be likely to continue Epi-PrEP
  • 60.1% said they would consistently use PrEP

Top barriers to taking PrEP while on vacation were schedule (27.1%), not returning to where they were staying (10.4%), too busy (8.3%), alcohol use (8.3%), unfamiliar environment (7.3%), and drug use (2.1%).

“Time-limited dosing strategies may be a realistic, feasible, acceptable, and useful option for some high-risk MSM whose behaviors are episodic but nonrandom,” the authors concluded. “Understanding different PrEP use patterns is essential for providing effective PrEP interventions. Access to low cost and sustainable PrEP access is a social justice issue that must be considered in both research and community-based public health programs designed to increase PrEP uptake and effective use over time.”

When interpreting their findings, the authors noted there are several limitations to their generalizability. The sample size was small, mostly white, and most identified as gay; knowing PrEP plasma concentrations would be measured could have affected adherence; and the medication and testing were free and could have served as motivators, especially for the MSM with difficulty accessing PrEP.

Reference

Egan JE, Ho K, Stall R, et al. Feasibility of short-term PrEP uptake for men who have sex with men with episodic periods of increased HIV risk. J Acquir Immune Defic Syndr. 2020;84(5):508-513. doi:10.1097/QAI.0000000000002382