ILLUSTRATIVE CASE
A 24-year-old cisgender man with no significant past medical history comes to your office requesting PrEP after starting a new sexual relationship. His partner is a 26-year-old cisgender man with known HIV. The patient reports that balancing graduate school and work has made him very forgetful, and he worries that he won’t remember to take a daily pill. Are there any other PrEP methods you can offer?
The efficacy of PrEP to reduce HIV acquisition has been established across varying populations at high risk for transmission.1 PrEP has been found to reduce the risk for sexual acquisition of HIV by nearly 99%.2
Although the use of PrEP in the United States has increased steadily since 2012, adherence to an oral formulation remains a significant issue. One study of > 13,000 people found that daily oral PrEP was discontinued by 52% of participants, only 60% of whom reinitiated the therapy after discontinuation.2 Although the federal government has required Medicaid and other insurance providers to cover PrEP in an effort to increase access to the medication, this does not necessarily increase adherence to a daily medication in an often otherwise healthy population.
Long-acting injectable forms of PrEP, which have a reduced dosing frequency that may support adherence, have been studied to potentially replace daily oral pills. This latest study compared cabotegravir (CAB-LA), a long-acting IM injection given every 8 weeks, to daily oral PrEP with tenofovir disoproxil fumarate–emtricitabine (TDF-FTC).1
STUDY SUMMARY
Decreased seroconversion without daily pills
This randomized, double-blind, double-dummy, noninferiority trial compared long-acting injectable vs daily oral PrEP formulations for the prevention of HIV across an international population. Patients were randomized to receive either CAB-LA 600 mg IM every 8 weeks or TDF-FTC 300/200 mg orally daily. The double-dummy methodology meant that those patients receiving active CAB-LA also received a daily oral placebo, while those patients receiving active TDF-FTC also received a placebo injection every 8 weeks.
Study participants were cisgender MSM or transgender women who have sex with men; ages 18 years and older; and in good health but considered to be at high risk for HIV infection. To be included, participants had to have a negative HIV serologic test at enrollment, undetectable blood HIV RNA viral load within 14 days of enrollment, and creatinine clearance ≥ 60 mL/min. Exclusion criteria included intravenous (IV) drug use within 90 days of enrollment, coagulopathy, buttock implants or fillers, a seizure disorder, or a QTc interval > 500 ms.1
The intention-to-treat population included 4566 patients: 2282 in the CAB-LA group and 2284 in the TDF-FTC group. Demographic characteristics—including age, race, geographic region, and cohort (MSM vs transgender women)—were not significantly different between groups at baseline. The study lasted 153 weeks, and > 86% of patients were retained at 1 year (median follow-up, 1.4 years; interquartile range, 0.8-1.9).
Continue to: The primary efficacy and safety...
