PURPOSE OF REVIEW: Preexposure prophylaxis for HIV prevention is highly 
effective when taken as prescribed. Adherence to required dosing regimens for 
protection may pose challenges. Long-acting agents for HIV prevention may have 
the potential to improve adherence via favorable pharmacokinetics supportive of 
infrequent dosing. This review focuses on the potential benefits and 
considerations for the study and use of 2 long-acting injectable agents, 
cabotegravir (GSK1265744LA, CAB LA) and rilpivirine (TMC278LA, RPV LA), for use 
as chemoprophylaxis for HIV prevention.
RECENT FINDINGS: Oral RPV is United States Food and Drug Administration approved 
for HIV treatment (in combination with other antiretrovirals). Both CAB LA and 
RPV LA are currently in phase 2a safety/tolerability/pharmacokinetic studies in 
anticipation and support of future efficacy evaluation. Both agents have 
favorable pharmacokinetics, and use is complicated by injection site reactions.
SUMMARY: Long-acting injectable formulations, if safe and well tolerated, may 
improve pharmacokinetic coverage of exposures to HIV infection. Complexities 
around safety, tolerability, and starting/stopping protocols require careful 
consideration.