Before 2021, oral medication was the only option for HIV prevention and treatment, but adherence has always been a challenge. Now patients can get long-acting bimonthly injections in place of a daily pill, but this regimen presents new difficulties.
Long-acting cabotegravir (CAB-LA; Apretude, ViiV Healthcare) for pre-exposure prophylactic (PrEP) and cabotegravir-rilpivirine (CAB/RPV; Cabenuva, ViiV) for treatment are attractive alternatives for a variety of reasons, especially because adherence is a known limitation with antiretroviral therapy (ART). Every other month, clinic appointments may be more manageable than taking daily oral medications, especially for patients who have transient or chaotic lifestyles. Other patients cannot tolerate oral medications and need an alternative. Still others, especially those who believe they must hide their HIV medication, prefer the privacy of the clinic visits.
New data from three recent posters presented at CROI 2024, held in Denver, shed light on which patients are interested in injectable medications and what barriers they face to continued access.
What the Data Say
In a survey of U.S. women with HIV, 43% preferred the idea of long-acting injectable ART (poster 1247). Young patients, those who took oral medications less consistently (<95% of the time) and those with a history of substance abuse were more likely to fall into this group.
However, the long-acting treatments aren’t for everyone; 36% of respondents still preferred daily oral medication. “We’ve created a product that’s good for some people, but it is not unproblematic,” said Morgan Philbin, PhD, an HIV researcher who studies equity and access to care at the University of California, San Francisco, and was the lead author on the poster. The injection can be uncomfortable and requires privacy since it is administered in the buttocks. There also may be other issues like transportation which can make getting to the clinic challenging.
The uptick in clinic time that comes with bimonthly injections creates logistical challenges for patients and clinicians. “On the oral pill, patients come in every four to six months. That shift to once every other month is a lot,” Dr. Philbin said. And from the clinic’s perspective, “if someone is coming in three times more frequently than before, who is seeing them?” she asked.
Two posters using data from the University of California, San Diego’s Owen Clinic, looked at factors that predict patient adherence to these appointments.
In the first poster, a retrospective cohort study of patients on injectable CAB/RPV for HIV treatment, younger age predicted lower adherence (missed injection appointments). A missed appointment in the year prior to starting injections was also significantly associated with a missed injection (P<0.001) (poster 264).
The study also looked at late injections, which means the patient failed to reschedule a visit for the injection in the recommended window (at least seven days from the scheduled dose). While the study recorded only a few late injections and the vast majority were within 14 days (42/44), those patients were more likely to be younger and male sex assigned at birth.
“The concern is if people are late for their injection—outside that seven-day dosing window—the drug levels may decrease, and if they decrease you could have a viral replication start to occur,” said Lucas Hill, PharmD, BCACP, AAHIVP, the lead author on the study, and an HIV pharmacist specialist at Owen. If the virus starts to replicate, it could develop resistance to the injectable medication as well as a cross-resistance that may render two major classes of HIV drugs ineffective, Dr. Hill said.
Similarly, the second poster from UC San Diego, a retrospective cohort of PrEP patients, found that younger age was associated with discontinuation of CAB-LA (poster 1105). Coverage from somewhere other than a PrEP assistance program and missed injections were predictors of injection discontinuation. The study also reported that most people who adopted injectable PrEP were patients who already took oral PrEP and either needed or wanted an alternative.
Based on all three studies, it is clear that there is a need for alternative deliveries of HIV medications. But it’s also the case that patients need support in maintaining the treatment they want. This is especially true for young people who appear to be most interested in injectables but struggle most with adherence.
“We know young people are interested because it’s not something they have to do every day. And habits are hard when your life is more chaotic,” said Jill Blumenthal, MD, an infectious disease specialist at UC San Diego Health and a co-author on the injectable PrEP study. Clinicians must consider ways to work with young patients, understand the barriers they face—like scheduling or transportation—and find unique ways to support them as they begin injectables, she said.
These findings about preference toward injectables, predictors of discontinuation or missed injections aren’t intended to guide which patients are offered injectable options, the experts said. But they should help “steer the discussion you have with the patients,” Dr. Hill said.
Understanding the barriers that have prevented visits for some patients and helping them overcome the barriers could improve the management of these patients. “We have a responsibility as a community that works to prevent and treat HIV to try and deal with these logistics,” Dr. Hill said.
The sources reported no relevant financial disclosures.
This article is from the June 2024 print issue.