US: Despite initial interest, many don’t switch to long-acting cabotegravir/rilpivirine

Only half of a group of people living with HIV (PLWH) who had expressed interest in switching to long-acting injectable treatment ultimately did so, according to the results of a single-center study in California.

About This Study

“Single center experience evaluating and initiating people with HIV on long-acting cabotegravir/rilpivirine” was published online on Nov. 29, 2022, in AIDS. The lead author is Lucas A. Hill, Pharm.D., a clinical pharmacist at the University of California-San Diego.

Key Research Findings

This analysis looked at 383 individuals attending a single California HIV primary care clinic in 2021-2022 who had stated interest in transitioning from their current oral antiretroviral regimen to long-acting antiretroviral therapy (LA-ART) with injectable cabotegravir/rilpivirine (Cabenuva). They were referred to a clinical pharmacy team for assessment, additional clinical work-up, evaluation of insurance coverage, and initiation of LA-ART.

Just 53% of participants actually started the regimen. Pre-existing resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs) was the most common reason for not commencing LA-ART (28% of participants), followed by difficulty in attending the clinic or being contacted (20%); the participant changing their mind (19%); detectable viral load (8%); lack of complete drug resistance test results (8%); integrase inhibitor resistance (4%); problems with insurance coverage (4%); concerns about out-of-pocket costs (3%); and active hepatitis B coinfection (2%).

Discussion Highlights and Implications for Practice

The study authors found it notable that financial concerns were not a large factor in keeping people from beginning the regimen, as they expected monetary issues to be a greater deterrent.

Consistent clinic attendance and being easy to contact were study requirements for initiating the regimen, based on the need for individuals to receive follow-up injections within a narrow timeframe; as such, the authors wrote that it was not surprising that inconsistent clinic attendance or being difficult to contact were among the top reasons for not initiating LA-ART. However, they cautioned that further research was needed to determine whether such a requirement is warranted.

Anecdotally, participants who changed their mind about starting LA-ART after initially expressing interest cited the frequency of clinic appointments, concerns about injection site pain, and limited real-world experience with this form of treatment. These statements show the need for addressing patients’ concerns individually, the authors wrote.

Because baseline drug resistance is an issue with cabotegravir/rilpivirine, the study authors recommended proviral DNA resistance testing before initiating LA-ART. NNRTI-experienced PLWH may not be good candidates for this regimen, they noted.

Study limitations included its retrospective nature and the potentially subjective classification of reasons for not starting the regimen. However, quantifying these reasons may help increase uptake among PLWH who could benefit from long-acting treatment, study authors suggested.

By Barbara Jungwirth