Long-acting CAB plus RPV preferred over daily ART despite injection site reactions

Long-acting injections of cabotegravir (CAB) plus rilpivirine (RPV) were found to be tolerable over the long term among patients with HIV infection, according to findings published in Open Forum Infectious Diseases.

When asked about ideal therapy for HIV management, many patients indicate a preference for a less frequent dosing schedule. Long-acting CAB plus RPV injections present a viable option for addressing this preference as the recommended frequency of administration is once monthly or once every 2 months.

To assess the occurrence of injection site reactions (ISRs) associated with the use of long-acting CAB plus RPV injections, researchers affiliated with ViiV Healthcare pooled safety data that were captured from patients with HIV infection in phase 3/3b trials. Trends in ISRs through week 96 were evaluated, and health care providers (HCPs) who administered the injections were surveyed about optimal injection techniques.

The pooled study population comprised 937 patients who were naive to long-acting antiretroviral therapy with CAB plus RPV injections, among whom 920 received the treatment. Overall, the median patient age was 39 years, 22% were women, 15% were Black, and the median BMI was 24.9 kg/m².

Of 34,939 CAB+RPV LA injections administered during the study period, 8453 ISRs were documented. The most common ISR was pain at the injection site (20%), with infrequent occurrences of nodule (1%), induration (<1%), discomfort (<1%), and swelling (<1%).

The researchers noted that ISRs were more common with RPV (22%) than with CAB (18%).

Most ISRs were rated as grade 1 (83%) or grade 2 (16%) in severity, and no grade 4 or 5 events were reported. Overall, 2% of the population withdrew from the study due to ISRs. The rate of withdrawal due to ISRs was higher among Asian participants (10%) than in White (2%) or Black (<1%) patients.

The median duration of ISRs was 3 (IQR, 2-4) days, with most (87%) events lasting 7 days or fewer. Data captured from 28 ISR events that were documented as “not recovered/resolved” indicated pain in 32%, pruritus in 25%, nodule in 21%, discomfort in 7%, fibrosis in 7%, induration in 4%, and necrosis in 4% of the events.

Nodule ISRs occurred more frequently in women (24%) than in men (18%); patients whose race/ethnicity was categorized as “other” (44%) vs Black (22%), White (18%), and Asian (13%) patients; and patients who received injections every 4 weeks (23%) vs every 8 weeks (13%). In addition, painful ISRs occurred more frequently in men (21%) than in women (17%), patients with BMIs below 30 kg/m² (21%) vs 30 kg/m² and above (16%), and White patients (21%) vs Black patients (13%).

The rate of ISRs decreased during the study period, with 71%, 24%, and 15% of the population reporting occurrence at weeks 4, 48, and 96, respectively.

A total of 181 HCPs completed the survey on optimal injection techniques. The HCPs most commonly endorsed using a slow injection speed (66%), room-temperature injections (58%), relaxing the gluteal muscle prior to injection (53%), and distracting the patient (34%) as the most effective techniques to minimize injection site pain.

Study limitations include the lack of blinding in the administration of long-acting CAB plus RPV injections, the higher frequency of safety assessments for patients who received injections every 4 vs 8 weeks, and insufficient power to detect significant trends.

According to the researchers, “These findings were broadly comparable across regions, reinforcing that simple techniques routinely used by injectors can be used to optimize the administration of CAB+RPV LA [long-acting injections].”

Disclosure: This research was supported by ViiV Healthcare and Janssen Research & Development, and multiple study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

By Jessica Nye, PhD

References:

Teichner P, Chamay N, Elliot E, et al. Cabotegravir + rilpivirine long-acting: overview of injection guidance, injection site reactions, and best practices for intramuscular injection administration. Open Forum Infect Dis. Published online May 25, 2024. doi:10.1093/ofid/ofae282