Genotyping not required for sustained effectiveness of long-acting cabotegravir plus rilpivirine: evidence from the RELATIVITY cohort.

OBJECTIVES: Long-acting injectable cabotegravir and rilpivirine (LAI CAB+RPV) provides an alternative to daily therapy for people with HIV (PWH) with virologic suppression. Although genotypic testing is recommended before switching, its real-world clinical value is unclear. We assessed outcomes after switching to LAI CAB+RPV with or without available genotypes in the Spanish RELATIVITY cohort.

DESIGN: RELATIVITY is a multicenter, ambispective cohort study assessing the effectiveness and safety of LAI CAB+RPV in adults with HIV across 58 centers in Spain.

METHODS: Posthoc analysis of 3146 participants, focusing on the availability of genotypic resistance data before switching.

RESULTS: Of the 3146 participants, 53.5% ( n = 1682) did not have genotypes available. The median follow-up was 13.3 months [interquartile range (IQR) 8.6, 18.9] in the no-genotype group and 14.9 months (IQR 9.0, 19.2) in the genotype group ( P  = 0.003). Both groups maintained high virological suppression rates (>93%) up to the 23rd month of follow-up, with no significant differences observed in virological or immunological outcomes. Virologic failure rates (0.5% vs. 1.0%; P  = 0.476) and permanent discontinuation rates (6.1% vs. 6.6%; P  = 0.804) were similar. Of the 20 participants with virologic failure, 12 had genotype data. After resuming oral antiretroviral therapy, 8 of those with and 4 of those without the genotype achieved undetectable viral loads. Adherence to injection schedules and changes in body mass index were comparable.

CONCLUSIONS: In this large real-world cohort, the absence of genotypic data did not affect LAI CAB+RPV effectiveness in virologically suppressed PWH. Limitations, including ambispective design, short follow-up, and low non-B subtype prevalence, may limit generalizability.