Contemporary Single and Multi-Tablet HIV Treatment Regimens Are Associated With Similar Levels of Viral Suppression.

BACKGROUND: Single-tablet regimens (STRs) are widely used to treat HIV but are often substantially more expensive than multi-tablet regimens (MTRs). Few data exist comparing the effectiveness of STRs compared to contemporary once-daily MTRs. METHODS: We merged data on persons with HIV (PWH) insured through WA State Medicaid in 2023 with statewide, public health HIV RNA surveillance data and used Poisson regression to estimate the relative risk (RR) of viral suppression (HIV RNA <200 copies/mL) associated with different antiretroviral therapy (ART) regimens. Models adjusted for sex, age, race, ethnicity, time since HIV diagnosis, housing status, healthcare system providing care, region, and receipt of Ryan White services. RESULTS: A total of 2599 (90.4%) of 2874 PWH were virally suppressed. In multivariate analysis, lower levels of viral suppression were significantly associated with female sex at birth, younger age, being unstably housed, and use of darunavir-containing MTRs, but not other ART regimens. Viral suppression was lower among persons treated with 2025 US guideline recommended 1st-line MTRs (dolutegravir [DTG] + emtricitabine [FTC]/tenofovir alafenamide [TAF], DTG + FTC/tenofovir disoproxil fumarate [TDF], DTG + lamivudine [3TC]) than bictegravir (BIC)/FTC/TAF, however, this difference was not significant (88.9% vs 91.6%, RRadj = 0.98, 95% CI 0.94-1.01). Viral suppression did not significantly vary between persons on BIC/FTC/TAF and 1st-line MTRs among unstably housed persons (78.8% vs 78.2%, RR = 1.00, 95% CI 0.84-1.19). CONCLUSIONS: Differences in viral suppression between contemporary STRs and 1st-line MTRs, if any, are likely small. Factors other than drug efficacy-including cost-should inform decisions to use STRs versus 1st-line MTRs.