Comparative effectiveness of first-line antiretroviral therapy: results from a large real-world cohort after the implementation of dolutegravir.

Objective: We aimed to assess the effectiveness of first-line antiretroviral therapy (ART) regimens in achieving viral suppression at 12 months, from 2014 to 2017 in Brazil.

Design: A retrospective cohort study utilizing programmatic data from the Brazilian HIV Program.

Methods: Adults (aged 15-80 years) who started ART from January 2014 to July 2017 and had a viral load 365 (±90) days after treatment initiation were included. Associations with achieving viral suppression (<50 copies/ml) at 365 (±90) days were assessed using logistic regression. Our main study variable was ART regimen, and covariates included year of ART initiation, sex/exposure group, age, education, race, region, baseline CD4 and viral load counts, and adherence measured by pharmacy refill data. We performed both intent-to-treat and per-protocol analogous analyses.

Results: Out of 107 647 ART-naive patients, 71.5% initiated with tenofovir/lamivudine/efavirenz (TLE) and 10.5% with tenofovir/lamivudine/dolutegravir (TLD). Median age and CD4 cell counts were 34 [interquartile range (IQR) 26-46] and 379 cells/μl (IQR 190-568), respectively; 68.0% were men. Viral suppression by 12 months was 84.0% [95% confidence interval (95% CI) 83.7-84.2] with TLE and 90.5% (95% CI 90.0-91.0) with TLD, and below 80% for protease-inhibitor-based regimens. In the multivariable intent-to-treat-analogous analysis, controlling for cofactors related to viral suppression including adherence, the adjusted odds ratio (aOR) for TLD's viral suppression relative to TLE was 1.56 (95% CI 1.40-1.75). Findings were robust to secondary per-protocol analogous and sensitivity analysis.

Conclusion: Our results showed the superiority of dolutegravir- over efavirenz- and protease-inhibitor-based regimens in suppressing viral replication in a real-word cohort of HIV-positive adults. This superiority was not driven by higher levels of adherence with dolutegravir-based regimens.