Background: In early 2017, the Ministry of Health of Brazil (MoH) released new antiretroviral treatment (ART) guidelines, which set Lamivudine+Tenofovir+Dolutegravir as the preferred first-line regimen for HIV treatment. In this study, we used real-world programmatic data from Brazil aiming to describe the observed effectiveness of different regimens in the initial response to ART, using the six-month viral load (VL) count.
Methods: Programmatic data from two information systems from the MoH were used; they gather data on every VL and CD4 counts performed within the country''s public health system, and on every ART dispensation. Patients aged 15 and over, who started ART from January 2014 to June 2017 and had a 6-month VL (180±90 days after treatment initiation) were included. The outcome was failure to achieve initial virologic suppression (VS), defined as presenting the 6-month VL above 50 copies/mL. Univariable and multivariable analyses were performed, with unconditional logistic regression models assessing the likelihood of the outcome according to the initial ART regimen, controlling for adherence level, sex, age and CD4 and VL at treatment initiation. Adherence level was calculated using pharmacy refill data.
Results: Of the 103,240 patients included in the analysis, 67.6% were male; median values of age, baseline CD4, baseline VL and adherence were 34 years old, 394 cells/mm3, 38,057 copies/mL and 96.2%, respectively. Overall, 76.9% achieved a VL< 50 copies/mL. The most common regimens were 3TC+TDF+EFZ (74.0%), 3TC+TDF+DTG (7.2%), 3TC+AZT+LPV/r (4.9%), 3TC+TDF+ATV/r (4.6%), 3TC+AZT+EFZ (3.5%) and 3TC+TDF+LPV/r (2.0%). VS ranged from 63.7% with 3TC+TDF+LPV/r to 85.2% with 3TC+TDF+DTG. In the multivariable analysis, with 3TC+TDF+DTG as the reference, aOR (95%CI) of failing to achieve VS were 1.42 (1.32-1.52) for 3TC+TDF+EFZ, 1.51 (1.35-1.68) for 3TC+AZT+EFZ, 2.11 (1.91-2.32) for 3TC+TDF+ATV/r, 2.41 (2.18-2.66) for 3TC+AZT+LPV/r and 2.62 (2.32-2.95) for 3TC+TDF+LPV/r.
Conclusions: The observed effectiveness of 3TC+TDF+DTG was markedly superior after controlling for possible confounders, with all other regimens showing 42%-162% higher odds of not achieving initial virologic suppression. Our results support the decision made by the MoH to switch its recommendations for preferred first-line ART from Efavirenz to Dolutegravir-containing regimens.

Table 1: Baseline characteristics and results of the multivariable logistic regression model for VL>50 copies/mL (n=103,240)
[Table 1: Baseline characteristics and results of the multivariable logistic regression model for VL>50 copies/mL (n=103,240) ]