Introduction:
Since 2015, integrase strand transfer inhibitors (INSTI)-based regimens have been considered as the preferred option for antiretroviral therapy (ART)-naive patients. The main objective of this study was to identify the ART-regimens selected for treatment-naïve patients during 2015 in two tertiary hospitals, determine the rate of virological failure at 24 and 48 weeks, and compare the results with those of previous years (2012-2014).

Material and methods:
Four-year retrospective study. Adult ART-naïve patients who had started treatment between 2012 and 2015 were selected. Clinical data, laboratory tests performed, and ART selected were recorded.

Results:
A total of 536 patients were included, 137 from 2015 and 399 from 2012-2014. The most common ART regimens prescribed in 2015, compared to 2012-2014, were INSTI-based regimens (68.6% vs. 4.8%), followed by non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimens (20.4% vs. 52.8%) and PI-based regimens (10.9% vs. 42.5%). Most patients received a single-tablet regimen (78.8% vs. 51.9%). In 2015, 72.3% of patients had a viral load (VL) < 50 copies/ml at week 24 and 83.9% at week 48, compared to 55.1% and 74.7%, respectively, in 2012-2014. During the 48-week follow-up, the ART regimen was changed in 22.6% of patients in 2015 and 29.3% in 2012-2014. The main reason was simplification (45.2% vs. 22.2%) followed by side effects (25.8% vs. 38.5%).

Conclusions:
In 2015, INSTI-based regimens were prescribed in nearly 70% of ART-naïve patients. This change in trend in the starting ART regimen results in a greater number of patients achieving a VL < 50 copies/ml at weeks 24 and 48 and in a reduction in ART changes due to adverse effects.