The efficacy of switching to a fixed-dose combination of rilpivirine/tenofovir disoproxil fumarate/emtricitabine was similar to that of switching to an integrase strand transfer inhibitor (InSTI)-based regimen with tenofovir/emtricitabine in patients with HIV and virologic suppression, with both regimens resulting in similar virologic outcomes, according to a retrospective study published in BMC Infectious Diseases.
Patients included in this retrospective analysis (n=675) had <50 HIV-RNA copies/mL and were receiving either rilpivirine or an InSTI plus tenofovir disoproxil fumarate/emtricitabine. At least one HIV-RNA level was quantified in each patient using a kinetic polymerase chain reaction system. Investigators assessed and compared the durability of each regimen using the Kaplan-Meier method and log-rank test, respectively.
Of the included patients, a total of 466 switched to a rilpivirine-based regimen and 209 switched to an InSTI-based treatment strategy consisting of dolutegravir (18%), raltegravir (39%), and elvitegravir/cobicistat (43%). One-year cumulative probabilities (95% CI) for virologic failure were low for the rilpivirine and InSTI groups (0.97% [0.36%-2.62%] and 1.83% [0.57%-5.77%], respectively), with no significant differences between the 2 groups (P =.328).
In addition, there were no differences between groups with regard to treatment failure (P =.209), with cumulative probabilities at one year being 9.73% (7.21%-13.06%) in the rilpivirine group and 8.75% (5.25%-14.4%) in the InSTI group.
The duration of residual viremia was also similar between the rilpivirine and InSTI groups (9% [interquartile ratio 0.5%-49%] and 17% [interquartile ratio 0.5%-50%], respectively; P =.087).
At switch, there was a significant association with treatment failure and protease inhibitor therapy vs non-nucleoside reverse transcriptase inhibitors (adjusted hazard ratio [aHR] = 0.52; 95% CI = 0.31-0.90; P =.018).
Treatment failure was also found to be associated with baseline estimated glomerular filtration rate (aHR = 0.78/10-units increments; 95% CI = 0.67-0.90; P =.001), baseline hemoglobin level (aHR = 0.78/1-unit increments; 95% CI = 0.64-0.94; P =.009), and baseline total/high-density lipoprotein-cholesterol ratio (aHR = 1.19/0.5-unit increments; 95% CI = 1.06-1.34; P =.004).
Because of the nonrandomized design and baseline differences among patients who switched to either rilpivirine/tenofovir disoproxil fumarate/emtricitabine or an InSTI, the findings from this study are limited.
In addition to the main findings, this study demonstrated that discontinuation appeared to occur more frequently among those taking an InSTI who switched to raltegravir, which suggests that the practicing “clinician should preferentially switch patients [who have virologic suppression] to a once-daily regimen.”
Gianotti N, Poli A, Nozza S, et al. Durability of switch regimens based on rilpivirine or on integrase inhibitors, both in association with tenofovir and emtricitabine, in HIV-infected, virologically suppressed patients. BMC Infect Dis. 2017;17(1):723.