Treatment with Symtuza (darunavir 800 mg/cobicistat 150 mg/emtricitabine 200 mg/tenofovir alafenamide 10 mg), the first darunavir-based single-tablet treatment regimen for HIV, results in and maintains high virologic suppression rates, according to study findings presented at the 2018 Infectious Disease Week conference held in San Francisco, California.
Prior study findings coming out of the 2 phase 3 trials (AMBER and EMERALD) led to the approval of Symtuza for the treatment of HIV-1 in treatment-naïve and certain virologically suppressed patients in July. The single-tablet regimen combines darunavir, which has shown a high barrier to resistance, and tenofovir alafenamide, which is associated with improved renal and bone outcomes compared with disoproxil fumarate.
The previously published results from the phase 3, randomized, blinded, noninferiority AMBER trial demonstrated that Symtuza is noninferior to darunavir/cobicistat plus emtricitabine/tenofovir disproxil fumarate for virologic response at 48 weeks and yielded improved renal and bone safety profiles versus the control. A current analysis, presented at Infectious Disease Week, took a look at results of the study for subgroups based on viral load, CD4+
cell counts, and stage of infection at baseline.
Among the 725 patients, baseline demographics were generally similar between the 2 cohorts. The majority had viral loads of 100,000 copies/mL or less (82%), a CD4+
count of 350 cells/µL or higher (72%), and clinical stage 1 infection (84%) at baseline. Virologic response rates were 91.4% among the Symtuza cohort and 88.4% among controls, and results were similar across viral load, CD4+
count, and clinical stage subgroups.
Overall rates of serious adverse events (4.7% vs 5.8%), grade 3 to 4 adverse events (5.2% vs 6.1%), and adverse event–related discontinuations (1.9% vs 4.4) were similar among Symtuza and control cohorts, as well as across subgroups.
“Together with previously reported results for AMBER, these findings show that initiating ART with Symtuza is highly effective in treatment-naïve patients regardless of demographic (age, gender, race) and clinical (viral load, CD4+
cell count) characteristics at baseline,” wrote the authors. “Rapid initiation of Symtuza may be an appropriate option for individuals newly diagnosed with HIV-1 infection but with unknown baseline HIV-1 clinical characteristics.”
More results from the randomized, open-label, multicenter, inferiority EMERALD trial were also presented at the conference. In August, week 48 results
supported the efficacy and safety of switching from boosted protease inhibitor (BPI)-based regimens to Symtuza, regardless of prior treatment regimen in the patient population.
Following week 48, patients could continue on Symtuza or switch from the BPI-based regimen to Symtuza at week 52 in a single-arm extension phase until week 96. Of the 1141 patients, 1080 continued into the extension phase, with 728 continuing on Symtuza and 352 making the late switch to Symtuza.
Over the 44 weeks of treatment, 2.3% of patients in the late switch cohort experienced virologic rebound, but many of the rebounders were resuppressed by week 96. By week 96, 90.7% of patients who continued on Symtuza were virally suppressed and 93.8% of those in the late switch cohort had maintained virologic suppression.
There were few serious adverse events and adverse event–related discontinuations in both cohorts. Improvements in renal and bone parameters were maintained in the Symtuza arm and observed in the control cohort.