IAS 2019 — QUATUOR results challenge the daily dosing therapy status quo

  • Laura Vargas-Parada, Ph.D.
  • Conference Reports
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  • The ANRS 170 QUATUOR trial compared efficacy and safety by using regular 3-drug regimens taken 4 days a week vs a current triple antiretroviral therapy (ART) daily regimen (CAR) showing noninferiority in maintaining viral suppression. 

Why this matters 

  • Every-other-day ART could improve tolerability, convenience, and cost of ART by reducing the number of pills an HIV-infected person must take.

Study design 

  • Open-label, phase 3.
  • Participants randomly allocated to 2 groups were taking a range of 3-drug regimens; all had been virally suppressed for more than 12 months.
  • Primary endpoint was Kaplan-Meier estimated proportion of participants with treatment success (viral load [VL] 

Key results  

  • Screening: from September 7, 2017 to January 22, 2018. 
  • 636/647 were included in modified intent-to-treat analysis (318 per group):
    • Median age: 49 (interquartile range, 41-55) years.
    • 85% were male.
    • VL ucleoside reverse transcriptase inhibitors (NRTIs): 56.3% tenofovir disoproxil/emtricitabine (FTC), 16.3% tenofovir alafenamide (TAF)/FTC, 27.4% abacavir (ABC)/lamivudine (3TC); third agent: 6% protease inhibitor, 46% non-NRTI, 48% integrase strand transfer inhibitor. 
  • Week-48 treatment success rates:
    • 95.6% in 4/7 days group vs 97.2% with CAR (adjusted difference: −1.6%; 95% CI −4.5% to 1.3%), demonstrating noninferiority. 
    • 1.9% in 4/7 group; 1.3% participants with CAR experienced virological failure. 
  • No difference in adverse events between groups. 
  • Moderate improvement in estimated glomerular filtration rate seen in 4/7 days group: +5.5 (−1.2 to +13.6) mL/minute vs +1.3 (−6.1 to +7.5) mL/minute in CAR (P<.001>


  • Ongoing study, presented without peer review at a conference. 

Expert comment 

  • In a statement, IAS President and IAS 2019 International Scientific Chair Anton Pozniak said: “Ultimately, the advances we are seeing in science are about giving people living with HIV more choices.”