Background: Following the results of the GARDEL trial, dual therapy (DT) has been explored in different studies. Generic fixed dose combinations (FDC) of Darunavir/ritonavir (DRV/rtv) 800/100 mg and Tenofovir/Lamivudine(TDF/3TC) are available in Argentina. This study compares DRV/rtv plus 3TC to standard-of care triple therapy (TT) based on these same drugs plus Tenofovir (TDF).
Methods: ANDES is a randomized, open-label, phase IV study, designed to assess the antiviral efficacy, safety and tolerability of DT with DRV/rtv (800/100 mg) FDC, plus 3TC (300 mg), compared to TT with DRV/RTV (800/100 mg) plus TDF/3TC (300/300mg) FDC in treatment-naïve HIV-1 infected patients. Primary endpoint: proportion of patients with viral load (pVL) < 50 copies/mL at week 48. Preplanned analyses at week 24, measured by the proportion of patients with pVL < 400 copies/mL (ITT-exposed analysis, FDA snapshot algorithm) are reported. Identifier:NCT02770508.
Results: Out of 182 patients screened, 145 were randomized to receive: DT (n:75) or TT (n:70). Screening failure rate 20%. At baseline: 91% were male; median age 30 years; CDC stage A: 92%; 24% had pVL >100,000 copies/mL. At week 24, 94.7% (n:71) of patients receiving DT and 97.1% (n:68) receiving TT were responders (pVL < 400 copies/mL), difference -2.5 % (95% CI:-7.9-2.9) Patients with baseline pVL >100,000 copies/mL (n:35) showed 100% response in both arms. One patient had virological failure at W24 due to non-compliance (control arm). Mean CD4+ increases were similar in both arms (DT=206 cells/mm3; TT=204 cells/mm3).Sixty-seven grade 2-3 possible/probable related adverse events (AEs) were reported in 51 patients (36%), most frequent were gastrointestinal (22%) and rash (14%). AEs incidence was similar in both arms; one patient was discontinued due to a drug-related grade 3 adverse event (rash).
Conclusions: A generic combination of DRV/RTV in fixed-dose plus 3TC showed non-inferiority to a generic triple drug regimen of DRV/RTV plus TDF/3TC at 24 weeks. These results, if confirmed at week 48, may provide further evidence about the potential efficacy of dual therapy based on 3TC and a drug with a high genetic barrier.