Safety and Efficacy of Vadadustat Once-Daily and 3-Times-Weekly in Dialysis-Dependent Chronic Kidney Disease Patients with Anemia.

Background: Vadadustat is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor for treating anemia in chronic kidney disease (CKD). This study investigated safety and efficacy of once-daily and 3-times-weekly dosing in patients with dialysis-dependent (DD)-CKD compared with darbepoetin alfa (DA).

Methods: This phase 3b, randomized (1:1:1; vadadustat once-daily [starting dose: 300 or 450 mg], vadadustat 3-times-weekly [starting dose: 600 or 750 mg], DA), open-label, active-controlled, noninferiority trial included conversion (weeks 0-20) and maintenance (weeks 20-52) periods. Primary and secondary efficacy endpoints were mean change in hemoglobin from baseline during the primary (PEP, weeks 20-26) and secondary (SEP, weeks 46-52) evaluation periods. Other endpoints included proportion of patients requiring ESA rescue (hemoglobin <9.5 g/dL or with increases in dose ≥50% or ≥100% in DA group). Safety endpoints included treatment-emergent adverse events (TEAEs) and serious AEs (SAEs).

Results: Least squares (LS) mean treatment difference between vadadustat once-daily and DA from baseline to PEP was -0.27 g/dL (95% CI, -0.55 to 0.01); the lower bound met the noninferiority threshold (-0.75 g/dL). The LS mean treatment difference between vadadustat 3-times-weekly and DA from baseline to PEP was -0.53 g/dL (95% CI, -0.80 to -0.25), which did not meet the lower bound noninferiority threshold. The LS mean change from baseline to the SEP between DA and vadadustat once-daily was -0.40 (95% CI, -0.79 to -0.02), and for vadadustat 3-times-weekly was -0.42 (95% CI, -0.81 to -0.02). Proportion of patients who received ESA rescue during weeks 2-52 was higher in the DA group than vadadustat groups. Similar TEAEs and treatment-emergent SAEs were observed across groups.

Conclusions: Vadadustat once-daily, but not 3-times-weekly, was noninferior to DA in the correction and maintenance of hemoglobin in patients with DD-CKD converted from an ESA; safety profiles were similar across groups.

Trial registration: EudraCT 2019-004851-36/ClinicalTrials.gov identifier: NCT04313153.