Trial Evaluating the Efficacy and Safety of Oral Vadadustat Once Daily (QD) and Three Times Weekly (TIW) for the Maintenance Treatment of Anemia in Hemodialysis Subjects Converting From Erythropoiesis-Stimulating Agents (ESAs)

This study consists of three periods:

1. Screening Period
2. Conversion and Maintenance Treatment Period
3. Safety Follow-up Period

Individual participants will participate in total trial duration of approximately 64 weeks.

• Vadadustat (Drug): oral tablets
• Darbepoetin alfa (Drug): intravenous or subcutaneous solution

Primary outcomes

• Change From Baseline in Hb to the Average Over the Primary Evaluation Period (PEP) (Weeks 20 to 26) [Baseline; Weeks 20 to 26]: The Baseline Hb was defined as the average of the last 2 central laboratory Hb values taken on or prior to the first dose date. The average for the PEP was calculated as the average of all Hb measurements from the central laboratory within the three visit windows during Weeks 20 through 26, regardless of intercurrent events. Analysis was conducted using an analysis of covariance (ANCOVA) model with multiple imputation for missing data with randomization stratification factors and Baseline Hb as covariates. Change from Baseline was calculated as PEP value minus the Baseline value.

Secondary outcomes

• Change From Baseline in Hb to the Average Over the Secondary Evaluation Period (SEP) (Weeks 46 to 52) [Baseline; Weeks 46 to 52]: The Baseline Hb was defined as the average of the last 2 central laboratory Hb values taken on or prior to the first dose date. The average for the SEP was calculated as the average of all Hb measurements from the central laboratory within the three visit windows during Weeks 46 through 52, regardless of intercurrent events. Analysis was conducted using an ANCOVA model with multiple imputation for missing data with randomization stratification factors and Baseline Hb as covariates. Change from Baseline was calculated as SEP value minus the Baseline value.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Receiving chronic, outpatient three times weekly (TIW) in-center hemodialysis for end-stage renal disease for at least 12 weeks prior to Screening
* Hemodialysis adequacy as indicated by single-pool Kt/Vurea ≥ 1.2 using the most recent historical measurement within 8 weeks prior to or during Screening
* Use of any approved erythropoiesis-stimulating agents (ESAs) for at least the 8 weeks prior to Screening Visit 2
* Two hemoglobin (Hb) values, at least 4 days apart, measured by the central laboratory during Screening within the following prespecified ranges:

  1. Hb values between 8.0 and 11.0 grams per deciliter (g/dL) (inclusive) in the United States;
  2. Hb values between 9.0 and 12.0 g/dL (inclusive) in Europe
* Serum ferritin ≥ 100 nanograms per milliliter (ng/mL) and transferrin saturation (TSAT) ≥ 20% during Screening
* Folate and vitamin B12 measurements ≥ lower limit of normal during Screening

Exclusion Criteria:

* Anemia due to a cause other than chronic kidney disease (e.g., sickle cell disease, myelodysplastic syndromes, bone marrow fibrosis, hematologic malignancy, myeloma, hemolytic anemia, thalassemia, or pure red cell aplasia)
* Participants meeting cut-off of the following equivalent mean weekly doses calculated over 8 weeks prior to Screening Visit 2

  1. Methoxy polyethylene glycol-epoetin beta > 50 micrograms (µg)/week;
  2. Darbepoetin alfa > 100 µg/week;
  3. Epoetin analogues > 23000 International Units (IU)/week
* Active bleeding or recent blood loss within 8 weeks prior to randomization
* Red blood cell transfusion within 8 weeks prior to randomization
* Current uncontrolled hypertension.
* Acute coronary syndrome (hospitalization for unstable angina or myocardial infarction), surgical or percutaneous intervention for coronary, cerebrovascular or peripheral artery disease (aortic or lower extremity), surgical or percutaneous valvular replacement or repair, sustained ventricular tachycardia, hospitalization for heart failure (HF) or New York Heart Association Class IV HF, or stroke within 12 weeks prior to or during Screening.
* Known hypersensitivity to vadadustat, darbepoetin alfa, or any of their excipients

Participant flow

Outcome results

• Change From Baseline in Hb to the Average Over the Primary Evaluation Period (PEP) (Weeks 20 to 26) (Primary), Least squares mean, Grams per deciliter (g/dL): Vadadustat QD 0.07 +/- 0.12; Vadadustat TIW -0.19 +/- 0.12; Darbepoetin Alfa 0.34 +/- 0.12
• Change From Baseline in Hb to the Average Over the Secondary Evaluation Period (SEP) (Weeks 46 to 52) (Secondary), Least squares mean, g/dL: Vadadustat QD 0.04 +/- 0.15; Vadadustat TIW 0.03 +/- 0.15; Darbepoetin Alfa 0.44 +/- 0.15

Adverse events

Time frame: From first dose of study drug (Day 1) up to Week 56 (from first dose of study drug to last dose + 4 weeks of follow-up)

Serious adverse events by term

95 more terms not shown.

Other adverse events by term

Limitations and caveats: Per the protocol, data was collected by the arm to which participants were randomized and not by dose received in vadadustat QD or vadadustat TIW arms.

• Results publication: Kooienga L, Burke S, Kathresal A, Luo W, Yang Z, Zhang Z, Zwiech R, Hernandez GT. Safety and Efficacy of Vadadustat Once Daily and Three Times Weekly in Patients With Dialysis-Dependent CKD With Anemia. Kidney360. 2024 Nov 1;5(11):1652-1661. doi: 10.34067/KID.0000000567. Epub 2024 Sep 4. PMID 39231617
• Results publication: Natale P, Palmer SC, Jaure A, Hodson EM, Ruospo M, Cooper TE, Hahn D, Saglimbene VM, Craig JC, Strippoli GF. Hypoxia-inducible factor stabilisers for the anaemia of chronic kidney disease. Cochrane Database Syst Rev. 2022 Aug 25;8(8):CD013751. doi: 10.1002/14651858.CD013751.pub2. PMID 36005278

• Study Protocol (PDF, 2021-03-17)
• Statistical Analysis Plan (PDF, 2022-06-06)

• Chief Medical Officer, Study director, Akebia Therapeutics

NIH grants: 2019