Pharmacotherapeutic group: Anti-anaemic preparations, other anti-anaemic preparations, ATC code: B03XA08
Mechanism of action
Vadadustat is a hypoxia-inducible factor prolyl-hydroxylase inhibitor which leads to increased cellular levels of hypoxia-inducible factor thereby stimulating endogenous erythropoietin (EPO) production, increasing iron mobilization and RBC production, resulting in a gradual rate of rise in Hb (see Figures 1, 2, 3 and 4).
Pharmacodynamic effects
After a single dose of vadadustat (80 mg to 1200 mg) in healthy male subjects, a dose-dependent increase in EPO was observed.
Cardiac electrophysiology
Vadadustat did not cause any clinically significant QTc prolongation following a 600 mg and 1200 mg dose.
Clinical efficacy and safety
The efficacy and safety of vadadustat given once daily for the treatment of anaemia in adult patients with CKD was demonstrated compared to darbepoetin alfa in global multi-centre, randomised, active- controlled, non-inferiority, open-label studies of 3923 DD patients. and 3476 NDD patients.
Patients with diagnosis of NDD-CKD with an eGFR > 60 mL/min/1.73 m2 using the 2009 Chronic Kidney Disease Epidemiology Collaboration creatinine equation at screening were excluded from pivotal studies.
Patients were randomised 1:1 to receive vadadustat with a starting dose of 300 mg once daily or darbepoetin alfa administered subcutaneously or intravenously as per prescribing information for 52 weeks to assess the efficacy endpoints. Vadadustat was titrated in increments of 150 mg up to 600 mg to achieve the patient's Hb target. After 52 weeks, patients were continued study treatment to assess long-term safety until the event-driven major adverse cardiovascular event (MACE) endpoints were reached. The primary efficacy endpoint for each study was the difference in mean change of Hb from baseline to the primary evaluation period (Weeks 24 to 36). The key secondary efficacy endpoint was the difference in mean change of Hb from baseline to the secondary evaluation period (Weeks 40 to 52). The primary safety endpoint was time to first MACE. MACE was defined as all-cause mortality, non-fatal myocardial infarction and non-fatal stroke.
Treatment of anaemia in dialysis-dependent patients
Two studies (INNO2VATE 1 and INNO2VATE 2) were conducted in adult DD-CKD patients with baseline Hb values between 8.0 to 11.0 g/dL in the United States (US) and 9.0 to 12.0 g/dL outside the US. INNO2VATE 1 included patients with incident DD-CKD who initiated dialysis within 16 weeks of beginning their trial participation and who were ESA-naive, had limited prior ESA use or were maintained on ESAs. INNO2VATE 2 included patients on chronic maintenance dialysis for more than 12 weeks who had converted from prior ESA therapy. In both studies, vadadustat was non-inferior to darbepoetin alfa in correcting and maintaining or maintaining Hb levels across geographic-specific target Hb ranges [10.0 to 11.0 g/dL in the US and 10.0 to 12.0 g/dL in Europe and rest of world (ROW)] at weeks 24 to 36 and weeks 40 to 52 in adult DD-CKD patients with anaemia. Results for the primary and secondary efficacy endpoints are provided in Table 3. Course of Hb during treatment in individual studies is provided in Figure 1 and Figure 2. Examination of age, gender, race and region subgroups did not identify differences in response to vadadustat among these subgroups.
Table 3 INNO2VATE STUDIES
| | INNO2VATE 1 | INNO2VATE 2 |
| Hb (g/dL) | Vadadustat N = 181 | Darbepoetin alfa N = 188 | Vadadustat N = 1777 | Darbepoetin alfa N = 1777 |
| Baseline mean (SD) | 9.37 (1.07) | 9.19 (1.14) | 10.25 (0.85) | 10.23 (0.83) |
| Primary endpoint Weeks 24 to 36 mean (SD) | 10.36 (1.13) | 10.61 (0.94) | 10.36 (1.01) | 10.53 (0.96) |
| Adjusted mean change from baseline (LSM) [95% CI] | 1.26 [1.05, 1.48] | 1.58 [1.37, 1.79] | 0.19 [0.12, 0.25] | 0.36 [0.29, 0.42] |
| Estimated treatment difference [95% CI] vadadustat – darbepoetin alfa | -0.31 [-0.53, -0.10] | -0.17 [-0.23, -0.10] |
| Key secondary endpoint Weeks 40 to 52 mean (SD) | 10.51 (1.19) | 10.55 (1.14) | 10.40 (1.04) | 10.58 (0.98) |
| Adjusted mean change from baseline (LSM) [95% CI] | 1.42 [1.17, 1.68] | 1.50 [1.23, 1.76] | 0.23 [0.16, 0.29] | 0.41 [0.34, 0.48] |
| Estimated treatment difference [95% CI] vadadustat – darbepoetin alfa | -0.07 [-0.34, 0.19] | -0.18 [-0.25, -0.12] |
CI: confidence interval; LSM: least squares mean; SD: standard deviation
Figure 1: Mean (+/-SD) of change from baseline in Hb (g/dL) for INNO2VATE 1 incident dialysis
Figure 2: Mean (+/-SD) of change from baseline in Hb (g/dL) for INNO2VATE 2 prevalent dialysis
Cardiovascular outcomes - dialysis-dependent CKD patients
The incidence of MACE was evaluated as part of the long-term safety evaluation of the two global efficacy studies in DD-CKD patients. Vadadustat met the composite primary safety endpoint defined as non-inferiority of vadadustat to darbepoetin alfa in time to occurrence of MACE for the global study population (1.3 NI margin [HR (95% CI) was 0.96 (0.83, 1.11)]. The results were consistent for the primary endpoint and the individual components of the primary endpoint (see Table 4). The results for the primary MACE endpoint were also supported by the results from key secondary endpoints using expanded MACE definitions. These results showed that vadadustat did not decrease the time to MACE plus hospitalization for heart failure; MACE plus thromboembolic events excluding vascular access; cardiovascular (CV) MACE (all-cause mortality, non-fatal MI or non-fatal stroke); CV death or all-cause mortality compared to darbepoetin.
Table 4: INNO2VATE analysis* of the composite 3-point MACE and individual cardiovascular endpoints
| | Vadadustat N = 1947 n (%) | Darbepoetin alfa N = 1955 n (%) | Hazard ratio [95% CI] |
| Any major adverse cardiovascular events (MACE) | 355 (18.2) | 377 (19.3) | 0.96 [0.83, 1.11] |
| All-cause mortality | 253 (13.0) | 253 (12.9) | |
| Non-fatal myocardial infarction | 76 (3.9) | 87 (4.5) | |
| Non-fatal stroke | 26 (1.3) | 37 (1.9) | |
*The MACE analyses were conducted on randomised subjects who received at least 1 dose of study treatment.
CI: confidence interval; MACE: major adverse cardiovascular events.
Treatment of anaemia in non-dialysis-dependent patients
Two studies (PRO2TECT 1 and PRO2TECT 2) were conducted in NDD-CKD adult patients. PRO2TECT 1 included patients diagnosed with CKD with baseline Hb values less than 10.0 g/dL and who were not previously treated with an ESA. PRO2TECT 2 included patients diagnosed with CKD with baseline Hb levels between 8.0 and 11.0 g/dL in the US and between 9.0 and 12.0 g/dL outside of the US who were previously treated with an ESA for anaemia. In both studies, vadadustat was non- inferior to darbepoetin alfa in correcting and maintaining or maintaining Hb levels across geographic- specific target Hb ranges [10.0 to 11.0 g/dL in the US and 10.0 to 12.0 g/dL in Europe and ROW] at weeks 24 to 36 and weeks 40 to 52 in adult NDD-CKD patients with anaemia (see Figures 3 and 4). Results for the primary and secondary efficacy endpoints are provided in Table 5. Examination of age, gender, race and region subgroups did not identify differences in response to vadadustat among these subgroups.
Table 5: PRO2TECT STUDIES
| | PRO2TECT 1 | PRO2TECT 2 |
| Hb (g/dL) | Vadadustat N = 879 | Darbepoetin alfa N = 872 | Vadadustat N = 862 | Darbepoetin alfa N = 863 |
| Baseline mean (SD) | 9.11 (0.80) | 9.14 (0.78) | 10.42 (0.89) | 10.39 (0.94) |
| Primary endpoint Weeks 24 to 36 mean (SD) | 10.39 (0.99) | 10.35 (1.03) | 10.77 (0.98) | 10.77 (0.99) |
| Adjusted mean change from baseline (LSM) [95% CI] | 1.43 [1.34, 1.52] | 1.38 [1.29, 1.47] | 0.41 [0.34, 0.48] | 0.42 [0.35, 0.49] |
| Estimated treatment difference [95% CI] vadadustat – darbepoetin alfa | 0.05 [-0.04, 0.15] | -0.01 [-0.09, 0.07] |
| Key secondary endpoint Weeks 40 to 52 mean (SD) | 10.48 (1.05) | 10.45 (1.01) | 10.8 (1.04) | 10.79 (1.05) |
| Adjusted mean change from baseline (LSM) [95% CI] | 1.52 [1.42, 1.62] | 1.48 [1.38, 1.59] | 0.43 [0.35, 0.52] | 0.44 [0.35, 0.52] |
| Estimated treatment difference [95% CI] vadadustat – darbepoetin alfa | 0.04 [-0.06, 0.14] | -0.00 [-0.10, 0.09] |
CI: confidence interval; LSM: least squares mean; SD: standard deviation
Figure 3: Mean (+/-SD) of change from baseline in Hb (g/dL) for PRO2TECT 1 ESA naive
Figure 4: Mean (+/-SD) of change from baseline in Hb (g/dL) for PRO2TECT 2 ESA treated

Cardiovascular outcomes - non-dialysis-dependent CKD patients
The incidence of MACE was assessed as part of the long-term safety evaluation of the two global efficacy studies in NDD-CKD patients. Vadadustat did not meet the composite primary safety endpoint defined as non-inferiority of vadadustat to darbepoetin alfa in time to first occurrence of MACE (all-cause mortality, non-fatal MI or non-fatal stroke) for the global study population. The HR (95% CI) was 1.17 (1.012, 1.36*) with the upper bound exceeding the pre-specified non-inferiority margin of 1.3 (see Table 6). The difference between the two treatments with respect to MACE (38 patients or 2.1%) was driven primarily by non-fatal myocardial infarction (22 patients (1.3%)) and all-cause mortality (10 patients (0.5%)).
Table 6: PRO2TECT analysis* of the composite 3-point MACE and individual cardiovascular endpoints
| | Vadadustat N = 1739 n (%) | Darbepoetin alfa N = 1732 n (%) | Hazard ratio [95% CI] |
| Any major adverse cardiovascular events (MACE) | 382 (22.0) | 344 (19.9) | 1.17 [1.01, 1.36] |
| All-cause mortality | 284 (16.3) | 274 (15.8) | |
| Non-fatal myocardial infarction | 66 (3.8) | 44 (2.5) | |
| Non-fatal stroke | 32 (1.8) | 26 (1.5) | |
*The MACE analyses were conducted on randomised subjects who received at least 1 dose of study treatment.
CI: confidence interval; MACE: major adverse cardiovascular events
Paediatric population
The Agency has deferred the obligation to submit the results of studies with Vafseo in one or more subsets of the paediatric population for the treatment of symptomatic anaemia associated with CKD on chronic maintenance dialysis as per paediatric investigation plan (PIP) decision, for the granted indication (see section 4.2 for information on paediatric use).