Akebia Therapeutics (Nasdaq: AKBA) and U.S. Renal Care (USRC) announced that the VOICE trial, a study comparing Vafseo (vadadustat) to erythropoiesis-stimulating agents (ESAs) in dialysis patients with anemia due to chronic kidney disease, was stopped early following a planned interim analysis.

The trial's primary investigator halted the study after an Independent Data Monitoring Committee and Trial Steering Committee recommended stopping based on prespecified criteria. The interim analysis, with a data cutoff of June 1, 2026, covered 2,116 enrolled patients.

Results showed a win odds of 1.16 (95% CI 1.06–1.28, p=0.0016) on the primary composite endpoint of all-cause mortality and all-cause hospitalization, meeting criteria for both non-inferiority and superiority. Hospitalizations were statistically significantly lower in the Vafseo group at 1.11 per patient year versus 1.23 for ESA, an incidence rate ratio of 0.90 (95% CI 0.824–0.988). Mortality rates showed no statistically significant difference: 8.77% versus 8.78% per 100 patient years, with an incidence rate ratio of 1.00 (95% CI 0.718–1.391).

The VOICE trial used a three-times-weekly dosing regimen administered in-center during hemodialysis. Vafseo is approved by the U.S. Food and Drug Administration for once-daily use in adults who have been on dialysis for at least three months, with U.S. availability beginning in January 2025.

Geoffrey A. Block, M.D., Associate Chief Medical Officer at USRC, said the trial was designed to test "clinically important areas of differentiation between Vafseo and ESAs," adding that the reduction in the primary composite endpoint was "driven by a reduction in hospitalization."

Glenn M. Chertow, M.D., professor at Stanford University School of Medicine and member of the trial's Executive Steering Committee, noted the results were "nearly identical" to those from a post-hoc analysis of the phase 3 INNO2VATE program, where vadadustat was dosed daily at home.

Akebia and USRC said they expect to submit the VOICE trial data for presentation at an upcoming scientific meeting.