New Anemia Drug GSK1278863 Tested as Replacement for EPO in Kidney Disease Patients
A Phase IIa trial explores whether the HIF-PHI drug daprodustat can safely replace EPO injections in hemodialysis patients with anemia.
Summary
Chronic kidney disease patients on dialysis frequently develop anemia and require regular injections of recombinant human erythropoietin (rhEPO) to maintain healthy red blood cell levels. This Phase IIa trial by GlaxoSmithKline tested whether GSK1278863, now known as daprodustat, could serve as an oral replacement for rhEPO in approximately 68 hemodialysis-dependent patients. Daprodustat works by inhibiting hypoxia-inducible factor prolyl hydroxylase, tricking the body into responding as if it were at high altitude and naturally boosting red blood cell production. The four-week randomized active-controlled study assessed safety, efficacy, and pharmacokinetics after switching patients from stable rhEPO doses. Findings aimed to define the dose-response relationship between daprodustat and hemoglobin levels. This early trial was a stepping stone toward daprodustat's eventual FDA approval as a more convenient oral anemia therapy for kidney disease patients.
Detailed Summary
Anemia is one of the most debilitating complications of chronic kidney disease, affecting the majority of patients requiring dialysis. For decades, recombinant human erythropoietin injections have been the standard of care, but they require frequent clinic-based administration and carry cardiovascular risks at high doses. The search for a safer, orally bioavailable alternative has driven significant pharmaceutical investment.
This Phase IIa randomized controlled trial, sponsored by GlaxoSmithKline, enrolled approximately 68 hemodialysis-dependent adults with anemia and hemoglobin values between 9.5 and 12.0 g/dL. Patients were on stable rhEPO regimens for at least four weeks before enrollment. They were then switched to GSK1278863 — daprodustat — a hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI) that stimulates endogenous erythropoietin production by mimicking the cellular response to low oxygen. The parallel-group, multi-center design included a two-week screening phase, four weeks of active treatment, and a two-week follow-up.
The primary scientific objective was to characterize the dose-hemoglobin response relationship for daprodustat in this population, alongside safety and pharmacokinetics. Because only the abstract is publicly available, specific hemoglobin changes and adverse event rates cannot be reported here.
The clinical implications are substantial. If an oral agent can reliably maintain hemoglobin levels comparable to injectable rhEPO, it could transform dialysis care by reducing clinic burden, improving patient compliance, and potentially offering a more physiologic erythropoiesis stimulus. Daprodustat subsequently received FDA approval in 2023 for CKD-related anemia, validating this early investigational work.
Caveats include the short four-week treatment window, small sample size, and Phase IIa exploratory design, which limits conclusions about long-term cardiovascular safety. This trial should be viewed as dose-finding groundwork rather than definitive evidence.
Key Findings
- GSK1278863 (daprodustat) was tested as an oral switch from injectable rhEPO in hemodialysis patients over 4 weeks.
- Target hemoglobin range of 9.5–12.0 g/dL was used to select stable, well-characterized patients at enrollment.
- The trial aimed to define dose-response relationship between daprodustat and hemoglobin maintenance.
- Daprodustat acts as a HIF-PHI, stimulating natural erythropoietin production rather than replacing it exogenously.
- This Phase IIa study contributed to daprodustat's eventual FDA approval for CKD anemia in 2023.
Methodology
Phase IIa randomized, active-controlled, parallel-group, multi-center trial enrolling approximately 68 hemodialysis-dependent adults switched from stable rhEPO to daprodustat. The study design included a 2-week screening phase, 4-week treatment phase, and 2-week follow-up. Primary endpoints covered safety, efficacy, and pharmacokinetics with a dose-response focus.
Study Limitations
Summary is based on the abstract only; specific hemoglobin outcomes, adverse event rates, and pharmacokinetic data are not publicly available. The four-week treatment window is too short to assess long-term cardiovascular safety, a known concern with ESA therapy. The small sample size (~68 patients) and exploratory Phase IIa design limit generalizability.
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