According to a retrospective study published by researchers at Saitama Medical Center, Jichi Medical University, the dose conversion ratio between the hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitors roxadustat and daprodustat is approximately 10:1 in non-dialysis chronic kidney disease (CKD) patients. The analysis, which evaluated 15 patients switched from roxadustat to daprodustat between 2020 and 2023, found that hemoglobin levels and iron metabolism parameters remained stable following the conversion after appropriate dose adjustments.
Understanding HIF-PH Inhibitors in CKD Anemia Management
Among chronic kidney disease (CKD) patients, anemia frequently presents as a major complication linked to accelerated loss of renal function, reduced well-being, and an elevated likelihood of death [1-3]. To combat this, oral HIF-PH inhibitors have emerged as therapeutic agents by stabilizing hypoxia-inducible factors through the stabilization of HIF by inhibiting the activity of the HIF-PH domain to stimulate natural erythropoietin production. While roxadustat is administered orally thrice weekly, at bedtime, daprodustat is administered orally once daily, after breakfast. Prior network meta-analyses suggest roxadustat was reported to be superior to other HIF-PH inhibitors with respect to its effect on anemia in CKD patients, whereas daprodustat has been shown to have less drug-drug interaction potential and can be administered with cation-containing agents, according to background data cited by the study authors.
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Study Design and Patient Cohort Details
The institutional review board at Saitama Medical Center approved the retrospective review under protocol RIN 22-004. The charts of individuals aged 20 or older with an estimated glomerular filtration rate (eGFR) under 60 mL/min/1.73 m2 and a documented treatment timeline consisting of roxadustat use for 12 months or longer followed by daprodustat use for at least 12 months were examined by the researchers. Individuals undergoing renal replacement therapy like hemodialysis, peritoneal dialysis, and renal transplantation were excluded.
Out of 26 initial candidates, 15 patients met all strict inclusion criteria. The cohort comprised 5 men and 10 women with a mean age of 76.5 ± 9.3 years. Baseline staging showed one patient in CKD stage G3b, four in stage G4, and ten in stage G5, reflecting an advanced non-dialysis population with a mean baseline eGFR of 14.3 ± 9.4 mL/min/1.73 m2. Comorbidities within the group included hypertension in 93.3% of participants, diabetes mellitus in 33.3%, and prior stroke in 13.3%.
Calculating the 10:1 Dose Conversion Ratio
Before the medication switch, patients received a mean roxadustat dose of 51 ± 18 mg/administration. Over the 12 months following the transition to daprodustat, clinicians systematically titrated doses to maintain stable hemoglobin concentrations, which averaged 11.2 ± 0.9 g/dL at baseline. By 12 months post-switch, the mean daprodustat dose reached 5.2 ± 2.8 mg/administration. Dividing the pre-switch roxadustat dose of 51 mg by the 12-month daprodustat dose of 5.2 mg established an approximate dose conversion ratio of 10:1.
Throughout the observation window, secondary clinical markers—including serum ferritin concentrations, transferrin saturation (TSAT), urinary protein-to-creatinine ratios, and eGFR change rates—showed no statistically significant alterations.
Clinical Implications and Study Limitations
Frequently Asked Questions
What is the recommended dose conversion ratio between roxadustat and daprodustat?
According to clinical data from Saitama Medical Center, the approximate dose conversion ratio is 10:1, meaning 51 mg of roxadustat corresponds roughly to 5.2 mg of daprodustat.
Do iron supplement regimens need to change when switching between these drugs?
Data show that transferrin saturation and serum ferritin levels remain stable after the switch, suggesting that routine iron management adjustments are generally unnecessary.
Can these findings be applied to patients on dialysis?
No. The study exclusively evaluated non-dialysis chronic kidney disease patients ranging from CKD stage G3b to G5.
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