Phosphate binders do not appear to substantially affect the efficacy of the hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI) daprodustat, according to preliminary study findings presented at Kidney Week 2020 Reimagined, a virtual meeting sponsored by the American Society of Nephrology.
In the GSK PHI113633 trial (NCT01977482) of 216 patients receiving hemodialysis, 77% of the daprodustat group and 85% of the control group (receiving human recombinant erythropoietin) were taking phosphate binders at baseline and had comparable phosphate control (mean serum phosphate 1.76 vs 1.67 mmol/L, respectively). Baseline hemoglobin (Hb) did not differ meaningfully between the HIF-PHI and control groups (10.39 g/dL daprodustat vs 10.55 g/dL placebo), including the subsets taking phosphate binders (10.38 vs 10.48 g/dL, respectively).
At 24 weeks, achieved Hb differed only slightly among daprodustat patients taking and not taking phosphate binders: 10.40 g/dL for the phosphate binder group vs 10.79 g/dL the patients not taking phosphate binders, Borut Cizman, MD, and colleagues from GlaxoSmithKline in Collegeville, Pennsylvania, reported. The final median dose of daprodustat was 6 mg, regardless of whether daprodustat users were taking calcium and/or noncalcium phosphate binders, or no binders.
“These results suggest that [phosphate binder] use does not have a major impact on [hemoglobin] values during the 24-week study,” Dr Cizman’s team stated. “Results of ASCEND-D, an ongoing, phase 3 dialysis study of daprodustat compared with conventional treatment, are awaited to confirm these initial observations.”
Disclosure: This clinical trial was supported by GlaxoSmithKline. Please see the original reference for a full list of authors’ disclosures.
- Cizman B, Meadowcroft, AM, Biswas N, Sprys M, Cobitz AR. Daprodustat interaction with phosphate binders has minimal impact on hemoglobin values in hemodialysis population. Presented at: Kidney Week Reimagined; October 19-25, 2020. Abstract: PO0293.
- Meadowcroft AM, Cizman B, Holdstock L, et al. Daprodustat for anemia: a 24-week, open-label, randomized controlled trial in participants on hemodialysis. Clin Kid J. 12(1):139–148. doi:10.1093/ckj/sfy014