Evaluation of switching treatment from high dose of darbepoetin to lower dose of roxadustat in Japanese hemodialysis patients

Hypoxia-Inducible Factor-Prolyl Hydroxyl Domain Inhibitors: From Theoretical Superiority to Clinical Noninferiority Compared with Current ESAs?

Anemia is a common complication of chronic kidney disease; it is mainly treated with erythropoiesis-stimulating agents (ESAs) and iron. Experimental studies extensively investigated the mechanisms involved in the body's response to hypoxia and led to the discovery of the hypoxia-inducible factor (HIF) pathway and the enzymes regulating its function. HIF-prolyl-hydroxyl domain (PHD) inhibitors are a new class of oral drugs developed to treat anemia in chronic kidney disease. By inhibiting the function of PHD enzymes, they mimic the exposure to moderate hypoxia and stimulate the production of endogenous erythropoietin and very likely increase iron availability. Some data also suggest that their efficacy and, consequently, dose needs are less influenced by inflammation than ESAs. Overall, data from phases 2 and 3 clinical development showed efficacy in anemia correction and maintenance for all of the class molecules compared with placebo (superiority) or erythropoiesis-stimulating agents (noninferiority). Three molecules, roxadustat, vadadustat, and daprodustat, underwent extensive clinical investigation to assess their safety on hard cardiovascular end points, mortality, and special interest events (including cancer and thrombosis). Aside from vadadustat in the nondialysis population, at the prespecified primary analyses, all three molecules met the noninferiority margin for the risk of major cardiovascular events compared with erythropoiesis-stimulating agents or placebo. The reason for this discrepancy is difficult to explain. Other safety signals came from secondary analyses of some of the other randomized clinical trials, including a higher incidence of thrombosis. A more extensive clinical experience with post-marketing data on hard safety issues is needed to define better when and how to use HIF-PHD inhibitors compared with already available ESAs.

Addition of roxadustat to erythropoiesis-stimulating agent (ESA) effectively corrects ESA-hyporesponsive anaemia in patients on peritoneal dialysis

WHAT IS KNOWN AND OBJECTIVE

Erythropoiesis-stimulating agent (ESA) hyporesponsiveness is an important cause for the undertreatment of anaemia. A decrease in haemoglobin (Hb) levels was observed during the initial stage of the conversion from ESA to roxadustat. The study aims to investigate the effectiveness and safety of adding roxadustat to an ESA for the treatment of ESA-hyporesponsive anaemia in patients on peritoneal dialysis (PD).

METHODS

Patients on PD with ESA-hyporesponsive anaemia were enrolled from January 2020 to April 2020 with a 24-week follow-up period. Patients were treated with roxadustat at a starting dose of 50 or 100 mg thrice weekly without changing the ESA dose. Roxadustat and ESA dose adjustments were made as needed to maintain Hb levels within 11.0 to 13.0 g/dl. Efficacy outcomes and safety were assessed.

RESULTS AND DISCUSSION

Nine patients were recruited in the study. Both the cumulative responsive rate and maintenance rate of Hb > 11 g/dl were 100%. Six patients required ESA dose reduction from ≥15,000 UI/week to ≤7000 IU/week at week 24. No drug-related severe adverse events were observed in this study.

WHAT IS NEW AND CONCLUSION

The addition of roxadustat effectively and smoothly corrected anaemia in patients who were hyporesponsive to ESA, and permitted reduction of the ESA dose.