Evaluation of the safety and immunogenicity of subcutaneous HX575 epoetin alfa in the treatment of anemia associated with chronic kidney disease in predialysis and dialysis patients
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AIM: To assess the safety and immunogenicity of subcutaneous (SC) HX575 (epoetin-α) in dialysis- and nondialysis-dependent adult patients with chronic kidney disease (CKD). METHODS: Open-label, single-arm, multicenter study in patients (n = 416) from Germany, Italy, Poland, Romania, Russia, Turkey, and Ukraine. RESULTS: Mean (standard deviation (SD)) age was 52.3 (15.8) years, all patients were Caucasian, and similar proportions were male/female. 250 patients (60.1%) were erythropoiesis-stimulating agent (ESA)-naïve, and 166 (39.9%) were receiving ESA maintenance therapy at study start; mean (SD) on-study treatment duration with HX575 was 43.4 (15.8) weeks and 45.3 (13.7) weeks, respectively. Binding antierythropoietin (EPO) antibodies were detected by radioimmunoprecipitation (RIP) assay in 7 patients (1.7%; incidence 0.019); 5 of these were ESA-naïve at study entry. No patient developed neutralizing antibodies as determined in a cell-based epoetin neutralizing assay. Of the 7 patients with a positive binding anti-EPO RIP assay, 4 tested negative at later time points while continuing HX575 treatment. Three patients had low titers of anti-EPO antibodies at the last study assessment. There were no clinical signs of immunogenicity or hypersensitivity. CONCLUSIONS: SC HX575 was effective for correcting and maintaining correction of anemia, and the mean weekly dose remained stable over time.
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Prospective multicenter study of HX575 (biosimilar epoetin-α) in patients with chronic kidney disease applying a target hemoglobin of 10--12 g/dl.

HX575 was approved in the European Union in August 2007 as the first-ever biosimilar epoetin-α product. The present study extended the safety database on HX575 by monitoring adverse events (AEs) in clinical practice. Hemoglobin (Hb) levels and HX575 doses were recorded for the assessment of efficacy. This open, 6-month single-arm study was conducted in 10 European countries with a target enrollment of 1,500 patients with anemia due to chronic kidney disease (CKD). HX575 was intravenously (i.v.) administered aiming at an Hb target of 10 - 12 g/dl. Most patients (92.3%) had already received erythropoiesis stimulating agents (ESAs) treatment before enrolment into this study; the recorded treatments mainly comprised i.v. or subcutaneous (s.c.) administration of epoetin-α, epoetin-ß or darbepoetin. The study period covered 770 patient years. The observed AE profile was in line with expectations for this patient population. Thrombotic vascular events (TVEs) were reported in 11.9% of patients (0.2612 per patient year). Tumor incidence was 1.4% (0.0299 per patient year). No subject developed anti-epoetin antibodies. Mean Hb levels were effectively maintained between 11.2 and 11.3 g/dl following the conversion from a broad spectrum of pre-study ESA treatments with stable overall mean i.v. HX575 doses. The proportion of patients within the Hb target range increased from 57.5% at baseline to 66.8% at study end.

Comparison of the pharmacokinetic and pharmacodynamic profiles of one US-marketed and two European-marketed epoetin alfas: a randomized prospective study.

BACKGROUND: HX575, licensed under the brand names Binocrit®, Epoetin Alfa Hexal®, and Abseamed®, was approved in 2007 as the first biosimilar recombinant human erythropoietin alfa (epoetin alfa) in the EU using Erypo®/Eprex® as reference product. OBJECTIVES: The aim of this study was to investigate the bioequivalence and potency of registered epoetin alfa products that have not been compared before in a randomized controlled clinical study. METHODS: The study was conducted in two parts: part A compared the European-marketed HX575 and the US-marketed Epogen®; part B compared the European-marketed Erypo®/Eprex® and HX575 manufactured at two different drug substance production sites (HX575-TT denoting the already-approved technology-transfer product from an additional manufacturing site). In analyses across both study parts, Epogen® was exploratorily compared with Erypo®/Eprex®. A dense-sampling 48-hour pharmacokinetic profile was recorded at steady state after 11 doses of 100 IU epoetin alfa per kg of bodyweight. The hemoglobin response over 4 weeks of study medication administration was analyzed as the primary efficacy surrogate parameter using an ANCOVA model with the baseline value as co-variate. The per-protocol population comprised a total of 268 subjects, 76 in part A (equally randomized to HX575 or Epogen®) and 192 in part B (equally randomized to HX575, HX575-TT, or Erypo®/Eprex®). Pairs of study arms were compared in terms of the ratio of the mean epoetin alfa area under the curve (AUC) and the ratio of the mean hemoglobin area under the effect curve (AUEC). RESULTS: Bioequivalence was shown in all pair-wise comparisons with the 90% confidence intervals of the AUC ratios falling within the standard bioequivalence limits of 80-125%. Moreover, an equivalent pharmacodynamic response was achieved with all compared epoetin alfa products, as confirmed by the hemoglobin AUEC ratio's 90% CI falling within the predefined acceptance margins of 96.8-103.2%. Thus, bioequivalence and equivalent potency was demonstrated for HX575 and Epogen® in part A of the study, as well as for HX575, HX575-TT and Erypo®/Eprex® in part B of the study. Pair-wise comparison across study parts indicated similar pharmacokinetic and pharmacodynamic profiles of Epogen® and Erypo®/Eprex®. All compared epoetin alfa products were well tolerated and had a similar safety profile. No subject developed anti-erythropoietin antibodies upon administration of study medication. CONCLUSION: The results show, for the first time in a prospective randomized clinical study, equivalent bioavailability at steady state and similar potency of the US-marketed Epogen® and the European-marketed Binocrit®. Differences in the formulation between the epoetin alfa products had no apparent clinical impact. The high degree of similarity between Epogen® and Erypo®/Eprex® provides justification for linking and comparing results from clinical studies that were conducted using either US- or European-marketed epoetin alfa products.