Pharmacokinetic and pharmacodynamic study of three products of epoetin alfa as single subcutaneous dose in healthy volunteers.

Hemax® is an epoetin alfa product developed by Biosidus S.A. in Argentina at the end of the 1980s and has been present in that market since 1991. The initial presentation was a lyophilized powder containing albumin as stabilizer, to best adapt to environmental conditions in developing countries; more recently, a prefilled syringe, albumin-free presentation was developed, since this presentation has become the preferred standard in many markets. The primary objective was to compare the pharmacokinetic profile of different formulations of epoetin alfa after a single subcutaneous administration to healthy volunteers of 40 000 IU of Eprex/Erypo® and Hemax® PFS. This clinical trial was conceived following an open-label, randomized, three-way three-period cross-over balanced, and sequential design. The study was conducted on 24 healthy volunteers. To analyze similarity between Hemax® PFS and the innovator product, Eprex®, area under the curve (AUC) and Cmax of both products have been compared. The 90% CI lower limit for the geometric mean ratios was higher than 80% for any comparisons, and the 90% CI upper limit for these geometric ratios was below 125% for all the comparisons made, thus demonstrating equivalence between both products. The comparison between Hemax® PFS and Eprex® resulted in similar 90% CI for Cmax , AUC(0-120 h) and AUC(0-inf) ratios, all of them within the 80-125% interval, with a power above 95% for each ratio. These findings suggest biosimilar patterns for absorption velocity (with Tmax close to 15 h), absorption extent, and elimination (with an elimination half-life close to 25-30 h for each formulation).

Applying metabolomics to detect growth hormone administration in athletes: Proof of concept.

Growth hormone (GH), an endogenous peptide regulating anabolism and lipolysis in humans, is known to be abused by athletes to improve their performance. Despite the development of two distinct screening methods, few positive cases have been reported by the antidoping authorities, probably due to the quick turnover of GH and the masking effects of age, ethnicity, and sex. Apart from growth regulation, GH is known to affect several metabolic pathways in humans including ketosis, amino-acid uptake, and protein breakdown. It is reasonable to imagine observing its markers of effects through the leading tool on metabolism study, metabolomics. In this proof-of-concept study, a cohort of well-trained volunteers was split in two equal groups and administered with micro-doses of EPO or EPO + GH every second day for 2 weeks. Urine and plasma samples were collected before, during, and after treatment and analyzed using metabolomics and lipidomics approaches. The results show that, by applying a direct discriminant analysis on the treated groups, it is possible to distinguish the treatments, and to use this difference to classify them correctly. High intragroup variability is observed, due to the subject-specific effect of the hormones. Through time 0 centering the data, a longitudinally tracking of the group was performed and a higher difference was observed between the groups, including a perfect classification of the samples before and after the treatments.

Optimal EPO dosing in hemodialysis patients using a non-linear model predictive control approach.

Anemia management with erythropoiesis stimulating agents is a challenging task in hemodialysis patients since their response to treatment varies highly. In general, it is difficult to achieve and maintain the predefined hemoglobin (Hgb) target levels in clinical practice. The aim of this study is to develop a fully personalizable controller scheme to stabilize Hgb levels within a narrow target window while keeping drug doses low to mitigate side effects. First in-silico results of this framework are presented in this paper. Based on a model of erythropoiesis we formulate a non-linear model predictive control (NMPC) algorithm for the individualized optimization of epoetin alfa (EPO) doses. Previous to this work, model parameters were estimated for individual patients using clinical data. The optimal control problem is formulated for a continuous drug administration. This is currently a hypothetical form of drug administration for EPO as it would require a programmable EPO pump similar to insulin pumps used to treat patients with diabetes mellitus. In each step of the NMPC method the open-loop problem is solved with a projected quasi-Newton method. The controller is successfully tested in-silico on several patient parameter sets. An appropriate control is feasible in the tested patients under the assumption that the controlled quantity is measured regularly and that continuous EPO administration is adjusted on a daily, weekly or monthly basis. Further, the controller satisfactorily handles the following challenging problems in simulations: bleedings, missed administrations and dosing errors.

Structure-Function Relationships for Recombinant Erythropoietins: A Case Study From a Proposed Manufacturing Change With Implications for Erythropoietin Biosimilar Study Designs.

Comparability studies used to assess a proposed manufacturing change for a biological product include sensitive analytical studies to confirm there are no significant differences in structural or functional attributes that may contribute to clinically meaningful changes in efficacy or safety. When a proposed change is relatively complex or when clinically relevant differences between the product before and after the change cannot be ruled out based on analytical studies, nonclinical and clinical bridging studies are generally required to confirm overall comparability. In this study, we report findings from a comparability assessment of epoetin alfa before and after a proposed manufacturing process change. Although differences in glycosylation attributes were observed, these were initially believed to be irrelevant to the product's pharmacology. This assumption was initially supported via nonclinical and clinical pharmacology studies, but a clinically meaningful difference in potency was ultimately observed in a phase 3 clinical study conducted in a sensitive patient population using a sensitive study design. These results indicate that the nonclinical assessments of structure-function relationships were insufficiently sensitive to identify clinically relevant differences resulting from differences in the glycosylation profile. This case study highlights important findings that may be relevant in the development of biosimilar epoetin alfa products.

HX575: established biosimilarity in the treatment of renal anemia and 10 years of clinical experience.

Erythropoiesis-stimulating agents, such as recombinant human erythropoietin, are commonly used for the treatment of anemia in patients with chronic kidney disease (CKD). In 2007, HX575 (Binocrit®) became the first biosimilar epoetin alfa to be approved by the European Medicines Agency (EMA). The decision to approve a biosimilar is based on the totality of evidence obtained in a comprehensive comparability exercise that involves extensive analytical characterization, nonclinical studies and clinical studies. The development process for HX575 included extensive analytical characterization and comparison with the reference epoetin alfa. This was followed by a clinical development program, comprising Phase I pharmacokinetic/pharmacodynamic studies to show bioequivalence to the reference medicine and a confirmatory Phase III study to demonstrate therapeutic effectiveness in anemia related to CKD. In addition to the comparability exercises, extensive clinical experience over the last decade also confirms that HX575 provides an effective treatment for CKD-related anemia, with a favorable safety profile. Growing clinical experience with EMA-approved biosimilars, including HX575, should offer additional reassurance to health care professionals and patients that these agents are as effective and well tolerated as others in the therapeutic class.

Erythropoietin Does Not Alter Serum Profiles of Neuronal and Axonal Biomarkers After Traumatic Brain Injury: Findings From the Australian EPO-TBI Clinical Trial.

OBJECTIVE: To determine profiles of serum ubiquitin carboxy-terminal hydrolase L1 and phosphorylated neurofilament heavy-chain, examine whether erythropoietin administration reduce their concentrations, and whether biomarkers discriminate between erythropoietin and placebo treatment groups. DESIGN: Single-center, prospective observational study. SETTING: A sub-study of the erythropoietin-traumatic brain injury clinical trial, conducted at the Alfred Hospital, Melbourne, Australia. PATIENTS: Forty-four patients with moderate-to-severe traumatic brain injury. INTERVENTIONS: Epoetin alfa 40,000 IU or 1 mL sodium chloride 0.9 as subcutaneous injection within 24 hours of traumatic brain injury. MEASUREMENTS AND MAIN RESULTS: Ubiquitin carboxy-terminal hydrolase L1, phosphorylated neurofilament heavy-chain, and erythropoietin concentrations were measured in serum by enzyme-linked immunosorbent assay from D0 (within 24 hr of injury, prior to erythropoietin/vehicle administration) to D5. Biomarker concentrations were compared between injury severities, diffuse versus focal traumatic brain injury and erythropoietin or placebo treatment groups. Ubiquitin carboxy-terminal hydrolase L1 peaked at 146.0 ng/mL on D0, significantly decreased to 84.30 ng/mL on D1, and declined thereafter. Phosphorylated neurofilament heavy-chain levels were lowest at D0 and peaked on D5 at 157.9 ng/mL. D0 ubiquitin carboxy-terminal hydrolase L1 concentrations were higher in diffuse traumatic brain injury. Peak phosphorylated neurofilament heavy-chain levels on D3 and D4 correlated with Glasgow Outcome Score-Extended, predicting poor outcome. Erythropoietin did not reduce concentrations of ubiquitin carboxy-terminal hydrolase L1 or phosphorylated neurofilament heavy-chain. CONCLUSIONS: Serum ubiquitin carboxy-terminal hydrolase L1 and phosphorylated neurofilament heavy-chain increase after traumatic brain injury reflecting early neuronal and progressive axonal injury. Consistent with lack of improved outcome in traumatic brain injury patients treated with erythropoietin, biomarker concentrations and profiles were not affected by erythropoietin. Pharmacokinetics of erythropoietin suggest that the dose given was possibly too low to exert neuroprotection.

Comparable pharmacokinetics and pharmacodynamics of two epoetin alfa formulations Eporon® and Eprex® following a single subcutaneous administration in healthy male volunteers.

PURPOSE: This study aimed to assess and compare the pharmacokinetic (PK) and pharmacodynamic (PD) properties following a single subcutaneous injection of epoetin alfa (Eporon®) with those of the comparator (Eprex®) in healthy male subjects. SUBJECTS AND METHODS: A randomized, double-blind, two-sequence, crossover study was conducted. Subjects were randomly assigned to receive a single dose, that is, 4,000 IU, of the test or comparator epoetin alfa. After 4 weeks, all subjects received the alternative formulation. The primary PK parameters, maximum observed concentration (Cmax) and area under the curve extrapolated to infinity (AUCinf), were calculated with the serum erythropoietin (EPO) concentrations from blood samples collected for 144 h after dosing. The reticulocyte, hematocrit, hemoglobin and red blood cell counts were measured up to 312 h as PD markers. The primary PD parameters, maximum observed effect (Emax) and area under the effect curve (AUEC), were obtained from the baseline-corrected reticulocyte count. The serum EPO concentration and the reticulocyte count were used to assess the concentration-response relationship. The tolerability and immunogenicity profiles were assessed together. RESULTS: Forty-two subjects completed the study. The mean EPO concentration-time profiles were comparable between the two formulations. The geometric mean ratios (90% CI) of the Cmax and AUCinf were 0.908 (0.843-0.978) and 1.049 (0.999-1.101), respectively, both of which were within the regulatory range of 0.80-1.25. Additionally, the PD and tolerability profiles were similar between the two formulations. The time-matched serum EPO concentration and PD markers presented a counterclockwise hysteresis, suggesting a time delay between the measured concentration and the response. Both formulations were well tolerated, and production of anti-drug antibodies was not observed. CONCLUSION: The two epoetin alfa formulations had similar PK, PD and tolerability profiles. Furthermore, both formulations had a similar time-matched serum EPO concentration and erythropoietic response profile. Thus, the two formulations are expected to be used interchangeably in clinical settings.

Pharmacokinetic and Pharmacodynamic Equivalence of Epoetin Hospira and Epogen After Single Subcutaneous Doses to Healthy Male Subjects.

PURPOSE: The purpose of this study was to evaluate the pharmacokinetic (PK) and pharmacodynamic (PD) equivalence of single 100 U/kg subcutaneous doses of Epoetin Hospira and Epogen in healthy male subjects as part of an overall program to demonstrate biosimilarity of Epoetin Hospira to the reference product Epogen. METHODS: This single-center, open-label, randomized, 2-period, crossover study was conducted in 81 healthy male subjects. Subjects were randomized to Sequence 1, in which they received 100 U/kg of Epoetin Hospira or to sequence 2, in which they received 100 U/kg Epogen subcutaneously in the first study period and the alternative treatment in the second study period. Blood was collected for determination of baseline-adjusted epoetin concentrations (BAECs) for pharmacokinetics and for determination of reticulocyte percentage of total erythrocytes for pharmacodynamics throughout both study periods. The primary PK end points were the geometric mean ratios (GMRs) of the 2 treatments for AUC0-t and Cmax based on the BAEC, and the primary PD end points were the GMRs of the 2 treatments for AUC0-t and Cmax for reticulocyte percentage. FINDINGS: The GMRs of Epoetin Hospira to Epogen for the BAEC-derived PK parameters were 1.05 for AUC0-t with a 90% CI of 1.01 to 1.11, and 1.09 for Cmax with a 90% CI of 1.01 to 1.18, with both 90% CIs contained within the prespecified equivalence margin of 0.80 to 1.25. The GMRs (Epoetin Hospira/Epogen) for the reticulocyte percentage-derived PD parameters were 1.01 for AUC0-t with a 95% CI of 0.98 to 1.05, and 1.02 for Cmax with a 95% CI of 0.98 to 1.06, with both 95% CIs contained within the prespecified equivalence margin of 0.80 to 1.25. Overall, the adverse events were of similar frequency (11.7% and 13.9% for Epoetin Hospira and Epogen, respectively) and severity between treatments. One subject had a positive anti- recombinant human erythropoietin antibody result by radioimmunoprecipitation assay before dosing and throughout the conduct of the study with negative neutralizing antibodies and with no evidence of clinical deterioration or impact on the pharmacokinetics, pharmacodynamics, or safety. IMPLICATIONS: The results of this study established the PK and PD equivalence of single 100 U/kg subcutaneous doses of the proposed biosimilar Epoetin Hospira to the reference product Epogen in healthy male subjects and support the overall demonstration of biosimilarity of Epoetin Hospira and Epogen.

Pharmacodynamic and Pharmacokinetic Equivalences of Epoetin Hospira and Epogen(®) After Multiple Subcutaneous Doses to Healthy Male Subjects.

PURPOSE: The purpose of this study was to evaluate the pharmacodynamic (PD) and pharmacokinetic (PK) equivalences of multiple doses of the proposed biosimilar Epoetin Hospira to the reference product Epogen(⁎), when each is administered three times per week over 28 days to healthy male subjects METHODS: This single center, open-label, randomized, parallel group study was conducted in 129 healthy male subjects. Subjects were randomized to receive 100 U/kg Epoetin Hospira or 100 U/kg Epogen, each administered subcutaneously 3 times per week over 28 days. Blood was collected for determination of hemoglobin (Hb) concentrations for PD properties and for determination of epoetin concentrations for PK properties. The primary PD end point was the geometric mean ratio (GMR) of the 2 treatments for area under the effect curve for Hb from day 1 through 48 hours after the final dose of study drug administration on day 26, and the primary PK end point was the GMR of the 2 treatments for AUC0-48 and Cmax for epoetin after the final dose of study drug on day 26. FINDINGS: The GMR (Epoetin Hospira/Epogen) for the area under the effect curve for Hb from day 1 through 48 hours after the final dose of study drug administration on day 26 was 1.006 with a 95% CI of 0.996 to 1.016, which was contained within the prespecified equivalence margin of 0.965 to 1.035. The GMRs (Epoetin Hospira/Epogen) for the epoetin-derived PK parameters were 0.974 for AUC0-48 with a 90% CI of 0.896 to 1.059, and 0.938 for Cmax with a 90% CI of 0.839 to 1.049, with both 90% CIs contained within the prespecified equivalence margin of 0.80 to 1.25. The incidence (21.2% and 23.8% for Epoetin Hospira and Epogen, respectively) and severity of adverse events were similar between the 2 groups. One subject in each treatment group had a positive recombinant human erythropoietin antibody result by radioimmunoprecipitation assay before dosing and throughout study conduct with negative immunoglobulin M and neutralizing antibodies and with no evidence of clinical deterioration or of impact on PD, PK, or safety profile. IMPLICATIONS: The results of this study established PD and PK equivalences of multiple subcutaneous doses of the proposed biosimilar Epoetin Hospira to the reference product Epogen in healthy male subjects, and supported the overall demonstration of biosimilarity of Epoetin Hospira and Epogen.

Pharmacokinetic and Pharmacodynamic Comparison of Two Recombinant Human Erythropoietin Formulations, PDA10 and Eprex, in Healthy Korean Male Volunteers: A Randomized, Double-Blinded, Single-Dose, Two-Period Crossover Study.

BACKGROUND AND OBJECTIVES: A new biosimilar human recombinant epoetin alfa product (PDA10) has been developed by PanGen Biotech Inc., Korea. This study was planned to demonstrate the pharmacokinetic and pharmacodynamic comparability of PDA10 to an existing epoetin alfa (Eprex) after a single intravenous administration to healthy adult male volunteers. METHODS: A randomized, double-blinded, single-dose, crossover study was conducted in 30 subjects. The subjects were assigned randomly to one of two sequence groups, and single doses of 100 IU/kg PDA10 or Eprex were administered intravenously on each of 2 treatment days separated by a 4-week washout period. Plasma erythropoietin concentrations were measured using an enzyme-linked immunosorbent assay and the pharmacokinetic parameters of the two treatments were compared. The time course and area under the effect curve (AUEC) of absolute reticulocyte counts were used as surrogate parameters for the pharmacodynamic evaluation. Adverse events (AEs) were recorded. RESULTS: A total of 30 subjects were enrolled, and 27 completed the study. The geometric mean ratios (PDA10/Eprex) of erythropoietin for maximum plasma concentration (C max) and area under the plasma concentration-time curve to the last measurable concentration (AUC0-last) after intravenous administration of 100 IU/kg were 1.00 (90% confidence interval [CI] 0.96-1.05) and 0.96 (90% CI 0.93-1.00). The absolute reticulocyte counts of PDA10 and Eprex were similar, as determined from the maximum reticulocyte count and AUEC0-last values. Treatment-emergent AEs were mild and occurred in seven subjects. CONCLUSION: PDA10 and Eprex met the regulatory criteria for bioequivalence with respect to their pharmacokinetic profiles and pharmacodynamic actions.

Assessment of hemoglobin responsiveness to epoetin alfa in patients on hemodialysis using a population pharmacokinetic pharmacodynamic model.

A population pharmacokinetic pharmacodynamic (PK/PD) model describing the effect of epoetin alfa on hemoglobin (Hb) response in hemodialysis patients was developed. Epoetin alfa pharmacokinetics was described using a linear 2-compartment model. PK parameter estimates were similar to previously reported values. A maturation-structured cytokinetic model consisting of 5 compartments linked in a catenary fashion by first-order cell transfer rates following a zero-order input process described the Hb time course. The PD model described 2 subpopulations, one whose Hb response reflected epoetin alfa dosing and a second whose response was unrelated to epoetin alfa dosing. Parameter estimates from the PK/PD model were physiologically reasonable and consistent with published reports. Numerical and visual predictive checks using data from 2 studies were performed. The PK and PD of epoetin alfa were well described by the model.