Physicochemical and biological evaluation of JR-131 as a biosimilar to a long-acting erythropoiesis-stimulating agent darbepoetin alfa.

Renal anemia is predominantly caused by a relative deficiency in erythropoietin (EPO). Conventional treatment for renal anemia includes the use of recombinant human EPO (rhEPO) or a long-acting erythropoiesis-activating agent named darbepoetin alfa, which is a modified rhEPO with a carbohydrate chain structure that differs from native hEPO. We have developed a biosimilar to darbepoetin alfa designated JR-131. Here, we comprehensively compare the physicochemical and biological characteristics of JR-131 to darbepoetin alfa. JR-131 demonstrated similar protein structure to the originator, darbepoetin alfa, by peptide mapping and circular dichroism spectroscopy. Additionally, mass spectroscopic analyses and capillary zone electrophoresis revealed similar glycosylation patterns between the two products. Human bone marrow-derived erythroblasts differentiated and proliferated to form colonies with JR-131 to a similar degree as darbepoetin alfa. Finally, JR-131 stimulated erythropoiesis and improved anemia in rats similarly to darbepoetin alfa. Our data show the similarity in physicochemical and biological properties of JR-131 to those of darbepoetin alfa, and JR-131 therefore represents a biosimilar for use in the treatment of renal anemia.

Glycan analysis of erythropoiesis-stimulating agents.

Erythropoiesis stimulating agents (ESAs) are a group of therapeutic glycoproteins used to treat anaemia caused by chronic kidney disease or chemotherapy. A variety of ESA products are available in the European Union, including innovator, biosimilar and second-generation medicines. Glycosylation is a critical quality attribute of ESA products, as it has a crucial influence upon in vivo biological activity. In this study, a combination of chromatography and mass spectrometry analysis has been used to characterise and compare the glycosylation profiles of five ESA products; Eprex® (epoetin alfa), NeoRecormon® (epoetin beta), Binocrit® (epoetin alfa biosimilar), Silapo (epoetin alfa biosimilar) and Aranesp® (darbepoetin alfa). The methods utilised include mixed-mode anion-exchange/hydrophilic interaction chromatography (AEX/HILIC-MS) for N-glycan identification and quantitation, and HILIC-MS for O-glycan characterisation. The products exhibit notable differences in N- and O-glycosylation, including attributes such as sialic acid occupation, O-acetylation, N-acetyllactosamine extended antennae and sulphated/penta-sialylated N-glycans, which have the potential to cause divergence of therapeutic potencies. The study highlights the need for continued monitoring of ESA product glycosylation, ideally allied to pharmacological data, in order to ensure consistency and therapeutic equivalence between products and enhance our understanding of ESA structure-activity-relationships.

Comparison of the Pharmacokinetic-Pharmacodynamic Relationships of Two Darbepoetin Alfa Formulations in Healthy Male Volunteers.

OBJECTIVE: This study compared the pharmacokinetic (PK), pharmacodynamic (PD), and safety properties of the test (CJ-40001) and reference (NESP®) versions of darbepoetin alfa following a single subcutaneous (SC) or intravenous (IV) administration in healthy male subjects. METHODS: A single-blind, randomized, single-dose, two-period, two-intervention crossover study was conducted, with two separate parts consisting of SC or IV administration. In each period, either a test or reference product was administered via the SC or IV route. Serial blood samples for PK analysis and the reticulocyte, hematocrit, hemoglobin, and red blood cell counts for PD analysis were collected for up to 360 or 264 h after SC or IV administration, respectively. The PK and PD parameters were calculated using non-compartmental methods. The 90% confidence intervals of the geometric mean ratios for the PK and PD parameters between the two interventions were estimated. Safety and anti-drug antibody profile assessments were performed. RESULTS: The mean darbepoetin alfa concentration-time profiles were comparable between the two products for SC and IV administration. Additionally, the PD and safety profiles were similar between the two products. Anti-drug antibody reactivity was negative for all samples from both intervention groups for SC and IV administration. The time-matched serum darbepoetin alfa concentration and the PD markers presented a counter-clockwise hysteresis, which suggests a time delay between the exposure and response. CONCLUSION: The test and reference darbepoetin alfa formulations had similar PK, PD, and safety profiles. Thus, it is expected that the two formulations are able to be used interchangeably in clinical settings. ClinicalTrials.gov Identifier: NCT03542916.

Comprehensive Physicochemical and Biological Characterization of the Proposed Biosimilar Darbepoetin Alfa, LBDE, and Its Originator Darbepoetin Alfa, NESP®.

BACKGROUND: For regulatory approval, the comparability of a biosimilar product to an originator product should be ensured through thorough physicochemical and biological characterization. OBJECTIVE: To evaluate the biosimilarity between LBDE, the proposed biosimilar darbepoetin alfa, and NESP®, its originator, we performed a comprehensive physicochemical and biological characterization study. METHODS: Primary and higher-order protein structures were analyzed using Lys-C peptide mapping with liquid chromatography-mass spectrometry (LC-MS), disulfide bond identification, circular dichroism, and fluorescence spectroscopy. Glycosylation and isoform distribution were analyzed using MS, LC, and capillary zone electrophoresis. Size variants were evaluated with size-exclusion chromatography-high-performance liquid chromatography (SEC-HPLC) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Biological characterization included binding affinity for human erythropoietin receptor, in vitro cell proliferation, and in vivo potency. Pharmacokinetics (PK) were evaluated using rats through two injection routes. RESULTS: Non-reducing and reducing Lys-C peptide mapping showed a highly similar peak profile, confirming that LBDE and NESP® have the same primary structure and disulfide bonds. Glycosylation and isoform analyses showed that the attached N-glycan and O-glycan structures were the same and their relative contents were similar. Spectroscopic analysis of LBDE showed indistinguishable spectra with NESP®. For both LBDE and NESP®, a very small amount of size variants was found in SEC-HPLC, and no minor bands were detected in SDS-PAGE. Furthermore, LBDE did not show any difference with NESP® in the in vitro and in vivo functional analyses. PK parameters of LBDE were in good agreement with those of NESP®. CONCLUSION: LBDE shows high similarity to NESP® with regard to structure and function.

Comparative Assessment of the Effect of Hyper-glycosylation on the Pattern and Kinetics of Degradation of Darbepoetin Alfa using a Stability-Indicating Orthogonal Testing Protocol.

Darbepoetin alfa (DA); hyper-glycosylated Erythropoietin alfa (EPO) is an essential treatment of anemia in patients with chronic kidney failure and cancer. In this study, DA and EPO were subjected to physicochemical stress factors that might be encountered during production, transport and storage (pH, temperature, agitation, repeated freeze-thaw and oxidation). An orthogonal stability-indicating assay protocol comprised of SE-HPLC, RP-HPLC, ELISA and SDS-PAGE was developed and validated to investigate the effect of further glycosylation of DA on the pattern and kinetics of degradation. Results showed a relatively higher stability and lower tendency to form high molecular weight aggregates in the case of DA when compared to EPO, under equivalent stress conditions. Dimers and aggregates were formed for both drugs across the whole pH range and following incubation at temperatures higher than 2-8°C or repeated freeze/thaw. The same observation was noted upon agitation of standard samples prepared in the formulation buffers at high speed and upon oxidation with hydrogen peroxide. The agreement between SE-HPLC, supported with spectral purity data and ELISA confirmed the specificity of both techniques for the intact drugs. Results of RP-HPLC and SDS-PAGE indicated that dimerization occurred through disulfide and bi-tyrosine covalent bonds in the case of pH and oxidation, respectively. It was evident that aggregation was significantly suppressed upon increasing the glycan size and under any of the studied stress factors loss of the glycan has not been observed. These observations supported with the slow kinetics of degradation confirmed the superiority of glyco-engineering over chemical pegylation to enhance the stability of EPO. Formation of such potentially immunogenic product-related impurities at all tested stress factors confirmed the need for orthogonal testing protocols to investigate the complex pattern of degradation of such sensitive products.

Mass spectrometric characterisation of darbepoetin alfa biosimilars with C-terminal arginine residues.

Human erythropoietin (EPO) and recombinant human EPO (rEPO) are approximately 30-kDa glycosylated proteins comprising 165 amino acids. Darbepoetin alfa (NESP) is a glycosylated protein encompassing five changes in the amino acid sequence of human EPO, which contains two extra sugar chains. NESP is under patent protection in the USA until May 2024 and in Europe until July 2016, which suggests that the number of NESP biosimilars might substantially increase. The detailed characterisation of biosimilar products are required to ensure the identity and purity of the biosimilar products in terms of safety and efficacy for patients. In this study, a mass spectrometric characterisation of NESP biosimilar products is demonstrated. The study comprises a time-of-flight mass spectrometry characterisation for the asialo-NESPs after sialidase digestion and primary structure characterisation using bottom-up analysis after endoproteinase Glu-C digestion of the core protein. The study revealed that there was a wide range of glycoforms spaced by 365 Da intervals, namely, HexHexNAc units, which indicated that NESP biosimilars likely contained more N-acetyllactosamine units in their molecules. The bottom-up analysis also showed that the NESP biosimilars, as well as a rEPO biosimilar, contain not only the des-arginine product but also the C-terminal arginine product comprising 166 amino acids, whereas the innovator products contain des-arginine EPO comprising only 165 amino acids. The C-terminal arginine EPO would be used as a potential marker for doping with EPO bisimilaras. These findings also point to a need for the investigation of immunogenicity and comparability for the biosimilar products. Copyright © 2016 John Wiley & Sons, Ltd.

Capillary Electrophoresis Method for the Assessment of Erythropoiesis-Stimulating Agents in Final Formulations.

Capillary electrophoresis (CE) comprises several separation modes that can be used to characterize proteins in terms of physico-chemical properties such as isoelectric point or molecular weight, or in terms of purity/heterogeneity for the presence of charge or size variants. In glycoproteins the heterogeneity occurring as a consequence of variable amounts of terminal sialic acid residues on glycan moieties can be detected by CE. As such, a capillary zone electrophoresis (CZE) method was found suitable for the detection of isoforms of several erythropoiesis-stimulating agents (Bietlot and Girard, J Chromatogr A 759:177-184, 1997; Boucher et al., J Pharm Biomed Anal 71:207-213, 2012). In particular, the method can be used to analyze finished products containing erythropoietin-α, erythropoietin-ß, or darbepoetin-α regardless of the formulation and without the need for sample pretreatment. The major excipients encountered in the various formulations included polysorbate 80, polysorbate 20, or human serum albumin. The ability of the method to resolve isoforms of the active ingredient in finished product enables the comparison of the isoform profile with that of the corresponding drug substance, allowing the assessment of the structural integrity and content of the active ingredients in finished products.

Purification and Characterization of Recombinant Darbepoetin Alfa from Leishmania tarentolae.

Darbepoetin alfa is a biopharmaceutical glycoprotein that stimulates erythropoiesis and is used to treat anemia, which associated with renal failure and cancer chemotherapy. We herein describe the structural characterization of recombinant darbepoetin alfa produced by Leishmania tarentolae T7-TR host. The DNA expression cassette was integrated into the L. tarentolae genome through homologous recombination. Transformed clones were selected by antibiotic resistance, diagnostic PCRs, and protein expression analysis. The structure of recombinant darbepoetin alfa was analyzed by isoelectric focusing, ultraviolet-visible spectrum, and circular dichroism (CD) spectroscopy. Expression analysis showed the presence of a protein band at 40 kDa, and its expression level was 51.2 mg/ml of culture medium. Darbepoetin alfa have 5 isoforms with varying degree of sialylation. The UV absorption and CD spectra were analogous to original drug (Aranesp), which confirmed that the produced protein was darbepoetin alfa. Potency test results revealed that the purified protein was biologically active. In brief, the structural and biological characteristics of expressed darbepoetin alfa were very similar to Aranesp which has been normally expressed in CHO. Our data also suggest that produced protein has potential to be developed for clinical use.