Validation of an Immunoassay for Anti-thymidine Phosphorylase Antibodies in Patients with MNGIE Treated with Enzyme Replacement Therapy
Erythrocyte encapsulated thymidine phosphorylase is recombinant Escherichia coli thymidine phosphorylase encapsulated within human autologous erythrocytes and is under development as an enzyme replacement therapy for the ultra-rare inherited metabolic disorder mitochondrial neurogastrointestinal enc...
Main Authors: | , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Elsevier
2018-12-01
|
Series: | Molecular Therapy: Methods & Clinical Development |
Online Access: | http://www.sciencedirect.com/science/article/pii/S2329050118300846 |
id |
doaj-3f454fa28ac74ca78eedd5841cfa3eb9 |
---|---|
record_format |
Article |
spelling |
doaj-3f454fa28ac74ca78eedd5841cfa3eb92020-11-25T00:13:23ZengElsevierMolecular Therapy: Methods & Clinical Development2329-05012018-12-011118Validation of an Immunoassay for Anti-thymidine Phosphorylase Antibodies in Patients with MNGIE Treated with Enzyme Replacement TherapyMichelle Levene0Dario Pacitti1Charlotte Gasson2Jamie Hall3Marcia Sellos-Moura4Bridget E. Bax5Molecular & Clinical Sciences Research Institute, St. George’s, University of London, London, UKMolecular & Clinical Sciences Research Institute, St. George’s, University of London, London, UKBiomarker, Bioanalysis and Clinical Sciences, Envigo CRS, Cambridgeshire, UKBiomarker, Bioanalysis and Clinical Sciences, Envigo CRS, Cambridgeshire, UKOrphan Technologies, Zuercherstrasse 19, Rapperswil, SwitzerlandMolecular & Clinical Sciences Research Institute, St. George’s, University of London, London, UK; Corresponding author: Bridget E. Bax, Molecular & Clinical Sciences Research Institute, St George’s, University of London, London SW17 0RE, UK.Erythrocyte encapsulated thymidine phosphorylase is recombinant Escherichia coli thymidine phosphorylase encapsulated within human autologous erythrocytes and is under development as an enzyme replacement therapy for the ultra-rare inherited metabolic disorder mitochondrial neurogastrointestinal encephalomyopathy. This study describes the method validation of a two-step bridging electrochemiluminescence immunoassay for the detection of anti-thymidine phosphorylase antibodies in human serum according to current industry practice and regulatory guidelines. The analytical method was assessed for screening cut point, specificity, selectivity, precision, prozone effect, drug tolerance, and stability. Key findings were a correction factor of 129 relative light units for the cut-point determination; a specificity cut point of 93% inhibition; confirmed intra-assay and inter-assay precision; assay sensitivity of 356 ng/mL; no matrix or prozone effects up to 25,900 ng/mL; a drug tolerance of 156 ng/mL; and stability at room temperature for 24 hr and up to five freeze-thaws. Immunogenicity evaluations of serum from three patients who received erythrocyte encapsulated thymidine phosphorylase under a compassionate treatment program showed specific anti-thymidine phosphorylase antibodies in one patient. To conclude, a sensitive, specific, and selective immunoassay has been validated for the measurement of anti-thymidine phosphorylase antibodies; this will be utilized in a phase II pivotal clinical trial of erythrocyte encapsulated thymidine phosphorylase. Keywords: assay validation, bridging immunoassay, enzyme replacement therapy, MNGIE, thymidine phosphorylasehttp://www.sciencedirect.com/science/article/pii/S2329050118300846 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Michelle Levene Dario Pacitti Charlotte Gasson Jamie Hall Marcia Sellos-Moura Bridget E. Bax |
spellingShingle |
Michelle Levene Dario Pacitti Charlotte Gasson Jamie Hall Marcia Sellos-Moura Bridget E. Bax Validation of an Immunoassay for Anti-thymidine Phosphorylase Antibodies in Patients with MNGIE Treated with Enzyme Replacement Therapy Molecular Therapy: Methods & Clinical Development |
author_facet |
Michelle Levene Dario Pacitti Charlotte Gasson Jamie Hall Marcia Sellos-Moura Bridget E. Bax |
author_sort |
Michelle Levene |
title |
Validation of an Immunoassay for Anti-thymidine Phosphorylase Antibodies in Patients with MNGIE Treated with Enzyme Replacement Therapy |
title_short |
Validation of an Immunoassay for Anti-thymidine Phosphorylase Antibodies in Patients with MNGIE Treated with Enzyme Replacement Therapy |
title_full |
Validation of an Immunoassay for Anti-thymidine Phosphorylase Antibodies in Patients with MNGIE Treated with Enzyme Replacement Therapy |
title_fullStr |
Validation of an Immunoassay for Anti-thymidine Phosphorylase Antibodies in Patients with MNGIE Treated with Enzyme Replacement Therapy |
title_full_unstemmed |
Validation of an Immunoassay for Anti-thymidine Phosphorylase Antibodies in Patients with MNGIE Treated with Enzyme Replacement Therapy |
title_sort |
validation of an immunoassay for anti-thymidine phosphorylase antibodies in patients with mngie treated with enzyme replacement therapy |
publisher |
Elsevier |
series |
Molecular Therapy: Methods & Clinical Development |
issn |
2329-0501 |
publishDate |
2018-12-01 |
description |
Erythrocyte encapsulated thymidine phosphorylase is recombinant Escherichia coli thymidine phosphorylase encapsulated within human autologous erythrocytes and is under development as an enzyme replacement therapy for the ultra-rare inherited metabolic disorder mitochondrial neurogastrointestinal encephalomyopathy. This study describes the method validation of a two-step bridging electrochemiluminescence immunoassay for the detection of anti-thymidine phosphorylase antibodies in human serum according to current industry practice and regulatory guidelines. The analytical method was assessed for screening cut point, specificity, selectivity, precision, prozone effect, drug tolerance, and stability. Key findings were a correction factor of 129 relative light units for the cut-point determination; a specificity cut point of 93% inhibition; confirmed intra-assay and inter-assay precision; assay sensitivity of 356 ng/mL; no matrix or prozone effects up to 25,900 ng/mL; a drug tolerance of 156 ng/mL; and stability at room temperature for 24 hr and up to five freeze-thaws. Immunogenicity evaluations of serum from three patients who received erythrocyte encapsulated thymidine phosphorylase under a compassionate treatment program showed specific anti-thymidine phosphorylase antibodies in one patient. To conclude, a sensitive, specific, and selective immunoassay has been validated for the measurement of anti-thymidine phosphorylase antibodies; this will be utilized in a phase II pivotal clinical trial of erythrocyte encapsulated thymidine phosphorylase. Keywords: assay validation, bridging immunoassay, enzyme replacement therapy, MNGIE, thymidine phosphorylase |
url |
http://www.sciencedirect.com/science/article/pii/S2329050118300846 |
work_keys_str_mv |
AT michellelevene validationofanimmunoassayforantithymidinephosphorylaseantibodiesinpatientswithmngietreatedwithenzymereplacementtherapy AT dariopacitti validationofanimmunoassayforantithymidinephosphorylaseantibodiesinpatientswithmngietreatedwithenzymereplacementtherapy AT charlottegasson validationofanimmunoassayforantithymidinephosphorylaseantibodiesinpatientswithmngietreatedwithenzymereplacementtherapy AT jamiehall validationofanimmunoassayforantithymidinephosphorylaseantibodiesinpatientswithmngietreatedwithenzymereplacementtherapy AT marciasellosmoura validationofanimmunoassayforantithymidinephosphorylaseantibodiesinpatientswithmngietreatedwithenzymereplacementtherapy AT bridgetebax validationofanimmunoassayforantithymidinephosphorylaseantibodiesinpatientswithmngietreatedwithenzymereplacementtherapy |
_version_ |
1725394588681633792 |