RESUMEN
Therapeutic proteins and emerging gene and cell-based therapies are attractive therapeutic tools for addressing unmet medical needs or when earlier conventional treatment approaches failed. However, the development of an immune response directed against therapeutic agents is a significant concern as it occurs in a substantial number of cases across products and indications. The specific anti-drug antibodies that develop can lead to safety adverse events as well as inhibition of drug activity or accelerated clearance, both phenomena resulting in loss of treatment efficacy. The European Immunogenicity Platform (EIP) is a meeting place for experts and newcomers to the immunogenicity field, designed to stimulate discussion amongst scientists across industry and academia, encourage interactions with regulatory agencies and share knowledge and the state-of-the-art of immunogenicity sciences with the broader scientific community. Here we report on the main topics covered during the EIP 10th Open Symposium on Immunogenicity of Biopharmaceuticals held in Lisbon, 26-27 February 2019, and the 1-d training course on practical and regulatory aspects of immunogenicity held ahead of the conference. These main topics included immunogenicity testing, clinical relevance of immunogenicity, immunogenicity prediction, regulatory aspects, tolerance induction as a mean to mitigate immunogenicity and immunogenicity in the context of gene therapy.
Asunto(s)
Anticuerpos/inmunología , Productos Biológicos/inmunología , Animales , Europa (Continente) , HumanosRESUMEN
Immunogenicity assessment of fully human monoclonal antibody-based biotherapeutics requires sensitive and specific ligand binding assays. One of the components of specificity is the depletion of signal by a relevant biotherapeutic that is commonly based on an arbitrary depletion criterion of inhibition of the original response or reduction of the signal below the screening assay cut point (ACP). Hence, there is a need to develop a statistically derived physiologically relevant specificity criterion. We illustrate an optimization approach to determine the concentration of biotherapeutic required for the specificity evaluation. Naïve donor sample sets with and without circulating drug and antitherapeutic/drug antibody (ADA) were prepared. Next, a depletion cut point (DCP) using naïve and ADA-containing donor sets with the optimized biotherapeutic concentration was evaluated. A statistically derived design of experiment was used to establish a validated DCP. A reliable DCP requires naïve (no ADA) donors treated only with an optimized concentration of biotherapeutic. The additional DCPs generated using two distinct concentrations of ADA-spiked sample sets led to a physiologically irrelevant criterion that was not necessarily representative of real-time samples. This increased the risk of false positives or negatives. In this study, well-defined bioanalytical and statistical methods were employed to validate a DCP to confirm the presence of biotherapeutic specific ADA in human serum samples. A physiologically relevant and effective strategy to confirm specificity in immune reactive samples, especially those that are close to the ACP, is proposed through this study.
Asunto(s)
Anticuerpos Monoclonales/sangre , Fenómenos Inmunogenéticos/fisiología , Inmunoglobulina G/sangre , Análisis por Matrices de Proteínas/normas , Eliminación de Secuencia/inmunología , Terapia Biológica/normas , Femenino , Humanos , Fenómenos Inmunogenéticos/efectos de los fármacos , Masculino , Análisis por Matrices de Proteínas/estadística & datos numéricos , Eliminación de Secuencia/genéticaRESUMEN
Antibodies elicited by protein therapeutics can cause serious side effects in humans. We studied immunogenicity of a recombinant fusion protein (FPX) consisting of two identical, biologically active, peptides attached to human Fc fragment. EpiMatrix, an in silico epitope-mapping tool, predicted promiscuous T-cell epitope(s) within the 14-amino-acid carboxy-terminal region of the peptide portion of FPX. On administration of FPX in 76 healthy human subjects, 37% developed antibodies after a single injection. A memory T-cell response against the above carboxy-terminus of the peptide was observed in antibody-positive but not in antibody-negative subjects. Promiscuity of the predicted T-cell epitope(s) was confirmed by representation of all common HLA alleles in antibody-positive subjects. As predicted by EpiMatrix, HLA haplotype DRB1*0701/1501 was associated with the highest T-cell and antibody response. In conclusion, in silico prediction can be successfully used to identify Class II restricted T-cell epitopes within therapeutic proteins and predict immunogenicity thereof in humans.
Asunto(s)
Biología Computacional/métodos , Simulación por Computador , Epítopos de Linfocito T/inmunología , Epítopos Inmunodominantes/inmunología , Modelos Inmunológicos , Proteínas Recombinantes de Fusión/inmunología , Adolescente , Adulto , Algoritmos , Formación de Anticuerpos/inmunología , Técnicas Químicas Combinatorias , Evaluación Preclínica de Medicamentos/métodos , Evaluación Preclínica de Medicamentos/tendencias , Epítopos de Linfocito T/química , Femenino , Humanos , Epítopos Inmunodominantes/química , Masculino , Persona de Mediana Edad , Modelos Moleculares , Valor Predictivo de las Pruebas , Relación Estructura-Actividad Cuantitativa , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/uso terapéutico , Linfocitos T Colaboradores-Inductores/inmunologíaRESUMEN
Recombinant adeno-associated virus (rAAV) vectors have emerged as highly promising for use in gene transfer for a variety of reasons, including lack of pathogenicity and wide host range. In addition, all virus-encoded genes have been removed from standard rAAV vectors, resulting in their comparatively low intrinsic immunogenicity. For gene replacement strategies, transgenes encoded by rAAV vectors may induce less robust host immune responses than other vectors in vivo. However, under appropriate conditions, host immune responses can be generated against rAAV-encoded transgenes, raising the potential for their use in vaccine development. In this review, we summarize current understanding of the generation of both undesirable and beneficial host immune responses directed against rAAV and encoded transgenes, and how they might be exploited for optimal use of this promising vector system.