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ELISA - Humoral Immunity

We offer full-service development of ELISAs for measuring specific antibodies or antigens. Alternatively, we can transfer an existing ELISA into our lab.

	Different types of ELISAs can be developed: sandwich ELISAs double-sandwich ELISAs competitive ELISAs
Several assay formats can be developed: Quantitative assays: an accurate standard is available for generation of a calibration curve (examples: the toxicokinetics of an administered compound, the fluid concentration of antigens such as cytokines or other soluble makers, etc.). Quasi-quantitative: an accurate standard is not available. This is often the case for immunogenicity studies where no standard can be obtained. Two approaches can be used, depending on the availability of specific polyclonal or monoclonal antibodies from the same animal species. If polyclonal/monoclonal antibodies are not available, a titration approach can be developed. If polyclonal/monoclonal antibodies are available, a calibrating curve can be generated after defining its concentration in arbitrary units.
Validation of a specific ELISA includes: intra-/inter-assay variability determination of upper and lower detection limits repeatability, intermediate precision assay cut-point determination QC acceptance criteria linearity sample stability recovery matrix interference		Main Guidelines: FDA/CDER/May 2001 “Bioanalytical method validation” ICH Q2(R1) 2005 (previously Q2A/B) “validation of analytical procedures: text and methodology”

ELISA applications:

Toxicokinetics:

If ELISAs are performed during preclinical studies, regulatory bodies require these assays to be GLP validated and tested. We offer a custom approach to developing and validating a specific sandwich ELISA for your recombinant protein.

Immunogenicity Studies:

During preclinical studies or clinical trials, it is important to evaluate the immunogenicity of biotech products.
Using a custom approach, we can develop and validate a specific sandwich ELISA for measuring total and specific immunoglobulins. During the validation, we evaluate the assay cut-off point, sensitivity, intra-/inter-assay variability, sample stability, and so on.
Texcell can also assess the seroneutralization capacity for positive samples.

Main Guidelines:
ICH S6 (CPMP/ICH/302/95) “Note for guidance on preclinical safety evaluation of biotechnology-derived pharmaceuticals”
EMEA/CHMP/BMWP/246511/2005 “Concept paper on guideline on immunogenicity assessment of therapeutic proteins”
FDA/CDER/Oct 2002 Guidance for Industry “Immunotoxicology evaluation of investigational new drugs”
Standardization Paper “Recommendation for the design and optimization of Immunoassays used in detection of host antibodies against biotechnology products” A.R. Mire-Sluis et al. / Journal of Immunological Methods 289(2004)1-16
FDA/CDER/May 2001 “Bioanalytical method validation”
ICH Q2(R1) 2005 (previously Q2A/B) “validation of analytical procedures: text and methodology”

Endpoint Bioassays (Potency assays):

During pre-clinical studies, bioassays (see III-6) can be designed for evaluating the immune system activity of a drug compound. For example, PBMCs isolated from patients or blood donors can be cultured in the presence of the drug or food supplement. At the culture endpoint, commercial or custom ELISAs are used to detect the cytokines (or other soluble markers) of interest in supernatants in order to assess the drug's efficacy.

Pharmacokinetics:

Measurement of drug concentrations in body fluids (generally in the serum) during clinical trials (Phases I to III). The context is quite similar to that of biodistribution studies (see Biodistribution section). We offer extensive validation of your ELISA according to the “Bioanalytical method validation” guideline (published by the FDA in May 2001) and the ICH Q2(R1) 2005 (previously Q2A/B) “Validation of analytical procedures: text and methodology” guideline.

Pharmacodynamics:

Measurement of a drug's efficacy during clinical trials (Phases I to III). Drug efficacy can be evaluated by quantification of biological markers (cytokines, antibodies, growth factors, etc.). We offer extensive validation of ELISAs according to the “Bioanalytical method validation” guideline (published by the FDA in May 2001) and the ICH Q2(R1) 2005 (previously Q2A/B) “Validation of analytical procedures: text and methodology” guideline.