Anti-idiotype reagents

We develop anti-idiotypic (anti-ID) reagents to innovator and biosimilar therapeutic antibodies for use in bioanalytical assays. 

We develop anti-idiotypic (anti-ID) reagents to innovator and biosimilar therapeutic antibodies for use in bioanalytical assays. Our high quality, highly specific Affimer® reagents can be rapidly identified from the Affimer® phage library and developed to meet specific assay requirements. Our reagents can advance drug development timelines and guarantee a consistent, secured supply throughout the preclinical research and clinical trials process.

Anti-ID reagents are molecules that specifically bind the idiotype of an antibody. An idiotype is the unique set of variable residues, typically found in the complementarity determining regions (CDRs), that defines a particular antibody. Anti-ID reagents are powerful tools that can detect a specific antibody within a complex IgG background. During the process of therapeutic antibody development, anti-ID reagents are used in pharmacokinetic (PK) assays to monitor drug levels in preclinical and clinical samples.

Anti-ID reagents can bind their specific target antibody in three different modes:

  • Competing: Binding to the paratope of the monoclonal antibody and competing with its target antigen – used to measure free drug.
  • Non-competing: Binding near the paratope but still allowing the antibody to bind its target antigen – used to measure total drug.
  • Complex specific: Binding specifically the antibody-target complex but not the unbound antibody or the unbound target – used to measure target bound drug.

Each of these binding modes have a different utility in designing and developing therapeutic monoclonal antibody drug monitoring assays.

Benefits of Affimer® reagents in the design of PK assays:

  • Rapid development: Our proven anti-ID Affimer® binder process typically takes 12 weeks, helping you to meet tight product development timelines.
  • High target specificity: Enables accurate and reproducible detection of therapeutic antibodies in complex matrices using a simple universal capture assay.
  • Reproducibility: Recombinant bacterial production process allows for batch to batch consistency and secure supply of critical reagents throughout the drug development process.
  • Fully validated: Validation of Affimer® reagents by leading CRO, Covance, shows that they meet regulatory requirements for critical reagent in PK assays. The calibration curves for our anti-ID Affimer reagents are validated in accordance with FDA regulatory guidelines.
  • Proven track record: 100% success rate in developing inhibitory anti-ID Affimer® reagents.
Product catalogue

Browse our catalogue of Anti-idiotype reagents available for evaluation.


Webinar: Affimer® proteins validated as critical PK assay reagents