Related Experiment Video
Updated: Jun 8, 2026
Laboratory Scale Production and Purification of a Therapeutic Antibody
Published on: January 24, 2017
Use of tissue cross-reactivity studies in the development of antibody-based biopharmaceuticals: history, experience,
Michael W Leach1, Wendy G Halpern, Carol W Johnson
1Therapeutic Area Lead, Biocorrection, Drug Safety Research and Development, Pfizer, Andover, Massachusetts 01810, USA.
Abstract:
Tissue cross-reactivity (TCR) studies are screening assays recommended for antibody and antibody-like molecules that contain a complementarity-determining region (CDR), primarily to identify off-target binding and, secondarily, to identify sites of on-target binding that were not previously identified. At the present time, TCR studies involve the ex vivo immunohistochemical (IHC) staining of a panel of frozen tissues from humans and animals, are conducted prior to dosing humans, and results are filed with the initial IND/CTA to support first-in-human clinical trials. In some cases, a robust TCR assay cannot be developed, and in these cases the lack of a TCR assay should not prevent a program from moving forward. The TCR assay by itself has variable correlation with toxicity or efficacy. Therefore, any findings of interest should be further evaluated and interpreted in the context of the overall pharmacology and safety assessment data package. TCR studies are generally not recommended for surrogate molecules or for comparability assessments in the context of manufacturing/cell line changes. Overall, the design, implementation, and interpretation of TCR studies should follow a case-by-case approach.
Insights
Tissue cross-reactivity (TCR) studies screen antibody therapeutics for off-target binding using immunohistochemistry. While valuable, TCR assay development challenges and variable correlation with outcomes necessitate a case-by-case interpretation within broader safety assessments.
Area of Science:
- Biopharmaceutical Development
- Immunohistochemistry
- Drug Safety Evaluation
Background:
- Tissue cross-reactivity (TCR) studies are crucial screening assays for antibody-based therapeutics.
- These studies identify potential off-target binding sites and confirm on-target binding.
- TCR assays are typically performed ex vivo using immunohistochemical (IHC) staining of tissue panels before human trials.
Purpose of the Study:
- To define the role and application of TCR studies in antibody development.
- To provide guidance on the interpretation and limitations of TCR assay findings.
- To emphasize a flexible, case-by-case approach to TCR study design and implementation.
Main Methods:
- Utilizes ex vivo immunohistochemical (IHC) staining of human and animal tissue panels.
- Involves screening antibody and antibody-like molecules with complementarity-determining regions (CDRs).
- Results are submitted in Investigational New Drug (IND) or Clinical Trial Application (CTA) packages.
Main Results:
- TCR studies primarily detect off-target binding.
- They can also identify previously unrecognized sites of on-target binding.
- A robust TCR assay is not always achievable, and its absence should not halt development.
- The correlation of TCR findings with toxicity or efficacy is variable.
Conclusions:
- TCR studies are a valuable tool but should be interpreted cautiously within the overall safety data.
- Findings require further evaluation alongside pharmacology and safety assessments.
- TCR studies are generally not recommended for surrogate molecules or manufacturing comparability assessments.
- A case-by-case strategy is essential for designing, executing, and interpreting TCR studies.
Related Concept Videos
00:42Cross-reactivity
01:31Hybridoma Technology
Hybridoma Selection
Commonly used fusion techniques — electroporation, polyethylene glycol...