| Tissue Cross-Reactivity Screening |
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When submitting an IND for a therapeutic biological molecule such as a humanized
monoclonal antibody, the FDA recommends that a comprehensive tissue
cross-reactivity evaluation be included as defined in the document "Points to
Consider in the Manufacture and Testing of Monoclonal Antibody Products for
Human Use". This document outlines a GLP protocol for the immunohistochemistry
screening of the therapeutic molecule and its isotype control at two different
dilutions across triplicate specimens of 32 frozen human tissue types. Because
GLP studies require the disclosure of all results, the optimal assay conditions
for each antibody should be determined under R&D conditions before
proceeding. LifeSpan's "RangeFinder" service is a timely, cost effective
approach to gaining this valuable information.
“RangeFinder” Study Plan
The following is the standard tissue cross-reactivity screening
protocol. Before a final agreement is executed, this study plan is customized
to address the specific characteristics of the antibody under study.
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Phase I: Initial Characterization
| Step 1: LifeSpan
scientists will determine the specificity and staining conditions for the
experimental antibody and the appropiate isotype control. A 5-step
dilution series of each antibody will be used to stain suggested positive and
negative control tissues, as well as tissues suggested by LifeSpan that are
known to commonly exhibit non-specific signal under standardized
immunohistochemical conditions. It is recommended that the client also provide
or identify a cell line that over-expresses the target.
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| Step 2: A LifeSpan
pathologist will analyze the resulting slides. A LifeSpan representative will
contact the client to verbally inform them of the results and make a
recommendation for either assay optimization procedures, or to move forward
with Phase II. The client has the right to cancel the study upon LifeSpan's
disclosure of these results.
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| Step 3: LifeSpan will
conduct mutually agreed upon assay optimization procedures as necessary.
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Phase II: Preliminary Cross-Reactivity Screen and Reporting
Step 4: Using the
optimal dilutions, the experimental antibody and its isotype control will be
used to immunolabel one specimen each of 32 frozen normal human tissue types.
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| Adrenal |
Endothelium |
Lymph node |
Skin |
| Bladder |
Eye |
Ovary |
Spinal cord |
| Blood cells |
Fallopian tube |
Pancreas |
Spleen |
| Bone marrow |
Gastrointestinal tract |
Parathyroid |
Testis |
| Breast |
Heart |
Pituitary |
Thymus |
| Cerebellum |
Kidney |
Placenta |
Thyroid |
| Cerebral Cortex |
Liver |
Prostate |
Ureter |
| Colon |
Lung |
Skeletal muscle |
Uterus |
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Frozen Cervix 40X |
Frozen Thymus medulla 40X |
Frozen Ureter epithelium 40X |
Frozen Thyroid 20X |
Frozen Ovary 20X |
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| Step 5: An anatomical
pathologist will analyze the resulting immunolabeled tissues and each tissue
type will be given a score of 0 to 4 depending upon staining intensity. In the
event that unusual background issues are encountered, the client will be
notified and additional optimization efforts will be outlined if appropriate.
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| Step 6: Results will be
delivered to the client in an electronic report that includes a description of
the materials and methods, a written summary of the results, and a table of the
immunohistological staining scores for each tissue. LifeSpan will also provide
the client with access to LifeSpan’s online detailed informatics page
containing curated public expression and localization data for the target gene
being studied. This information may be a helpful resource should unexpected
staining be encountered.
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Timeline
Study completion timeline depends upon the behavior of each antibody within the
assay. The study will be completed within 6 weeks of receipt of all study
reagents, longer if assay optimization is required.
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Pricing
To discuss a study plan in more detail and obtain pricing information contact
your local LifeSpan Sales
Representative
.
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