How We Can Support the Drug Development Pipeline

HER2 Testing (with FISH Confirmation)

Examples of immunostaining for HER2 protein (top), and FISH detection of the HER2 gene (bottom) in tumours over-expressing HER2

Over-expression of the membrane-associated receptor protein HER2 (erbB-2), as a consequence of gene amplification, occurs in 10-20% of breast cancers, and importantly is associated with a poorer prognosis.
Immunohistochemical demon-stration of HER2 protein over-expression in a breast tumour is a prerequisite for use of HER2-targeted therapies such as trastuzumab (Herceptin™). Source BioScience offers the FDA-approved, standardised and validated DAKO Herceptest™ or Ventana PATHWAY assays for assessment of HER2 protein expression, and the Abbott/Vysis Pathvysion™ assay for assessment of HER2 gene amplification status.

Evaluation

Specimens immunostained for HER2 protein are assessed visually by a registered pathologist, who will assign a score based upon an FDA-approved algorithm, of 0 to 3+; A score of 3+ is regarded as positive for HER 2 protein over-expression. Scores of 0 and 1+ are considered negative. Specimens achieving a score of 2+ are considered borderline, and are referred for FISH HER 2 gene analysis. FISH scores are expressed as ratios of HER2 gene copy number to copy number of chromosome 17. A score greater than 2 is considered evidence of HER2 amplification.
Patients achieving a score of 3+ by immunohistochemistry, or who are shown to be amplified by FISH, are considered eligible for Herceptin treatment.

For further information please contact us at: Pharma