Consumer Information on: Dako HER2 FISH pharmDx? - P040005S005
This is a brief overview of information related to FDA’s approval to market this product. See the links below to the Summary of Safety and Effectiveness Data (SSED) and product labeling for more complete information on this product, its indications for use, and the basis for FDA’s approval.
Product Name: HER2 FISH pharmDx™ PMA Applicant: Address: Approval Date: Approval Letter:
PMA Applicant:Dako Denmark A/S
Address:Produktionsvej 42, DK-2600 Glostrup, Denmark
Approval Date:October 20, 2010
Approval Letter:http://www.accessdata.fda.gov/cdrh_docs/pdf4/p040005s005a.pdf 
What is it? HER2 FISH pharmDx™ is a laboratory test that uses DNA probes with fluorescent dyes attached to count how many copies of the HER2 gene , located on chromosome 17, are present in a cancer tissue sample. This test, which uses a fluorescent in situ hybridization  (FISH) method, has been used in patients with breast cancer and now can be used in patients with spreading (metastatic ) stomach (gastric) cancer. If the test result indicates that too many copies of the HER2 gene (gene amplification ) are present in the cancer cell, then a gastric cancer patient may be eligible for treatment with the cancer drug Herceptin® (Trastuzumab).
How does it work?
- The doctor takes a small sample from the patient’s stomach cancer and examines it (biopsy).
- The sample is embedded in paraffin wax and a thin slice is cut and attached to a glass microscope slide.
- With special chemicals and heat treatment, a red fluorescent-tagged DNA probe binds to matching DNA in the HER2 gene and a green fluorescent-tagged DNA probe binds to the matching central portion of chromosome 17 in cells on the slide.
- A trained medical professional uses a fluorescence microscope to check the quality of the slide and to count the number of red and green signals. The ratio of red to green signals shows if there are too many copies of HER2 in the tumor sample.
- A doctor (pathologist ) that is trained to read the slides uses a microscope to check the quality, interprets the staining pattern, and reports the results to the ordering doctor.
When is it used? For gastric cancer patients whose tumor characteristics suggest that they might be candidates for Herceptin® therapy.
What will it accomplish? The Dako HER2 FISH pharmDx™ test, when used with other clinical information and laboratory tests, helps to determine if a patient with metastatic gastric cancer is eligible for Herceptin® treatment which may prolong their life.
When should it not be used?
When gastric cancer patients whose tumor characteristics suggest that they are not candidates for Herceptin® therapy .
Additional information : Summary of Safety and Effectiveness and labeling  are available online.