INFORM HER2 Dual ISH DNA Probe Cocktail – P100027
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: INFORM HER2 Dual ISH DNA Probe Cocktail
Manufacturer: Ventana Medical Systems, Inc.
Address: 1910 East Innovation Park Drive, Tucson, AZ 85755 USA
Approval Date: June 14, 2011
Approval Letter: http://www.accessdata.fda.gov/ cdrh_docs/pdf10/p100027a.pdf
What is it? The INFORM HER2 Dual ISH DNA Probe Cocktail is a laboratory test that uses DNA probes, with color-forming (chromogenic) dyes attached, to count how many copies of the HER2 gene, located on chromosome 17, are present in a tissue sample. This test, which uses a variation of fluorescence in situ hybridization (ISH), is based on color detection, rather than fluorescence, and is used with samples of tumor tissue removed from breast cancer patients. This test is used by a doctor (pathologist) trained to identify diseases by studying slices of cells and tissues placed on microscope slides. If the test result indicates that too many copies of the HER2 gene (gene amplification) are present in the cancer cell, then a breast cancer patient may be eligible for treatment with the anti-cancer drug Herceptin® (Trastuzumab).
How does it work?
- The doctor takes a small tissue sample (biopsy) from the patient’s breast cancer and examines it.
- The tissue is embedded in a block of paraffin wax and a thin slice is cut from the block and attached to a glass slide.
- Using special chemicals and heat treatment, the patient tissue section on the microscope slide is treated with a specific modified DNA probe for the HER2 gene and with a second modified DNA probe for the matching central portion of chromosome 17.
- The two modified DNA probes bound to the nuclei in the tumor biopsy mark the candidate cells.
- The probes are then bound by antibodies directed against the modification on the HER2 probe or against the modification of the chromosome 17 probe.
- The antibodies are detected using a color development kit that produces a black spot where a single copy of the HER2 gene is present or using a second kit that produces a red spot where a single copy of chromosome 17 is present.
- The color-labeled sample is placed under the microscope and examined by a medical professional who checks the quality of the chromogenic signals and counts the black or red spots in at least 20 cancer cells.
- The ratio of black to red signals shows if there are too many copies of the HER2 gene in the tumor sample.
- The results are reviewed by a pathologist, who makes the final diagnosis of HER2 gene amplification or no amplification.
- The presence of HER2 gene amplification indicates a patient is eligible for cancer treatment with Herceptin®.
When is it used? For breast cancer patients whose tumor characteristics suggest that they might be candidates for Herceptin® therapy.
What will it accomplish? The INFORM HER2 Dual ISH DNA probe cocktail, when used with other clinical information and laboratory tests, helps to determine if a patient with breast cancer is eligible for Herceptin® treatment which may prolong their life.
When should it not be used? When breast 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.