The US Food and Drug Administration (FDA) cleared for marketing a test that determines the likelihood of breast cancer returning within five to 10 years after a woman's initial cancer. It is the first cleared molecular test that profiles genetic activity.
The MammaPrint test uses the latest in molecular technology to predict whether existing cancer will metastasize (spread to other parts of a patient's body). The test relies on microarray analysis, a powerful tool for simultaneously studying the patterns of behaviour of large numbers of genes in biological specimens.
The recurrence of cancer is partly dependent on the activation and suppression of certain genes located in the tumour. Prognostic tests like the MammaPrint can measure the activity of these genes, and thus help physicians understand their patients' odds of the cancer spreading.
MammaPrint was developed by Agendia, a laboratory located in Amsterdam, Netherlands, where the product has been on the market since 2005, an US FDA press release stated..
"Clearance of the MammaPrint test marks a step forward in the initiative to bring molecular-based medicine into current practice," said Andrew C. von Eschenbach, M.D., Commissioner of Food and Drugs. "MammaPrint results will provide patients and physicians with more information about the prospects for the outcome of the disease. This information will support treatment decisions.
Agendia compared the genetic profiles of a large number of women suffering from breast cancer and identified a set of 70 genes whose activity confers information about the likelihood of tumour recurrence. The MammaPrint test measures the level of activity of each of these genes in a sample of a woman's surgically removed breast cancer tumour, then uses a specific formula, known as an algorithm, to produce a score that determines whether the patient is deemed low risk or high risk for spread of the cancer to another site. The result may help a doctor in planning appropriate follow-up for a patient when used with other clinical information and laboratory tests.
The MammaPrint is the first cleared in vitro diagnostic multivariate index assay (IVDMIA) device. Several months ago, FDA issued a draft guidance document concerning the need for these complex molecular tests to meet pre-market review and post-market device requirements even when the tests are developed and used by a single laboratory. Although FDA regulates diagnostic tests sold to laboratories, hospitals and physicians, it uses discretion when regulating tests developed and performed by single laboratories.
US FDA will hold a public meeting on February 8, 2007 to discuss its draft guidance document describing its regulatory approach to this type of test, the release added.
"There have been rapid advances in microarrays and other pioneering diagnostics, and a corresponding increase in the use and impact of these complex tests. This has prompted FDA to take a closer look at the potential risks as well as the benefits associated with such tests when they are developed and used in laboratories," remarked Steven Gutman, M.D., Director, Office of In Vitro Diagnostic Device Evaluation. "This test clearance takes into account the development of these innovative technologies and ensures public health by carefully evaluating their performance."
Prior to clearance, FDA requested evidence that the MammaPrint had been properly validated for its intended use. Agendia submitted data from a study using tumour samples and clinical data from 302 patients at five European centres. These studies confirmed that the test was useful in predicting time to distant metastasis in women who are under age 61 and in the two earliest stages of the disease (Stage I and Stage II) and who have tumour size equal to or less than five centimeters and no evidence that the cancer has spread to nearby lymph nodes (lymph node negative). FDA plans to publish a special controls guidance document within the next 60 days describing types of data that should support claims for genetic profiling for breast cancer prognosis.
According to the American Cancer Society, an estimated 178,480 new cases of invasive breast cancer will be diagnosed among women in the United States this year and over 40,000 women are expected to die from the disease.