CancerCompass message board discussion started by Gdpawel on 3/6/2007 http://www.cancercompass.com/message-board/message/all,10113,0.htm Thu, 24 Jul 2008 00:00:00 GMT Thu, 24 Jul 2008 00:00:00 GMT http://backend.userland.com/rss RSS.NET: http://www.rssdotnet.com/ A new laboratory test that identifies patients who benefit most from targeted cancer drugs was introduced at the annual meeting of the American Society of Clinical Oncology (ASCO) as the test's accuracy is sure to save hundreds of lives per year. This could help solve the problem of knowing which patients can tolerate costly, new treatments and their harmful side-effects. The "smart" drugs do not work for everyone, and a test to determine the efficacy of these drugs in a patient could be the first crucial step in personalizing treatment to the individual.According to Chemical & Engineering News, targeted "small-molecule" therapies ruled at the annual ASCO meeting of oncologists. The most exciting results shown came from studies of multitargeted tyrosine kinase inhibitors, small molecules that act on multiple receptors in the cancerous cells, like Tykerb and Sutent. The trend is away from the monoclonals to the small molecules, a trend which the new EGFRx™ Assay may be able to hasten.The EGFRx™ Assay will test molecularly-targeted anti-cancer drugs therapies Iressa, Tarceva, Sutent and Nexavar, because of being small molecules. The monoclonal antibodies like Herceptin and Erbitux are "enormous" molecules. These very large molecules don't have a convenient way of getting access to the large majority of cells. Plus, there is multicellular resistance, the drugs affecting only the cells on the outside may not kill these cells if they are in contact with cells on the inside, which are protected from the drug. The cells may pass small molecules back and forth.However, drugs like Avastin (although a monoclonal antibody) can be tested with the EGFRx™ Assay because the target of Avastin is not the cells themselves, but rather a hormone (VEGF) secreted by the tumor cells. The Avastin complexes with free VEGF and blocks its action. The EGFRx™ Assay can discriminate between the activity of different targeted drugs and identify situations in which it is advantageous to combine the targeted drugs with other types of cancer drugs. All the more reason to "test the tumor first."Most patients are treated not with a targeted therapy drug alone but with a combination of chemotherapy drugs. Therefore, existing DNA and RNA tests do not reflect the way cancer medicine is practiced today. The EGFRx™ Assay, developed by The Weisenthal Cancer Group relies upon a technique known as "Whole Cell Profiling" in which living tumour cells are removed from an individual cancer patient and exposed in the laboratory to the new drugs.A variety of metabolic and apoptotic measurements are then used to determine if a specific drug was successful at killing the patient's cancer cells. The whole cell profiling method differs from other tests in that it assesses the activity of a drug upon combined effect of all cellular processes, using several metabolic (cell metabolism) and morphologic (structure) endpoints, at the cell "population" level (measuring the interaction of the entire genome), rather than at the "single cell" level. Other tests, such as those which identify DNA or RNA sequences or expression of individual proteins often examine only one component of a much larger, interactive process.Over the past few years, researchers have put enormous efforts into genetic profiling as a way of predicting patient response to targeted therapies. However, no gene-based test can discriminate differing levels of anti-tumor activity occurring among different targeted therapy drugs. Nor can an available gene-based test identify situations in which it is advantageous to combine a targeted drug with other types of conventional cancer drugs. So far, only Whole Cell Profiling has demonstrated this critical ability.Not only is this an important predictive test that is available "today," but it is also a unique tool that can help to identify newer and better drugs, evaluate promising drug combinations, and serve as a "gold standard" correlative model with which to develop new DNA, RNA, and protein-based tests that better predict for drug activity.These "targeting" drugs are expensive, costing patients and insurance carriers $5,000 to $7,000 or more per month of treatment. Patients, physicians, insurance carriers, and the FDA are all calling for the discovery of predictive tests that allow for rational and cost-effective use of these drugs.The Whole Cell Profiling approach, holds the key to solving some of the problems confronting a healthcare system that is seeking ways to best allocate available resources while accomplishing the critical task of matching individual patients with the treatments most likely to benefit them.Source:http://weisenthal.org/ex_targeted_egfr_kinase.pdf http://weisenthal.org:80/slide.057.jpg http://weisenthal.org:80/slide.058.jpg Gdpawel Tue, 06 Mar 2007 00:00:00 GMT Medicare Contractor Establishes Reimbursement Coverage Policy for Cell Culture Assay Tests <p>National Heritage Insurance Company (NHIC), the contractor that administers Medicare programs in California, has established a positive coverage policy for Cell Culture Assay Tests known as Chemosensitivity (Resistance) Testing for a tumor specimen from a Medicare patient obtained anywhere within the United States, but submitted for testing by one of the approved laboratories located within California. Medicare bills for Chemosensitivity (Resistance) Testing are billed through NHIC because the test is conducted by the approved laboratories in California. <p>The Chemosensitivity (Resistance) Test can help see what treatments have the best opportunity of being successful for "high" risk cancer patients. The test measures the response of "live" tumor cells to drug exposure. Following this exposure, the assays measure both cell metabolism and cell morphology (Functional Profiling). The integrated effect of the drugs on the whole cell, resulting in a cellular response to the drug, measuring the interaction of the entire genome. Assays based on "cell-death" occur in the entire population of tumor cells. <p>This cell culture assay technology has been clinically validated for the selection of optimal chemotherapy regimens for individual patients. It is a laboratory analysis based on tumor tissue profiling that uses "fresh" human tumor biopsy or surgical specimen to determine which drugs or combinations of chemotherapeutic agents have the highest likelihood of response for individual cancer patients. <p>Following the collection of "fresh" tumor cells obtained from surgery or tru-cut needle biopsies, a cell culture assay is performed on the tumor sample to measure drug activity (sensitivity and resistance). This will pinpoint which drug(s) are most effective. Tissue, blood, bone marrow, and ascites and pleural effusions are possibilities, providing tumor cells are present. At least one gram of fresh tissue is needed to perform the tests, and a special kit is obtained in advance from the lab.The treatment program developed through this approach is known as assay-directed therapy. <p>Individualized assay-directed therapy is based on the premise that each patient's cancer cells are unique and therefore will respond differently to a given treatment. This is in stark contrast to standard or empiric therapy, which chemotherapy for a specific patient is based on average population studies from prior clinical trials. <p>The decision had been made that the assay is a perfectly appropriate medical service, worthy of coverage on a non-investigational basis. What is of particular significance is that they abandoned the artificial distinction between "resistance" testing and "sensitivity" testing and are providing coverage for the whole FDA-approved kit. Drug "sensitivity" testing is merely a point a little farther along on the very same continuum which "resistance" testing resides. <p>Cell cuture assay tests based on "cell-death" have proven very effective in identifying novel treatment combinations for a variety of cancers. The value of cell-death assays is that they can and do accurately predict clinical outcomes and define novel chemotherapeutic synergies. It can help see what treatments will not have the best opportunity of being successful (resistant) and identify drugs that have the best opportunity of being successful (sensitive). <p>The current clinical applications of in vitro chemosensitivity testing is ever more important with the influx of new "targeted" therapies. Given the technical and conceptual advantages of "functional profiling" of cell culture assays together with their performance and the modest efficacy for therapy prediction on analysis of genome expression, there is reason for renewed interest in these assays for optimized use of medical treatment of malignant disease. <p>The payment provided will be sufficiently realistic that all Medicare patients for whom this testing is indicated will be able to get it with only the routine 20% co-payment, as Medi-gap insurance secondaries are mandated to provide payment for co-pays for Medicare-approved services. <p>The coverage became effective for claims for services performed on or after February 19, 2007. The decision is posted at: <p>http://www.medicarenhic.com/cal_prov/policies.shtml http://www.medicarenhic.com/cal_prov/articles/chemoassaytest Gdpawel Sat, 07 Jul 2007 00:00:00 GMT