Chemosensitivity Testing

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Researchers have seen that whether a tumor was a breast tumor, prostate tumor, lung tumor or colon tumor, it didn't correlate to how the cancers interacted with standard anticancer drugs. Their findings suggest that traditional cancer treatments, which have established different drug regimens for lung, prostate or ovarian cancer, for example, should be replaced with therapies that use drugs deemed to be of highest benefit based on the tumor's pharmacologic profile. Treatment choice would be determined by how each patient's tumor reacts to anticancer drugs, regardless of the tumor's anatomical origin.

The drug effect is independent of where the tumor came from in the body. Under current treatment selection methods virtually no chemotherapeutic drug has been successful in more than 50 percent of patients with advanced cancer. But instead of considering a drug that works only ten percent of the time a failure, it would be better to consider such a drug effective for one in ten tumors and to search for the agents among the current orificenal of chemotherapeutic drugs that will work for the rest. Having a good tumor-drug match not only would improve survival rates, it would be cost-effective, and the high cost of the newer cancer therapies reinforces the necessity of choosing the right therapy the first time around.

The introduction of new "targeted" drugs has not been accompanied by specific predictive tests allowing for a rational and economical use of the drugs. Given the technical and conceptual advantages of Cell Culture Assays together with their performance and the modest efficicay of therapy prediction on analysis of genome expression, there is reason for a renewal in the interest for these for optimized use of medical treatment of malignant disease.

Clinical study results published at the annual meeting of the American Society of Clinical Oncology (ASCO) show that a new laboratory test, called EGFRx™, has accurately identified patients who would benefit from treatment with the molecularly-targeted anti-cancer therapies. The finding is important because the EGFRx™ test, which can also be applied to many emerging targeted cancer drugs, could help solve the growing problem of knowing which patients should receive costly, new treatments that can have harmful side-effects and which work for some but not all cancer patients who receive them. The test 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.

The new test relies upon what is called "Functional Profiling" in which living tumor 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 combined metabolic and morphologic endpoints. 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.

The whole cell profiling method makes the statistically significant association between prospectively reported test results and patient survival. Using the EGFRx™ Assay and the "functional profiling" method, can correlate test results which are obtained in the lab and reported to physicians prior to patient treatment, with significantly longer or shorter overall patient survival depending upon whether the drug was found to be effective or ineffective at killing the patient's tumor cells in the laboratory.

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 has been described that 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 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.

Genomic testing is not the answer, without cell culture analysis. In developing a program to discover gene expression microarrays, which predict for responsiveness to drug therapy, the way to identify informative gene expression patterns is to have a gold standard and that cell culture assays are by far the most powerful, efficient, useful gold standard to have.

The assay is the only assay that involves direct visualization of the cancer cells at endpoint. This allows for accurate assessment of drug activity, discriminates tumor from non-tumor cells, and provides a permanent archival record, which improves quality, serves as control, and assesses dose response in vitro (includes newly-emergent drug combinations).

http://weisenthalcancer.com/Patient%20Pages/QuickFacts.htm

http://weisenthalcancer.com/Patient%20Pages/cytoRxpatients.htm

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A new class of anti-cancer drugs selectively targets cells within the body that have a specific molecular defect that is believed to cause dangerous cell behaviors such as uncontrolled proliferative growth and high metastatic potential - behaviors that typically are associated with aggressive cancer. The defect occurs within the interior of the cell in a region that is called the tyrosine kinase domain and it involves a complicated chemical process called EGFR signaling.

The drugs are called anti-EGFR drugs or tyrosine kinase inhibitors. When the drugs work, they can be highly beneficial, causing tumor shrinkage or promoting stable disease and extending survival. However, as with most of the newer, targeted therapy drugs, tyrosine kinase inhibitors only work for a small percentage of the patients who receive them. In various studies, response rates in single agent and combined anti-EGFR drug therapy ranged from around 10% to 66%, depending upon the cancer type and the patient population involved. Further, the drugs are expensive and have been associated with toxic side effects. Finally, to make matters worse, no molecular (gene-based) test has been proven to tell reliably who will benefit from anti-EGFR treatment.

In contrast, the Weisenthal Cancer Group EGFRx™ profile has been shown to correlate highly with patient response to anti-EGFR treatment and with overall patient survival. Reported prospectively, EGFRx™ profile results reliably identified patients who did or did not respond to treatment with anti-EGFR drugs and also those who achieved superior survival after treatment.

The EGFRx™ targeted therapy profile includes analysis of the following targeted drugs: erlotinib (Tarceva), gefitinib (Iressa®), sorafenib (Nexavar®), and sunitinib (Sutent®). For certain types of cancer, a drug called imatinib (Gleevec®), which works in a very different way, may be tested.

http://weisenthalcancer.com/Professionals%20Pages/EGFRxProfessionals.htm

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Medicare Contractor Establishes Reimbursement Coverage Policy for Cell Culture Assay Tests

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 or Oncologic In Vitro Chemoresponse Assays 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 Southern California. Medicare bills for this testing are billed through NHIC because the test is conducted by the approved laboratories in California.

This pre-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.

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.

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.

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.

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.

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).

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.

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.

The coverage became effective for claims for services performed on or after February 19, 2007. The decision is posted at:

http://www.medicarenhic.com/cal_prov/articles/chemoassaytest_0107.htm

NHIC Medicare Services reimburses qualified laboratories in Southern California for cell culture assay tests on a Medicare patient anywhere in the United States.

Likewise, Highmark Medicare Services reimburses a qualified laboratory in Pennsylvania for cell culture assay tests on a Medicare patient anywhere in the United States.

NHIC has jurisdiction over Southern California, so that is who gets billed when the laboratory is located in California.

Highmark has jurisdiction over laboratories in Pennsylvania, so that is who gets billed when the laboratory is located in Pennsylvania.

The coverage decision is posted at:

http://www.highmarkmedicareservices.com/bulletins/partb/news06132007.html