Precision Therapeutics, Inc presented new data at the 2009 American Society of Clinical Oncologist (ASCO) Annual Meeting support the use of a laboratory test, ChemoFX, to help physicians predetermine the effectiveness of chemotherapy in treating a woman's endometrial cancer. Investigators found a significant correlation between the test results from 405 patient specimens analyzed using ChemoFx and published patient response rates for each chemotherapeutic regimen, suggesting less effective therapies could be eliminated prior to patient administration. Endometrial cancer is the most common gynecologic cancer among women in the US.
Limiting a patient’s exposure to chemotherapy is important, however determining the appropriate treatment the first time for a woman with endometrial cancer can be challenging, said Dr. Warner K. Huh, MD., Lead Investigator and Associate Professor, Division of Gynecologic Oncology, University of Alabama at Birmingham, These data suggest a more targeted approach could be achieved by testing the effect of various chemotherapeutic agents on a woman’s tumor before a therapy is administered to the patient, potentially bypassing use of ineffective therapies.
Published data suggest that individual patients will only respond to a single chemotherapy agent 30 percent of the time and while combination therapy can increase a patient’s response up to 60 percent, finding the combination that will achieve that response can prove difficult. The unintended consequences of ineffective treatment include, but are not limited to, patient exposure to the toxic aspects of the chemotherapy and delay in the patient receiving potentially beneficial treatments. ChemoFx is a test that quantifies an individual cancer patient’s probable tumor response to various chemotherapeutic and biologic agents — providing both sensitivity and resistance information.
We are very pleased with the results of this study and the correlation between the test results generated using ChemoFX and published response rates for commonly used chemotherapy, said Dr. Holly Gallion, MD, Vice President Medical Affairs, Precision Therapeutics, Inc., This is a significant step toward ensuring women receive the most effective chemotherapy, early in the treatment process, with limited exposure to therapies that may provide minimal benefit.
Tumor specimens were collected from December 1, 2007 to July 15, 2008 from 405 consecutive patients with endometrial carcinoma and were tested in vitro for a response using the ChemoFx assay. Tumors were categorized prospectively as responsive , intermediately responsive (IR) or nonresponsive (NR) to each drug or combination of drugs tested. The in vitro response rates were compared to reported response rates from clinical trials.
The International Federation of Gynecology and Obstetrics (FIGO) stage distribution was 171 stage I patients, 32 stage II patients, 106 stage III patients, 57 stage IV patients, 37 recurrent patients, and 2 unknown patients. The assay was successfully completed for 360 (89 percent) cases. The majority of tumors (73 percent) exhibited varying degrees of responsiveness to different drug(s). No significant difference in response rate was observed between primary and recurrent tumors or between stage I/II and III/IV tumors.
In vitro tumor response rates were similar to reported treatment response rates for all treatments except single-agent carboplatin. Investigators concluded that a drug response marker can provide clinically useful information to optimize individual chemotherapy regimens for women with endometrial cancer.