A prospective study slated for publication has demonstrated that Precision Therapeutics' ChemoFx test was able to predict whether ovarian cancer patients would live longer if they took a particular chemotherapy.
The study, accepted for publication in Gynecologic Oncology, found that recurrent ovarian cancer patients treated with a chemotherapeutic that the ChemoFx test predicted they would be "sensitive" to lived 14 months longer than patients who received a chemotherapeutic to which the test determined they would likely not be sensitive. Overall, the study found a 65 percent improvement in overall survival between the two groups.
Precision Therapeutics is hoping that the results from the prospective study will spur further adoption of ChemoFx and convince payors to more readily reimburse for the test.
Precision Therapeutics currently has Medicare coverage for ChemoFx, and the company states on its website that the test has been reimbursed by 450 commercial insurance companies. However, it isn't clear how many contracts Precision Therapeutics has with commercial payors.
UnitedHealthcare's July 2013 medical policy for chemosenstivity and chemoresistance assays, such as ChemoFx, states that such tests are "unproven" for predictive response to chemotherapy. "Well-designed prospective, randomized controlled clinical trials are needed to determine the impact of chemosensitivity and chemoresistance assays on tumor response and patient survival," UHC notes in its policy.
Aetna also considers chemosensitivity assays "experimental and investigational" and highlights the need for more evidence for coverage.
"With this new prospective data on ChemoFx, which demonstrates an overall survival advantage of over a year, we expect to achieve two things: Conclusively demonstrate the value of this personalized medicine test's impact on the treatment of cancer to the clinical community and demonstrate to payors the value that technology of this nature can have in the treatment of cancer," Precision Therapeutics CEO Sean McDonald told PGx Reporter.
Conducted in collaboration with the Yale University School of Medicine and 30 other cancer centers across the US, researchers prospectively collected tissue samples from more than 260 women with persistent or recurrent ovarian cancer for analysis by ChemoFx. Patients' oncologists in the trial were blinded to the results from ChemoFx and used their clinical judgment to place the patients on one of 15 protocol-designated chemotherapies.
Meanwhile, for each of the treatments assigned to the patients, ChemoFx predicted whether a patient was likely to be "sensitive," have an "intermediate" response, or be "resistant" to it. Researchers then monitored patients for overall survival and progression-free survival, and gauged the difference in these outcomes between two groups: patients who were assigned treatments by their oncologists that they were likely to be "sensitive" to as determined by ChemoFx and those that received treatments for which ChemoFx determined they would not respond well.
The study found that patients treated with agents deemed "sensitive" by ChemoFx experienced a median progression-free survival of 8.8 months versus 5.9 months for those patients treated with "intermediate" and "resistant" chemotherapies. Mean overall survival was 35.5 months for the "sensitive" group compared to 23.9 months for the "intermediate" and "resistant" groups. There was no difference in outcomes between patients in the ChemoFx-determined "intermediate" and "resistant" treatment groups.
Based on these results, the researchers led by Thomas Rutherford at the Yale School of Medicine concluded that ChemoFx accurately characterized chemotherapeutic responses for patients with tumors that were sensitive or resistant to platinum-based chemotherapies. The ability of ChemoFx to gauge treatment response was independent of other influencing factors in multivariate analysis, they wrote in an abstract.
ChemoFx is a live cell test that determines whether patients with various gynecologic cancers, specifically ovarian, endometrial, cervical, and gynecologic sarcomas, will respond to various chemo treatments. The test "captures the contribution of the genetic and epigenetic factors involved in driving response to a specific therapy," McDonald told PGx Reporter. ChemoFx is a phenotypic assay.
After healthcare providers collect patients' fresh tumor tissue or fluid samples, they are analyzed in Precision Therapeutics' Pittsburgh lab where the cells are grown and the malignant cells are treated with single agents or combination chemotherapies. Then a report is sent to the doctor detailing how each patient's cancer cells responded to the different treatments.
Separately, in addition to ChemoFx results, Precision Therapeutics also provides doctors who request it a comprehensive tumor profile of patients that includes information about specific biomarker pathways that might influence chemotherapeutic response. However, the study published in Gynecologic Oncology only looked at how ChemoFx's response predictions affected ovarian cancer patients' survival.
Precision Therapeutics has received more than 24,000 gynecologic specimens for analysis by ChemoFx in the last two years from more than 1,500 doctors and currently receives specimens from 271 medical institutions. Healthcare providers have used the test to determine patient treatment with 147,000 chemotherapy drugs since 2011.
The company first published data in 2006 in the International Journal of Gynecological Cancer showing that ovarian cancer patients could live longer if oncologists used ChemoFx to inform their choice of which chemotherapeutics to prescribe.
At the 2008 annual meeting of the American Society for Clinical Oncology, researchers led by Thomas Herzog of Columbia University and elsewhere presented data from a retrospective study involving ovarian cancer tumor samples from nearly 200 women that suggested that using ChemoFx to pick chemotherapies for patients could impact their survival.
The company's list price for ChemoFx analysis for one drug is $500, and Medicare reimburses $400 for chemoresponse analysis for a single agent.
Precision Therapeutics is performing the ChemoFx test through its CLIA certified lab in Pennsylvania. According to McDonald, the company currently sells the test with the help of 20 internal sales representatives. "But we are looking at plans to expand that force based on the release of this new data and the launching of two additional genetic oncology products which are set to launch within the next six months," he said.
The company is planning to launch GeneFx Colon and GeneFx Lung. The colon cancer test is a microarray-based diagnostic based on a gene signature that determines if stage II colon cancer patients are at heightened risk of recurrence five years after surgery. The lung cancer test is also a microarray-based gene expression test that assesses whether non-small cell lung cancer patients at higher or lower risk of death after surgery.