Medical Device Daily
Ciphergen Biosystems (Fremont, California) reported Thursday on the publication of data validating the use of its protein biomarkers to discriminate between women with ovarian cancer from women with benign ovarian tumors and other non-gynecologic diseases.
The study data appear in the current issue of Cancer Epidemiology, Biomarkers & Prevention.
Eric Fung, MD, PhD, Ciphergen's chief scientific officer, told Medical Device Daily, “Basically, what this study has shown is that the markers we're pursuing are first of all validated in an independent population, and I think whenever clinicians and laboratorians want to assess the quality of a test they want to make sure that the markers have been validated over and over again.”
The company said that using its SELDI Protein Chip technology — its platform for the rapid discovery and assaying of biomarkers toward the detection of disease, primarily for oncology — the new study successfully reproduced findings from an earlier study, only this time in an independent study population.
For the independent population study, the power of the markers was evaluated in terms of their ability to discriminate 42 women with ovarian cancer from 65 women with benign ovarian tumors and 76 women with gastrointestinal disorders.
The earlier study compared women with ovarian cancer and healthy controls.
A class prediction algorithm, using the markers in combination with age, had specificity of 94.3% and sensitivity of 78.6%
As in the previous study, Ciphergen said the current study demonstrated that the markers it is using “improved specificity in distinguishing ovarian cancer from other diseases, including benign ovarian disease.”
“Many women have ovarian tumors, but the vast majority of these ovarian tumors are benign,” Fung said. “The challenge is to find out which of these women with ovarian tumors actually have cancer.”
Ciphergen is in an alliance with Quest Diagnostics (Lyndhurst, New Jersey), which will be pursuing an approval path under Analyte Specific Reagent guidance from the FDA for this type of test, Fung said. Simultaneously, Ciphergen will be pursuing a pathway to FDA approval of such as test as an in vitro diagnostic. It said it will do that by conducting a prospective clinical trail to support an FDA submission.
Although Fung said he could not give a specific timetable for completion, Ciphergen hopes to submit its application for clearance to the FDA in 2007.
The data collected in this most recent study also “are helpful in shedding some light into how these markers might have even more broad use,” particularly in the area of gastrointestinal disorders, Fung told MDD. For example, he said, ovarian cancer is often called the “silent killer,” because women appear to be asymptomatic when they are diagnosed with the disease, often at a very late stage.
“It turns out that if we do some questionnaires with women who have had ovarian cancer and [ask them] to recall their symptoms that they have had even before the diagnosis…” they often say that they actually had gastrointestinal symptoms, such as bloating or constipation, as well as urinary symptoms. He added that “there is good literature” supporting this type of subtle but fairly definitive early symptomology.
“I think that what that means is that ovarian cancer is not the silent killer that is sort of known to be,” he said.
Ciphergen's research program in the area of ovarian cancer is focused on three different uses of the biomarkers. The lead candidate is a test to distinguish between ovarian cancer tumors and benign ovarian cancers, which this current study supports. A second test is one for predicting recurrence of ovarian cancer and outcome. The third test being investigated is one for monitoring women considered through other methods to be at high risk of developing ovarian cancer.
Ciphergen describes its ovarian cancer as “an advanced diagnostic program” with a panel of biomarkers that provides risk stratification information for ovarian cancer based on a series of studies involving more than 2,000 clinical samples from more than five sites.
Collaborators with Ciphergen on its diagnostic program include the John Hopkins School of Medicine (Baltimore), the University of Texas M.D. Anderson Cancer Center (Houston), University College London, and the University of Kentucky (Lexington, Kentucky).