Shareholders of Ciphergen Biosystems Inc. watched the stock climb 21.4 percent Monday on news that the company's technology looked promising in detecting early stage ovarian cancer.
The Fremont, Calif.-based firm said its ProteinChip System was used to discover three protein biomarkers that, when combined, form the basis of a clinical assay designed to detect Stage I/II ovarian cancer. Each of the proteins was sequenced and identified with the use of the ProteinChip System. Two are cleaved products of precursor proteins and are present in the serum at a fraction of the concentration of their corresponding full-length proteins. The markers were a processed form of ITIH4, a truncated form of transthyretin and apolipoprotein A1.
"This is one of the largest, most rigorously designed clinical studies that we're aware of to try to find biomarkers associated with a disease," Matt Hogan, Ciphergen's chief financial officer, told BioWorld Today. "And in this case, the disease is one that if you can detect it early, the survival rate is profoundly different than if you catch it late."
Results of the study, performed in collaboration with the Johns Hopkins School of Medicine, were published in the Aug. 16, 2004, issue of Cancer Research. The research stems from work at the Baltimore school's Biomarker Discovery Center, created by Ciphergen about four years ago. Through an evaluation of 503 patients - who either had ovarian cancer, benign pelvic disease or were healthy - findings showed that the pattern of three biomarkers was able to diagnose early stage ovarian cancer with 74 percent sensitivity at 97 percent specificity.
In comparison, Ciphergen said the only available tumor marker for ovarian cancer, CA125, has a sensitivity of about 30 percent to 50 percent for Stage I/II ovarian cancer. It is approved only for monitoring for recurrence after treatment.
"There is no good diagnostic right now for the detection of early stage ovarian cancer," Hogan said, adding that physicians typically discover the disease somewhat by chance, during patient exams for other problems. "So we think this is a very promising piece of data."
Ciphergen's SELDI-based ProteinChip System generated protein-expression profiles from serum from the women, and the combined improvement in sensitivity and specificity is reflected in the higher area under the curve (AUC) of the receiver operator characteristic for the three-marker pattern (AUC=92 percent). The study included purification and identification of the three markers, believed to be host-response proteins, two of which had undergone post-translational modifications.
The company licensed the test from Johns Hopkins, and recruited an additional 1,500 samples to validate the published results. One arm of the larger study will evaluate the three biomarkers' ability to monitor for recurrence after treatment, as CA125 is used.
Data from that arm could be used to establish equivalency to the approved biomarker in order to support FDA approval for monitoring uses, an approval path Hogan said Ciphergen could explore. But he added that such plans are not yet concrete, as the company also might seek approval for diagnosing the disease from the outset.
"This test's likely use in the next couple of years would be for women that are considered at risk for ovarian cancer," Hogan noted. "And more likely, this would be one more tool for a physician who might then go on to a transvaginal ultrasound before making a final decision. It's one more tool for a physician to figure out what to do with a patient, as opposed to use by itself [to suggest] a major decision like surgery."
Prior ProteinChip-related discoveries by Ciphergen and collaborators, both at Johns Hopkins and elsewhere, include biomarkers that can be used for the diagnosis of intra-amniotic infection, pancreatic cancer, Alzheimer's disease and for organ rejection following kidney transplantation.
Ciphergen's stock (NASDAQ:CIPH) gained 58 cents Monday to close at $3.29.