By Lisa Seachrist
GAITHERSBURG, Md. - An FDA advisory panel unanimously refused to recommend Zila Inc.'s OraTest for approval to help physicians and dentists detect malignancies in suspicious-looking oral pharyngeal lesions.
Citing numerous protocol violations and missing data, the Oncologic Drugs Advisory Committee voted 13-0 to deny the Phoenix-based company's request to endorse the two-step oral rinse designed to aid in detecting all sites of cancer, defining borders of cancerous lesions and selecting sites for biopsy. In addition, the panel had problems with the fact that the company was going after an indication it wasn't testing.
"The company is using a screening study to support an indication as a diagnostic aid," said panel member David Johnson, director of medical oncology at Vanderbilt University Medical School in Nashville. "There is a serious need for this indication, but the company needs to do the study to test that."
OraTest is a two-step mouth rinse that uses toluidine blue dye (tolonium chloride) to specifically stain cancerous cells as compared to normal cells. The company is working on the test because malignant and benign lesions in the oral cavity can be deceptively similar in appearance.
Because most of the lesions are benign, physicians and dentists are more likely to assume the lesions are benign and choose not to biopsy. As a result, by the time oral carcinoma is diagnosed, more than 50 percent of the lesions are late-stage malignancies that require extensive and disfiguring surgery.
The company likened OraTest to the Pap smear that has turned cervical cancer into a very curable disease via early detection.
During its presentation, Zila gave little data to support its marketing request, relying on case study reports. The FDA identified 17 lesions out of 367 patients that served as the basis for the company's application. Ken Kobayashi, FDA reviewer for the application, highlighted the multiple protocol violations and large amount of missing data and concluded in his presentation that the study "provided little support for the indication."
"The data are wholly inadequate," Johnson said. "I can not think of a single credible scientific organization that would accept this data to support its conclusions. I don't see how we can approve this."
The panel, however, did encourage the company to complete its screening study adhering to protocol, noting the need for the product.
Zila's stock (NASDAQ:ZILA) plummeted 44 percent in the last hour of trading Wednesday as news of the panel's assessment reached Wall Street. The stock closed at $5.375, down $4.25. n