Cancer diagnostics system developer TriPath Imaging (Burlington, North Carolina) suffered a more than 12% decline in its shares Tuesday after reporting that it was withdrawing for FDA consideration its premarket approval supplement (PMA-S) seeking expanded claims for the FocalPoint GS Imaging System.

The action came after the agency notified the company that the PMA-S must be amended to include additional data to support the intended claims. The additional data was needed due to problems in the handling of slide samples in its clinical trials, the company said.

The company’s shares fell 97 cents to close at $6.87.

Paul Sohmer, MD, TriPath president, CEO and chairman, in a Tuesday morning conference call acknowledged that the withdrawal is “obviously a setback in our efforts to bring a guided screening product to the U.S. market as quickly as possible.” He also acknowledged “a tough competitive battle for market share.”

Though unnamed, that competitor is Cytyc (Marlborough, Massachusetts), developer of the ThinPrep System, used as an adjunctive system for analysis of Pap smear assays. The companies also are doing battle in the courts.

“I would anticipate that the competition will try to use this news to our advantage,” Sohmer said. “However,” he added, “we know that our growing list of lab customers and their clients made the decision to switch to TriPath products, based on their ability to improve the detection of phytological abnormalities with increased operating efficiency.”

He claimed superiority for the company’s Surepath liquid-based Pap test, “because it is scientifically compelling and clinically effective, its use is associated with a significant reduction in cost, and it is the designated collection vehicle for an array of potentially redefining molecular diagnostic products that are currently under development.”

A key reason for the additional data request, the company said, “relates to the use of slides from a previous clinical study along with new slides prepared specifically for the FocalPoint GS clinical trial.”

The FocalPoint GS trial protocol “required that a certain number of abnormal slides be studied. In order to reach that number, new prospective slides prepared specifically for the trial were combined with a group of abnormal slides from a previous clinical study.”

It said that this protocol was part of its “binding agreement” with the FDA but that “it appeared that the new and old slides were interpreted differently by cytotechnologists in the manual screening portion of the trial and the data generated from the new and old slides were too inconsistent to be pooled together for statistical analysis.”
It said it will do further studies on new abnormal slides “to reach the required number of slides that are comprised entirely of new abnormal slides.”

It said also that clinical samples in the trial designated as “High Risk Slides” were handled by the testing laboratories as “Non-High Risk Slides” and so must be evaluated independently.

The company made the PMA-S submission to the FDA in October 2004. With the filing, TriPath submitted data from a prospective, multi-site clinical study designed to evaluate the FocalPoint GS Imaging System-assisted screening of its SurePath liquid-based Pap test.

The FocalPoint GS Imaging System is designed to perform automated primary cervical cytology screening and analysis to distinguish between normal and abnormal Pap smears. “It combines the automated sorting and ranking capability of the currently approved FocalPoint Slide Profiler with FocalPoint GS guided screening of areas of interest on SurePath thin-layer slides,” the company said at the time.

Sohmer said that the company will collect the additional trial data required by the FDA and that it has begun discussions with the agency concerning specific data requirements. He said the talks would be concluded and the new protocol developed “at the earliest possible date.”

He said that the PMA-S could be resubmitted “in 2006,” and that the company will provide a more specific timeline during its 3Q earnings conference call on Nov. 10.

In a statement, the company said it is assessing the financial impact of the PMA-S withdrawal and will provide an update on this issue as well during the 3Q conference call.

Sohmer cited continued progress of early commercialization efforts of its molecular diagnostic products and imaging systems.

“Last month’s marketing clearance of the Ventana Image Analysis System [from Ventana Medical Systems; Tucson, Arizona] when used with tissues stained for HER-2/neu [for breast cancer analysis] is the latest example of the expanding opportunities available to us in this exciting area.”

He reported that the first public presentation of data from studies performed with the company’s cervical cancer slide-based products would take place on Oct. 4 in Paris.

“While we plan to remain aggressive in our cytology business, we are just as focused on realizing the value of our investments in potentially redefining molecular diagnostic products,” Sohmer said. Upcoming conference presentations, he said, “represent an important milestone for our molecular diagnostic product research and development programs.”

An analyst meeting scheduled for Nov. 10 will provide a review of studies of the company’s Pro Ex C molecular markers and an overview of its product pipeline in the area of molecular diagnostic products and imaging systems.

TriPath Oncology, a subsidiary of TriPath Imaging, develops molecular diagnostic products for malignant melanoma and cancers of the cervix, breast, ovary and prostate.