FDA advisory panel rejects breast device

An FDA advisory panel last week voted unanimously against approving an electrical impedance device designed as an adjunct to mammography.

The Obstetrics and Gynecology Devices Panel of the Medical Devices Advisory Committee voted 10-0 on Aug. 29 against a premarket approval application for the device, called the T-Scan 2000 ED. It was developed by Mirabel Medical Systems, an Israeli company with U.S. headquarters in Austin, TX.

Panel members cited concerns about device's sensitivity, the size and population of the study used to support the company's application, the number of cancers detected among subjects, and risks associated with additional screening events.

The recommendation casts a long shadow over the future of the T-Scan 2000 ED. While not required to implement the decisions of its advisory panels, the FDA usually follows them, particularly when members reach a strong consensus. Executives at Mirabel's Austin headquarters were not available for comment at press time.

In its public hearing on Aug. 29, the FDA panel acknowledged the need for additional tools to help physicians screen women aged 30 to 39, the population for which Mirabel's device is intended. The company failed to present a convincing argument for its approval, however, as indicated by the panel's vote.

Mirabel proposed its T-Scan 2000 ED as a prescreening device for asymptomatic women with a negative clinical breast exam and a negative family history for breast cancer. It is designed to analyze differences in electrical impedance of breast tissue, homing in on cancerous lesions.

The company's pivotal study had two components. One assessed sensitivity by testing a study population "enriched" with biopsy-positive women aged 30 to 45. The second assessed specificity by testing normal 30 to 39-year-old subjects. The panel found the data wanting on both counts.

The panel noted that the FDA showed flexibility when working with the company to develop the study design. Although T-Scan is intended for women aged 30 to 39 who are at low risk for breast cancer, the agency agreed to allow subjects outside those criteria to be added to the sensitivity arm of the study. The research was conducted at multiple sites in the U.S. and Israel.