TARGET'S GUGLIELMI DETACHABLE COIL SYSTEM 510(K) STATUS

TARGET'S GUGLIELMI DETACHABLE COIL SYSTEM 510(K) STATUS is under discussion with FDA following reports from ongoing clinicals of a device problem that "may contribute to the occurrence of an ischemic stroke," the firm said Oct. 5. The 510(k) application, which has been pending at FDA since November 1992, could be affected by design modifications that are being planned to address the problem cited in the reports. The GDC is an electrically detached micro-coil that fills the cavity of an aneurysm, and is believed thereby to promote clotting and to protect against aneurysm rupture. Clinical trial investigators have notified the firm that magnetic resonance imaging examinations of 13 patients have shown artifacts attributable to small metallic particles created during electrolytic detachment of the GDC. Two of the 13 patients with artifacts have experienced ischemic strokes. The reports came from five different investigational sites; three sites reported the particles after Sept. 24 and two prior to that date. "Although inconclusive, the presence of these particles, along with other pre-existing medical conditions, may contribute to the occurrence of an ischemic stroke," the company said in a release. The firm hypothesizes that the problem results from the device's power being left on after electrolytic detachment of the platinum coil, which creates the potential for further electrolysis of the stainless steel stem to which the coil was attached. The electrolysis of the stainless steel can in turn create particles such as those discovered on the 13 MRI examinations. Approximately 1,200 patients at 80 sites worldwide have been treated with the GDC during clinicals over the past three years. Five hundred of these patients have been in the U.S.; the firm's investigational device exemption allows for up to 600 patients at 20 U.S. sites. The firm said "early clinical results from these trials are promising." Since an MRI examination is not included in the standard IDE protocol, Target currently is attempting to determine how many MRIs have been performed on patients and obtain the results from those examinations. The firm informed all GDC clinical investigators of its concerns in a recent letter and left the decision to treat additional patients to the individual physician's discretion. FDA is aware of Target's letter and agrees with this course of action, according to the firm. The company is notifying investigators of the potential for continued electrolysis and is recommending that physicians change their procedures to account for that possibility. One factor in the company's decision to allow continuing procedures is that all patients in the clinicals have high risk or inoperable aneurysms for which there is no suitable therapeutic alternative. To correct the artifact problem, Target is modifying all of its GDCs so that only one electrolytic detachment is necessary. To date, the most frequently used GDC has two points that require detachment. A single detachment version of the device is included under the firm's original IDE and has been used already in a limited number of clinicals. Devices requiring only a single detachment are expected to be shipped to all accounts beginning in January. Target also is planning a second device modification. The company is beginning animal tests with the revised device and expects to "quickly" file a patent application for it. Questions under discussion between Target and FDA include whether the company will need to file a new 510(k) for the modified device or if the company can simply supplement its existing application with additional data. "We expect to work closely with the FDA to ensure the continuation of patient safety throughout the duration of these clinical trials," Target President and CEO Gary Bang said in the release. Bang added that the device problem is likely to affect earnings for the quarter ended Sept. 30 by between $500,000 and $2 mil.