NMT Medical Inc has received conditional approval from the FDA for its pivotal clinical trial to evaluate the effectiveness of transcatheter closure of a common cardiac defect using the Company's proprietary STARFlex cardiac septal repair implant compared to best medical therapy.
Commenting on the approval, John E. Ahern, President and Chief Executive Officer of NMT, said, "The conditional approval allows for patient enrollment into the clinical trial while responding to the FDA's request for additional information, and to answer remaining questions related to the trial. Enrollment is expected to begin sometime after a follow-up meeting with the FDA."
The cardiac defect being evaluated is called a patent foramen ovale (PFO) and, under certain conditions, acts like a flap valve between the right and left atria of the heart. The PFO may allow embolic material in the venous circulation to pass, unfiltered by the lungs, to the arterial circulation where it can then travel to an artery in the brain and potentially cause a stroke or TIA (transient ischemic attack). Stroke is the third leading cause of death in the United States and is the leading cause of permanent disability in adults. The PFO defect may be a contributing factor in over 100,000 patients per year that have suffered a stroke or TIA.
NMT's clinical study, named Closure 1, is designed to evaluate its STARFlex implant's effectiveness in preventing recurrent stroke and TIA in patients after their initial event. The study is expected to enroll 1,600 patients, with half receiving a STARFlex implant, and half receiving traditional medical therapy. Follow up will measure recurrent events over a period of two years.
"This is a landmark study that we expect will answer a fundamental question that neurologists the world over have been asking: Is closing a PFO with an endovascular device better for preventing new strokes than traditional medical therapy?" stated Anthony Furlan, the study's national Principal Investigator.
Dr. Furlan, who is the head of the stroke program at the Cleveland Clinic and was instrumental in developing the study with NMT, emphasized that a superiority study was a requirement. "PFO closure using implants is gaining acceptance for those patients who have failed medical therapy," Furlan continued. "What we now need to know is whether or not STARFlex closure is a better prevention therapy for patients after their first stroke."
More than 80 leading stroke and interventional cardiology centers in the United States have committed to participate in this study. Data management and analysis will be performed by the Harvard Clinical Research Institute (HCRI) in Boston.
Mark Reisman, director of cardiovascular research at the Swedish Medical Center in Seattle and the lead interventional cardiologist investigator of the study, stated, "The enthusiasm I have seen from both neurologists and interventional cardiologists about this study is strong. I am confident that this study will answer the question of which is the better therapy. The list of centers and clinicians involved with this study is impressive. I believe NMT has assembled the right team to design, advise and execute this study."
The procedure to implant STARFlex is a simple procedure. It usually lasts about 30 to 45 minutes and is typically conducted in the cardiac catheterization lab. STARFlex is designed to close the defect with native tissue growing over the implant in about six months. Patients can return to normal activity soon after the procedure. The STARFlex is an advanced design implant, which offers advantages in terms of being able to automatically adjust to variations in PFO and atrial septal anatomy in patients. Over 10,000 PFOs have been closed globally with NMT's implant technology. STARFlex is a third generation design and is commercially available in Europe.