NMT Medical Announces Significant Changes to Its Clinical Trial Plans in the United States

NMT Medical Announces Significant Changes to Its Clinical Trial Plans in the United States

Company Shuts Down PFO/Migraine Trial and Increases Investment in PFO/Stroke Trial that is Nearing Enrollment Completion

BOSTON--(BUSINESS WIRE)--NMT Medical, Inc. (NASDAQ: NMTI) today announced that the Company is closing down its patent foramen ovale (PFO)/migraine trial, MIST II, to focus its resources on its PFO/stroke opportunity. The move is expected to save the Company approximately $14 million over the next two to three years as it redistributes investments originally budgeted for MIST II. As a result of this decision, NMT has ceased patient enrollment in MIST II, which was being conducted at 20 centers in the United States.

“We determined that it was in the best interest of NMT and its shareholders to terminate further enrollment in MIST II to better allocate those resources toward our ongoing stroke initiatives,” said President and Chief Executive Officer John E. Ahern. “MIST II, which was approved by the U.S. Food and Drug Administration (FDA) in September 2005, and redesigned in August 2006, had a rigorous patient screening process. Despite frequent discussions with the FDA and substantial enrollment initiatives designed to accelerate that process, the resulting patient randomization progressed more slowly than anticipated. Even though more than 1,400 patients have been screened for enrollment in the trial, only a handful of those patients have met the requirements to be randomized.”

“Due to the strict enrollment requirements, MIST II has become an expensive endeavor with little likelihood of being completed in a reasonable timeframe,” continued Ahern. “While NMT continues to believe in the relationship between PFO and migraine, it has become clear that an acceptable enrollment dynamic was not possible and completing the study would require more time and financial resources than we are willing to commit at this time. Therefore, we believe it is in the best interest of those involved to close the study. A portion of the savings will be used to further finance CLOSURE I, our pivotal PFO/stroke and transient ischemic attack (TIA) clinical trial nearing enrollment completion in the U.S.”

“The decision to close MIST II was a difficult one, but in light of the enrollment challenges, a necessary and appropriate one,” said Stewart Tepper, MD, Associate Clinical Professor of Neurology at the Yale University School of Medicine and co-principal investigator of the MIST II trial. “The PFO/migraine connection needs to be studied and understood. Future study designs should address patient inclusion/exclusion criteria and their impact on the enrollment process.”

Mark Reisman, MD, Director of Cardiovascular Research at Swedish Medical Center, Seattle, Washington and co-principal investigator of the MIST II trial, added, “We need to identify the patients that have the highest likelihood to benefit from PFO closure. I remain committed to the scientific evaluation of the PFO/migraine connection and am eager to participate in defining future trial designs.”

Ahern said, “We and our research teams continue to recognize a link between PFO and migraine headaches in some patients. In the MIST I study we learned the treatment effect of PFO closure in migraine headache patients supports further investigation. Results from that pilot study which was conducted in the United Kingdom, are currently expected to be published in the peer-reviewed journal, Circulation, early this year. As the leader in the field, NMT remains committed to studying the PFO/migraine connection. We will continue to actively explore other options to investigate this connection outside of the MIST II trial design, particularly in determining which migraine patient subsets benefit from PFO closure. The CLOSURE I stroke/TIA trial includes a migraine sub-study which, when combined with the data from our MIST I and ongoing MIST III studies, will help with our efforts to design a scientifically sound PFO/migraine study that can succeed with patient enrollment.”

“Strategically, reallocating the additional resources to complete the CLOSURE I study is the best decision at this time,” concluded Ahern. “We believe we are on track to be the first to complete enrollment and submit the data for U.S. regulatory approval for a PFO/stroke indication. We received confirmation from an independent interim analysis of CLOSURE I data that the study is appropriately powered to provide a statistically significant result. Positive data from the study will help assure NMT’s continued leadership in addressing the PFO/stroke and TIA market, which we believe is a potential $4 billion opportunity.”

About NMT Medical, Inc.

NMT Medical is an advanced medical technology company that designs, develops, manufactures and markets proprietary implant technologies that allow interventional cardiologists to treat structural heart disease through minimally invasive, catheter-based procedures. NMT is currently investigating the potential connection between a common heart defect that allows a right to left shunt or flow of blood through a defect like a patent foramen ovale (PFO) and brain attacks such as embolic stroke, migraine headaches and transient ischemic attacks (TIAs). A common right to left shunt can allow venous blood, unfiltered and unmanaged by the lungs, to enter the arterial circulation of the brain, possibly triggering a cerebral event or brain attack. More than 27,000 PFOs have been treated globally with NMT's minimally invasive, catheter-based implant technology.

Stroke is the third leading cause of death in the United States and the leading cause of disability in adults. Each year, 750,000 Americans suffer a new or recurrent stroke and an additional 500,000 Americans experience a TIA. The prevalence of migraines in the United States is about 10%. Of the 28 million migraine sufferers in America, those who experience aura and have a PFO may represent a three million patient subset.

For more information about NMT Medical, please visit www.nmtmedical.com.

This press release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements - including statements regarding the MIST I, MIST II, MIST III and CLOSURE I trials, regulatory approvals for the Company's products in the United States, Europe and elsewhere abroad, and the Company's investment in product development - involve known and unknown risks, uncertainties or other factors that may cause actual results, performance or achievements of the Company to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. Factors that may cause such a difference include, but are not limited to, the Company's ability to develop and commercialize new products, a potential delay in the regulatory process with the U.S. Food and Drug Administration and foreign regulatory agencies, as well as risk factors discussed under the heading “Risk Factors” included in the Company's Annual Report on Form 10-K for the year ended December 31, 2006, Quarterly Report on Form 10-Q for the period ended September 30, 2007 and subsequent filings with the U.S. Securities and Exchange Commission.