Clinical Data From the Pivotal Penumbra Stroke Trial Presented at the International Stroke Conference's Late Breaking Science Session

Business Wire, Feb 22, 2008

A New Generation of Mechanical Devices for Clot Removal in Acute Ischemic Stroke Patients Establishes New Standards for Safety and Efficacy.

NEW ORLEANS -- Clinical results from the pivotal trial of the Penumbra System were presented today at the 2008 ASA International Stroke Conference in New Orleans by Dr. Cameron McDougall, Chief of Endovascular Neurosurgery at Barrow Neurological Institute, on behalf of the Penumbra Stroke Trial investigators.

The Penumbra Stroke Trial is a prospective, single arm, multi-center trial that enrolled 125 patients at 24 international centers. Patients in the trial presented within 8 hours from symptom onset, had an NIH Stroke Scale (NIHSS) score of [greater than or equal to] 8, and a complete occlusion of a large intracranial vessel. In December 2007, based on the results of this pivotal trial demonstrating the Penumbra System to be a safe and effective treatment for the removal of intracranial occlusions, FDA granted 510(k) clearance of the Penumbra System for revascularization of intracranial vessels in patients with acute ischemic stroke.

Primary endpoints, analyzing revascularization efficacy and device safety, as well as their comparative historical controls were prospectively defined and agreed upon with FDA prior to the start of the trial. They were: revascularization of the occluded vessel, and procedure and device-related serious adverse events. Results showed an 81.6% rate of revascularization (TIMI score 2 or 3) of the occluded vessel verses the 48.2% historical control (p < 0.0001), and a 3.2% procedural serious adverse events (SAE) rate verses the 7.1% historical control. There were no device-related SAEs and no SAEs were attributed to device malfunction or breakage. All angiographic and clinical results were adjudicated and reviewed by an independent core laboratory, clinical events committee and safety monitoring board.

Secondary endpoints, analyzing clinical and functional outcome, included symptomatic intracerebral hemorrhage in 14 out of 125 (11.2%) patients, asymptomatic intracerebral hemorrhage in 21 out of 125 (16.8%) patients, [greater than or equal to] 4 point improvement in NIHSS at discharge achieved by 57.8% of patients, modified Rankin Score (mRS) [?] 2 at 90 days achieved by 25% of patients, and all cause mortality of 26.4% and 32.8% at 30 and 90 days respectively. The clinical and functional outcomes in this 125 patient cohort are in the range of previously published data on treatment outcome in acute stroke. Penumbra is currently considering clinical trials with a randomized, concurrent control arm that would generate relevant data about the treatment effect of the Penumbra System on such clinical and functional endpoints.

The 103 patients out of 125 (81.6%) whose intracranial vessels were opened by the Penumbra System had better results across every measure of clinical and functional outcome including modified Rankin Score [?] 2 at 90 days, [greater than or equal to] 4 point improvement in NIHSS at discharge, and 30 and 90 day mortality, than the patients not revascularized. This finding confirms results from previously published studies that consistently demonstrate better outcomes for patients whose vessels are opened following a stroke, rather than remaining closed.

The Penumbra System is a package of tools used by neuro interventional specialists to remove clots from the large vessels of the brain that are causing a stroke. It works on the proximal surface of the occlusion, optimizing safety and eliminating the need for navigation beyond the clot. The Penumbra System is comprised of an aspiration platform containing multiple devices that are size-matched to the specific neurovascular anatomy allowing clots to be gently aspirated out of intracranial vessels.

The Penumbra System is CE Marked and has been commercially available in Europe since June, 2007. After receiving FDA clearance in December, 2007, it is now commercially available in the United States.

ABOUT PENUMBRA

Penumbra, Inc. (www.penumbrainc.com) is a medical device company committed to delivering clinically beneficial products that help patients suffering from stroke and other neurovascular diseases. Penumbra's global headquarters is located in the east San Francisco Bay city of San Leandro, California with sales operations in the United States, Europe.