HOUSTON, May 25 /PRNewswire-FirstCall/ -- Cyberonics, Inc. today announced that data from two recent brain imaging studies of patients with VNS Therapy for treatment-resistant depression (TRD) were presented at the annual American Psychiatric Association meeting May 20-25, 2006 in Toronto, Canada. The studies, conducted by Charles R. Conway, M.D., Assistant Professor of Psychiatry and Medical Director, Adult Inpatient Psychiatry Unit, Saint Louis University School of Medicine, provide new insight into the acute and long-term effects of VNS (vagus nerve stimulation) Therapy on the brain and add to the increasing body of evidence regarding the VNS Therapy(TM) mechanism of action in TRD.
The first study, entitled “Cerebral Blood Flow During Vagus Nerve Stimulation for Depression,” used positron emission tomography (PET) scans to identify regions of the brain showing changes in regional cerebral blood flow (rCBF) in response to acute vagus nerve stimulation in patients with TRD. Statistically significant, VNS-induced increases in rCBF were seen in 12 brain regions, and decreases were seen in nine brain regions. The significant increases in blood flows occurred in brain regions identified with metabolic abnormalities in mood disorders.
The second study, entitled “Subacute and Chronic Brain Metabolic Change with Vagus Nerve Stimulation in Depression,” utilized fluorodeoxyglucose (FDG) PET scans to demonstrate longer-term (3, 6, 12 months and again at 24 months) metabolic changes in brain regions as the result of VNS Therapy. The results of this study showed that subacute and chronic VNS causes different patterns of metabolic change consistent with “evolving” brain change. Activation/deactivation occurred in regions of the brain previously identified as along the pathway of the vagus nerve and demonstrated to be involved in mood disorder treatment responses to other treatment modalities (e.g., ECT, pharmacotherapy).
“This research advances our understanding of the short and long-term mechanisms of action of VNS Therapy as an effective antidepressant treatment,” commented Dr. Conway. “Our acute findings are consistent with prior brain imaging studies demonstrating that acute VNS Therapy modulates activities in the areas of the brain implicated in mood disorders. Our long-term findings importantly identify a new rationale for the unique sustained and improving response observed in patients with TRD treated with VNS Therapy.”
“These new research findings add to a growing body of mechanism of action data that improve our understanding of how VNS Therapy produces its antidepressant effects and how VNS Therapy’s mechanism of action is distinct from other antidepressant treatments,” added Richard L. Rudolph, M.D., Vice President, Clinical and Medical Affairs and Chief Medical Officer for Cyberonics. “Cyberonics has a long-standing commitment to mechanism of action research on VNS Therapy. We are currently sponsoring a significant number of mechanism of action studies at renowned research institutions to further elucidate the biological effects of VNS Therapy and identify potential opportunities to improve its effectiveness and expand its use into additional indications.”
In July 2005, the FDA approved VNS Therapy as an adjunctive long-term treatment of chronic or recurrent depression for patients 18 years of age or older who are experiencing a major depressive episode and have not had an adequate response to four or more adequate antidepressant treatments. VNS Therapy is the first FDA-approved implantable device-based treatment for depression and the first treatment developed, studied, approved and labeled specifically for patients with TRD. Peer-reviewed data published in Biological Psychiatry and the Journal of Clinical Psychiatry confirm the association of VNS Therapy with significant antidepressant benefits that are sustained and/or increase over time for patients with chronic or recurrent treatment-resistant depression.
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Information on Cyberonics, Inc. and VNS Therapy is available at http://www.cyberonics.com and http://www.vnstherapy.com .
Cyberonics, Inc.
CONTACT: Helen Shik, Vice President of Schwartz Communications,+1-781-684-0770, or fax, +1-781-684-6500, or hshik@schwartz-pr.com , forCyberonics, Inc.
