Release issued 30th January 2009

Rockville, MD, January 30, 2009 – Supernus Pharmaceuticals Inc. today announced the initiation of a Phase IIa U.S. clinical trial of its product candidate SPN810 in the treatment of serious conduct problems in the setting of ADHD. The trial is a proof-of-concept, open-label study with pediatric subjects randomized according to weight group and titrated to receive one of four doses over a six-week treatment period. The primary objective is to measure safety and tolerability, with a secondary measure of efficacy in reducing symptoms of serious conduct problems.

SPN810 is a molecule that has been previously approved in the United States for treatment of other indications. It has a mechanism of action that is promising for the treatment of aggression and serious conduct problems. Serious conduct problems include symptoms of engaging in fights and knowingly destroying property. It has been reported that up to 25% of pediatric patients treated for ADHD exhibit such symptoms.

“Currently there are no products approved for conduct disorder in the setting of ADHD, and SPN810 represents a novel approach to addressing this unmet medical need,” said Jack Khattar, Supernus president and CEO.   “We are excited about the potential of SPN810 and the advancement it may represent for ADHD patients with this condition.  Supernus continues to focus on novel therapies that are designed to bring meaningful benefits to patients with diseases involving the central nervous system.”

About Supernus

Supernus Pharmaceuticals, Inc. is focused on developing specialty CNS products designed to improve patient compliance, reduce side effects, and address unmet medical needs. The company's extensive expertise in product development is well proven over the past 18 years. Supernus started its operations in December 2005 when it purchased significantly all the assets of Shire Laboratories, Inc. Products using the technologies and expertise of Supernus, and when formerly Shire Laboratories, include: Adderall XR®, Carbatrol® and Equetro® that are marketed by Shire or its sub-licensees, Oracea®  and Sanctura® XR that are marketed by Galderma and Allergan, respectively.

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CONTACT:
David A. Theil, CPA
Chief Financial Officer
Supernus Pharmaceuticals, Inc.
Tel: 301 838-2561 www.supernus.com