News Release Details

Rockville, MD, January 27, 2010 – Supernus Pharmaceuticals Inc., today announced that its Phase IIa U.S. clinical trial for SPN 810 in children with ADHD and persistent serious conduct problems met the primary endpoints of safety and tolerability, as well as showed statistically significant reduction versus baseline in conduct problems across all doses. The trial was initiated in 2009 and was a proof-of-concept, open-label study in children 6 to 12 years of age, assigned to one of four doses over a six-week treatment period, after 2-5 weeks' titration.

"The product showed reductions of 32% at the lowest tested dose and 55% at the highest tested dose in persistent serious conduct problems with aggression as a key feature," said Dr. Robert Findling, MD, the lead investigator for the study. "This is a clinically meaningful and very encouraging set of data. Serious conduct problems are quite prevalent in children with ADHD and there are currently no approved treatments for this unmet medical need." Results were measured by the conduct problem subscale of the Nisonger Child Behavioral Rating Form (NCBRF)

"We are very excited about these positive results and the future development of SPN 810. The product is one of several programs in our emerging ADHD portfolio," said Jack Khattar, Supernus President and CEO.

Attention-deficit-hyperactivity disorder (ADHD) is characterized by inattention, impulsivity and hyperactivity, and the CDC estimates that 4.5 million school-aged children in the United States have been diagnosed with ADHD. Children with ADHD sometimes also exhibit persistent serious conduct problems, such as maladaptive aggressive behaviors. Untreated, persistent serious conduct problems place these children at risk of persistent aggressive and anti-social behavior, such as knowingly destroying property, physically attacking people, and bullying.

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 20 years. Supernus started its operations in December 2005 when it purchased substantially all the assets of Shire Laboratories, Inc. Products using the technologies and expertise of Supernus, and when formerly Shire Laboratories, include: Adderall XR^®, Carbatrol^®, Equetro^® and Intuniv^TM that are marketed by Shire or its sub-licensees; and Oracea^® and Sanctura^® XR that are marketed by Galderma and Allergan, respectively.

CONTACT:
Russell "Rip" Wilson
Chief Financial Officer
Supernus Pharmaceuticals, Inc.
Tel: 301 838-2522