News Release Details

Rockville, MD, July 28, 2009 — Supernus Pharmaceuticals, Inc. today announced that it recently closed a second non-dilutive financing transaction that brings the total funds raised to date against royalties from its partnered products to more than $110 million. In April 2008, the company announced a $75 million transaction secured by royalties generated from partnered products using Supernus technologies.

"We are pleased to be able to raise a significant amount of cash in this challenging environment to further develop our pipeline and accelerate our progress towards becoming a leading specialty pharmaceutical company treating diseases of the central nervous system (CNS)," said Jack Khattar, President and Chief Executive Officer.

"In addition, we have expanded our R&D portfolio to include mazindol as a potential treatment for ADHD," Khattar said. "We have in-licensed significant intellectual property in the ADHD area and believe mazindol could be a promising new treatment."

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 currently has two epilepsy products in late-stage development, with SPN-804 in Phase III and Trokesa^TM expected to enter Phase III in the next few months. Both products are designed to offer epilepsy patients an effective anti-convulsant therapy with much-needed lower side effects and the convenience of once-per-day dosing. In addition, the company is developing a portfolio of three products including mazindol in the ADHD area.

The company's extensive expertise in product development is well proven over the past 19 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^®, which are marketed by Shire or its sub-licensees; and Oracea^® and Sanctura^® XR, which are marketed by Galderma and Allergan, respectively.

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