Questcor Receives FDA Action Letter for H.P. Acthar(R) Gel for Treatment of Infantile Spasms.

UNION CITY, Calif. -- Questcor Pharmaceuticals, Inc. (AMEX:QSC) announced today that it has received a "not approvable" letter from the U.S. Food and Drug Administration (FDA) for H.P. Acthar([R]) Gel (repository corticotropin injection) for the treatment of infantile spasms. The letter indicates that Questcor's Supplemental New Drug Application (sNDA) is not approvable in its current form. As per the FDA's request, the Company will schedule a meeting with the agency to discuss the action letter as soon as possible. Until the Company is able to meet with the FDA, it can not comment on the specifics of the letter. Questcor expects to work closely with the agency to gather the necessary data to support a future approval.

"While we are disappointed that we are unable to add the treatment of infantile spasms to our label at this time, we continue to believe that Acthar Gel represents an essential treatment option for this devastating pediatric condition," said James Fares, Questcor's President and Chief Executive Officer. "We are committed to meeting with the FDA to better understand their requirements and to rapidly initiate the work to resolve their questions as quickly and efficiently as possible. We are also in the process of evaluating our ongoing development and commercial strategies in light of this development."

The sNDA provided clinical data to support the addition of the infantile spasms indication to the current Acthar Gel label. Supportive information included historical data on the use of Acthar Gel in the treatment of infantile spasms, including the results from randomized clinical trials involving greater than 250 patients, which were published in peer-reviewed medical literature.

About Infantile Spasms - Infantile spasms (IS) is a seizure disorder of early childhood also known as West Syndrome. The onset is predominantly in the first year of life, typically between 3 to 6 months. The typical pattern of IS is a sudden bending forward and stiffening of the body, arms, and legs; although there can also be arching of the torso. Spasms tend to begin soon after arousal from sleep. Individual spasms typically last for 1 to 5 seconds and occur in clusters, ranging from 2 to 100 spasms at a time. Infants may have dozens of clusters and several hundred spasms per day. Infantile spasms usually stop by age 5, but are often replaced by other seizure types. Infantile Spasms is characterized by seizures, hypsarrhythmia (abnormal, chaotic brain wave patterns), and mental retardation. Other neurological disorders, such as cerebral palsy, may be seen in 30-50% of those with IS. The incidence of IS is estimated to be about 1 per 2,000 to 4,000 live births. It is the most frequent type of epileptic encephalopathy, the group of conditions in which epilepsy determines cognitive deterioration. No drug is currently approved in the United States for the treatment of IS. Patients diagnosed with this disorder are typically treated with a variety of agents, including Acthar Gel.

About Acthar Gel - H.P. Acthar Gel([R]) is a natural adrenocorticotropic hormone (ACTH) designed to provide a prolonged release after intramuscular or subcutaneous injection. Acthar Gel is currently indicated for the treatment of acute exacerbations of multiple sclerosis, and for several other diseases and disorders.

For full prescribing information and safety information on Acthar Gel, please visit http://www.acthar.com.

About Questcor - Questcor Pharmaceuticals, Inc.([R]) (AMEX:QSC) is a specialty pharmaceutical company that develops and commercializes therapeutics for the treatment of neurological disorders. Questcor currently markets H.P. Acthar([R]) Gel (repository corticotropin injection), an injectable drug indicated for the treatment of exacerbations associated with Multiple Sclerosis and Doral([R]) (quazepam) that is indicated for the treatment of insomnia, characterized by difficulty in falling asleep, frequent nocturnal awakenings, and/or early morning awakenings. For more information, please visit www.questcor.com.

Note: Except for the historical information contained herein, this press release contains forward-looking statements that involve risks and uncertainties. Such statements are subject to certain factors, which may cause Questcor's results to differ from those reported herein. Factors that may cause such differences include, but are not limited to, Questcor's ability to accurately forecast and create the demand for its products, the gross margin achieved from the sale of its products, Questcor's ability to enforce its product returns policy, the accuracy of the prescription data purchased from independent third parties by Questcor, the sell-through by Questcor's distributors, the inventories carried by Questcor's distributors, and the expenses and other cash needs for the upcoming periods, Questcor's ability to obtain finished goods from its sole source contract manufacturers on a timely basis if at all, Questcor's potential future need for additional funding, Questcor's ability to utilize its net operating loss carry forwards to reduce income taxes on the sale of its non-core products, research and development risks, uncertainties regarding Questcor's intellectual property and the uncertainty of receiving required regulatory approvals in a timely way, or at all, other research, development, marketing and regulatory risks, and the ability of Questcor to implement its strategy and acquire products and, if acquired, to market them successfully and find marketing partners where appropriate, as well as the risks discussed in Questcor's annual report on Form 10-K for the year ended December 31, 2006 and other documents filed with the Securities and Exchange Commission. The risk factors and other information contained in these documents should be considered in evaluating Questcor's prospects and future financial performance.

Questcor undertakes no obligation to publicly release the result of any revisions to these forward-looking statements, which may be made to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events.