Orexo confirms Canadian Regulatory Filing of Abstral

Uppsala, February 4, 2010 – Orexo AB (STO: ORX) today confirms that its partner, ProStrakan Group plc (LSE: PSK) has announced that the New Drug Submission made by their Canadian partner, Paladin Labs Inc., for AbstralTM has been accepted for review by Health Canada, the Canadian Government Department with responsibility for public health. AbstralTM, developed by Orexo AB is a new, rapidly disintegrating, sublingual formulation of fentanyl, a long-established opioid used for the management of episodes of breakthrough pain experienced by cancer patients who are already receiving opioid analgesics for their chronic pain. The submission has been granted priority review status by Health Canada and review of the application is therefore expected to conclude in 180 days. Commenting on today’s announcement, Torbjörn Bjerke, Orexo’s President and CEO, said: “AbstralTM is currently helping thousands of patients in Europe and the submission in Canada is another important step towards international marketing of the product.” For further information, contact: Torbjörn Bjerke, President and CEO Tel: +46 (0)708-66 19 90 E-mail: torbjorn.bjerke@orexo.com Claes Wenthzel, Executive Vice President and CFO Tel: +46 (0)708-620 122 E-mail: claes.wenthzel@orexo.com About AbstralTM AbstralTM is a fast-disintegrating tablet for sublingual administration of fentanyl, intended for the management of breakthrough cancer pain in patients who are already receiving opioid analgesics. It is based on Orexo’s unique and patented sublingual tablet technology in which a rapidly disintegrating tablet is placed under the tongue and the active substance is absorbed by the mucous membrane. Currently AbstralTM is sold in Sweden, UK, Germany, Spain, Greece and France. An NDA for AbstralTM has been filed in the US by the partner ProStrakan and in Japan the product is being prepared for registration by the partner Kyowa Hakko Kirin. About Orexo Orexo is a pharmaceutical company focusing on developing treatments for pain and inflammation. The company has four products on the market as well as a broad project portfolio in late stages of development. Sales and product development are mainly carried out through worldwide partnership agreements with larger pharmaceutical companies. Orexo has 108 employees, and has its head office located in Uppsala, Sweden. More information can be found at www.orexo.com. Note: This is information that Orexo AB (publ) is required to disclose pursuant to the Swedish Financial Instruments Trading Act and/or the Swedish Securities Markets Act. The information was provided for public release on February 4, 2010 at 12:00 CET.