Orexo

Earnings Release • Apr 29, 2008

Press release April 29, 2008

Orexo reports positive results from phase I study for OX19

Data from a phase I study confirms that Orexo's new nasal spray formula for the administration of the desmopressin peptide for incontinence, shows significantly better uptake than nasal sprays currently on the market. Next step for Orexo is to seek partnership for further development of the product.

Many elderly people suffer from nocturia and in particular amongst women, incontinence is a common problem. Treatment with the peptide desmopressin is currently the most effective treatment for many of these patients.

Orexo's ambition is to develop improved drug formulations of desmopressin for a more efficient treatment of nocturia and incontinence. Orexo has developed a new nasal spray formulation for the administration of desmopressin, and results from a recently completed phase I study confirm significantly better absorption for the new nasal spray formulation than for current nasal spray on the market.

In the clinical study, Orexo compared its new nasal powder spray with a current liquid nasal spray in 13 healthy volunteers.

The study showed that the uptake of desmopressin into the blood stream was three times higher than that of the current liquid nasal spray, with no delay in time to reach maximal plasma concentration. The drug concentrations in the blood showed lower variability compared to the reference product. Reduced variability is essential for a reproduceable effect. The study also showed excellent tolerance of both spray formulations and no unexpected adverse events.

The study also included a sublingual tablet formulation. However, the bioavailability of desmopressin did not increase enough to reach the primary objective for the sublingual tablet formula.

"We are pleased with the results of the study. Next step will be to seek a partner for the continued development of the nasal powder formulation of desmopressin.", says Torbjörn Bjerke, President and CEO, Orexo AB.

For more information, please contact: Torbjörn Bjerke, President and CEO, Orexo AB Tel: +46 (0)708-66 19 90 E-mail: torbjorn.bjerke@orexo.com

Claes Wenthzel, Executive Vice President & CFO, Orexo AB Tel: +46 (0)18-780 88 44 E-mail: claes.wenthzel@orexo.com

TO THE EDITORS

About Orexo

Orexo is a pharmaceutical company, focusing on development of new, patented drugs by combining welldocumented substances with innovative technologies, and the development of new treatments for respiratory and inflammatory diseases.

Orexo has a broad and competitive late-stage product portfolio, including two marketed products, five products in clinical phase and two undergoing registration.

To date, Orexo have out-licensed the market rights for Rapinyl for the US, the EU and Japan markets, the worldwide market rights for Sublinox (OX22) and OX-NLA, and a out-license and research collaboration with Boehringer Ingelheim regarding the development of a new class of drugs to treat pain and inflammation. Also, Orexo has established a Nordic sales force by entering into a joint venture with ProStrakan.

Orexo has head office in Uppsala and is listed on the OMX Nordic Exchange Stockholm, Small Cap (ticker: ORX).

www.orexo.com