Orexo AB (Orexo) today announced the successful completion of an acceptability
study comparing Zubsolv (OX219) to Suboxone Film, which is the leading product
for treatment of opioid dependence. The study shows that 9 out of 10
participants would choose Zubsolv over Suboxone Film for a daily treatment.
Zubsolv is a new sublingual tablet formulation of buprenorphine and naloxone for
treatment of opioid dependence. The product is based on elements of Orexo’s
proprietary sublingual platform technology, which comprises enhanced trans
-mucosal absorption of active pharmaceutical ingredients, mucosal micro-particle
adhesion, as well as taste masking, formulated in a rapidly disintegrating
sublingual tablet. These features are important attributes for pharmaceuticals
administered sublingually. Improvement in taste and dissolve time has previously
been associated with an enhanced treatment adherence in opioid dependent
patients(1).

A previous preference study, which compared Zubsolv to the Suboxone Tablet,
demonstrated that 8 out of 1o participants preferred Zubsolv. The current study
was undertaken to assess the acceptability of Zubsolv in comparison to the
Suboxone Film. The study was a cross-over trial in which 28 participants were
given either Zubsolv or Suboxone Film in random order on separate study days.
Key results indicate that Zubsolv was preferred by more than 8 out of 10 of the
participants on all acceptance parameters tested, i.e. overall acceptability,
taste masking, after taste experience, mouth-feel, and ease of administration.
The study also confirmed a fast dissolve time for Zubsolv. When asked
specifically about which product the participants would choose for a daily
treatment, 9 out of 10 participants reported they would select Zubsolv.

Zubsolv has been submitted and has been accepted for review by the FDA, with
approval projected for July 2013 and the US launch being planned for September
2013.

"The positive results in this study are very encouraging, and confirm that
Zubsolv is well positioned to take a substantial share of the growing USD 1.5
billion market for treatment of opioid dependence. I am confident that the
higher acceptability of Zubsolv will translate into an improved treatment
adherence, and that it will aid in attracting a higher proportion of the five
million patients currently suffering from opioid dependence into treatment. ”
said Anders Lundström, President and CEO of Orexo.

On the basis of the results from this study, a comprehensive clinical program
designed to fully explore and document the therapeutic potential of Zubsolv is
being initiated. The first wave of studies will cover treatment initiation,
treatment adherence and patient experiences during treatment of opioid dependent
people with Zubsolv, and will help further differentiate Zubsolv from its
competitors.

For further information, please contact:
Anders Lundström, President and CEO
Tel: +46 706-67 22 66, E-mail: anders.lundstrom@orexo.com

(1) Reckitt Benckiser Pharmaceuticals H1, 2012 presentation. July 2012

About the study
The study was a cross-over trial performed in healthy adult subjects under
Naltrexone block, in which 28 participants were given either Zubsolv or Suboxone
Film in random order on separate days. The study compared a number of important
product attributes including overall product acceptability, taste, aftertaste,
mouth feel and ease of drug administration. Each product attribute was scored by
all study participants using a visual analog scale (VAS).

About Zubsolv™
Zubsolv is a novel sublingual formulation of buprenorphine and naloxone using
Orexo’s extensive knowledge in sublingual technologies. Zubsolv is intended for
maintenance treatment of people suffering from opioid dependence. Through
application of its proprietary technologies Orexo has increased the
bioavailability of the active ingredient, accelerated dissolve time, reduced
tablet size and improved taste resulting in a preference of Zubsolv in
comparison with Suboxone tablet. Zubsolv has the potential to be the first new
entrant into a growing USD 1.5 billion market, with more than five million
patients suffering from opioid dependence and where a majority of patients are
not adequately treated today. Market potential for Zubsolv is at peak estimated
at above USD 500 million in sales annually.

About Orexo
Orexo AB is an emerging specialty pharma company developing improved treatments
using proprietary drug delivery technology. Orexo’s expertise is within the area
of reformulation technologies and especially sublingual formulations. The
company has a portfolio of revenue-generating US and EU approved products
currently marketed under license and a pipeline of several reformulations of
approved compounds for areas of unmet medical need. Orexo also has collaboration
projects with several international pharma companies. Orexo AB, with its
headquarters in Sweden, is listed on NASDAQ-OMX. The largest shareholders are
Novo A/S and HealthCap.

For more information about Orexo please visit www.orexo.com.

Orexo is required under the Financial Instruments Trading Act to make the
information in this press release public. The information was submitted for
publication at 08:00 am CET on November 28, 2012.