Top-line data from a Phase 3 clinical trial demonstrates that Zubsolv® is as effective as Suboxone® film in the treatment of opioid dependence

Uppsala, Sweden – June 25, 2014 – Orexo announces top-line data from a Phase 3
clinical trial demonstrating that Zubsolv® (buprenorphine/naloxone CIII
sublingual tablet) is as effective as Suboxone® film in the treatment of opioid
dependence. The results from a randomized, non-inferiority, multicenter,
comparative trial (N=758) establish that, despite a 29 % lower dose, Zubsolv
provides equivalent efficacy compared to Suboxone film in patients who are
opioid dependent. The Induction, STabilization, Adherence and Retention Trial
(ISTART) (Study OX219-006), sponsored by Orexo, was the largest trial ever
conducted with buprenorphine (N=758).

The primary endpoint of the ISTART study was retention in treatment at Day 15
with Zubsolv and Suboxone film. The study showed that there was no difference in
retention in treatment at Day 15 [Zubsolv arm: 83% (273/329); Suboxone film arm:
82.5% (269/326)]. As previously announced an additional co-primary endpoint
assessed Zubsolv as a treatment for induction of buprenorphine maintenance
therapy compared to generic buprenorphine monotherapy. There was no difference
in retention at Day 3 [Zubsolv arm: 93.3% (309/329); generic buprenorphine arm:
92.6% (302/326)] in the per protocol set.

Similar improvements for both groups were observed in Clinical Opiate Withdrawal
Scale (COWS), Subjective Opiate Withdrawal Scale (SOWS), and opioid cravings VAS
total scores. Physicians and patients, using the Clinical Global Impression (CGI
-I) and Patient Global Impression (PGI-I) Improvement scales, reported that both
treatments resulted in an average score of “much improved” from baseline at
study end.

“The ISTART study confirms Zubsolv is appropriate and effective for maintenance
treatment of patients with opioid dependence,” said Erik Gunderson, MD, FASAM,
the principle investigator of the study. “When you consider that Zubsolv with a
29% lower dose has similar efficacy to Suboxone film, a preferred taste, child
-resistant packaging, and fast dissolve time, physicians have an important
alternative treatment option in the fight against this public health epidemic.”

Nikolaj Sorensen, Chief Executive Officer of Orexo, noted, “This is another
example of Orexo’s commitment in advancing the treatment of opioid dependence
for the patients who suffer from this disease and in supporting the physicians
who treat them. To our knowledge, this is the largest clinical trial ever
conducted to assess buprenorphine for the treatment of opioid dependence. These
data provide evidence that Orexo’s advanced formulation technology is medically
meaningful and we are proud to offer a product that is efficacious, convenient
and safe at a lower dose, decreasing the amount of buprenorphine available for
diversion. Finally, this comprehensive study indicates that a good clinical
outcome can be obtained using Zubsolv for induction treatment followed by
maintenance treatment. With this data all physicians should feel comfortable
offering and switching their patients suffering from opioid dependence to
Zubsolv from their existing treatment with buprenorphine and naloxone”.

For further information, please contact:
Nikolaj Sorensen, President and CEO
Tel: +46 (0)703-50 78 88, E-mail: ir@orexo.com

About the ISTART Trial
The IStart Trial was a randomized, non-inferiority, multicenter study to assess
early treatment efficacy of Zubsolv versus SUBOXONE film and to explore
switching between treatments. The primary endpoints were retention in treatment
at Day 15 and Day 3. Secondary efficacy assessments included scores on the COWS
and SOWS, and opioid cravings VAS, CGI and PGI improvement from baseline, and
switching between Zubsolv and Suboxone film. 758 opioid dependent adult subjects
were randomized. On days 1 and 2, patients received a blinded, fixed dose of
Zubsolv (5.7/1.4 mg and 5.7/1.4 or 11.4/2.8 mg, respectively) or generic
buprenorphine monotherapy (8 mg and 8 or 16 mg, respectively). On Day 3, the
patients on generic buprenorphine were switched to Suboxone film and patients in
the Zubsolv arm continued to receive Zubsolv. Stabilization doses were titrated
to a maximum daily dose of 17.1/4.2 mg and 24/6 mg for Zubsolv and Suboxone
film, respectively, based upon clinical symptoms.

About Orexo AB
Orexo is a specialty pharma company with commercial operations in the United
States and R&D in Sweden developing improved treatments using proprietary drug
delivery technology and commercial operations in the United States. The company
is commercializing its proprietary product, Zubsolv®, for maintenance treatment
of opioid dependence, in the United States. Zubsolv is a novel formulation of
buprenorphine and naloxone using Orexo’s extensive knowledge in sublingual
technologies. Orexo has a portfolio of two approved and revenue generating
products currently marketed under license in the EU and US. Orexo AB, with its
headquarters in Sweden, is listed on NASDAQ OMX Stockholm Exchange and its
American Depositary Receipts (ADRs) trade on the OTCQX marketplace in the U.S.
under the symbol, “ORXOY”. The largest shareholders are Novo A/S and HealthCap.

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

About Zubsolv®
Zubsolv (buprenorphine and naloxone) sublingual tablet (CIII) is indicated for
the maintenance treatment of opioid dependence and should be used as part of a
comprehensive treatment plan, which includes counseling and psychosocial
support. Treatment should be initiated under the direction of physicians who are
certified under the Drug Addiction Treatment Act of 2000, and who have been
assigned a unique identification number (“X” number).
Zubsolv sublingual tablets can be abused in a manner similar to other opioids,
legal or illicit. Clinical monitoring appropriate to the patient’s level of
stability is essential. Liver function tests should be monitored before and
during treatment. Children who take Zubsolv sublingual tablets can have severe,
possibly fatal, respiratory depression. Emergency medical care is critical. Keep
Zubsolv sublingual tablets out of the sight and reach of children.
Adverse events commonly observed with the sublingual administration of
buprenorphine/naloxone sublingual tablets during clinical trials and post
-marketing experience are headache, nausea, vomiting, hyperhidrosis,
constipation, signs and symptoms of withdrawal, insomnia, pain and peripheral
edema.

Further information on Zubsolv can be found at www.zubsolv.com.

Suboxone is a registered trademark of Reckitt Benckiser Healthcare (UK) Ltd.

Orexo AB (publ) discloses the information provided herein pursuant to the
Financial Instruments Trading Act and/or the Securities Markets Act. The
information was submitted for publication at 8:30 am CET on June 25, 2014.