Aerocrine announces supplement to prospectus

Not for publication, release or distribution, directly or indirectly, in or into
the United States, Canada, Australia, Hong Kong, Singapore, South Africa, Japan
or New Zealand.

Aerocrine announces a supplement to the prospectus that was made public on 17
April 2012. The supplement has been prepared as a result of the following three
events;

  · Aerocrine announced on 30 April 2012, after several years of litigation,
that the bankruptcy court overseeing the claims to the Apieron Inc estate has
authorised the trustee to pay Aerocrine USD 1.3 million in a compromise against
claims.

  · On 3 May 2012, Aerocrine published its interim report for the period January
– March 2012.

  · Aerocrine announced on 4 May 2012 that the company has decided to call for
conversion of the company’s convertible bonds 2010/2015.

The supplement to the prospectus is available at www.aerocrine.com and
www.remium.com and at Aerocrine’s offices, Sundbybergsvägen 9, SE-171 73 Solna,
Sweden. The prospectus can also be ordered from Aerocrine by telephone +46
(0)8–629 07 80.

For further information, please contact:

Scott Myers, President and CEO of
Aerocrine                                                        Michael
Colérus, CFO

Tel: +46-(0)8-629
0780
                      Tel: +46-(0)8-629 0785

E-mail: scott.myers@aerocrine.com
                                      E-mail: michael.colerus@aerocrine.com

About Aerocrine

Aerocrine AB (publ.) is a medical technology company focused on the improved
management and care of patients with inflammatory airway diseases. As the
pioneer and leader in the technology to monitor and manage airway inflammation,
Aerocrine markets NIOX® Flex and NIOX MINO®. Both products enable fast and
reliable management of airway inflammation and may therefore play a critical
role in more effective diagnosis, treatment and follow-up of patients with
inflammatory airway diseases such as asthma. Aerocrine is based in Sweden with
subsidiaries in the US, Germany and the UK. Aerocrine’s shares were listed on
the Stockholm Stock Exchange on 15 June 2007.

Aerocrine discloses the information provided in this press release pursuant to
the Securities Markets Act. The information was provided for public release on 4
May 2012 at 4 pm CET.

This press release does not constitute an offer of any securities of Aerocrine.
The rights issue is not directed to shareholders or other investors domiciled in
the United States, Canada, Australia, Hong Kong, Singapore, South Africa, Japan
or New Zealand, or in any other country where participation in the issue would
require additional prospectuses, registration or other measures other than those
pursuant to Swedish law or would conflict with regulations in such country. No
shares, interim shares, subscription rights or other securities issued by
Aerocrine have been or will be registered in accordance with the United States
Securities Act of 1933, or in accordance with any securities legislation in any
state of the United States or any province in Canada. Accordingly, no new
shares, interim shares, subscription rights or other securities issued by
Aerocrine may be transferred or offered for sale in the United States or Canada,
other than in such exceptional cases that do not require registration. The
rights issue is directed only at (i) persons who are outside the United Kingdom;
(ii) investment professionals falling within Article 19(5) of the Financial
Services and Markets Act 2000 (Financial Promotion) Order 2005 (as amended); or
(iii) persons to whom it can otherwise lawfully be directed at.