Circassia Pharmaceuticals : US Filing of Duaklir NDA & Tudorza Supplement NDA

Circassia Announces Submission of Duaklir® New Drug Application and Tudorza® Supplemental New Drug Application in the United States

Ø Duaklir® NDA for treatment of chronic obstructive pulmonary disease (COPD)

Ø Tudorza® sNDA for inclusion of COPD exacerbation reduction and cardiovascular safety data in label

Oxford, UK - 1 June 2018:Circassia Pharmaceuticals plc ('Circassia' or 'the Company'; LSE: CIR), a specialty pharmaceutical company focused on respiratory disease, today announces the submission of a New Drug Application (NDA) to the United States Food and Drug Administration (FDA) for Duaklir® Pressair® for the treatment of chronic obstructive pulmonary disease (COPD).

The Company also announces the concurrent submission of a supplemental New Drug Application (sNDA) for Tudorza® Pressair® for the inclusion of clinical data demonstrating cardiovascular safety and reduction of COPD exacerbations in the product's prescribing information.

Under the Prescription Drug User Fee Act (PDUFA), the review period for the NDA and sNDA will be confirmed in the Day 74 communication from the FDA.

Steve Harris, Circassia's CEO, said:'The regulatory submissions for Duaklir® and Tudorza® represent a major milestone for Circassia, coming just one year after we established our transformational collaboration for their commercialisation with AstraZeneca. We believe that Duaklir®, if approved, has the potential to provide an important treatment option for the significant number of patients with COPD in the United States. In addition, the positive cardiovascular safety and COPD exacerbation reduction results achieved in the Tudorza® ASCENT study offer the potential to include unique new information in the product's prescribing information, if approved.'

About Duaklir® Pressair®

Duaklir® is a fixed-dose combination of the long-acting muscarinic antagonist (LAMA) aclidinium and the long-acting beta agonist (LABA) formoterol. It is administered twice daily via the easy-to-use, breath-actuated, multi-dose inhaler, Pressair®. The product is approved in approximately 50 countries worldwide, including in the European Union, under a number of brand names. In April 2017, Circassia and AstraZeneca established a commercial collaboration in the United States under which Circassia has exclusive US commercialisation rights to Duaklir® and AstraZeneca is responsible for the product's development and regulatory submission.

The Duaklir® NDA is supported by a broad clinical database, and includes data from the AMPLIFY study, results from two previous Duaklir® phase III studies, ACLIFORM and AUGMENT, and exacerbation data from the ASCENT trial.

About Tudorza® Pressair®

Tudorza® contains the LAMA aclidinium administered twice daily via the Pressair® inhaler. Tudorza® was first approved in the United States in 2012 for use in the treatment of COPD, and under Circassia's commercial collaboration with AstraZeneca, Circassia is responsible for the product's promotion and AstraZeneca for completing its clinical studies and regulatory submissions.

Tudorza®'s sNDA includes data from the recently completed phase IV ASCENT study. The study, which was conducted in patients with moderate to very severe COPD and cardiovascular disease and / or risk factors, demonstrated Tudorza® is effective at reducing COPD exacerbations with no increase in cardiovascular events, and reducing hospitalisations due to COPD exacerbations, in this at-risk population. If the sNDA is approved, Tudorza® will be the only LAMA in the United States with these data in its label.

About Circassia

Circassia is a world-class specialty pharmaceutical business focused on respiratory disease. Circassia sells its novel, market-leading NIOX® asthma management products directly to specialists in the United States, United Kingdom and Germany, and in a wide range of other countries through its network of partners. In 2017, the Company established a commercial collaboration with AstraZeneca in the United States in which it promotes the chronic obstructive pulmonary disease (COPD) treatment Tudorza®, and has the commercial rights to NDA-stage COPD product Duaklir®. For more information please visitwww.circassia.com.

Contacts

Circassia

Steve Harris, Chief Executive Officer Tel: +44 (0) 1865 405 560

Julien Cotta, Chief Financial Officer

Rob Budge, Corporate Communications

JP Morgan Cazenove

James Mitford / James Deal Tel: +44 (0) 20 7742 4000

Numis Securities

Clare Terlouw / Freddie Barnfield Tel: +44 (0) 20 7260 1000

FTI Consulting

Simon Conway / Mo Noonan Tel: +44 (0) 20 3727 1000

Forward-looking statements

This press release contains certain projections and other forward-looking statements with respect to the financial condition, results of operations, businesses and prospects of Circassia. The use of terms such as 'may', 'will', 'should', 'expect', 'anticipate', 'project', 'estimate', 'intend', 'continue', 'target' or 'believe' and similar expressions (or the negatives thereof) are generally intended to identify forward-looking statements. These statements are based on current expectations and involve risk and uncertainty because they relate to events and depend upon circumstances that may or may not occur in the future. There are a number of factors that could cause actual results or developments to differ materially from those expressed or implied by these forward-looking statements. Any of the assumptions underlying these forward-looking statements could prove inaccurate or incorrect and therefore any results contemplated in the forward-looking statements may not actually be achieved. Nothing contained in this press release should be construed as a profit forecast or profit estimate. Investors or other recipients are cautioned not to place undue reliance on any forward-looking statements contained herein. Circassia undertakes no obligation to update or revise (publicly or otherwise) any forward-looking statement, whether as a result of new information, future events or other circumstances.

Aclidinium is marketed under a number of brand names around the world, including Tudorza®, Eklira® and Bretaris®

Duaklir® is a registered trademark in Europe and other markets; use of the US trademark is subject to review and approval by the FDA

Duaklir® and Tudorza® are registered trademarks of Almirall S.A.; Pressair® is a registered trade mark of the AstraZeneca group of companies