CIR.L Regulatory News (CIR)

Circassia Initiates Grass Allergy Immunotherapy Registration Study

Ø Second allergy programme moves into final phase of clinical testing

Ø Lead programme targeting cat allergy on track to report phase III results Q2 2016

Oxford, UK - 25 May 2016: Circassia Pharmaceuticals plc ("Circassia" or "the Company"; LSE: CIR), a specialty biopharmaceutical company focused on allergy and respiratory disease, today announces the initiation of the registration field study for its novel grass allergy immunotherapy. The study, which will be conducted in over 100 centres in the US, Canada and Europe, will enrol approximately 1,500 subjects. In previous clinical trials the grass allergy product candidate has achieved encouraging results, with the optimal regimen demonstrating efficacy in subjects who were followed over three grass pollen seasons after completing the short-course treatment before the start of the first season.

Principal Investigator, Professor of Medicine, David Bernstein MD, University of Cincinnati College of Medicine, said: "Grass pollens are a major cause of seasonal allergies, and associated nasal and eye allergic symptoms can significantly impact allergy patients' quality of life, work or school performance and social functioning. Circassia's investigational new treatment represents an exciting novel therapeutic approach, which previous studies suggest may induce sustained long-term allergen tolerance with a short course of therapy. We look forward to undertaking this large-scale field study to confirm the potential role this promising short-course immunotherapy can play in treating grass allergy."

Steve Harris, Circassia's Chief Executive, commented: "The start of this registration study represents an important milestone for Circassia as we progress our second novel allergy treatment into the final phase of clinical testing. Grass allergy is extremely common, affecting millions of people around the world. However, there is currently no short, simple, long-lasting treatment approved, and we believe our next generation immunotherapy has the potential to address this significant unmet need. We also believe our technology has the potential to revolutionise allergy treatment more broadly, and we are looking forward to receiving the results from our cat allergy pivotal phase III study in the coming weeks."

Study design

The registration study is an innovative, adaptive-design field trial, which, based on discussions with regulators in Europe and the US, is designed to meet regulatory requirements on both sides of the Atlantic. The first stage of the randomised, double-blind, placebo-controlled, parallel-group, multicentre study will enrol and evaluate approximately 400 subjects, while concurrently recruiting participants for the second stage. Subjects will be aged 12 - 75 years old, and will have a clinical history of grass allergy, laboratory confirmed grass pollen sensitivity and problems controlling their symptoms. Controlled asthmatics with grass allergy are eligible for inclusion in the trial following an earlier successful safety study in this patient group.

The initial 400 study subjects will receive a course of treatment of 8 x 6nmol doses over 14 weeks or placebo, which will be completed before the grass pollen season. The subjects will subsequently report on the Combined Score of allergy symptoms and rescue medication use during the grass pollen season. Following favourable results the second stage will enrol subjects from the pre-identified cohort and will be sized according to first-stage performance to achieve appropriate powering. It is currently anticipated that the second stage will enrol approximately 1,100 subjects. The dose regimen and design will be the same in both stages of the study, and the primary end-point will be the difference between the treatment and placebo groups' Combined Scores at the peak of the pollen season. Results from the full study are anticipated in H2 2018.

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Enquiries

About grass allergy

Grass allergy, commonly called hay fever, is extremely prevalent. In Europe and the US, 17% - 27% of the population are sensitised to grass pollen allergens. These allergens are universally recognised as a major cause of allergic diseases in humans, including asthma, allergic rhinoconjunctivitis and dermatitis. Grass allergy is a seasonal condition and can debilitate sufferers during the months when pollen is released, resulting in significant healthcare costs, workplace/school absences and the inability to spend time outdoors.

About Circassia's grass allergy immunotherapy

Circassia's novel product candidate contains a mixture of seven peptides designed to generate a similar frequency of T-cell response to that generated by whole grass allergen. The immunotherapy contains epitopes derived from Rye, Timothy and Bermuda grass, and these are conserved in other grasses, including Velvet, Orchard, Kentucky blue and Canary grass. In a phase IIb clinical study, a short course demonstrated a significant improvement in symptoms at the end of the season compared with placebo. Efficacy was also demonstrated after a second grass season, and in patients who were followed over three consecutive pollen seasons the initial treatment effect was maintained despite no further doses.

About Circassia

Circassia is a world-class specialty biopharmaceutical business focused on allergy and respiratory disease. The Company has an established commercial infrastructure, marketed products, a pipeline of near-term therapies and a portfolio of next generation treatments targeting multi-billion dollar market opportunities. Circassia sells its novel, market-leading products for asthma management directly to allergy / asthma specialists in the United States and Germany. Its products are also promoted in a number of other countries by the Company's international network of partners.

Circassia's broad-based development pipeline includes a range of treatments for allergy and respiratory disease. Circassia's most advanced next-generation immunotherapy is currently in phase III testing for cat allergy, and is the first in a new class of treatments, Synthetic Peptide Immuno-Regulatory Epitopes (SPIREs). Three other SPIREs, targeting house dust mite, ragweed and grass allergies, have completed clinical proof-of-concept phase IIb studies. Circassia's lead asthma treatment, which targets substitution of GSK's Flixotide® pMDI, is approved in the UK, and the Company is developing therapies targeting direct substitution of Seretide® pMDI and Serevent® pMDI. The Company is also developing a number of novel treatments, including a fixed dose 'triple' combination containing an inhaled corticosteroid, long-acting beta agonist and long-acting muscarinic antagonist. For more information on Circassia please visit www.circassia.com.

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.