Published 25th May 2016

Circassia initiates Grass Allergy Immunotherapy Registration study

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.