Circassia Initiates Phase II Trials of Novel Grass and Ragweed Allergy Therapies and Advances Phase III Plans for cat Allergy T-

Extended Clinical Portfolio Now Includes Four Mid-Stage Development Programmes

OXFORD, England, September 30, 2010 /PRNewswire/ -- Circassia Ltd, a specialty biopharmaceutical company focused on allergy, today announced that it has further advanced the clinical development of three of its leading T-cell allergy vaccines.' In recent weeks, Circassia has initiated phase II clinical testing of its grass allergy (hayfever) therapy, begun the final stage of phase II testing with its ragweed allergy treatment and progressed phase III development plans for its cat allergy therapy. This progress builds on four earlier successful phase II studies of Circassia's ToleroMune(R) technology, which scientifically validated the use of novel T-cell vaccines in treating allergies and identified the optimal dosing approach.

Following these advances, Circassia now has four allergy therapies in late-stage development:

1. Cat allergy. The company's most advanced T-cell vaccine is currently completing its final phase II study. The trial, which includes over 200 patients in Canada, is the first to test Circassia's room-temperature-stable ToleroMune formulation. In parallel, Circassia is progressing phase III development plans for its cat allergy therapy, following a positive endorsement from the European Medicines Agency's scientific advice process.

2. Ragweed allergy. Circassia has initiated the final phase II trial with its ragweed allergy ToleroMune therapy. This 275-patient trial builds on a recently completed phase II study, which demonstrated the potential clinical benefits Circassia's T-cell vaccine can offer ragweed allergy sufferers.

3. Grass allergy (hayfever). Circassia recently initiated phase II clinical testing of its grass allergy T-cell vaccine. Results from the study are anticipated in 2011.

4. House dust mite allergy. Circassia's therapy for house dust mite allergy began phase II testing in early 2010. The initial study is near completion.

"These recent clinical advances demonstrate Circassia's commitment to bringing its unique T-cell allergy vaccines to market as rapidly as possible," said Steve Harris, Circassia's CEO. "Since the founding of Circassia just four years ago, our ToleroMune(R) technology has successfully completed multiple phase II studies, and we now have four therapies in mid-stage development, targeting some of the most common allergies in the world. As a result, our growing clinical database demonstrates the potential of our novel T-cell vaccines to provide allergy sufferers with short, simple and convenient treatment, whilst minimising the risk of severe and sometimes life-threatening side effects associated with many existing immunotherapies."

About Circassia's allergy T-cell vaccines

Circassia's range of allergy T-cell vaccines is based on its proprietary ToleroMune(R) technology. This technology utilises allergen epitopes to generate regulatory T cells that suppress allergic immune responses. Clinical results with Circassia's allergy T-cell vaccines show that short treatment regimes can greatly reduce patients' allergic reactions, without the need for adjuvants or other immune stimulators, while proving extremely well tolerated. As a result, the company's allergy treatments offer major potential clinical benefits compared with existing therapies, and consequently have significant market opportunities. Over 150 million people suffer from allergic rhinitis in the US and Europe, and the current treatment market is approximately $12 billion per year.

ToleroMune technology has additional potential regulatory and supply chain benefits. The short peptides utilised in Circassia's vaccines are manufactured chemically, in contrast to existing allergen immunotherapies, which are purified from natural sources. Circassia's approach applies the chemistry, manufacturing and control standards associated with conventional pharmaceuticals to its allergy T-cell vaccines. This fits with changes in the European regulatory environment, where authorities are increasingly treating allergen immunotherapies as pharmaceutical products, and requiring elimination of the batch-to-batch potency variability that is an intrinsic feature of many current treatments.

About Circassia

Circassia has a highly experienced management team with a proven track record in product development and commercialisation. Having successfully completed three fundraising rounds the company is backed by a syndicate of world-class venture capital and institutional investors, including Imperial Innovations, Invesco Perpetual, Goldman Sachs and Lansdowne Partners.

    For more information please visit http://www.circassia.co.uk

    Contacts

    Steve Harris
    CEO
    Circassia
    Tel: +44(0)1865-784574

    Rob Budge
    RJB Communications
    Tel:    +44(0)1865-760969
    Mobile: +44(0)7710-741241

SOURCE Circassia Ltd