Circassia Extends its Clinical-Stage Portfolio With Phase II Trials of T-Cell
Vaccines Against House Dust Mite and Cat Allergies

OXFORD, England, Jan. 19 /CNW/ - Circassia Ltd, a specialty biopharmaceutical company focused on allergy, today announced that it has initiated phase II clinical trials of its T-cell vaccines targeting house dust mite and cat allergies. With the start of these studies, and the ongoing trial of Circassia's ragweed allergy (hay fever) T-cell vaccine, the company now has three clinical development programmes in phase II. Each of these builds on earlier successful phase II results with the company's ToleroMune(R) technology, which scientifically validated the novel use of T-cell vaccines in the treatment of allergy, and identified the optimal dosing regimens to progress into late-stage development.

In Circassia's cat allergy trial, which is underway in Canada , 210 patients will be randomised to receive placebo or one of two regimes of the company's T-cell vaccine. This study is the first to test Circassia's novel room-temperature-stable ToleroMune formulation. This offers great potential practical advantages compared with existing allergy desensitisation treatments, which are inherently unstable and require cold chain distribution and storage. During the study, the volunteers will be exposed to aerosolised cat dander in an environmental exposure chamber, both before and after treatment, to measure the effect of the ToleroMune T-cell vaccine.

Circassia has also initiated the first clinical study of its T-cell vaccine against house dust mite allergy, which is underway in Quebec , Canada . The double-blind, placebo-controlled, randomised trial will include 50 allergy patients. The active treatment groups will receive four standardised doses of the ToleroMune T-cell vaccine over several weeks. This approach contrasts with current immunotherapies, which require many months of escalating doses and maintenance treatment over a number of years. During the trial investigators will 'challenge' the volunteers with house dust mite allergens to assess the therapeutic effect of Circassia's T-cell vaccine.

"The start of these two studies demonstrates the rapid clinical advance of Circassia's T-cell vaccines. With this further broadening of our portfolio, Circassia now has three development programmes in phase II, targeting some of the most common allergies in the world," said Steve Harris , Circassia's CEO. "We are committed to continuing this rapid pace of development, to ensure we can bring these breakthrough T-cell vaccines to market as soon as possible. We believe that patients can benefit greatly from our ToleroMune allergy therapies, which offer the prospect of simple, convenient and effective treatment while minimising the risk of the 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 cat allergy T-cell vaccine show that short treatment regimes can greatly reduce patients' symptoms, without the need for adjuvants or other immune stimulators, while proving extremely well tolerated. As a result, the company's allergy T-cell vaccines 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.

For further information: Steve Harris, CEO, Circassia, Tel: [phone]; Rob Budge, RJB Communications, Tel: [phone], Mobile: [phone]