Last updated on April 24, 2014 at 5:50 EDT

Circassia’s ToleroMune® Cat Allergy Treatment Maintains Symptom Improvement Two Years After Start of Short-Course Therapy

February 25, 2013

OXFORD, England and SAN ANTONIO, February 25, 2013 /PRNewswire/ –

Circassia Ltd, a specialty biopharmaceutical company focused on allergy, today
announced the results of a phase II clinical study showing that a short course of just
four doses of its ToleroMune(R) cat allergy therapy maintained improvements in patients’
symptoms two years after the start of treatment. The results were presented at the 2013
Annual Meeting of the American Academy of Allergy, Asthma and Immunology (AAAAI) in San
Antonio, USA on Sunday 24 February.

The phase II study originally measured improvements in nasal and ocular allergy
symptoms (Total Rhinoconjunctivitis Symptom Score; TRSS) in 202 patients, following
treatment with ToleroMune(R) therapy or placebo. Two years after the start of the study,
and having received no further ToleroMune(R) treatment, 50 of the original patients
returned to reassess their symptoms while exposed to cat allergens. The results show that
at the end of the cat allergen challenge, patients who had previously been treated with
four doses of ToleroMune(R) therapy over 12 weeks had a significant improvement in
symptoms two years later, compared with placebo (p<0.05; 50.0% TRSS improvement on
ToleroMune(R) treatment vs 14.9% on placebo). These patients also maintained a substantial
reduction in symptoms throughout their entire exposure to cat allergens over the four day
challenge (38.3% TRSS improvement vs 13.4% on placebo). In addition, the results show that
these patients maintained consistent symptom improvements both 12 and 24 months after the
start of treatment. The ToleroMune(R) therapy was well tolerated with a safety profile
comparable to placebo.

Commenting on the results, co-author of the AAAAI conference presentation, Professor
Mark Larche, Canada Research Chair in Allergy and Immune Tolerance, McMaster University
and St. Joseph’s Healthcare, Hamilton, said, “Sustaining such a substantial improvement in
patients’ allergy symptoms two years after the start of the study is remarkable. Achieving
this with a short course of just four doses is even more impressive. These results suggest
that ToleroMune(R) therapy has the potential to revolutionise treatment for cat allergy

“These excellent clinical results are extremely encouraging, and strongly support
Circassia’s decision to progress to phase III at the end of last year,” said Steve Harris,
Circassia’s CEO. “Offering patients sustained symptom control without the need for ongoing
treatment is an important objective for allergy therapy. In this study, our ToleroMune(R)
treatment reduced symptoms by two and a half to three times the level achieved by several
other allergy therapies in similar studies, and maintained the improvement over a
significant period, demonstrating its potential to greatly improve the lives of patients
around the world.”

About cat allergy

Allergies are a significant global health issue. Allergic rhinoconjunctivitis (ARC)
affects up to 30% of adults and 40% of children in developed countries, and its prevalence
is rising. ARC reduces quality of life and impacts school and work attendance and
performance. In Continental Europe and the USA, cat allergy is one of the most common
forms of the disease, and affects 10 – 15% of those with ARC and / or asthma. As cat
dander is widespread in the human environment, and widely found in public buildings,
patients with cat allergy may experience significant symptoms despite attempting to avoid
exposure. Current treatment options include temporary symptom suppression with
antihistamines, corticosteroids and cromones, or long-term whole allergen immunotherapy,
which can require treatment for three to five years and has the potential to induce
life-threatening anaphylactic reactions.

About ToleroMune(R)

Circassia’s cat allergy treatment is based on the company’s novel, proprietary
ToleroMune(R) technology. This uses rationally-designed combinations of synthetic peptides
to generate regulatory T cells to control allergic responses and induce immune tolerance.
Circassia’s ToleroMune(R) cat allergy treatment consists of seven peptides identified from
the major cat allergen Fel d 1. It has successfully completed a number of phase II
studies, which demonstrate that courses of short, simple treatment can substantially
reduce patients’ symptoms and have a favourable safety profile. In long-term follow up,
patients’ symptoms remained greatly improved two years after the start of the study,
despite no further treatment after the initial four doses given over 12 weeks. Circassia’s
cat allergy treatment entered phase III clinical testing in October 2012.

About Circassia

Circassia was founded by a team of highly experienced biotechnology scientists and
entrepreneurs. The company is based in the UK on the Oxford Science Park, and its joint
venture with McMaster University (Adiga Life Sciences Inc) is located in Hamilton, Canada.
Circassia’s ToleroMune(R) technology was developed originally by scientists at Imperial
College, London. Having successfully completed five fundraising rounds, Circassia has
raised approximately GBP105 million ($178 million) and is backed by a syndicate of
world-class institutional investors, including Imperial Innovations and Invesco Perpetual.

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


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

SOURCE Circassia

Source: PR Newswire