Circassia Ltd, a specialty biopharmaceutical company focused on the fields of allergy and critical care, announced the start of a further phase-II clinical study of its ToleroMune technology in the field of cat allergy. The trial builds on positive results achieved in an earlier phase-II study, which demonstrated the potential clinical benefits of the ToleroMune approach to allergy desensitization.

In the previous phase-II clinical trial, patients experienced substantially reduced reactions to cat allergens after a single administration of ToleroMune therapy. The current study builds on this work, and will explore different 4-dose treatment regimens, which are designed to enhance the patients' response and determine the best therapeutic approach. During the study, patients will receive a controlled dose of cat allergen in an environmental exposure chamber both before and after treatment, and will then complete a questionnaire to score their allergic rhinitis symptoms. This will allow investigators to evaluate the impact of the different treatment regimes. The double-blind, randomized, placebo-controlled trial will include a total of 120 volunteers with confirmed cat allergies. The study, which is already underway in Canada, is progressing well with approximately 20% of patients enrolled for screening so far.

"This study is of great importance for Circassia as it is designed to define the most effective treatment regime for our ToleroMune allergy products, and in particular for the phase-III studies of our cat-allergy therapy that are planned to begin in the second half of 2009," said Steve Harris, Circassia's CEO. "The results of our trials to date show that our ToleroMune approach offers patients substantial potential benefits. Conventional allergy treatments either address symptoms only or require many doses over a period of months under specialist supervision because they can result in serious, even life-threatening adverse reactions. In contrast, Circassia's anti-allergy technology has the potential to provide effective but shorter treatments, while minimizing the threat of severe side-effects."