Cat allergy setback for Circassia

The results have come as a complete shock to Oxford-based Circassia. In a Phase III trial, its first Synthetic Peptide Immuno-Regulatory Epitope (SPIRE) did not reduce cat allergy symptoms better than a placebo. Both did have a marked effect on the subjects’ combined allergy symptoms and rescue medication use. However, the immunotherapy did no better than the placebo, thereby failing the primary endpoint of the trial. “Such a dramatic placebo effect was not a feature of our earlier phase II studies,” said CEO Steve Harris.“However, in this large-scale trial it eliminated the ability to identify a treatment effect despite dramatic improvements in subjects’ allergy symptoms and rescue medication use.”

The cat allergy therapy is the first in a line of allergy treatments in Circassia’s pipeline. They all belong to the synthetic peptide immuno-regulatory epitope class. Circassia had hoped to open up the multi-billion-dollar allergy market with its therapeutic approach. Immunotherapy for grass and dust mite allergy were also far advanced. Now, however, the company will stop the recently initiated registration study of its grass allergy treatment and the preparation for a dose-ranging study of the ragweed allergy therapy. It may also halt the development of its dust mite allergy products. Circassia plans to review the study’s dataset in order to to understand the results and assess the implications for its allergy portfolio. Only the birch allergy treatment will likely continue its Phase II study, which is nearing completion. “At the same time, we will continue to focus resolutely on our wider portfolio, rapidly growing the sales of our market-leading Niox asthma management products and advancing our pipeline of respiratory products,” added Harris.

The stock market reacted swiftly to the news. In just a few hours, Circassia’s share value fell from around 240 pence to about 89 pence, bringing the value of the shares to about a third. In 2014, Circassia had managed a record IPO at London Stock Exchange, raising £200m (US$287m).