BioWorld International Correspondent

LONDON - Circassia Holdings Ltd. raised £6 million (US$11.7 million) in its first formal private funding round since being spun out of Imperial College London in 1998 to commercialize a technology for attenuating allergenic peptides as the basis for allergy vaccines.

The funds will enable the company to complete Phase II development of its lead product, a vaccine against cat allergy, and progress to Phase II two further vaccines, against ragweed pollen and house dust mite.

Charles Swingland, company chairman, told BioWorld International, "In the end the fund raising was heavily oversubscribed, and we had to cut back. When we started out to raise money in the middle of last year we had problems getting traction. In the end, investors came along all together, like buses."

The lead investor in the round, putting in £2 million, is Imperial Innovations plc, the technology transfer arm of Imperial College. The other investors are Landsdowne Partners Ltd., of London, and Tudor Capital, of Boston. That is the first time Imperial Innovations has acted as lead, and marks a shift in maturity following the flotation of the company in July 2006, and the appointment in September 2006 of Russ Cummings, formerly of Scottish Equity Partners and 3i plc, as chief investment officer.

Swingland joined Circassia at its formation, staying with the company when it was acquired by DNA vaccines specialist PowderJect Pharmaceuticals plc, of Oxford, UK, in 2002. While PowderJect took Peptide Antigen Desensitization forward to GMP manufacturing and completed analytical toxicology, the technology hit a road block following the sale of PowderJect to Chiron Inc., of Emeryville, Calif., in 2003.

Meanwhile, Swingland and fellow executive Steven Harris left to run Zeneus Pharma plc, a sales and marketing company formed from the buyout of part of Elan Corp., of Dublin, Ireland. Then last year Chiron handed back rights to the Circassia technology to Imperial College, and Swingland and Harris got their old jobs back, as chairman and CEO, respectively.

"During the hiatus at Chiron, Imperial Innovations has emerged as a more forceful entity, and has done a great deal to help us get Circassia going again," said Swingland.

Raising £6 million means it will be possible to fast track the cat allergy vaccine to Phase IIb, at which point the company will assess its commercialization strategy.

Swingland said the attraction of the technology is that it is based on a long-established strategy for desensitizing people to allergens believed to have originated in the historic region of Circassia, in the Caucasus Mountains. This involves administering increasing and repeated doses of allergens. Although the approach forms the basis of current therapies, they require repeated and frequent injections, and there remains a risk of provoking a serious immune reaction.

Circassia's technology involves engineering allergenic peptides to remove the risk of overreaction, while maintaining their ability to desensitize the subject. In addition to identifying T-cell-specific peptide epitopes of allergens, Circassia's approach exploits the observation that in order to be effectively presented to the immune system, desensitizing peptides must be appropriately bound to the major histocompatibility complex (MHC, or tissue type) molecules. Previous attempts at using the peptide desensitization approach ignored that requirement, potentially explaining the limited efficacy. Circassia's vaccine accommodates that by containing a mixture of peptides selected on the basis of MHC binding. In early trials, subjects became immune to cats after only four injections.

Circassia has in-licensed rights to engineer peptides that cause a number of allergies. According to Swingland, the technology is relevant to autoimmune diseases and transplant rejection. It also may be possible to formulate the vaccine so that it can be administered sublingually.