U.K. biotech Circassia eyes $285M in a London IPO

With the U.S. market for biotech IPOs still roiling, the U.K.'s Circassia is planning to test whether there's a complementary appetite across the Atlantic, planning a huge $285 million offering on the London Stock Exchange to get its allergy immunotherapies through clinical study.

The company's lead program is Cat-SPIRE, a Phase III vaccine employing synthetically produced peptides that can train the immune system to gradually get over a cat allergy. Unlike other allergy immunotherapies, Circassia's platform technology avoids exposing patients to whole allergens, cutting back on side effects and speeding up results, CEO Steve Harris told Reuters. In addition to its cat candidate, the company has a fleet of Phase II vaccines for house dust mites, grass and ragweed, all of which promise to improve symptoms after just a four-dose course of treatment.

And if its $285 million float goes according to plan, Circassia will be able to get its vaccines to market without the help of a deep-pocketed partner, Harris told the Wall Street Journal. The company plans to build up a sales force in the U.S. and Europe in anticipation of a Phase III readout on Cat-SPIRE by 2016, Harris said, figuring it can go it alone and eventually reach profitability.

Circassia CEO Steve Harris

Circassia's London debut would be the largest U.K. IPO in at least 25 years, according to Bloomberg, and $285 million would far outstrip any of last year's hauls for U.S. biotech entrants.

The company has raised about $171 million since its foundation in 2006, largely through chief shareholder Imperial Innovations, which disclosed an equity stake of 19.7%.

Oxford Immunotec ($OXFD), another Imperial portfolio company, went public in the U.S. last year with a $64 million initial offering, and Harris said Circassia considered following suit before deciding to keep its shares closer to home.

"We're a British company, with British technology, based in Oxford. Why wouldn't we go to London?" Harris told the Journal. "And wouldn't it be great to have a vibrant U.K. market?"

Circassia's synthetic peptide platform, dubbed ToleroMune, was developed by scientists at Imperial College in London.

- get more from Reuters
- read the WSJ story (sub. req.)
- here's Bloomberg's take
- check out Imperial's statement