Cat-Allergy Shot From Circassia May Limit Need for Pills

Cat-Allergy Shot From Circassia May Limit Need for Pill-Popping
Circassia Holdings Ltd. is awaiting approval from U.S. regulators to begin a $33 million final-stage trial of its cat-allergy vaccine on 1,200 people in September or October, Chief Executive Officer Steven Harris says. Photographer: Torsten Silz/AFP/Getty Images

Circassia Holdings Ltd. wants to offer people who can’t own cats or visit friends and relatives who do a vaccine that will end the sneezing, coughing, swelling, itching and watery eyes they suffer from the animals’ dander.

Mid-stage tests on the shot have shown it’s more than twice as effective at reducing these symptoms than existing pills and sprays, Chief Executive Officer Steven Harris said. The closely held Oxford, England-based biotechnology company is awaiting clearance from U.S. regulators to begin a $33 million final-stage trial of the vaccine on 1,200 people in September or October, he said in an interview at Circassia's offices.

About one-third of U.S. households have cats and 13 million Americans suffer allergies to the animals and might benefit if Circassia’s vaccine is eventually approved, the company says. That may threaten sales of treatments such as New Brunswick, New Jersey-based Johnson & Johnson’s Zirtek, sold over-the-counter in the U.S. as Zyrtec, and nasal steroid sprays such as GlaxoSmithKline Plc’s Flonase.

“I do expect the Phase 3 trial will look encouraging,” said Robert Wood, a professor of pediatrics and director of allergy and immunology at Johns Hopkins Children’s Center in Baltimore, who worked on a similar vaccine two decades ago that failed and isn’t involved in Circassia’s research. “It’s something that would have a market and would certainly add to the allergist’s armamentarium.”

$6.8 Billion Market

The global market for prescription antihistamines to combat allergies is estimated at $6.8 billion, according to IMS Health, a Danbury, Connecticut-based health-care information company. There’s a race to offer more effective treatments because, according to Wood, 20 percent to 40 percent of people in developed countries suffer from some type of hypersensitivity and the number has been rising.

People who have allergies are also at increased risk of developing asthma, a phenomenon known as the “allergic march,” the American Academy of Allergy Asthma and Immunology says. With the number of people with asthma in the U.S. having risen 21 percent to 24.6 million from 2001 to 2009, according to the U.S. Centers for Disease Control and Prevention, demand for new allergy treatments is increasing.

In addition to its cat-allergy vaccine, Circassia is doing mid-stage tests on shots for ragweed, grass pollen and house dust mites, the three other most common allergies that can interfere with daily activities. It also has different technologies with potential use in rheumatoid arthritis, psoriasis and peanut allergy.

Avoiding Triggers

Allergies are best treated by avoiding whatever triggers them, said Wood. That’s not always practical, he says.

“If you can change your environment, that would be ideal,” Wood says. “Some of them are easier than others, but most are not completely avoidable.”

Circassia’s technology is based on research that Mark Larche and A. Barry Kay, who hold small stakes in the company, did at Imperial College London in the 1990s. The ToleroMune T-cell vaccine they developed uses short sequences of amino acids, known as epitopes and drawn from the allergic substance, to try to build tolerance in the person’s immune system and shut down its allergic response. Steroid sprays reduce nasal swelling, congestion and mucus, while antihistamine pills block a protein called histamine and suppress the swelling, itching and sneezing that it causes.

ImmuLogic’s Failure

A T-cell epitope vaccine tested by ImmuLogic Pharmaceutical Corp. in the 1990s failed because it caused some patients to develop temporary asthma-like symptoms, including chest tightness and difficulty breathing. ImmuLogic didn’t get U.S. Food and Drug Administration approval and went out of business.

“That was a product that was the beginning of this mode of thinking,” Wood said.

Circassia’s vaccines are different, Harris said. ImmuLogic used longer amino acid sequences and very large doses, which are more likely to cause adverse reactions, he said. Circassia’s vaccines have had “an excellent safety profile with no evidence of the reactions seen by ImmuLogic,” he said.

Circassia has tested the cat-allergy vaccine in 450 people in early- and mid-stage tests. Allergy sufferers received four doses four weeks apart and were monitored every 30 minutes for three hours a day over four days in a chamber with cat dander spread around it. Symptom relief as reported by patients had as much as a three-fold difference with Circassia’s vaccine than with existing treatments, said Harris. A year later, “the treatment effect got stronger,” with a four-fold difference, he said.

Desensitization Shots

The vaccines are intended for people with moderate to severe, chronic allergies. If approved, the products could go head-to-head with desensitization injections that allergists give in some countries and other treatments that have to be taken daily, including tablets such as J&J’s Zirtek, now available generically, and nasal steroid sprays such as Glaxo’s Flonase or Merck & Co.’s Nasonex.

Flonase, which is available generically, brought London-based Glaxo 138 million pounds ($216 million) in sales last year. Merck of Whitehouse Station, New Jersey, logged sales of $1.29 billion from Nasonex.

Circassia has gotten scientific advice for a final-stage trial from the European Medicines Agency and is awaiting feedback from a meeting with the FDA on July 26, Harris said. The company has a contractor ready to conduct the trial at 100 sites.

FDA Feedback

“We’ve got everything in place to do that,” except for the feedback from the meeting with the FDA, Harris said.

Circassia’s ToleroMune technology can be adapted for use in other allergies by swapping in amino acid sequences from those allergens, Harris said. Early- and mid-stage trials for those indications are under way and have shown similar results without raising safety concerns, he said.

The cat allergy shot is probably the easiest to develop of the four that Circassia is targeting, Wood said. Single proteins are responsible for the allergies that most people suffer from cats and from grass pollen, he said, whereas there are multiple proteins for most other allergies.

“It’s much more complicated for others,” Wood said. “That doesn’t mean it’s impossible, but something like grass pollen and cat were targeted for these because they are much more straightforward in terms of being able to identify a single allergen you can target.”

Circassia Investors

The company has raised 105 million pounds since it was founded in 2006, Harris said. Investors include Invesco Perpetual, Goldman Sachs Group Inc., Lansdowne Partners, Fleming Family & Partners Ltd. and Imperial Innovations Group Plc, the technology-transfer company that grew out of Imperial College London.

Circassia is also in a contest with other allergy vaccine developers. Biomay AG, a closely held biotechnology company based in Vienna, is pursuing a vaccine for grass pollen allergy, or hay fever, that uses a different technology and is in mid-stage trials.

Biomay Chief Executive Officer Rainer Henning said he expects its BM32 vaccine, which requires three doses over two months, to sell for about 2,000 euros ($2,450) if approved.

Harris declined to estimate how much Circassia would charge for its vaccines.

Circassia has enough cash to complete development of the cat-allergy vaccine and its planned mid-stage trials, he said. The company employs about 20 people.

Investors aren’t pressing Circassia to do an initial public offering or sell itself anytime soon, said Harris, who as CEO of Zeneus oversaw its 2005 acquisition by Cephalon Inc. for $360 million. Generating more data is a higher priority, he said.

“At the moment we’re keeping all our options open,” Harris said.

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