Up to 17% of Americans are allergic to cats, with about half of those showing clinical symptoms if they get too close. Worldwide, millions of people itch and sneeze from cat allergies, with asthmatic kids hit particularly hard. And, worse still, current treatments are onerous and frequently come with nasty side effects.
Relief may be at hand though, from a vaccine developed by a U.K. company called Circassia. Backers of the treatment say it could cut the number of visits patients need to make for treatment, and provide a stronger and less compromised remedy.
Cats release allergenic proteins when they clean themselves. The compounds are left in the animals’ fur, or escape into the atmosphere. The allergen is light and sticky, allowing it to get into buses, trains, and schools, and even houses where cats have never been.
The standard treatment at the moment is a series of injections of the allergy itself to build up immunity. Patients start by going to the doctor for about eight months of weekly injections, followed by jabs at longer intervals. Alternatively, patients can also take drugs, such as antihistamines or steroids, for the symptoms.
Neither approach is anything like optimal, according to Steve Harris, Circassia’s CEO. "Efficacy is relatively modest, and the side effects are significant, because you’re delivering the very thing people are allergic to," he says, referring to the injections. "It’s also an arduous process and compliance is poor."
The immunotherapy drug is also inconsistent. Batches vary because companies make it by combing real material from cats and processing it into injectable form.
By contrast, Circassia focuses on a small part of the protein, producing synthetic versions of amino acids called peptides. The idea is to switch off the specific cells that cause the allergic reaction. "What we’re trying to do here is stop the body from reacting to something it shouldn’t react to," Harris says.
Instead of the long regimen of jabs, the Circassia treatment is only four injections over 12 weeks, and the effect lasts at least a year, according to trials so far. When patients were exposed to cat dander for three hours a day over four days, they had "barely noticeable" symptoms. "This suggests that they will be able to be in the same room and interact with cats," Harris says.
Having recently passed through phase two stage, the drug is now in phase three, with approval expected in 2015, if all goes according to plan.
Circassia’s bigger goal is to develop treatments for lots of allergies, starting with house dust mites and ragweed. Other drugmakers are working on new remedies in tablet form, including Merck, which now has a new grass-allergy drug with the FDA. Maybe, in the future, allergy season won’t be so bad after all.