The first new drug treatment for asthma for more than a decade has dramatically reduced the symptoms in sufferers and could help hundreds of thousands of patients in Britain with the disease, researchers say.
Trials of the drug in 28 asthma patients showed it reduced breathlessness by up to three-and-a-half times compared with placebo, when they were exposed to cat hairs or house dust that would otherwise have triggered an attack.
Asthma is one of the most common allergic conditions, affecting more than five million patients in the UK and hundreds of millions worldwide. If the new treatment is proven to significantly reduce the impact of the disease, it is likely to be hailed as a blockbuster drug.
Evidence shows between 20 and 30 per cent of asthma sufferers – 1 to 1.5 million people in the UK – are not well controlled on existing drugs and are in danger of suffering an asthmatic attack leading to hospital admission. In 2005, more than 70,000 people were admitted to hospital with asthma in the UK and 1,318 died.
The drug, called pitrakinra, is the first of a new class of interleukin inhibitors which works in a different way from existing, steroid-based drugs. Scientists at the California biotech company Aerovance, who developed it, believe it will cause fewer side-effects and prove more effective in patients who are resistant to current treatments.
Malinda Longphre, who led the trials published in The Lancet today, said researchers had suspected for 20 years that signalling molecules called cytokines played a critical role in asthma but no one had been able to prove it.
"We are very excited. We are the first to show that inhibiting this part of the immune response affects the clinical outcome in asthma. This could be a new avenue for therapy for moderate to severe asthma. It is the first wholly new treatment approach [in asthma] since leukotrine antagonists hit the market over a decade ago."
Leukotrine antagonists were launched in the mid-1990s as a preventive treatment for mild asthma. They are taken orally and provided in addition to steroid drugs, which are routinely prescribed to asthma sufferers to prevent attacks.
Pitrakinra acts at a different point in the "inflammatory cascade" that causes asthma from either steroids or leukotrine antagonists. In the trials, 12 patients given the drug by injection saw their symptoms reduced by 26 per cent compared with placebo and 16 patients given it by nebuliser saw their symptoms cut by more than three-and-a-half times, after being challenged with an allergen such as cat hair.
Rick Fuller, spokesman for Aerovance, said: "We are looking at this as a treatment for the problem patients who are uncontrolled [on steroids]. We are not looking at it as a standard treatment for asthma. In the UK you could be talking of 250,000 to 500,000 patients who are not well controlled. It is probably more important to have a new treatment for them than for the mild patients that are well controlled."
In a commentary on the findings, published in The Lancet, Drs Patrick Holt and Peter Sly of the University of Western Australia say the discovery is "exciting and novel" and will "breathe new life into the debate over... how to design new drugs for [asthma]"
Professor Martyn Partridge, clinical adviser to Asthma UK, said: "There are groups of people for whom the current therapies don't help. But the percentage is lower than 20 to 30 per cent. I would say it was about 5 per cent [250,000 people]. We could do more good by using the existing drugs to better effect."
The battle for breath
* There are 5.2 million people in the UK diagnosed with asthma
* An estimated 2.6 million people have severe symptoms
* One in six people with severe asthma report weekly attacks so severe they cannot speak
* There were 1,318 deaths from asthma in 2005
* On average, four people a day die from asthma