People with hard to control asthma could benefit from a drug which has just been licensed in the UK.
The drug is given as an injection
Studies show Xolair (omalizumab) cuts asthma attacks among those with severe allergic asthma whose symptoms are not controlled by existing therapies.
The drug, one of a range which can be used for this group, is injected in hospital every two to four weeks.
It works by dampening down the body's immune response, which can rage out of control in this allergic condition.
About 1,400 people die from severe asthma each year in the UK, and a further 69,000 are hospitalised, in many cases for weeks.
The European Medicines Agency (EMEA) has approved omalizumab for people in this category who have allergic asthma and who are over 12 years of age.
It specifically targets the antibody immunoglobulin E (IgE), which is involved in the allergic process in asthma.
In trials involving 4,300 patients, the medicine has been shown to reduce asthma attacks and hospitalisations, and to help improve lung function and quality of life.
A spokeswoman from Asthma UK welcomed the drug's approval.
She said: "For 90% of people with asthma, existing treatments should be effective at controlling asthma.
"For the remaining 10%, their asthma is difficult to control and these people often experience the most severe symptoms and the highest use of emergency services.
"Omalizumab may be effective at treating people in this category who have allergic asthma and who are over 12 years of age."
This could be just under 10,000 of the 5.2 million people with asthma in the UK, experts estimate.
"Although this treatment may only be suitable for a relatively small group of people with asthma, it will increase the treatment options for those whose asthma is difficult to control."
She said that, as with all new medicines, it would be important to monitor closely for side-effects as the drug comes in to long-term use on a large scale.
Chairman of the British Lung Foundation Dr Mark Britton said: "It's a major new step in the treatment of allergic asthma."