Severe asthma can be controlled using biological therapies without the addition of regular high-dose inhaled steroids, which can have significant side effects, a new study has shown.

The study, published in the journal The Lancet, showed that 92 per cent of patients using the biologic therapy 'benralizumab' (a drug used for the treatment of asthma) could safely reduce inhaled steroid dose, and more than 60 per cent could stop all use.

"Biological therapies such as benralizumab have revolutionised severe asthma care in many ways, and the results of this study show for the first time that steroid-related harm can be avoided for the majority of patients using this therapy," said Professor David Jackson, Professor at King's College London, who led the study.

The study’s results could be transformative for severe asthma patients by minimising or eliminating the unpleasant, and often serious, side effects of inhaled steroids.

These include osteoporosis which leads to increased risk of fractures, diabetes and cataracts.

Asthma is one of the most common respiratory diseases worldwide - affecting almost 300 million people -- and around 3 to 5 per cent of these have severe asthma.

The study took place across 22 sites in four countries -- the UK, France, Italy, and Germany. A total of 208 patients were randomly assigned to taper their high-dose inhaled steroid by varying amounts over 32 weeks, followed by a 16-week maintenance period.

About 90 per cent of patients experienced no worsening of asthma symptoms and remained free of any exacerbations throughout the 48-week study, the researchers noted.

Benralizumab is a biological therapy that reduces the number of inflammatory cells called eosinophil.

This is produced in abnormal numbers in the airways of patients with severe asthma and is critically involved in the development of asthma attacks.