Safer relief for people suffering from severe asthma is a step closer with a large clinical trial finding a monocolonal antibody treatment called benralizumab can radically reduce the need for more dangerous high-dose steroid treatments.

Asthma impacts almost 300 million people worldwide, around 5 percent of whom have a severe version of this respiratory disease. They face a horrifying struggle to get enough air on a daily basis, with all the associated chest tightness, coughing, panic, and frequent hospital visits.

Patients with severe asthma rely on inhaling high doses of steroids to keep it under control. They work by reducing the body's inflammation in general, decreasing the production of mucus in the lungs as a consequence.

Yet high levels of steroids come with all sorts of risks, including increased diabetes, fractures, cataracts, and suppression of the adrenal system which helps regulate everything from metabolism to stress through hormones.

What's more, the value of such high doses of steroids in treating severe asthma remains debated. Lower doses have a proportionally larger impact, but patients have little other option than to resort to the riskier amounts when these fail.

The treatment investigated in a phase four clinical trial funded by its producer AstraZeneca, works in a far more targeted way. Benralizumab is a protein antibody that reduces the number of inflammation-causing immune cells called eosinophils, which are produced in abnormal amounts in severe asthma cases.

Benralizumab has been so effective that in the trial of over 200 patients across Europe an incredible 92 percent of them safely reduced the use of inhaled steroids, with more than 60 percent no longer needing them at all.

Almost 90 percent of patients in the steroid reduction group remained exacerbation-free by the end of the trial.

"More than half of patients reducing background medications met the definition for clinical remission at week 48," King's College immunobiologist David Jackson and colleagues write in their paper.

"The data further cement the central role of eosinophils in exacerbation pathogenesis and symptom control."

However, these promising results only apply to a very specific type of asthma, the researchers caution. They only tested people who responded well to benralizumab, patients who have severe eosinophilic asthma and don't respond as well to benralizumab likely still require the intensive steroid treatments.

Due to the risks from high steroid doses the Global Initiative for Asthma recommends lowering doses in patients who are responding positively to immune therapies. This research supports that recommendation, however the results may not be the same across all similar treatments.

"Patients controlled on benralizumab can have meaningful reductions in ICS therapy while maintaining asthma control," Jackson and team conclude.

This research was published in The Lancet.