Take a deep breath: Biologics are set to change the global treatment of severe asthma
Imagine being a young woman, who is told that the drug you are prescribed by your doctor is going to cause you to gain weight, and have uncontrollable mood swings. Or perhaps, a young man who is aware that your medication may cause cataracts in your eyes, changes to the shape of your face, or your blood pressure to increase. However, not taking the drug will mean that you cannot climb the stairs to your attic, go for a swim with your kids, socialise, or even work. This is the unfortunate dilemma for many young people diagnosed with severe asthma, which affects around 1 in 20 asthma patients worldwide; and is often treated by steroids such as prednisone – which results in nasty side effects.
The causes of severe asthma are not always known, but in some patients, it is thought that inflammation of the airways may be triggered by high levels of a particular white blood cell called an eosinophil. A new class of drugs is now being developed for these patients, that may change the way they are treated – biologics. These drugs target the underlying cellular changes which cause asthma, either by targeting immunoglobulins to combat allergic asthma, or by targeting cytokines such as interleukins and thymic stromal lymphopoietin, to work against eosinophilic asthma by lowering eosinophil levels.
With a range of new biologics coming onto the market, this is an exciting time for respiratory clinicians – if one biologic does not work for your patient, fear not – there are other options. Clinical trials are still required to make direct comparisons between these drugs as we are uncertain which are more effective and in which patients – but what we do know is that these drugs offer a great deal of hope to patients who do not respond to or cannot tolerate the side effects of standard treatments such as steroids and beta-agonists.
One concern that has been raised is that eosinophils play a role fighting infection caused by parasitic worms – so could drugs that lower eosinophil levels increase infection rates in patients in tropical countries? We do not yet have the evidence to show this, but it has been highlighted that this potential issue should be considered as these drugs become more widely used. Nevertheless, this remains an exciting time in the respiratory therapy field, with biologics set to revolutionise the treatment landscape for severe asthma over the next 5–10 years.
