These are excerpts from a 2012 JACI review by Peter Barnes (see the video at the end of this article):
Patients with severe asthma often have symptoms that are not controlled on maximum treatment with inhaled therapy.
SMART approach to poor medical adherence
Difficult-to-treat asthma can be due to poor adherence to controller therapy. This might be addressed by using combination inhalers that contain a corticosteroid and long-acting β(2)-agonist as reliever therapy ("SMART") in addition to maintenance treatment. However, the "SMART" approach is not yet FDA-approved for use in the U.S.
Severe asthma - differential diagnosis and management (click to enlarge the image):
New LABAs offer some hope
New bronchodilators with a longer duration of action are in development. Recent studies demonstrated the benefit of a long-acting anticholinergic bronchodilator in addition to β(2)-agonists in patients with severe asthma.
Biologics - only one is available (omalizumab), several in development
Anti-IgE therapy (omalizumab) is beneficial in selected patients with severe asthma.
Several new blockers of specific mediators are in clinical trials and might benefit patients with subtypes of severe asthma:
- prostaglandin D(2)
Broad-spectrum anti-inflammatory therapies that target neutrophilic inflammation are in development but adverse effects after oral administration necessitated trials of inhaled delivery.
Macrolide antibiotics in neutrophilic asthma
Macrolides might benefit some patients with infection by atypical bacteria, but recent results are not encouraging. They may still have an effect in patients with predominantly neutrophilic asthma.
Corticosteroid resistance and an old drug (theophylline)
Corticosteroid resistance is a major problem in patients with severe asthma. Several molecular mechanisms might lead to new therapeutic approaches. Drugs that could reverse steroid resistance include theophylline and nortriptyline.
Bronchial thermoplasty can be beneficial in selected patients with severe asthma
Subtypes and biomarkers may be the key to new, targeted treatments
Several subtypes of severe asthma are now recognized. It will be necessary to find biomarkers that predict responses to specific forms of therapy.
From the NHS Choices channel: Professor Peter Barnes from the National Heart and Lung Institute at Imperial College, London, explains what he would want to know if he was diagnosed with asthma:
Severe asthma: Advances in current management and future therapy. Barnes PJ. J Allergy Clin Immunol. 2012 Jan;129(1):48-59.