Asthma biologics are becoming a newer treatment option for severe refractory asthma. Drug manufacturers have many newer medications on the horizon to treat uncontrolled asthma. Approximately 300 million people worldwide have asthma and as many as 30% of patients with asthma may not achieve complete control despite undergoing combination high dose inhaled corticosteroid and long-acting beta-agonist therapy.
It is clear additional therapeutic options are necessary because patients continue to have uncontrolled asthma. Here we will discuss below asthma biologics that have been FDA approved and others that are seeking FDA approval.
Anti-Tumor Necrosis Factor alpha
Tumor necrosis factor alpha is a known proinflammatory cytokine, elevated levels have been found in sputum in patients with severe asthma. The TNF-alpha inhibitors, etanercept, infliximab and golinumab have been studied in patients with severe asthma. There has been mixed results with these asthma biologics and an unfavorable safety profile was seen with golinumab. These asthma biologics may actually play a better role in neutrophilic asthma, studies are still ongoing.
Omalizumab and Anti-IgE
This asthma biologic medication has been on the market since 2003 for use in patients with moderate to severe asthma with positive perennial allergen testing unable to be controlled despite use of inhaled steroids. Studies shoed reduced number of asthma exacerbations, mean albuterol use, asthma symptom score and improved quality of life.
Interleukin 4 is a well recognized player in eosinophil aggregation and as part of the Th2 pathway of inflammation. Altrakincept is being studied in moderate atopic asthma. Treatment group patients required less albuterol usage, but altrakincept and pascolizumab, another anti-IL-4 failed to demonstrate any clinical efficacy. It has been hypothesized that IL-4 antagonists are ineffective because of redundancy with the IL-13 pathway, postulating that dual inhibition may be required.
IL-5 plays a key role in eosinophil differentiation. The asthma biologics in this class are.
Mepolizumab, Reslizumab and Benralizumab. Mepolizumab and Reslizumab are currently on the market already. You can read about those medications more extensively if you click on the links. The results of treatment with anti-IL-5 biologics are impressive, but clinical benefit varies and efficacy relies on correctly identifying the appropriate population for a given treatment.
The only one in this class is, Lebrikizumab. Please click on the link to read more extensively about this asthma biologic medication.
Anti-IL-4, Anti-IL-13 and Anti-IL-4 alpha
Both dupilumab and pitraninra inhibit the shared alpha subunit of IL-4 receptors which creates a blockade in signaling of IL-4 and IL-13. Data from these studies suggest blockade of both IL-4 and IL-13 may have greater effects then blocking either individually. Dupilumab is also being studied for atopic dermatitis, please click on the link to read further about it.
When exploring asthma biologics, the mixed results are likely a consequence of lack of appropriate patient recruitment for the studies. These asthma biologics would be best used for a specific patient population with asthma and it will be up to the physician to determine which asthma biologic is appropriate for which patient.
More research is required to distinguish select populations that will best benefit from an individual biologic agent. Head to head studies of these new asthma biologics are imperative although not likely to happen. To read more about asthma biologics and new asthma medications, please see below.
Always speak to your asthma doctor about your current treatment and whether or not you feel your symptoms are controlled with the current medication you are taking, if not he/she could “step up” the treatment.