This finding suggests that targeting the signaling protein interleukin-5 (IL-5) could be an effective strategy to manage inflammation and asthma symptoms in this patient population.
The data was reported in the article, “Severe uncontrolled asthma with bronchiectasis: a pilot study of an emerging phenotype that responds to mepolizumab,” and published in the Journal of Asthma and Allergy.
Nucala, marketed by GlaxoSmithKline, is an engineered antibody designed to recognize and block pro-inflammatory signals from immune cells triggered by IL-5 activity. It was approved by the U.S. Food and Drug Administration and European Medicines Agency in 2015 as add-on maintenance treatment for patients who have a particularly severe type of asthma, called eosinophilic asthma.
This type of asthma is characterized by an increased number of eosinophils (a type of white blood cell) circulating in the blood, as well as infiltrated in the lungs, which lead to increased inflammation and obstruction of the respiratory airways.
Recent studies have shown that more patients with severe uncontrolled asthma develop bronchiectasis, and that 2.2% to 77% of severe asthma patients have bronchiectasis.
To date, no studies have suggested a treatment regimen that could be used on this patient population, which does not respond to common treatments recommended by the Global Initiative for Asthma guidelines.
Therefore, Italian researchers decided to explore the potential of the biological therapy Nucala to treat patients with severe eosinophilic asthma and bronchiectasis. Their study enrolled four patients who had late-onset severe asthma, and been diagnosed with bronchiectasis, as determined by chest computed tomography scans. Study participants were followed for one year at the Institute of Respiratory Diseases at the University of Foggia, in Italy.
All participants were treated with high-dose inhaled corticosteroids (ICS), in addition to inhaled long-acting β2 agonists (LABAs) and long-acting muscarinic receptor antagonists (LAMAs). Upon enrollment, participants started treatment with Nucala by injection at a dose of 100 mg every four weeks.
Researchers found that after one year of treatment with Nucala, the patients had significantly fewer eosinophils circulating in their blood and sputum samples — they showed fewer cells in the blood (0.12 versus 0.75 cells per microliter at the study’s start), and in the sputum (5.6% versus 9.6% at the beginning of the study). No changes in the number of other immune cells were reported.
Treatment with Nucala also significantly improved the patients’ lung function, as determined by clinically meaningful changes in forced expiratory volume in one second, and better results on asthma control tests.
“For the first time, to our knowledge, we demonstrated the efficacy of mepolizumab (Nucala) in patients not only with severe eosinophilic asthma but also with diagnosed bronchiectasis, in terms of reduction of eosinophils and increasing control of the disease,” the researchers wrote.
Patients treated with Nucala also experienced fewer respiratory acute events (pulmonary exacerbations) throughout the year, with a mean reduction from five exacerbations to 0.75 after one year of treatment.
While taking Nucala, patients could reduce their inhalation therapies. Three patients (70%) changed to a lower dose of ICS, and all patients stopped taking LAMAs.
“The efficacy of mepolizumab (Nucala) that we observed in patients with severe eosinophilic asthma and bronchiectasis might suggest that targeting the IL-5 in eosinophilic bronchiectasis may be a good therapeutic strategy, and may support further larger studies in this direction,” the team said.