Benralizumab is effective in treating eosinophilic asthma. It also improves the quality of life of individuals with poorly controlled asthma.
Breathlessness, recurrent exacerbations, and decreased quality of life are prevalent in individuals with severe asthma despite high-dose corticosteroids. The hallmarks of severe eosinophilic asthma include eosinophilic airway infiltration, inflammation, blockage, or constriction. Benralizumab, an anti-IL-5Ra, binds to the eosinophil IL-5 receptor and killer cell receptors, causing eosinophil levels to decrease within two hours of treatment and improving asthma control and quality of life. The effect of anti-IL-5 therapy on eosinophil depletion has a known action, but its impact on large and small airway anatomy and function has not been well studied.
This study, published in Chest, attempted to quantify 129Xe MRI ventilation defect changes after a single injection of benralizumab, and then to determine whether baseline mucus occlusions influenced prospective response.
Participants were 18 to 80 years old, with no history of exacerbation within 4 weeks, a blood eosinophil count of ≥ 300 cells/mL, reversibility of FEV1 following bronchodilator usage, and poorly controlled asthma, as measured by the Asthma Control Questionnaire (ACQ) 6 score of ≥ 1.5 at screening. St. George’s Respiratory Questionnaire, ACQ, MRI, eosinophil count, Asthma Quality of Life Questionnaire (AQLQ), spirometry, and oscillometry, were performed on day 0 and day 28 following a single 30-mg subcutaneous administration of benralizumab. CT scan mucus plugs were examined on day 0, and MRI VDP was measured on days 0 and 28.
On the 28th day after benralizumab, all individuals had significantly improved blood eosinophil counts, VDP, ACQ 6 scores, AQLQ scores and peripheral airway resistance. Moreover, the subgroup of nine participants with five or more mucus plugs had significantly improved VDP and ACQ 6 scores, but not the subgroup with fewer than five mucus plugs. Furthermore, a significant improvement in R5-19Hz (but not in central airways resistance or reactance) in all participants
The study concludes that all patients with poorly managed asthma and those with five or more mucus plugs experienced a significant improvement in asthma control 28 days after a single dose of benralizumab, but not participants with fewer than five mucus plugs. The percentage of MRI ventilation defects and the mucus plug score from the CT scan were predictors of the improvement in asthma control following the first dose of benralizumab.
McIntosh, M. J., Kooner, H. K., Eddy, R. L., Jeimy, S., Licskai, C., Mackenzie, C. A., . . . Parraga, G. (2022). Asthma Control, Airway Mucus, and (129)Xe MRI Ventilation After a Single Benralizumab Dose. Chest, 162(3), 520-533. doi:10.1016/j.chest.2022.03.003