Zileuton Improves Lung Function in Aspirin-Sensitive Asthma Patients

Efficacy of zileuton CR was tested in asthma patients without and without aspirin sensitivities
Efficacy of zileuton CR was tested in asthma patients without and without aspirin sensitivities

ATLANTA, GA—At the 2017 AAAAI Annual Meeting, two Phase 3 studies found that aspirin-sensitive asthma patients had greater improvements in pulmonary function after treatment with zileuton CR vs. asthma patients without aspirin sensitivity. 

Higher levels of 5-lipoxygenase (5-LO) activity and overproduction of cysteinyl leukotrienes are seen in patients with aspirin-sensitive asthma, which can cause bronchoconstriction, explained Tanya M. Laidlaw, MD, FAAAAI, from Brigham and Women's Hospital, Boston, MA. Study authors hypothesized that treatment with oral zileuton, an FDA-approved 5-LO inhibitor, could help patients with aspirin-sensitive asthma. 

Dr. Laidlaw and coauthors performed retrospective analysis of two Phase 3 placebo-controlled studies evaluating the safety and efficacy of zileuton CR during 1995–1997. They identified patients with self-reported history of asthma exacerbated by aspirin exposure ("Yes" or "No"). For each study arm, percent changes from baseline in FEV1, morning (AM) PEFR and evening (PM) PEFR were compared between zileuton and placebo treatment.

Study authors reported that 81 of 1,349 (6.0%) patients had self-reported aspirin-sensitive asthma. Of these patients, the median percent predicted FEV1 at baseline was 68.7% vs. 67.1% of patients without a history of aspirin-sensitive asthma. There were greater FEV1 responses from baseline among the aspirin-sensitive asthma subgroup who were treated with zileuton CR (22.8% vs. 6.1%; P=0.160) vs. the non-aspirin-sensitive asthma group (14.0% vs. 10.2%; P=0.034). 

Also, AM PEFR responses to zileuton CR vs. placebo were higher in the aspirin-sensitive asthma subgroup (27.8% vs. 4.8%; P=0.043) compared to the non-aspirin-sensitive asthma subgroup (15.8% vs. 11.4%; P=0.017). "Similar results were observed for PM PEFR responses," noted Dr. Laidlaw. 

In conclusion, treatment with zileuton CR led to greater improvements in pulmonary function in patients with aspirin-sensitive asthma vs. patients without a history of aspirin sensitivity.