Inhaled Interferon-Beta 1a Does Not Reduce Severe Asthma Exacerbations
This article is part of MPR's coverage of the American Thoracic Society's International Conference, taking place in San Diego, California. Our staff will report on medical research related to asthma and other respiratory conditions, conducted by experts in the field. Check back regularly for more news from ATS 2018.
SAN DIEGO — A study has shown that while inhaled interferon-beta 1a (IFN-β1a) did not reduce acute asthma exacerbations during respiratory viral infections, it did improve lung function (morning peak expiratory flow) during the treatment period. This research was presented at the American Thoracic Society International Conference, held May 18-23, 2018, in San Diego, California.
The study included 237 individuals with asthma on steps 4 to 5 of the Global Initiative for Asthma, who entered a waiting period upon initiation into the study. In the previous 2 years, these individuals had each experienced at least 2 acute exacerbations associated with respiratory viral infections. When symptoms of flu or cold presented, participants were randomly assigned within 48 hours to a 2-week course of either IFN-β1a or Rentschler, a placebo. Of the 121 participants who qualified for randomization, 61 were administered IFN-β1a. The primary outcome of the study was the rate of severe asthma exacerbations (systemic corticosteroid use ≥3 days, emergency room visit, or hospitalization) during the 14-day treatment period, and secondary outcomes included peak expiratory flow, concentration of serum CXCL10 protein, and sputum levels of 5 interferon-stimulated genes.
The rates of acute exacerbations were low, and showed no beneficial association with IFN-β1a (n=7) vs placebo (n=5). However, morning peak expiratory flow showed a statistically significant increase (19.7) in the first week of IFN-β1a treatment (P=.01). IFN-β1a also increased sputum interferon-stimulated genes and CXCL10 protein, both of which dropped to initial levels several days after the treatment course had ended. Regarding safety, the study drug was safe and well-tolerated by patients with slightly higher incidence of any adverse events in the treatment group vs placebo (29 vs 20); no deaths were reported.
Study researchers concluded that “Pharmacodynamic effect of IFN-β1a was confirmed, with increased levels of serum CXCL10 and sputum [interferon-stimulated genes]. The finding that asthma end points had already peaked at randomization suggests that early detection of asthma worsening is essential for an on-demand IFN-β1a therapy to be effective.” Patients with severe asthma who have high blood eosinophils or low serum interleukin-18 response "are potential subgroups for further investigation of inhaled IFN-β1a."
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McCrae C, Olsson M, Aurell M, et al. On-demand inhaled interferon-beta 1a for the prevention of severe asthma exacerbations: results of the INEXAS phase 2a study. Presented at: American Thoracic Society 2018 International Conference; May 18-23, 2018; San Diego, CA. Abstract 6165.