Patients whose asthma remains uncontrolled despite treatment may benefit from a new monoclonal antibody that targets an inflammatory cytokine known to be promoted in asthmatic airways, according to data presented at the annual congress of the European Respiratory Society.
Writing in the Sept. 7 issue of the New England Journal of Medicine, researchers reported on a phase 2, randomized placebo-controlled trial of three dosing regimens of subcutaneous tezepelumab, which targets the epithelial cell–derived cytokine thymic stromal lymphopoietin (TSLP). The trial involved 584 patients with uncontrolled asthma, despite treatment with long-acting beta-agonists and medium to high doses of inhaled glucocorticoids.
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At 70 mg every 4 weeks, exacerbation rates were 61% lower than in the placebo group; at 210 mg every 4 weeks, they were 71% lower; and at 280 mg every 2 weeks, they were 66% lower (P was less than .001 in comparisons between each group and the placebo).The overall annualized exacerbation rates by week 52 were 0.26 for the 70-mg group, 0.19 for the 210-mg group, and 0.22 for the 280-mg group, compared with 0.67 in the placebo group, regardless of a patient’s baseline eosinophil count. Patients treated with tezepelumab had a longer time to first asthma exacerbation. They also experienced a significantly higher change from baseline in their prebronchodilator forced expiratory volume in 1 second at week 52, when compared with patients on the placebo. “The observed improvements in disease control in patients who received tezepelumab highlight the potential pathogenic role of TSLP across different asthma phenotypes,” reported Jonathan Corren, MD, of the University of California, Los Angeles, and his coauthors. “... Although TSLP is central to the regulation of type 2 immunity, many cell types that are activated by or respond to TSLP, such as mast cells, basophils, natural killer T cells, innate lymphoid cells, and neutrophils, may play a role in inflammation in asthma beyond type 2 inflammation.”The incidences of adverse events and serious adverse events were similar across all groups in the study. Three serious adverse events – pneumonia and stroke in the same patient and one case of Guillain-Barré syndrome – in patients taking tezepelumab, were deemed to be related to the treatment.
Tezepelumab ‘most promising’ asthma biologic to date
Tezepelumab is the first biologic that has a substantial positive effect on two important markers of the inflammation of asthma – namely, blood eosinophil counts and the fraction of exhaled nitric oxide, noted Elisabeth H. Bel, MD, PhD, in an editorial accompanying the New England Journal of Medicine’s publication of this study (2017;377:989-91). It appears to be the broadest and most promising biologic for the treatment of persistent uncontrolled asthma to date, said Dr. Bel, of the department of respiratory medicine, Academic Medical Center, the University of Amsterdam.
The observation that tezepelumab reduces the level of both inflammatory markers shows that it hits a more upstream target and that it blocks at least two relevant inflammatory pathways in asthma, she noted. This is likely to be clinically relevant, since simultaneously increased exhaled nitric oxide levels and blood eosinophil counts are related to increased morbidity due to asthma.
The study was supported by tezepelumab manufacturers MedImmune (a member of the AstraZeneca group) and Amgen. Six of the seven authors are employees of MedImmune or Amgen. One author declared support and honoraria from several pharmaceutical companies, one declared a related patent, and five also had stock options in either MedImmune or Amgen.
Dr. Bel declared consultancies and grants from pharmaceutical companies including AstraZeneca.