Among patients with asthma and comorbid gastroesophageal reflux disease (GERD), the , according to a new post-hoc analysis of the phase 2b PATHWAY and phase 3 NAVIGATOR clinical trials.
GERD occurs in about 60% of asthma patients, and the comorbidity is associated with a greater risk of asthma exacerbations. “As we start doing subgroup analyses, we are looking at different comorbidities and reflux is one that’s very common and very impactful on asthma outcomes in a negative way, so it became an area of interest,” said Njira Lugogo, MD, who presented the study during a poster session at the annual meeting of the American College of Chest Physicians (CHEST). She is a professor of internal medicine and pulmonary critical care at the University of Michigan, Ann Arbor.
The analysis confirmed other findings, with comorbid GERD associated with more exacerbations, use of maintenance steroids, and high-dose inhaled steroids. “They had more disease activity, and the effect [of tezepelumab treatment] was similar whether you had reflux or didn’t have reflux. It did seem like the people without reflux had a slightly higher reduction in exacerbations, so maybe there is a slight difference, but overall it looked like both groups were really improving,” said Dr. Lugogo.
Tezepelumab is a newer biologic, having received Food and Drug Administration approval in 2021. It targets the epithelial cytokine thymic stromal lymphopoietin (TSLP), which contributes allergic inflammatory responses by acting on various innate immune cells, including dendritic cells, mast cells, and CD34+ progenitor cells. It is upregulated in the airways of asthma patients, with higher levels linked to more severe disease. A single-nucleotide polymorphism in the gene that codes TSLP has also been found to be protective against asthma, atopic asthma, and airway hyper-responsiveness.
Dr. Lugogo noted that TSLP could be a factor in how GERD may worsen trigger or worsen asthma. It is produced in the epithelium of the upper airway in response to injury, which could include aspiration into bronchial tubes attributable to GERD, and this could lead to a downstream inflammatory and immune response. “Reducing the production of or at least blocking TSLP from an epithelium that’s being irritated by acid reflux could have potential benefits. On the reverse side, could the continued presence of reflux blunt the expected response [to tezepelumab]? If someone has very severe reflux, maybe you’ve treated their asthma with tezepelumab, and they’re still having symptoms. Could it be a masquerading issue [where] you have untreated reflux contributing to ongoing symptoms, which you’re attributing to not being related to asthma? So it’s looking at it in two different ways,” said Dr. Lugogo.
TSLP is the only biologic available to treat patients with non–type 2 inflammation, which includes about 10% of adult patients, according to Dr. Lugogo. Its mechanism also influences eosinophilic and allergic asthma. When tezepelumab first became available, Dr. Lugogo noticed that physicians tended to switch to it from another biologic rather than starting it up front, but that may be changing. “I feel like more and more people are starting it up front as a therapeutic intervention, so there seems to be more and more people embracing its use in the treatment of severe asthma,” she said.
The analysis included 294 patients with asthma and GERD and 1,040 with asthma alone. Patients in the GERD comorbidity group were older (55.0 versus 48.6 years), had a higher mean body mass index (30.8 versus 27.8), and were more likely to be female (67.3% versus 63.0%).
Maintenance oral corticosteroid use was higher in the GERD group (17.0% versus 6.9%), as was use of high inhaled corticosteroid dose (78.2% versus 67.0%), frequency of nasal polyps in the previous 2 years (21.4% versus 13.8%), and experience of more than two exacerbations in the previous year (42.2% versus 34.6%).
There was a 65% reduction (95% confidence interval, 50%-76%) in annualized asthma exacerbation rate versus placebo with tezepelumab treatment in the GERD group, compared with a 58% reduction in the asthma-only group (95% CI, 48%-66%). The drug led to a 0.10 increase in forced expiratory volume in 1 second versus placebo (95% CI, 0.00-0.19) at week 52 in the GERD group, versus 0.15 (95% CI, 0.10-0.20) in the asthma-only group. Tezepelumab also improved week 52 ACQ-6 scores in the GERD group (–0.39 versus placebo; 95% CI, –0.63 to –0.14) and the asthma-only group (–0.32 versus placebo; 95% CI, –0.45 to –0.19).
The study adds to the evidence supporting tezepelumab as a promising new therapy, according to Muhammad Adrish, MD, who attended the poster session and was asked to comment on the study. “I think that this is a very interesting analysis in the sense that gastric reflux disease is a frequent comorbid condition that we see in patients with asthma, and a lot of these patients can have poor outcomes. When you look at the results from the data, you see that regardless of how sick they were and how much medication utilization these patients have at baseline, they still had a pretty decent response to tezepelumab. That speaks to the efficacy of that drug along a wide spectrum of patients,” said Dr. Adrish, who is an associate professor of pulmonary, critical care, and sleep medicine at Baylor College of Medicine, Houston.
The PATHWAY and NAVIGATOR studies were funded by Amgen. Dr. Lugogo has advised or consulted for AstraZeneca, Amgen, Regeneron, TEVA, Avillion, Sanofi, Novartis, Genentech, GSK, and Janssen. Dr. Adrish has no relevant financial disclosures.