Biologics lower exacerbation rates in severe asthma, allergic rhinitis

Treatment with either omalizumab (anti-immunoglobulin E [anti-IgE]) or nonomalizumab (non-anti-IgE) biologics reduced exacerbations in patients with severe asthma and allergic rhinitis, with the benefits being more evident among those taking nonomalizumab agents, according to the CHRONICLE trial presented at AAAAI 2023.

“Although there are multiple biologics approved for uncontrolled severe asthma such as monoclonal antibody therapies, they have different mechanisms of action with outcomes that may vary by type (eg, IgE therapies vs other biologics),” said lead author Dr Warner Carr from the Allergy & Asthma Associates of Southern California in Mission Viejo, California, US.

The ongoing real-world observational study analysed 598 adults (aged ≥18 years) with severe asthma, of whom 339 had a diagnosis of allergic rhinitis, treated by subspecialists in the US. Participants were given omalizumab (n=163) or nonomalizumab biologics (n=435). All patients were stratified according to allergic disease status, either based on a diagnosis of allergic rhinitis or elevated total IgE levels (150–400 IU/mL and ≥400 IU/mL).

At 6 months after biologic initiation, the overall rate of exacerbations was reduced by 47.8 percent (from 1.36 percent to 0.71 percent) in the omalizumab group and 55.3 percent (from 1.70 percent to 0.76) in the nonomalizumab group. [AAAAI 2023, abstract 43]

While those with allergic rhinitis, the decrease in exacerbation rate was more pronounced among those treated with nonomalizumab than those treated with omalizumab (58.8 percent vs 39.3 percent). This effect may be attributed to the fact that the omalizumab group had lower exacerbation rates than the nonomalizumab group before initiation (1.22 percent vs 1.60 percent).

Among patients with total IgE levels of ≥150–400 IU/mL, treatment with nonomalizumab was associated with a greater reduction in exacerbation rates compared with omalizumab (62.6 percent vs 44.3 percent).

There was also a greater reduction in exacerbations among patients with a total IgE level of 400 IU/mL who received nonomalizumab than omalizumab (77.8 percent vs 50.0 percent).

“[All] these differences should be interpreted in the context of biologic selection practices and differing patient characteristics between those receiving omalizumab and other biologics,” Carr said.

“Overall, among this large cohort of patients with severe asthma, exacerbations decreased following initiation of biologics, with greater magnitude among those with higher total IgE levels and in those treated with nonomalizumab agents,” he noted.

“These descriptive observations warrant continued research into this patient population and therapies,” he added.

Biologic initiation by age of asthma onset

“The efficacy of biologics for severe asthma treatment may vary by patient age at asthma onset due to the distinctly different mechanisms of action,” said Dr Dennis Ledford from the University of South Florida in Tampa, Florida, US, who presented the subgroup analysis of the CHRONICLE trial. [AAAAI 2023, abstract 44]

Among the subgroup of patients with early-onset asthma, the reduction in exacerbation rates was slightly higher in the omalizumab group vs the nonomalizumab group (51.5 percent vs 45.0 percent [aged <18 years] and 63.8 percent vs 54.9 percent [aged 18–39 years]).

Among those with late-onset asthma (aged ≥40 years), patients on nonomalizumab biologics achieved a greater reduction in exacerbation rates than those on omalizumab (60.8 percent vs 24.6 percent).

As a result, reductions in exacerbations varied by patient age of onset and biologic, Ledford noted.

We believe that this warrants consideration of age at asthma onset when selecting biologics that are approved for specific phenotypes of severe asthma, he added.