Anti-IL-5 biologics effective in severe asthma, but residual disease remains
Published online: October 15, 2020
Anti-IL-5 biologics (mepolizumab, reslizumab, benralizumab) have been shown to significantly reduce exacerbations and chronic oral corticosteroid (OCS) use in clinical trials in patients with severe asthma. However, in daily practice the response to these treatments is heterogeneous. Some patients show life-changing improvements, while others show suboptimal responses with troublesome residual disease manifestations. These incomplete treatment responses often prompt physicians to switch between anti-IL-5 biologics in order to obtain the best therapeutic response. Currently, only limited data exists about treatment response, switches, and residual disease manifestations after long term anti-IL-5 treatment.
In a recently published multicenter study in The Journal of Allergy and Clinical Immunology: In Practice, Eger et al. assessed real-life long term (2 year) treatment response to anti-IL-5 biologics in severe asthma patients enrolled in the Dutch Severe Asthma Registry. Super-responders were defined as patients free of any residual disease manifestation after 2 years of anti-IL-5 treatment, partial responders as patients experiencing residual disease manifestations at the 2 years follow-up, and non-responders as patients who stopped anti-IL-5 treatment within 2 years because of clinical worsening. The authors also explored predictors for super or non-response, the nature of residual disease manifestations in partial responders, and the frequency and reason why patients switched between anti-IL-5 biologics during the 2 years follow-up.
After 2 years of anti-IL-5 treatment, 83% of patients still used anti-IL-5 biologics, of whom 14% qualified as super-responders and 69% as partial responders. Eleven percent of patients had stopped treatment because of non-response. A shorter asthma duration and better lung function were significant predictors of a super-response, while adult-onset asthma, absence of nasal polyps, and a relatively low body mass index (BMI) showed a trend for an association. No predictors could be identified for non-response. The most common residual disease manifestations after 2-years follow-up were impaired lung function (59%), uncontrolled sino-nasal disease (58%), uncontrolled asthma symptoms (48%), and need for chronic OCS treatment (32%). During the 2 year follow-up, 41% of patients switched between biologics, mostly because of insufficient clinical responses.
In summary, although anti-IL-5 treatments have remarkable effects on exacerbations and OCS use, a significant proportion of patients still suffers from residual disease manifestations. The newer biologics that are in the pipeline targeting so-called “upstream” cytokines will hopefully tackle these remaining conditions as well.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.
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