Dupilumab Effectiveness in Severe Asthma: a Cohort Study From a Nationwide Early Access

Introduction:

Asthma is a worldwide burden affecting more than 300 millions patients. Although the vast majority of asthma patients suffer from mild to moderate diseases whose symptoms can be assessed with inhaled corticosteroids (CSI) and bronchodilators, 3.7% of them present with severe asthma (SA). SA is defined as an asthma remaining uncontrolled despite adherence with maximal optimized therapy and treatment of contributory factors, or that worsens when high dose treatment is decreased. SA represents a small proportion of patients but the very heart of the asthma problem with tremendous health costs, high morbidity and significant mortality. Thus it has been the center of therapeutic research interest for the past decade and different treatments have achieved development and reglementary approvals. Among them, dupilumab is a fully human monoclonal antibody targeting the alpha subunit of the interleukin 4 receptor, blocking both IL-4 and IL -13 pathways. It is therefore interacting with the type 2 inflammation response observed in eosinophilic asthma. The French Ministry of Health therefore opened a window of appeals for TUA from September 2017 to January 2018, allowing early access to dupilumab for SA patients demonstrating unacceptable steroids side effects and/or life-threatening exacerbations, irrespective of their T2 status. By that time indeed, phase 3 randomized clinical trials (RCT) on eosinophilic patients had not yet been published.

In this phase IV real-life study with no placebo group, the investigators aimed to describe patients' characteristics and to evaluate the efficacy and safety of Dupilumab on non-selected SA patients.

Method:

This multicenter retrospective observational real-life study was conducted at 13 public teaching hospitals across the country. All French SA patients who received dupilumab under the TUA between September 2017 and January 2018 were included in the survey, as long as they had received at least one injection and completed at least one follow-up visit in the first 12 months of treatment. No inclusion criteria were required, but patients' files had previously been screened through by health authorities and validated by Sanofi to allow dupilumab TUA. Physicians had had to certify that patients had SA with no other treatment available at that time, and that poor asthma control and/or severe steroid side effects required scaling up treatment. Patients were not required to have eosinophilia. However, patients were excluded from the TUA if they presented with previous hypereosinophilia > 1500/mm3, as symptomatic hypereosinophilia has previously been described with dupilumab in this particular population.