Clinical Response and Remission in Patients With Severe Asthma Treated With Biologic Therapies

Background: The development of novel targeted biologic therapies for severe asthma has provided an opportunity to consider remission as a new treatment goal.

Research question: How many patients with severe asthma treated with biologic therapy achieve clinical remission, and what predicts response to treatment?

Study design and methods: The Danish Severe Asthma Register is a nationwide cohort including all adult patients receiving biologic therapy for severe asthma in Denmark. This observational cohort study defined "clinical response" to treatment following 12 months as a ≥ 50% reduction in exacerbations and/or a ≥ 50% reduction in maintenance oral corticosteroid dose, if required. "Clinical remission" was defined by cessation of exacerbations and maintenance oral corticosteroids, as well as a normalization of lung function (FEV₁ > 80%) and a six-question Asthma Control Questionnaire score ≤ 1.5 following 12 months of treatment.

Results: Following 12 months of treatment, 104 (21%) of 501 biologic-naive patients had no response to treatment, and 397 (79%) had a clinical response. Among the latter, 97 (24%) fulfilled the study criteria of clinical remission, corresponding to 19% of the entire population. Remission was predicted by shorter duration of disease and lower BMI in the entire population of patients treated with biologic therapy.

Interpretation: Clinical response was achieved in most adult patients initiating biologic therapy, and clinical remission was observed in 19% of the patients following 12 months of treatment. Further studies are required to assess the long-term outcome of achieving clinical remission with biologic therapy.