The Role of Bronchial Biopsy in the Prediction of Response to Biologic Therapy in Severe Uncontrolled Asthma: A Prospective Study.

Abstract

Background: Up to two-thirds of patients with severe uncontrolled asthma (SUA) who received biologic therapy do not have a complete response.

Research question: Can bronchial biopsy (BB) play a role in the identification of patients with SUA who have a better response to biologic therapy?

Study design and methods: This prospective multicenter study included consecutive patients with SUA who were candidates for biologic therapy. They underwent bronchoscopy and BB prior to biologic therapy, and clinical response was evaluated 6 months later. BB was evaluated according to a previously validated pathological score (PS) and was compared with a score of type 2 (T2) inflammation (T2 score) that includes blood eosinophil count and fractional exhaled nitric oxide in predicting response to biologic therapy. Response was graded as super-response, good response, and partial/no response according to a composite score that includes exacerbations, oral corticosteroid steroid (OCS) use, asthma control test, and improvement in FEV₁.

Results: A total of 92 patients were recruited. Of the 92 patients recruited, 78 completed the study. Among them, 63 received an anti-IL-5 or IL-5 receptor (anti-IL5/5R) (mepolizumab, reslizumab, and benralizumab) while 15 received dupilumab. The proportion of super-responders was 36.5% in the anti-IL5/5R group and 26.6% in the dupilumab group (P = .126). The PS was the only variable independently associated with response; the T2 score was not. Super-responders had a statistically significantly higher PS. Response was better predicted by the PS compared with the T2 score in those receiving OCSs and especially in those taking anti-IL5/5Rs. Reduced eosinophil levels (< 10 eosinophils/field) were associated with poor response to biologic therapy.

Interpretation: Our findings indicate that BB is more precise in the prediction of response to biologic therapy than the T2 score, especially in those requiring OCSs or receiving anti-IL5/5Rs. Tissue eosinophilia is the main driver of this predictive capacity. However, other items in the PS related to bronchial remodeling might contribute to the identification of response to biologic therapy.