Real-world effectiveness of tezepelumab on clinical remission and small airway dysfunction in severe asthma: a 52-week prospective study

BACKGROUND: Clinical remission is an emerging goal in severe asthma (SA) management. While tezepelumab demonstrates broad efficacy, its real-world impact on remission - specifically in the context of small airway dysfunction (SAD) - remains incompletely defined. METHODS: This prospective, multicentre study enrolled 39 adults with SA treated with tezepelumab for 12 months. Clinical remission was defined by SANI criteria: complete oral corticosteroid (OCS) withdrawal, zero severe exacerbations, Asthma Control Test score ≥ 20, and stable/improved FEV₁. SAD remission required normalization of oscillometric parameters. RESULTS: At baseline, 44% of patients exhibited SAD. Tezepelumab eliminated severe exacerbations and achieved complete OCS withdrawal in 100% of evaluable patients. At 12 months, 77.4% of the overall evaluable cohort and 80.0% of those with baseline SAD achieved clinical remission. However, SAD remission was not observed; these patients maintained persistent oscillometric abnormalities despite reaching all clinical goals. CONCLUSION: Tezepelumab enables high rates of clinical remission regardless of baseline small airway status. In the SAD phenotype, symptomatic and inflammatory recovery dissociates from physiological SAD remission. Persistent mechanical abnormalities highlight the necessity of oscillometry to identify hidden residual disease in patients who otherwise appear to be in remission.