Attitudes and Practices Regarding Dosing Interval Extension of Biologics in Severe Asthma: A Nationwide Survey and Real-World Data From the Dutch RAPSODI Registry.

Abstract

Biologics in severe asthma are an effective but costly treatment. A personalized dosing strategy could reduce treatment burden and improve cost-effectiveness. To explore physician attitudes and real-world practices regarding dosing interval extensions for biologics in severe asthma. We assessed attitudes to dosing interval extension among Dutch pulmonologists prescribing biologics through a 28-item nationwide e-survey and investigated clinical practices using data from the Dutch severe asthma registry RAPSODI (Dutch Registry of Adult Patients with Severe asthma for Optimal DIsease management). Of 50 pulmonologists, 39 (78%) reported extending dosing intervals, primarily due to good clinical response (95%) and treatment costs (77%). Most required at least 1 year of stable asthma (82%), which respondents defined as 6-item Asthma Control Questionnaire score less than 1.5, stable lung function, absence of exacerbations, and no maintenance oral corticosteroids. Reported success rates exceeded 50% for 62% of respondents, with failures mainly due to exacerbations or worsening symptoms. Interval extension was more frequent among physicians treating more than 25 patients with severe asthma (P < .01). Major barriers included lack of evidence (63%) and experience (52%), yet 91% expressed a wish to extend intervals more often. In RAPSODI (n = 1603), 159 interval extensions were recorded in 138 patients across 14 hospitals. Median increase in interval relative to the standard interval was 50% (range, 12.5%-300%) with multiple sequential extensions in 14% of patients. In 2024, the annual incidence of extensions was 5.2%, and the prevalence was 11.4%. A vast majority of Dutch pulmonologists already apply dosing interval extension of biologics in severe asthma, however on a limited scale. Although the frequency is increasing, clinicians are reluctant to apply extension broadly due to limited experience and evidence, highlighting the need for evidence-based guidelines.