D1.451 - Adherence and persistence to biological treatments in patients with CRSwNP and comorbid asthma

Data on adherence to biological treatments in chronic polypotic rhinosinusitis (CRSwNP) are limited. We assessed adherence and persistence to biological CRSwNP treatments in patients with CRSwNP and comorbid asthma in Finland from June 2022 to Dec 2024.

As part of FINASTHMA COST study, all adult (≥18 years) asthma patients (ICD-10: J45 or ICPC-2: R96 recorded in national Finnish secondary or primary care registers) initiating dupilumab or mepolizumab for chronic polypotic rhinosinusitis between 2022–2023 were included. Register data on medication purchases were collected until December 31, 2024. Adherence was assessed as medication possession ratio (MPR) during the first follow-up year. Persistence was analyzed as time from treatment initiation to first non-persistence event (either treatment gap ≥ the normal purchase interval or switch). Oral corticosteroid (OCS) use and sinus surgeries after the first follow-up year was compared between adherent (MPR ≥80%) and non-adherent (MPR <80%) patients.

Overall, 238 patients initiated either dupilumab or mepolizumab. Adherence to initial biological treatment (MPR ≥80%) was observed in 168 (70.6%) patients while 70 (29.4%) patients were non-adherent. Mean MPR was 86.0 (SD 19.6) for the first treatment year and 77.4 (SD 21.9) for the first two treatment years. Median event-free persistence was 1.5 (95% confidence interval [CI]: 1.2–2.0) years. Biologic-specific adherence could not be compared between dupilumab and mepolizumab due to low number of mepolizumab patients (n=3). No sinus surgeries were done during the first year of biologic treatment in adherent or non-adherent groups. Mean annual OCS use was 145 (SD 426) mg for adherent patients and 356 (SD 1347) mg for non-adherent patients (p=0.067) during the first year of biologic treatment.

Overall, adherence to biological treatment for patients with CRSwNP and comorbid asthma was suboptimal as 71% were adherent first year and adherence tended to decline from the first to second year of treatment. The findings suggest a numerically lower OCS burden among adherent patients, warranting further investigation in larger or adjusted analyses.

Opportunity is raised to improve adherence and optimize treatment outcomes through patient education and shared decision making.