Treatment Eligibility of Real-life Mepolizumab-treated Severe Asthma Patients.

Abstract Background Severe asthma patients not meeting the strict trial eligibility criteria for mepolizumab are now routinely treated with this biological in clinical practice, but it remains unclear whether these ineligible patients respond differently to mepolizumab treatment. Objective This study investigated the extent and reasons for trial ineligibility of real-life, mepolizumab-treated severe asthma patients and compared characteristics of these patients with trial populations. Subsequently, therapeutic response in ineligible patients was assessed on the basis of oral corticosteroid (OCS) reduction. Methods Trial eligibility, population differences and therapeutic response were assessed using baseline characteristics of mepolizumab-receiving severe asthma patients treated in the Amsterdam University Medical Centres (UMC) and OCS dose at six months for OCS-dependent patients extracted from patients’ electronic health records. Eligibility criteria and population characteristics from trials investigating mepolizumab were extracted from their original publications. Results 82.4% of 119 mepolizumab-receiving, real-life severe asthma patients were ineligible for trial inclusion, wherein 42.9% and 39.5% were excluded on basis of in- and exclusion criteria, respectively. The clinical care population was older, more often male and demonstrating a better lung function under lower OCS maintenance dosages in comparison to trial populations. 50% of 66 ineligible, OCS-dependent mepolizumab-treated patients were able to reduce their maintenance OCS dosage to ≤ 5 mg prednisone/day. Conclusions A large proportion of the real-life, mepolizumab-treated severe asthma population would be excluded from trial participation and significant differences in population characteristics exist. Regardless, a large fraction of ineligible patients in clinical care maintenance OCS dosage under mepolizumab therapy.