4CPS-206 Abstract withdrawn

<h3>Background and Importance</h3> Efficiency criteria lead us to treat patients with severe uncontrolled asthma (SUCA) and high weight with drugs that are not dosed by weight, such as mepolizumab. In hospitals that do not carry out level monitoring, it is unknown if this could translate into underdosing of these patients and, most importantly, if this leads to worse control of the disease. <h3>Aim and Objectives</h3> To know the influence of body weight on the effectiveness of treatment with anti-IL5 drugs in patients diagnosed with SUCA. <h3>Material and Methods</h3> Retrospective observational study in which all patients diagnosed with SUCA who had received treatment with mepolizumab and reslizumab as part of standard clinical practice. As main variable effectiveness, the appearance of exacerbations after the start of biological treatment was studied, understood as the need for treatment with systemic corticosteroid (SC), depending on weight: ≤80 kg and &gt;80 kg. The demographic, clinical and analytical analyses were obtained from the electronic medical record (Diraya) and data related to the treatment of the electronic prescription (PRISMA). <h3>Results</h3> In August 2024, 128 patients had been treated with anti-IL5 drugs, 76 patients with mepolizumab (59.4%) and 26 patients with reslizumab (40.6%). The average age was 56 years for the cohort of mepolizumab and 60 years for reslizumab. The average weight in the mepolizumab group was 81.5 kg (57–144) vs 69 kg (57–99) in the reslizumab group. In the mepolizumab group, 32 patients weighed ≤80 kg compared to 48 patients in the reslizumab group. Patients weighing &gt;80 kg were 28 in the mepolizumab group and four in that of reslizumab. 16 patients in the mepolizumab group were excluded because their weight was not available. 53.3% of patients treated with mepolizumab (n=32) required SC compared to 46.1% (n=24) in the reslizumab group. Between patients with ≤80 kg, 62.5% of mepolizumab patients (20/32) required SC compared to 50% (24/48) in the group of reslizumab, OR=1.67 (95% CI, 0.27 to 10.33; p=0.58). In the group of patients with &gt;80 kg, 42.8% of patients treated with mepolizumab (12/28) underwent treatment with SC and none in the reslizumab group (0/4). <h3>Conclusion and Relevance</h3> According to the results patients on fixed dosage, treated with mepolizumab, suffer more exacerbations and, therefore, they require more of the use of systemic corticosteroids regardless of body weight. Weight-based dosing of reslizumab could be beneficial in terms of effectiveness. Patients &gt;80 kg appear to benefit from reslizumab dosing in our cohort. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest