S164 Mepolizumab improves and sustains asthma control and lung function in patients with severe asthma, independent of baseline IgE and FeNO in the real world: 2-year results from REALITI-A

<h3></h3> Introduction and objectives: REALITI-A study demonstrated mepolizumab effectiveness independent of immunoglobulin-E (IgE) and fractional exhaled nitric oxide (FeNO) levels in patients with severe asthma in preliminary 1-year analyses. However, additional longer-term real-world evidence on the effect of mepolizumab on asthma control and lung function may be useful to inform clinical decision making. <h3>Method</h3> REALITI-A, a 2-year, observational, prospective study enrolled patients (≥18 years) with severe asthma, newly prescribed mepolizumab (100-mg subcutaneously). Changes from baseline in asthma control (Asthma Control Questionnaire-5 [ACQ-5] scores, minimal clinically important difference: 0.5) and lung function (forced expiratory volume in 1 second [FEV₁]) were assessed for baseline FeNO subgroups (&lt;25, 25–50, ≥50 parts per billion [ppb]) and baseline IgE subgroups (&lt;60, 60–&lt;180, 180–&lt;500, ≥500 KU/L) at 1-year and 2-years post-mepolizumab exposure. <h3>Results</h3> ACQ-5 scores decreased across all FeNO subgroups 1-year post-mepolizumab exposure and were sustained at 2-years: &lt;25 ppb (least squares [LS] mean change from baseline [95% CI]: -1.21 [-1.58, -0.85]), 25–&lt;50 ppb ( -1.68 [-2.10, -1.25]), ≥50 ppb (-1.61 [-1.89, -1.34]; figure 1). ACQ-5 scores also decreased across all IgE subgroups at 1-year and were sustained at 2-years: &lt;60 KU/L (-1.53 [-1.82, -1.24]), 60–&lt;180 KU/L (-1.59 [-1.90, -1.27]), 180–&lt;500 KU/L (-1.64 [-1.96, -1.31]), ≥500 KU/L (-1.19 [-1.53, -0.84]). FEV₁ improved at Months 9–12 post-mepolizumab exposure for FeNO &lt;25 ppb and ≥50 ppb subgroups and was sustained at Months 21–24 (LS mean change from baseline [95% CI]: 133.1 [22.7, 243.6]; 220.6 [98.0, 343.2], respectively). FEV₁ also improved at Months 9–12 post-mepolizumab exposure for IgE &lt;60 KU/L, 60–&lt;180 KU/L and 180–&lt;500 KU/L, and was sustained at Months 21–24 (LS mean change from baseline [95% CI]: 167.6 [81.1, 254.1], 108.8 [-31.7, 249.3], 198.1 [107.7, 288.6], respectively). FEV₁ improvements were seen to a lesser extent in FeNO 25–&lt;50 ppb subgroup at 2-years (72.2 [-57.6, 202.1]) and IgE ≥500 KU/L subgroup at Months 21–24 (82.0 [-60.7, 224.8]). <h3>Conclusion</h3> Treatment with mepolizumab in a real-life setting improves asthma control and lung function after 1-year, with improvements sustained to 2-years, independent of baseline FeNO and IgE. <h3>Funding</h3> GSK (204710).