Blood eosinophils to direct oral corticosteroid treatment for patients with nasal polyps – an open label, non-inferiority, randomized control trial

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disorder. We aimed to evaluate the value of blood eosinophil count (BEC) for guiding oral corticosteroid therapy for CRSwNP. Methods: Subjects with CRSwNP were entered into a 2:1 randomized biomarker-directed corticosteroid versus standard therapy study base on the principle of potential benefits to patients. Subjects in the standard arm received oral prednisone (30mg/day) alone for 7 days, whereas in the biomarker-directed arm, prednisone (30mg/day), or nasal steroid spray (budesonide 256ug/day) was given according to the BEC which was measured to define eosinophil-high and -low CRSwNP (BEC ≥ and < 0.37×109/L, respectively). The primary outcome was the total nasal symptom scores (TNSS) of the two arms with the non-inferiority margin of 1.8. Secondary outcomes included nasal polyp size scores (NPSS) and SNOT-22. Patients were followed up the day after last dose of treatment. Results: A total of 105 subjects with CRSwNP were randomized into the biomarker-directed therapy group or the standard care group. The biomarker therapy demonstrated non-inferiority compared to standard care. There were no between-group differences for TNSS, NPSS and SNOT-22 improvements after treatment. Comparisons of TNSS, SNOT-22 and NPSS revealed no significant difference in terms of the effectiveness ratios of the biomarker-directed therapy and the standard care. Conclusion: A biomarker-directed strategy using the BEC can be used to direct corticosteroid therapy without increasing treatment failure or worsening of symptoms in patients with CRSwNP.