Efficacy of dupilumab and risk factors for dupilumab-induced hypereosinophilia in severe asthma: a preliminary study from China

ObjectiveDupilumab has been approved for the treatment of severe asthma with type 2 inflammation by inhibiting interleukin (IL)-4 and IL-13 signaling. However, dupilumab-induced hypereosinophilia (HE) has been reported and should not be ignored. The aim of this study was to investigate the efficacy of dupilumab in Chinese patients with severe asthma, whether HE affects its efficacy, and the possible risk factors for HE.Methods20 patients with severe asthma who received dupilumab treatment for at least 12 months in the First Affiliated Hospital of Guangzhou Medical University from 2019 to 2022 were included. We compared clinical data and laboratory tests results before dupilumab treatment and at 4 and 12 months after treatment. Based on whether dupilumab treatment triggers HE defined as blood eosinophil count (BEC) >= 1.5 x 109 cells/L, the patients were allocated into non-HE and HE groups.ResultsThe patients showed a significant increase in asthma control test (ACT) scores, a decrease in the number of exacerbations, a decrease in the proportion of patients taking an oral corticosteroid (OCS) and in the dose, and a significant improvement in the pulmonary function parameters FEV1/FVC (%) and FEV1 (% predicted) after 4 and 12 months of treatment with dupilumab. For type 2 inflammatory biomarkers, the levels of fractional concentration of exhaled nitric oxide (FeNO), sputum eosinophil count percentage (SEC%) and total immunoglobulin E (TIgE) decreased significantly, whereas BEC were higher after 4 months of treatment, but returned to baseline levels after 12 months. 8 patients (40%) developed asymptomatic HE after dupilumab, and the efficacy was not significantly different between the HE and non-HE groups. The earliest BEC elevation appeared at 1 month after treatment, but most of them declined after 6 months, and basically returned to the baseline level around 12 months of treatment. In addition, we further found that when patients had FeNO >= 60 ppb, food allergens positive and combined eosinophilic otitis media (EOM), their BEC increased significantly more than that of the control group after 4 months as well as 12 months of treatment.ConclusionsThis study demonstrated that dupilumab was efficacious in Chinese patients with severe asthma, and some patients developed asymptomatic, self-limited HE, which did not affect its efficacy. Additionally, FeNO >= 60 ppb, food allergens positive, and co-morbidities with EOM may be the risk factors for developing HE.