According to the findings of post hoc analysis of the QUEST study, Dupilumab demonstrates a substantial decrease in severe asthma exacerbations and enhances lung function in patients who have uncontrolled moderate-to-severe asthma. This improvement is witnessed in those having baseline blood eosinophil counts equal to or exceeding 150 cells/mL and/or fractional exhaled nitric oxide (FeNO) levels equal to or exceeding 20 parts per billion, regardless of whether they exhibit signs of an allergic asthma subtype.

The researchers set out to evaluate the effectiveness of Dupilumab in patients exhibiting a type 2 phenotype, whether they had an allergic asthma phenotype or not. Subjects > 12 years of age were administered either add-on Dupilumab at doses of 200/300 mg or a matched placebo every 2 weeks for a duration of 52 weeks. The definition of an allergic asthma phenotype included a baseline serum total IgE level of > 30 IU/mL and the presence of 1 or more perennial aeroallergen-specific IgE levels > 0.35 kU/L.

The study examined the annualized rate of severe asthma aggravations and alterations in prebronchodilator and postbronchodilator forced expiratory volume (FEV1) compared to baseline in individuals who had a baseline blood eosinophil count of higher than or equal to 150 cells/μL and/or a FeNO level of higher than or equal to 20 parts per billion. This assessment encompassed both nonallergic and allergic phenotypes. Among the 1902 patients included in the QUEST study, approximately 83.3% displayed elevated eosinophil counts and/or FeNO levels exceeding the thresholds set by the Global Initiative for Asthma.

Within this group, 56.9% exhibited indications of allergic asthma. Dupilumab demonstrated a significant drop in the rate of severe asthma exacerbations for those with allergic asthma (48.8%) as well as those without it (64.0%). Furthermore, it enhanced both prebronchodilator and postbronchodilator FEV1 in those having heightened type 2 biomarkers, regardless of whether they exhibited signs of the phenotype of allergic asthma. Dupilumab demonstrated a profound reduction in exacerbations and improved lung function among those patients.

Importantly, its effectiveness was consistent regardless of the patient's allergic status. This information implies that blood eosinophil levels and FeNO measurements are meaningful indicators for forecasting the response to Dupilumab treatment, while initial allergy tests conducted before treatment may have limited predictive utility.