PI-002 - FENO AND SMOKING HISTORY, NOT EOSINOPHILIA, MAY PREDICT THE EFFICACY OF TIOTROPIUM (SPIRIVA RESPIMAT) IN UNCONTROLLED ASTHMA PATIENTS DESPITE ICS/LABA TREATMENT: A PILOT STUDY.

S. Yoon¹, S. Lee², Y. Hwang¹, K. Kim¹, S. Kim¹, S. Kim², Y. Chang¹; ¹Seoul National University Bundang Hospital, Seoul, Republic of Korea, ²Hanyang University Seoul Hospital, Seoul, Republic of Korea.

Background: Asthma is a chronic airway inflammatory disease characterized by reversible airflow limitation. If asthma is not controlled with inhaled corticosteroids (ICS), a long-acting beta2 agonist (LABA) can be added, and if symptoms are still worse, long-acting anticholinergics such as tiotropium may be added. We evaluated biomarkers that could predict the effect of tiotropium, including the Th2 inflammatory phenotype.

Methods: We recruited patients diagnosed with asthma within 3 months and the symptoms were not controlled despite moderate or high-dose ICS-LABA treatment. Uncontrolled asthma was defined as a pre-bronchodilator (BD) FEV1 of less than 80% of the predicted value. Based on the peripheral blood eosinophil counts and fractional exhaled nitric oxide (FeNO), we classified the patients into T2 high (eosinophil >300 /l or FeNO>25 ppb) and T2 low (eosinophil < 300 /l and FeNO < 25 ppb) groups. The difference in pre-BD FEV1 before and after 4-weeks of tiotropium add-on therapy was evaluated as a major outcome variable, and changes in post-BD FEV1 and Asthma Control Test scores were also evaluated.

Results: A total of 27 patients were enrolled (T2 high 20, T2 low 7). There was no difference in the change of pre-BD FEV1 between the groups. In subgroup analysis, peripheral eosinophil count was not correlated with the change in pre-BD FEV1. However, the baseline level of FeNO showed a linear relationship to the change in pre-BD FEV1, and the greater the baseline level of FeNO, the greater the improvement in pre-BD FEV1. The change from baseline in post-BD FEV1 after tiotropium was increased in the smoking group.

Conclusion: Th2 phenotype considering eosinophil and FeNO could not predict the effect of tiotropium add-on therapy. However, the baseline FeNO level and smoking history might be biomarkers to predict the drug effect.