Comparison between the Effects of Generic and Original Salmeterol/Fluticasone Combination (SFC) Treatment on Airway Inflammation in Stable Asthmatic Patients
Kittipong Maneechotesuwan MD, PhD*, Jirawatana Assawabhumi BSc*, Kanokwan Rattanasaengloet BSc*, Tasneeya Suthamsmai MSc*, Sutat Pipopsuthipaiboon BSc*, Suthipol Udompunturak MSc**
Affiliation : * Division of Respiratory Diseases and Tuberculosis, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ** Department of Health Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Background : Little is known about the effect of inhaled corticosteroids (ICS)/long-acting β
2 agonists (LABA) in combination
on inflammatory markers in asthma. In addition, therapeutic equivalence of generic salmeterol/fluticasone combination
(SFC) and original SFC is as yet unknown.
Objective : To determine the effects of SFC and the effects of generic and original SFC on airway inflammation in patients with
mild-to moderate stable asthma.
Material and Method: A randomized double-blinded, crossover non-inferiority study was conducted to compare the anti-
inflammatory effects of generic SFC and original SFC on sputum eosinophils as a primary outcome and fractional exhaled
nitric oxide (FENO) as a secondary outcome.
Patients: The authors studied 51 mild-to-moderate asthmatic patients who ranged from 18 to 80 years of age and were treated
with ICS or ICS/LABA of any dose, and whose asthma was stable without an exacerbation episode for at least 3 months prior
to study entry.
Results : Both sputum eosinophils percentage and absolute eosinophil counts well correlated with FENO levels at baseline
prior to the initiation of study medications. Significant reduction in sputum eosinophil percentage was observed following
generic SFC and original SFC treatment. The degree of sputum eosinophil suppression by generic SFC was not inferior to
original SFC, and this was not affected by treatments with the sequence of generic SFC first vs. original SFC second or
original SFC first vs. generic SFC. In addition, there was no significant difference between treatments in terms of normalized
gain in asthma control scores, including the number of patients found to have improved asthma control, irrespective of
sequence, as change from baseline. However, this was not the case for the magnitude of FENO reduction that occurred after
generic SFC treatment to a significantly larger extent than original SFC treatment.
Conclusion : This short-term study demonstrated that there was no significant difference between generic SFC and original
SFC in terms of anti-inflammatory activity and the control of asthma symptoms. However, it is completely unknown whether
generic SFC could effectively prevent the development of asthma exacerbations on a long-term basis. Therefore, longer-term
studies are indicated to evaluate generic SFC’s relative efficacy on asthma exacerbations.
Keywords : Asthma, Salmeterol/fluticasone combination, Sputum eosinophils
