Inclusion and exclusion criteria: 1) Objectively secured asthma diagnosis, 2) Age 18-65 years, 3) ICS treatment equivalent to Budesonide 800 microgr daily or more with at least 80% adherence, 4) Serum-periostin < 50 ng/ml, 5) FeNO<20 ppb at all prior visits, 6) Blood-eosinophils<0.15 at screening, 7) no allergic asthma history, 8) never daily smoker, 9) no other respiratory diasease, 10) no daily treatment with immunosuppressives, 11) no pregnancy, and 12) no history of drug or alcohol abuse.