Study Design and Time Points of Assessment of FENO

Study Phase
ScreeningRun-inDouble-Blind Steroid StableDouble-Blind Steroid ReductionOpen-Label Extension
Week−7−6 or −4 to 00–1616–2828–52
Study treatmentNoneNoneOmalizumab or placeboOmalizumab or placeboOmalizumab
ICS dose, μg/d≥168–420 BDP or equivalent168–420 BDP*BDP 168–420 at stable doseBDP dose tapered over 8 weeks, then stable for 4 weeksBDP dosed as appropriate for maintenance (24 weeks)
FENOAll visits (assessed 4-weekly)All visits (assessed 2-weekly)Visits 15 and 19 (weeks 36 and 52)
  • * During the run-in, any patients on ICSs other than BDP were switched to an equivalent dose of BDP, and the dose was adjusted to maintain asthma control compatible with previous ICS treatment.