Table 1. Objectifiable parameters for a response to mepolizumab therapy after 6 months (at least 1 parameter should be fulfilled) (modified from [6]).

Nasal obstruction: improvement of the nasal congestion score (0 – 3) by > 0.5 or improvement of objective tests (e.g., increase in nasal inspiratory peak flow or nasal volume flow in active anterior rhinomanometry by > 20 L/min, reduction in resistance)

Nasal polyp score (NPS): Reduction of the endoscopically determined NPS (0 – 8) by > 1 score point compared to the initial value

SNOT-22/quality of life: reduction in SNOT-22 score (0 – 110) by > 8.9 (validated minimum clinically relevant difference)

Symptomatology in visual analog scale (VAS): reduction in total VAS symptoms (0 – 10 score points) by > 2

Smelling ability: improvement in the 16-point Sniffin‘ Sticks identification test by > 3 points (validated minimum clinically relevant difference)