Peak nasal inspiratory flow assessment of polyp size and response from SYNAPSE.

Background: In the phase III SYNAPSE study, mepolizumab plus standard of care reduced total endoscopic nasal polyp score (NPS) versus that with placebo in patients with chronic rhinosinusitis with nasal polyps.

Objective: Our aim was to investigate relationships between NPS and (1) peak nasal inspiratory flow (PNIF) and (2) patient-reported outcomes.

Methods: In this analysis, patients randomized 1:1 received mepolizumab, 100 mg, or placebo subcutaneously every 4 weeks (plus standard of care). Changes from baseline in PNIF (week 52), visual analog scale scores (overall symptoms, nasal obstruction, and loss of smell [weeks 49-52]), and total 22-Item Sino-Nasal Outcome Test score (week 52) were assessed in patients with or without improvements in NPS (improvement of ≥1 point) or without (improvement of <1 point or worsening).

Results: Patients with improvements in NPS had greater improvements in PNIF (a median of 50 L per minute [interquartile range (IQR) = 10.5-87.5] with mepolizumab vs a median of 40 L per minute [IQR = 0-85.0] with placebo) than did those patients without improvements in NPS (a median of 0.0 L per minute [IQR = -10.0 to 45.0] with mepolizumab vs a median of 0.0 L per minute [IQR = -30.0 to 30.0] with placebo). Similar results were seen for the following: change from baseline in overall symptoms (a median of -5.8 [IQR = -8.1 to -3.80] with mepolizumab and a median of -4.1 [IQR = -7.0 to -1.2] with placebo with improvement in NPS vs a median of -1.3 [IQR = -6.3 to 0.0] with mepolizumab and a median of -0.1 [IQR = -3.4 to 0.0] with placebo without improvement in NPS); change in nasal obstruction (a median of -5.7 [IQR = -8.2 to -3.5] with mepolizumab and a median of -4.5 [IQR = -7.3 to -1.2] with placebo with improvement in NPS vs a median of -1.3 [IQR = -6.6 to 0.0] with mepolizumab and a median of 0.0 [IQR = -3.6 to 0.0] with placebo without improvement in NPS); change in loss of smell (a median of -2.8 [IQR = -7.9 to 0.0] with mepolizumab and a median of -0.7 [IQR = -4.0 to 0.0] with placebo with improvement in NPS vs a median of 0.0 [IQR = -2.4 to 0.0] with mepolizumab and a median of 0.0 [IQR = -0.3 to 0.0]) with placebo without improvement in NPS); and change in visual analog scale score and 22-Item Sino-Nasal Outcome Test total score (a median of -37.0 [IQR = -52.0 to -24.0] with mepolizumab and a median of -29.0 [IQR = -43.0 to -9.0] with placebo with improvement in NPS vs a median of -16.0 [IQR = -42.0 to 0.0] with mepolizumab and a median of 0.0 [IQR = -27.0 to 0.0] with placebo without improvement in NPS).

Conclusion: Improvement in NPS was associated with improvements in PNIF and patient-reported outcomes irrespective of treatment. PNIF could be a useful noninvasive tool for monitoring nasal polyp size.