Add-on mepolizumab reduces nasal polyp size, obstruction in adults with CRSwNP

Adding mepolizumab to standard of care treatment significantly reduces nasal polyp size and obstruction in adults with chronic rhinosinusitis with nasal polyps (CRSwNP), according to the SYNAPSE* study presented at ERS 2020.

This phase III, double-blind, parallel-group trial involved 407 adults with severe chronic rhinosinusitis who had prior nasal polyp surgery. Participants were randomized to receive either subcutaneous (SC) mepolizumab 100 mg (n=206) or placebo (n=201) every 4 weeks in addition to standard of care for 52 weeks. [ERS 2020, abstract 4616]

A significantly reduced nasal polyp size, as shown by a reduced total endoscopic nasal polyp score from baseline to week 52, was achieved in the mepolizumab group compared with placebo group (median difference, -0.73, 95 percent confidence interval [CI], -1.11 to -0.34; p<0.001).

Mepolizumab-treated patients also demonstrated a significantly reduced visual analogue score (VAS) for nasal obstruction compared with placebo-treated patients from baseline to week 49–52 (median difference, -3.14, 95 percent CI, -4.09 to -2.18; p<0.001), with 44 percent and 23 percent of mepolizumab and placebo recipients, respectively, achieving a >5-point improvement in VAS score.

By week 52, significantly fewer patients were deemed to be in need of nasal surgery in the mepolizumab arm than in the placebo arm (9.0 percent vs 23.0 percent; hazard ratio, 0.43, 95 percent CI, 0.25–0.76; p=0.003).

The incidence of on-treatment adverse events (AEs) was comparable between the mepolizumab and placebo arms (82.0 percent vs 84.0 percent). Two serious AEs occurred which were not attributed to study drug. “No new safety signals were observed compared with previous studies,” noted lead author Dr Claire Hopkins from the ENT Department of Guy’s and St Thomas’s Hospital and King’s College in London, UK.

“Previous studies in patients with CRSwNP treated with mepolizumab 750 mg IV have shown reductions in nasal polyp size, improved symptoms, and a reduced need for nasal surgery,” said Hopkins.

“In conclusion, we demonstrated … that add-on mepolizumab is [an] effective and safe treatment in adults with CRSwNP, … [and] treatment effects were sustained until week 52 for all endpoints,” she said.

“[Furthermore,] the clinical benefits observed in SYNAPSE demonstrate the efficacy of the 4-weekly 100 mg SC dose [of mepolizumab] in patients who have failed standard of care treatment and are consistent with previous studies of mepolizumab 750 mg IV in patients with CRSwNP,” she added.

*SYNAPSE: Effect of mepolizumab in severe bilateral nasal polyps