Dexpramipexole effectively lowers blood and tissue eosinophils in subjects with chronic rhinosinusitis with nasal polyps
Section snippets
Rationale
Dexpramipexole is an oral investigational drug serendipitously noted to lower blood eosinophils in prior clinical studies in amyotrophic lateral sclerosis.
Methods
An open-label study of dexpramipexole 300 mg/day was undertaken in subjects with chronic rhinosinusitis with nasal polyps (CRSwNP) with a baseline blood absolute eosinophil count (AEC) ≥0.30x109/L and polyp eosinophilia. The primary endpoint examined was change in AEC from baseline to end of study. Change in nasal eosinophils from baseline to end of study was an exploratory endpoint. Data are shown from this ongoing study.
Results
Baseline AEC was 0.524x109/L in the 11 subjects studied to date. AEC at month 6 was 0.034x109/L, a 93% reduction (p=0.001). Seven of the 11 subjects had eosinophil counts reduced to 0.020x109/L or less at month 6. In the 10 subjects who had biopsies, polyp tissue eosinophilia was reduced from 190 to 11 eosinophils per high-powered field, a 94% reduction from baseline (p=0.004). Dexpramipexole was well tolerated with no drug-related serious adverse events. Five subjects elected to continue on a
Conclusions
In sum, dexpramipexole is a well-tolerated orally-available drug with robust blood and tissue eosinophil-lowering activity. Given that eosinophil lowering by dexpramipexole is greater than or equal to that of current biologics, its clinical activity in asthma and other eosinophil-associated diseases is of great interest. Based on its oral administration, safety profile, and convenience, dexpramipexole has the potential for use by a broader segment of asthma patients than is currently indicated