15 May 2018 - - Pittsburgh, Pennsylvania-based drug discovery and development company Knopp Biosciences LLC's Phase 2 study of dexpramipexole in hypereosinophilic syndromes (HES) has met its co-primary endpoints, the company said.
A team of investigators led by Dr. Amy Klion at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, undertook the open-label study of dexpramipexole as a steroid-sparing agent in subjects with HES.
Dexpramipexole had been observed to produce a significant, targeted reduction of peripheral blood eosinophils in earlier clinical trials in amyotrophic lateral sclerosis.
The trial enrolled 10 subjects and met the co-primary endpoints of: 1) percentage of subjects experiencing a ≥50% reduction in minimally effective dose and 2) reduction of glucocorticoid requirement among all subjects.
Three of the four responders meeting the primary endpoint exhibited complete hematological responses (eosinophil count of zero or near-zero) and were able to discontinue prednisone completely. These subjects have remained symptom-free, eosinophil-free, and steroid-free for 13-32 months while continuing dexpramipexole treatment, as reported in the article published in the journal Blood.
The investigators also reported that three of four responders who underwent biopsies had complete resolution of eosinophilia in affected skin or gastrointestinal tissue. Delayed and partial hematological responses were also noted in the trial.
Dexpramipexole was well tolerated, with no adverse events leading to drug interruption or discontinuation.
Privately held Knopp Biosciences is focused on delivering breakthrough treatments for inflammatory and neurological diseases of high unmet need. Its clinical-stage small molecule, dexpramipexole, is entering Phase 3 development in HES and Phase 2 clinical development in eosinophilic asthma.
Its preclinical platform is directed to small molecule treatments for neonatal epileptic encephalopathy, a devastating brain disorder of infants caused by a rare mutation in the KCNQ2 gene.