Dexpramipexole as an oral steroid-sparing agent in hypereosinophilic syndromes

• Published in: Blood 2018-08, Vol.132 (5), p.501-509
• Main Authors: Panch, Sandhya R., Bozik, Michael E., Brown, Thomas, Makiya, Michelle, Prussin, Calman, Archibald, Donald G., Hebrank, Gregory T., Sullivan, Mary, Sun, Xiaoping, Wetzler, Lauren, Ware, JeanAnne, Fay, Michael P., Dunbar, Cynthia E., Dworetzky, Steven I., Khoury, Paneez, Maric, Irina, Klion, Amy D.
• Format: Article
• Language: English
• Subjects: Administration, Oral; Adult; Aged; Antioxidants - administration & dosage; Clinical Trials and Observations; Eosinophils - drug effects; Female; Follow-Up Studies; Humans; Hypereosinophilic Syndrome - drug therapy; Hypereosinophilic Syndrome - pathology; Male; Middle Aged; Pramipexole - administration & dosage; Prognosis; Safety; Steroids
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2018-02-835330

Hypereosinophilic syndromes (HESs) are a heterogeneous group of disorders characterized by peripheral eosinophilia and eosinophil-related end organ damage. Whereas most patients respond to glucocorticoid (GC) therapy, high doses are often necessary, and side effects are common. Dexpramipexole (KNS-760704), an orally bioavailable synthetic aminobenzothiazole, showed an excellent safety profile and was coincidentally noted to significantly decrease absolute eosinophil counts (AECs) in a phase 3 trial for amyotrophic lateral sclerosis. This proof-of-concept study was designed to evaluate dexpramipexole (150 mg orally twice daily) as a GC-sparing agent in HESs. Dual primary end points were (1) the proportion of subjects with ≥50% decrease in the minimum effective GC dose (MED) to maintain AEC