Raptor Pharmaceutical Corp. ("Raptor" or the "Company") (Nasdaq: RPTP), today announced the publication of results from a Phase 2a clinical trial of a prototype formulation of its proprietary delayed-release cysteamine bitartrate ("DR Cysteamine") in patients with nephropathic
cystinosis ("cystinosis"). Ranjan Dohil, M.D., Professor of
Pediatrics at the University of California, San Diego, was lead author of the study to be published in the
Journal of Pediatrics and available online.
The Phase 2a study demonstrated proof-of-concept for DR Cysteamine, which is Raptor's proprietary, delayed-release, enteric-coated microbead formulation of immediate release cysteamine bitartrate contained in a gelatin capsule. Immediate-release cysteamine bitartrate ("IR Cysteamine") is the current standard of care for treating cystinosis. The results indicated that when given twice daily, the prototype DR Cysteamine formulation was effective at maintaining low white blood cell ("WBC") cystine levels (<2 nmol half-cystine/mg protein) in subjects with cystinosis. Results also indicated that the prototype DR Cysteamine effectively maintained trough WBC cystine levels within a satisfactory range when patients received approximately 60% of the previous total daily dose of IR Cysteamine.
Dr. Dohil stated, "We are seeking to improve tolerability and reduce dosing frequency requirements of IR Cysteamine which have been documented challenges for cystinosis patients, leading to widely reported instances of poor treatment compliance. We believe the results of the Phase 2a study bring us significantly closer to a potential treatment solution for cystinosis patients. The results from our trial indicate prototype delayed-release cysteamine formulation lead to improved tolerability and efficacy when administered twice-daily and at a lower total daily dose than IR Cysteamine. Based on these results, I believe that Raptor's final DR Cysteamine formulation has the potential to improve compliance and long-term treatment outcomes for cystinosis patients."
Based on these Phase 2a results, Raptor conducted a Phase 2b clinical trial using its final commercial formulation of DR Cysteamine and recently announced the following top-line Phase 2b results: DR Cysteamine demonstrated improved tolerability and the potential to reduce total daily dosage and administration frequency compared to IR Cysteamine.