Raptor Pharmaceutical Corp. ("Raptor" or the "Company") (Nasdaq: RPTP), today announced results from a Phase 2b clinical trial of its proprietary delayed-release cysteamine bitartrate ("DR Cysteamine") in patients with nephropathic cystinosis ("cystinosis"). The trial, conducted at the University of California, San Diego ("UCSD") General Clinical Research Center, evaluated safety, tolerability, pharmacokinetics and pharmacodynamics of a single dose of DR Cysteamine in nine cystinosis patients.
Phase 2b Clinical Trial Highlights:
- DR Cysteamine demonstrated improved tolerability and the potential to reduce total daily dosage and administration frequency compared to immediate-release cysteamine bitartrate.
- Pharmacokinetic evaluation showed that DR Cysteamine had a terminal half-life more than three times longer than the terminal half-life of immediate-release cysteamine bitartrate capsules.
- Twice-daily DR Cysteamine may achieve the same pharmacodynamic result while using a daily dose 30% lower than immediate-release cysteamine bitartrate capsules administered four times daily.
- No adverse events recorded during the clinical trial were determined by the principal investigator to be possibly or probably related to DR Cysteamine. Nine adverse events recorded in the clinical trial were determined to be possibly or probably related to immediate-release cysteamine bitartrate.
Raptor plans to meet with the Food and Drug Administration ("FDA") and European Medicines Agency ("EMEA") to discuss the results of its phase 2b study and its plans for a repeat-dose, pivotal, phase 3 clinical trial in cystinosis patients. Upon receiving FDA and EMEA concurrence, Raptor intends to initiate its phase 3 clinical trial at multiple sites in the US and Europe in the first quarter of 2010.
DR Cysteamine is Raptor's proprietary, enteric-coated micro-bead formulation of immediate release cysteamine bitartrate capsules, the current standard of care for treating cystinosis.
Bruce Barshop, M.D., Ph.D., Professor of Clinical Pediatrics at UCSD and principal investigator for the cystinosis clinical trial of DR Cysteamine, stated, "The excellent tolerability of DR Cysteamine, as demonstrated in this study, represents a major step forward in potentially improving the treatment of cystinosis. Raptor's formulation has the potential to improve dosing compliance and long-term outcomes for cystinosis patients."
Raptor's phase 2b clinical trial followed earlier clinical trials with an enteric-coated cysteamine prototype conducted by Ranjan Dohil, M.D., Associate Professor of Pediatrics at UCSD and funded by the Cystinosis Research Foundation ("CRF"). The CRF also supported Raptor's phase 2b clinical trial.
Patrice P. Rioux, M.D., Ph.D., chief medical officer of Raptor, said, "The results from our phase 2b trial are consistent with previous clinical findings from Dr. Dohil and support our plans to provide a twice-daily cysteamine therapy for cystinosis patients. We look forward to continuing our development program of DR Cysteamine in cystinosis with a phase 3 clinical trial."
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