Raptor Pharma Reports Data in Journal of Pediatrics Showed Procysbi Improved Life Quality

Raptor Pharmaceutical Corp.(Nasdaq: RPTP) today announced that data from its open label extension study ofdelayed-release cysteamine bitartrate (PROCYSBI^®) has been published in theJournal of Pediatrics [DOI: 10.1016/j.jpeds.2014.05.013]. The studydemonstrated that patients with nephropathic cystinosis who took PROCYSBI fortwo years were able to sustain optimal cystine control in their white bloodcells and preserve kidney function over the long term, and had significantimprovements in social, school and total functioning based on validatedquality of life measurement scales.The prospective, controlled, open label, single-arm study followed 40 patientswith nephropathic cystinosis treated with PROCYSBI for two years to assessefficacy in cystine depletion in peripheral white blood cells, to assess thedose required to maintain white blood cell (WBC) content of cystine below 1nmol ½ cystine/mg protein, to measure quality of life using the PediatricQuality of Life Inventory (PedsQL™), change in estimated glomerular filtrationrate, and change in height Z-score. The objective was to determine thelong-term effects of PROCYSBI therapy in patients with the disease.Control of WBC CystineOver two years of treatment, the mean WBC cystine was maintained under optimalcontrol of <1 nmol ½ cystine/mg protein, and the dose of PROCYSBI decreasedfrom 43.5 to 40.1 mg/kg/d (p = .05).Maintenance of Kidney FunctionKidney function deteriorates over time in nephropathic cystinosis patients whooften require a kidney transplant early in life. In this study, kidneyfunction as monitored by eGFR remained stable over two years of treatment.Change in Quality of LifeUsing the validated PedsQL™ score, investigators documented a significant andpersistent improvement in patients who had switched from immediate-releasecysteamine to PROCYSBI, over two years of treatment, in three measures: socialfunction (p = .049), school function (p = .004), and in total function (p =.048). Investigators assessed the subsequent change from all baseline valuesin the PedsQL™ and demonstrated that the changes persisted after two years ofPROCYSBI therapy. Changes in physical and emotional quality of life scalesover the two years of study were not changed."Long-term control of WBC cystine depletion below 1 nmol has never beenreported in a prospective manner in a cohort of patients," said Craig B.Langman, M.D., the Isaac A. Abt, M.D. professor of Kidney Diseases and head ofpediatric kidney diseases at Northwestern University Feinberg School ofMedicine and the Ann and Robert H. Lurie Children's Hospital of Chicago, andthe lead author on the paper. "Here, with delayed-release cysteamine, weprovide two years of data demonstrating disease control, preservation ofkidney function, stable somatic growth, and quality of life improvements.These data demonstrate that patients were able to remain adherent to theirdelayed-release cysteamine therapy for two years, something never beforedemonstrated in a controlled clinical trial in this population."There were no unexpected or serious safety concerns attributable to PROCYSBI.All 40 patients experienced one or more treatment-emergent adverse events: GIdisorders in 35 (87.5%), emesis in 28 (70.0%), headache in 14 (35.0%), upperrespiratory tract symptoms in 9 (22.5%), and diarrhea in 8 (20.0%).