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Raptor Pharmaceutical Announces Publication of Phase 3 Results in the Clinical Journal of the American Society of Nephrology

Provides an Update on the Nephropathic Cystinosis Program

NOVATO, Calif., May 3, 2012 (GLOBE NEWSWIRE) -- Raptor Pharmaceutical Corp. ("Raptor" or the "Company") (Nasdaq:RPTP), announced the online publication of an article titled, "A Randomized Controlled Crossover Trial with a Delayed Release Cysteamine Bitartrate in Nephropathic Cystinosis: Effectiveness on WBC Cystine Levels and Comparison of Safety" in the Clinical Journal of the American Society of Nephrology ("CJASN"). The CJASN is one of the most respected peer reviewed scientific journals among kidney related publications.

The article describes findings from Raptor's open-label, randomized, controlled, crossover Phase 3 clinical trial, referred to as RP103-03, the top-line results of which were reported by Raptor in July 2011, and presented by the clinical investigators as a late breaking poster at the American Society of Nephrology ("ASN") — Kidney Week 2011 in Philadelphia last November. The Phase 3 clinical trial enrolled 43 patients and was powered to show that Raptor's delayed-release formulation of cysteamine bitartrate, referred to as RP103, taken every 12 hours, was non-inferior to the currently-available immediate release cysteamine bitartrate treatment, Cystagon®, taken every 6 hours, for maintenance of white blood cell ("WBC") cystine levels in patients who were already well controlled on Cystagon®. The clinical trial also showed that RP103 met its primary endpoint at a lower total daily dose than Cystagon®.

Craig B. Langman, M.D., Head of Kidney Diseases, and the Isaac A. Abt, M.D., Professor of Kidney Diseases and Tenured Professor of Pediatrics, Northwestern University Feinberg School of Medicine, and lead author of the publication, said, "RP103 met the primary endpoint compared to Cystagon® at a less frequent dosing schedule, as well as a reduced total daily dose. As to tolerability, none of the severe adverse events reported in the study were considered unexpected, given the symptoms associated with the disease itself. The nature of the adverse events reported during the study was similar between the Cystagon® and the RP103 treatment periods."

Patrice P. Rioux, M.D., Ph.D., Chief Medical Officer of Raptor, said, "Two patients experienced 24% of the total gastrointestinal ("GI") adverse events ("AEs") recorded in the study, which accounted for 60% of the drug-related GI AEs while on RP103. However, I'm pleased to note that following an initial period of GI upset upon starting RP103, both of these patients have continued to use RP103 in our extension study and have remained on RP103 for almost one year. All but one patient out of all the patients who used proton pump inhibitors ("PPIs") while on the Cystagon® arm, did not use PPIs on a regular basis while on RP103. This may account for the higher total number of GI AEs reported under RP103 vs. Cystagon®."

The RP103 voluntary extension study, referred to as RP103-04, is ongoing with 38 enrolled patients of the original 41 patients who completed the Phase 3 clinical trial. Thirty-two of the Phase 3 patients have been on RP103 for at least 12 months with some patients now approaching 18 months on RP103. In addition, enrollment in the extension study has been expanded to include 13 children under 6 years old, and 5 patients with a functioning kidney transplant. The children are receiving their RP103 by sprinkling the capsule contents onto applesauce or administered through a gastric tube. Raptor plans to present data from the extension trial later this year.

In March, 2012, the European Medicines Agency ("EMA") validated Raptor's Marketing Authorization Application for RP103 for the potential treatment of nephropathic cystinosis. The MAA is now being reviewed by the EMA. Also in March, Raptor submitted a New Drug Application ("NDA") to the U.S. Food and Drug Administration ("FDA") seeking approval to market RP103 for the potential treatment of nephropathic cystinosis. Raptor requested a Priority Review of the NDA which, if granted by FDA, could lead to a decision for marketing approval for RP103 for the potential treatment of cystinosis in the U.S., in the fourth quarter of 2012.

About Nephropathic Cystinosis

Nephropathic cystinosis, an orphan disease, is estimated to effect a population of 2,000 patients worldwide, including 500 patients in the U.S. and 800 patients in Europe. Cystinosis patients have inherited a defective cystine transporter gene that results in body-wide cellular toxicity resulting from the abnormal buildup of the amino acid cystine in the lysosomes. Cystinosis is usually diagnosed in the first years of life and requires lifelong therapy. Cystine crystals accumulate in various tissues and organs, including the kidneys, brain, liver, thyroid, pancreas, muscles and eyes. Left untreated, the disease is fatal by the end of the first decade of life. RP103 reduces cellular toxicity by continuously removing cystine from the lysosome.

About Cysteamine and RP103

RP103 is Raptor's proprietary, delayed and extended release, oral medication designed to potentially treat the underlying metabolic cause of cystinosis. RP103 is an enteric coated, microbead formulation of cysteamine bitartrate that has been formulated to be sprinkled onto food for administration to patients too young to take oral capsules. As demonstrated in the Phase 3 clinical trial detailed in the publication in CJASN, the every 6 hour cysteamine dosing treatment may be reduced substantially to twice daily on RP103.

In December 2007, Raptor obtained an exclusive, worldwide license from the University of California, San Diego for the development of RP103 for nephropathic cystinosis and for cysteamine for other potential indications including Huntington's Disease, currently in a Phase 2/3 clinical trial in France, and non-alcoholic steatohepatitis ("NASH") currently in a Phase 2b clinical trial in the US. Raptor has been granted orphan product designation for RP103 for the potential treatment of nephropathic cystinosis by the EMA and FDA.

About Raptor Pharmaceutical Corp.

Raptor Pharmaceutical Corp. (Nasdaq:RPTP) ("Raptor") seeks to research, produce, and deliver medicines that improve life for patients with severe, rare disorders. Raptor currently has product candidates in clinical development designed to potentially treat nephropathic cystinosis, Non-alcoholic Steatohepatitis ("NASH"), Huntington's Disease ("HD"), aldehyde dehydrogenase deficiency ("ALDH2"), and thrombotic disorder.

Raptor's preclinical programs are based upon bioengineered novel drug candidates and drug-targeting platforms derived from the human receptor-associated protein and related proteins that are designed to target cancer and infectious diseases.

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This document contains forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. These statements relate to future events or our future results of operation or future financial performance, including, but not limited to the following statements: that Raptor will complete its extension trial or present data from its extension trial later this year; that the every 6 hour cysteamine dosing treatment will be reduced to twice daily on RP103; that FDA could render a decision regarding marketing approval of RP103 for the potential treatment of cystinosis in the U.S., in the fourth quarter of 2012; and that Raptor will be able to successfully develop RP103 or any of its other product candidates. These statements are only predictions and involve known and unknown risks, uncertainties and other factors, which may cause the Company's actual results to be materially different from these forward-looking statements. Factors which may significantly change or prevent the Company's forward looking statements from fruition include: that Raptor may be unsuccessful in developing any products or acquiring products; that Raptor's technology may not be validated as it progresses further and its methods may not be accepted by the scientific community; that Raptor is unable to retain or attract key employees whose knowledge is essential to the development of its products; that unforeseen scientific difficulties develop with the Company's process; that Raptor's patents are not sufficient to protect essential aspects of its technology; that competitors may invent better technology; that Raptor's products may not work as well as hoped or worse, that the Company's products may harm recipients; and that Raptor may not be able to raise sufficient funds for development or working capital. As well, Raptor's products may never develop into useful products and even if they do, they may not be approved for sale to the public. Raptor cautions readers not to place undue reliance on any such forward-looking statements, which speak only as of the date they were made. Certain of these risks, uncertainties, and other factors are described in greater detail in the Company's filings from time to time with the Securities and Exchange Commission (the "SEC"), which Raptor strongly urges you to read and consider, including: Raptor's annual report on Form 10-K, as amended by Form10-K/A, filed with the SEC on November 11, 2011 and December 19, 2011, respectively; and Raptor's quarterly report on Form 10-Q filed with the SEC on April 9, 2012; all of which are available free of charge on the SEC's web site at Subsequent written and oral forward-looking statements attributable to Raptor or to persons acting on its behalf are expressly qualified in their entirety by the cautionary statements set forth in Raptor's reports filed with the SEC. Raptor expressly disclaims any intent or obligation to update any forward-looking statements.

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Posted: May 2012