Nephropathic Cystinosis |
What is Nephropathic Cystinosis?
Nephropathic cystinosis is an inherited error of metabolism estimated to affect a population of 2,000 patients worldwide, including 500 in the U.S. and 800 in Europe. Cystinosis is usually diagnosed in the first year of life and requires lifelong therapy. In early childhood, these patients exhibit poor growth, vision problems (photophobia) and specific kidney problems (called Fanconi syndrome) that result in increased urination, thirst, and dehydration.
Without treatment, 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 first decade of life. Additional complications include muscle wasting, poor growth, difficulty swallowing, diabetes and hypothyroidism.
Current Standard of Care
Studies have shown that cysteamine therapy may delay and/or prevent kidney transplant and other clinical manifestations of the disease (Gahl 2007, Levtchenko 2006, Markello 1993, Kleta, Bernardini 2004). The goal of cysteamine treatment of nephropathic cystinosis is to reduce cystine levels in cells. However, patient compliance is challenging due to frequent dosing and gastrointestinal side effects (Levtchenko 2006, Kleta, Bernardini 2004, Kleta, Gahl 2004, Cystagon Package Insert).
Research and Development for Nephropathic Cystinosis Patients
Raptor is developing a delayed-release formulation of cysteamine, RP103 (DR Cysteamine). In March 2012, Raptor applied for marketing approval in the U.S. and E.U. of RP103 for the potential treatment of nephropathic cystinosis. Based on standard regulatory review timelines, Raptor anticipates decisions from EMA and FDA in the first calendar quarter of 2013.
Summary
Raptor’s Phase 3 clinical trial of RP103 was an outpatient study designed to compare the pharmacodynamics, pharmacokinetics, safety, and tolerability of RP103 versus Cystagon® in cystinosis patients. The endpoint was achieved at a lower average daily dose of RP103 compared to Cystagon®. On average, the total daily, steady-state dose of RP103 in patients in the Phase 3 clinical trial was 82% of their established, incoming dose of Cystagon®. The study was conducted at eight clinical research centers in the U.S. and Europe.
Related Studies
Raptor is currently conducting an ongoing extension study in which patients who have completed the Phase 3 clinical trial may elect to continue RP103 treatment. In a separate clinical trial, Raptor demonstrated bioequivalence between RP103 taken as whole capsules or administered as capsule contents sprinkled onto applesauce. Based upon this result, Raptor has expanded enrollment in the extension study to include cystinosis patients who are too young to swallow whole capsules and were ineligible for the pivotal Phase 3 clinical trial protocol. Raptor also has enrolled in its extension study patients who have undergone kidney transplants.
In addition to Raptor's efforts, a clinical study of cysteamine eye drops is underway to address the build-up of cystine crystals in the eyes of nephropathic cystinosis patients. This study is currently recruiting patients. Learn more about the ongoing clinical trial.
Community Support
Many dedicated researchers are seeking a cure for nephropathic cystinosis. Much of this research is supported by grants from not-for-profit foundations such as the Cystinosis Research Foundation and Cystinosis Research Network.
Additional Resources
Raptor Applies for Marketing Approval of RP103 for the Potential Treatment of Nephropathic Cystinosis in the U.S. and E.U.
In March 2012, Raptor received validation of its Marketing Authorization Application from the European Medicines Agency for RP103 cysteamine bitartrate delayed-release capsules (DR Cysteamine) for the potential treatment of nephropathic cystinosis. Raptor also submitted its New Drug Application with the U.S. Food and Drug Administration. .
Raptor’s Phase 3 Clinical Trial Meets Primary Endpoint
Raptor’s Phase 3 clinical trial of RP103 (Delayed-Release or DR Cysteamine) for the treatment of nephropathic cystinosis met the primary endpoint of non-inferiority compared to the currently marketed, immediate-release cysteamine bitartrate.
Cystinosis Patients in the News
Raptor featured on ABCNews.com.
A chance for survival from a rare kidney disease
Mother who donates kidney to daughter with cystinosis featured in AOL Health