Abstract | BACKGROUND AND OBJECTIVES: Immediate-release cysteamine bitartrate ( Cystagon; Mylan Pharmaceuticals, Canonsburg, PA) may prevent or delay kidney transplantation and other serious outcomes in patients with cystinosis, but has never been subjected to a prospective clinical trial. Cystagon efficacy requires strict lifelong dosing every 6 hours. Such a dosing schedule and Cystagon-associated side effects are often cited by patients as reasons for nonadherence. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This open-label, randomized, controlled, crossover trial was powered to show that a new delayed-release formulation of cysteamine bitartrate, RP103, taken every 12 hours, was noninferior to Cystagon for maintenance of white blood cell (WBC) cystine at levels associated with optimal outcomes in the disease. RESULTS: Forty-three patients were randomized. Using a mixed-effects statistical analysis model, the least-squares mean peak value of WBC cystine level was 0.62±0.05 nmol 1/2 cystine/mg protein after 12 hours under RP103 and 0.54±0.05 nmol 1/2 cystine/mg protein after 6 hours under Cystagon, a difference of 0.08±0.04 nmol 1/2 cystine/mg protein (95.8% confidence interval, 0-0.16). The average steady-state total daily dose of RP103 was 82% of the incoming steady-state total daily dose of Cystagon. There were three-fold more gastrointestinal side effects compared with using Cystagon. CONCLUSIONS:
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Authors | Craig B Langman, Larry A Greenbaum, Minnie Sarwal, Paul Grimm, Patrick Niaudet, Georges Deschênes, Elisabeth Cornelissen, Denis Morin, Pierre Cochat, Debora Matossian, Segolene Gaillard, Mary Jo Bagger, Patrice Rioux |
Journal | Clinical journal of the American Society of Nephrology : CJASN
(Clin J Am Soc Nephrol)
Vol. 7
Issue 7
Pg. 1112-20
(Jul 2012)
ISSN: 1555-905X [Electronic] United States |
PMID | 22554716
(Publication Type: Comparative Study, Journal Article, Randomized Controlled Trial, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
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Chemical References |
- Delayed-Action Preparations
- Cystine
- Cysteamine
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Topics |
- Adolescent
- Adult
- Child
- Cross-Over Studies
- Cysteamine
(administration & dosage)
- Cystine
(analysis, metabolism)
- Cystinosis
(drug therapy, metabolism)
- Delayed-Action Preparations
- Fanconi Syndrome
- Female
- Humans
- Leukocytes
(chemistry, metabolism)
- Male
- Nephrotic Syndrome
(drug therapy, metabolism)
- Young Adult
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