Clinical Trial: Phase 3 Study of Cysteamine Bitartrate Delayed-release (RP103) Compared to Cystagon® in Patients With Cystinosis

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: A Randomized, Crossover Pharmacokinetic and Pharmacodynamic Study to Determine the Safety and Efficacy of Cysteamine Bitartrate Delayed-release Capsules (RP103), Compared to Cystagon® in Patients

Brief Summary: Cystinosis is an inherited disease that if untreated, results in kidney failure as early as the first decade of life. The current marketed therapy is Cystagon® (cysteamine bitartrate) which must be taken every six hours for the rest of the patient's life to prevent complications of cystinosis. RP103 is a formulation of cysteamine bitartrate that is being studied to see if it may be able to be given less frequently, once every 12 hours, and have similar results to four times a day Cystagon®.

Detailed Summary: This is a multi-center, open-label, randomized, cross-over study to determine whether steady-state, twice a day treatment with Cysteamine Bitartrate Delayed-release Capsules(RP103) results in comparable depletion of white blood cell (WBC) cystine levels compared to the existing four times a day cysteamine treatment. It will involve up to 20 clinic visits plus intermittent home use of the RP103. Most of these clinic visits occur in clusters of 3-4 consecutive days. Eligible patients will be offered enrollment into a long-term follow up study.
Sponsor: Horizon Pharma USA, Inc.

Current Primary Outcome: The Steady-state White Blood Cell Cystine Levels of RP103 Compared to Cystagon® [ Time Frame: 4 weeks after the last subject has completed the study ]

Original Primary Outcome: To assess the steady-state white blood cell cystine levels of RP103 compared to Cystagon® [ Time Frame: Periodically over a 3 day window for each drug ]

Current Secondary Outcome:

  • Comparison of Cysteamine PK Profiles, Steady State Cmax, Between RP103 and Cystagon®. [ Time Frame: 4 weeks after the last subject has completed the study ]
  • Comparison of Cysteamine PK Profiles, Steady State Tmax, Between RP103 and Cystagon®. [ Time Frame: 4 weeks after the last subject has completed the study ]
  • Comparison of Cysteamine PK Profiles, AUC(0-t), Between RP103 and Cystagon®. [ Time Frame: 6 hours post dosing for Cystagon®; 12 hours post dosing for RP103. ]


Original Secondary Outcome:

  • To assess the safety and tolerability of RP103 compared to Cystagon® [ Time Frame: 27-37 days (duration of study) ]
  • To assess the steady state pharmacokinetics and pharmacodynamics of RP103 compared to Cystagon®. [ Time Frame: Periodically over a 3 day window for each drug ]
  • To compare the incidence of concomitant gastric acid reduction therapies [e.g., proton pump inhibitors (PPI)] between Cystagon® and RP103. [ Time Frame: 27-37 days (duration of study) ]


Information By: Horizon Pharma USA, Inc.

Dates:
Date Received: October 22, 2009
Date Started: June 2010
Date Completion:
Last Updated: April 11, 2017
Last Verified: April 2017