Conditions: Sickle Cell Disease
Keywords: Sickle Cell Disease SCD 6R-BH4 BH4 sapropterin dihydrochloride endothelial dysfunction Nitric Oxide NO
Allocation: NA | Intervention model: SEQUENTIAL
Enrollment: 32
Healthy volunteers: no

Brief summary:
This Phase 2a, multicenter, open-label, dose-escalation study is designed to assess the safety and biologic activity of daily oral administration of 4 escalating doses of sapropterin dihydrochloride over 16 weeks in subjects with sickle cell disease. During an optional extension phase, the study will assess the safety, tolerability, and efficacy of extended treatment with sapropterin dihydrochloride, for a total of up to 2 years; The extension phase of this study was terminated.

Detailed description:
This Phase 2a, multicenter, open-label, dose-escalation study was designed to assess the safety and biological activity of once-daily (or twice-daily \[BID\], only for the highest dose level) oral administration of 4 escalating doses of sapropterin dihydrochloride to subjects with Sickle Cell Disease (SCD); 32 subjects were enrolled in the dose-escalation phase of this study. Subjects received oral, once daily (for 2.5, 5, and 10 mg/kg/day) or BID (for 20 mg/kg/day) doses of sapropterin dihydrochloride during a 16-week, dose-escalation period, with dose levels increasing within subjects every 4 weeks, as follows: 2.5, 5, 10, and 20 mg/kg/day. At the highest dose level (20 mg/kg/day), the total dose of sapropterin dihydrochloride was divided, half of the tablets taken in the morning within 1 hour after a meal, and half approximately 12 hours later (or BID) within 1 hour after a meal. The extension phase of this study was terminated.

Arms:
arm 1: 2.5, 5, 10, 20 mg/kg/day of sapropterin dihydrochloride during a 16-week dose escalation phase, with dose levels increasing within subjects every 4 weeks, with an optional extension phase at the highest tolerated dose for up to a total of 2 years.

Interventions: intervention 1: Sapropterin Dihydrochloride
Intervention descriptions: intervention 1: Subjects will receive oral, once-daily (for 2.5, 5, 10mg/kg/day doses) or twice-daily (for the 20 mg/kg/day dose) sapropterin dihydrochloride during a 16-week dose escalation phase, with dose levels increasing within subjects every 4 weeks as follows: 2.5, 5, 10, and 20 mg/kg/day. Dosing was with 100 mg tablets and rounded to the nearest whole tablet. Each dose was taken within 1 hour after the morning meal. Subjects may continue in an optional extension phase at the highest tolerated dose for up to a total of 2 years.

Protocol document: