Clinical Trial: Efficacy of Betaine for Reduction of Urine Oxalate in Patients With Type 1 Primary Hyperoxaluria
Study Status: Completed
Recruit Status: Completed
Study Type: Interventional
Official Title: Efficacy of Betaine for Reduction of Urine Oxalate in Patients With Type 1 Primary Hyperoxaluria
Brief Summary:
The aim of this study is to assess the efficacy and safety of betaine in reducing urine oxalate excretion of Type 1 Primary Hyperoxaluria (PHI) patients.
Hypothesis:
Betaine will effectively reduce urine oxalate excretion in Primary Hyperoxaluria Type I patients.
Detailed Summary:
Our prior genotyping results have shown an association between the G170R allele and the clinical response to VB6. Patients homozygous for this change show a complete response and heterozygous patients a partial response. Since VB6 is a safe and completely effective treatment for patients homozygous for G170R, we will not study betaine in this group. Instead, 20 participants older than 6 years of age who are G170R compound heterozygous, non-G170R missense or truncating sequence change homozygous or heterozygous, will be selected for enrollment. Participants in whom VB6 provides a partial reduction in urine oxalate excretion (compound heterozygotes for the G170R mutation) will be maintained on a stable dose of VB6 (8 mg/kg/d) for two months before and throughout betaine treatment. Those who have demonstrated no response to VB6 will receive betaine alone.
Participants will be randomized to receive either betaine or placebo for the first 2 month arm of the study. Following 2 months of treatment and 2 months of washout, each participant will cross over to the other arm of the study. The other arm will consist of the participant being on 2 months of treatment of whatever they were not taking in the first arm (betaine vs. placebo). Neither the study staff nor the participant will know whether the participant is taking betaine for the first or second arm of the study, or the placebo for the first or second arm of the study. Only the pharmacy will know this.
Prior to the study, a complete history and physical examination, and baseline laboratory studies pertinent to the routine care of primary hyperoxaluria patients will be performed (Complete Blood Count (CBC) with differential, chemistry group, electrolytes, plasma oxalate and creatinine clearance, urinary supersaturation). All women capable of reproduction will receive a pregnan
Sponsor: Mayo Clinic
Current Primary Outcome: Urinary Oxalate Excretion [ Time Frame: baseline, 2 months, 6 months ]
The patients were randomly assigned oral betaine or placebo for 2 months, followed by a 2 month washout. Each patient then received the alternate study medication for 2 months.
Urinary Oxalate Excretion was measured by oxalate oxidase. Two 24 hour urine collections were obtained at baseline, and during the eighth week of each study period.
Original Primary Outcome: Assess the efficacy of betaine for treatment of partially VB6 responsive & VB6 refractory PHI patients. Participants will be treated with betaine & urinary oxalate excretion will be monitored with two 24-hour urine at baseline, 2 and 6 months.
Current Secondary Outcome:
Original Secondary Outcome:
Information By: Mayo Clinic
Dates:
Date Received: January 26, 2006
Date Started: February 2007
Date Completion:
Last Updated: November 21, 2013
Last Verified: November 2013
