Efficacy of Betaine for Reduction of Urine Oxalate in Patients With Type 1 Primary Hyperoxaluria

November 21, 2013 updated by: Mayo Clinic

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

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 pregnancy test prior to enrollment.

Participant will complete two 24-hour urine collections for calcium oxalate super-saturation (includes 24-hour urine oxalate excretion) at baseline, inclusive of creatinine determination for assessment of completeness. They will then begin Cystadane anhydrous solution (12 grams/day in subjects younger than 10 years of age, and 20 grams/day in subjects 10 years of age and older, in two divided doses). These doses of betaine have been shown to effectively treat pediatric patients with VB6-resistant homocystinuria and reverse Nonalcoholic Steatohepatitis (NASH) in adult patients, so we expect they will achieve sufficient intra-hepatocyte levels to have an effect in PHI.

A sample of each 24-hour urine will be stored frozen (-80ºC) to allow determination of indicators of oxidant stress, should urinary oxalate fall.

If effective, betaine could represent a new and safe treatment option for a subset of PHI patients, particularly those with either partially VB6 responsive or VB6 refractory hyperoxaluria, or those with adverse effects such as peripheral neuropathy from large doses of VB6. We do not anticipate any adverse medication effects specific to primary hyperoxaluria. However, as an extra safeguard for children with PHI, ten subjects older than 15 years of age will be tested first and if the agent is well tolerated in PHI patients, pediatric subjects older than 6 years of age will then be recruited for participation.

Study Type

Interventional

Enrollment (Actual)

15

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Minnesota
      • Rochester, Minnesota, United States, 55905
        • Mayo Clinic Hyperoxaluria Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

6 years to 70 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. A definitive diagnosis of Type 1 Primary Hyperoxaluria (PHI) as confirmed by hepatic angiotensinogen (AGT) deficiency, biochemical criteria (marked hyperoxaluria and hyperglycolic aciduria) or mutation analysis (having a known PHI mutation)
  2. Alanine-glyoxylate aminotransferase (AGXT) genotype known
  3. Hyperoxaluria not fully corrected by 3 months of continuous Vitamin B6 (VB6) at doses of 8 mg/kg/d or more
  4. Males or females, 6-70 years of age, inclusive
  5. Preserved renal function, as defined by measured glomerular filtration rate (GFR) > 30 ml/min/1.73 m^2
  6. Sexually active female patients of childbearing potential must practice adequate contraception during the treatment period and for 6 months after discontinuation of therapy. A pregnancy test obtained at entry prior to the initiation of treatment must be negative. Female patients must not be breast-feeding. Sexually active male patients must practice acceptable methods of contraception during the treatment period and for 6 months after discontinuation of therapy.
  7. Written informed consent for participation in this study.

Exclusion Criteria:

  1. Patients who are fully VB6 responsive (i.e., G170R homozygotes).
  2. Prior recipients of liver transplantation performed for correction of AGT deficiency.
  3. Pregnancy or breastfeeding
  4. Unwillingness of patient and/or partner to use contraception during treatment.
  5. Malignant disease (other than non-melanoma skin cancer) in the previous two years.
  6. Markedly reduced renal function (Stage IV Chronic Kidney Disease or measured or estimated GFR < 30 ml/min/1.73 m^2)
  7. Allergy to betaine or related compounds
  8. History of papilledema or increased intracranial pressure.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Betaine
Subjects were randomly assigned oral betaine 12 grams/day in subjects younger than 10 years of age, and 20 grams/day in subjects 10 years of age and older, in two divided doses. This was followed by a 2 month washout period. Subjects then received the alternative study medication, oral lactose placebo, in two doses daily, for 2 months.
Subjects were randomly assigned oral betaine 12 grams/day in subjects younger than 10 years of age, and 20 grams/day in subjects 10 years of age and older, in two divided doses, for 2 months.
Other Names:
  • Cystadane
Subjects received oral lactose placebo, in two doses daily, for 2 months.
Other Names:
  • Lactose
Placebo Comparator: Placebo
Subjects were randomly assigned to receive oral lactose placebo, in two doses daily, for 2 months. This was followed by a 2 month washout period. Subjects then received the alternative study medication, oral betaine 12 grams/day in subjects younger than 10 years of age, and 20 grams/day in subjects 10 years of age and older, in two divided doses, for 2 months.
Subjects were randomly assigned oral betaine 12 grams/day in subjects younger than 10 years of age, and 20 grams/day in subjects 10 years of age and older, in two divided doses, for 2 months.
Other Names:
  • Cystadane
Subjects received oral lactose placebo, in two doses daily, for 2 months.
Other Names:
  • Lactose

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.

baseline, 2 months, 6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Carla G Monico, M.D., Mayo Clinic Hyperoxaluria Center, Rochester MN

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

February 1, 2007

Primary Completion (Actual)

September 1, 2011

Study Completion (Actual)

September 1, 2011

Study Registration Dates

First Submitted

January 26, 2006

First Submitted That Met QC Criteria

January 26, 2006

First Posted (Estimate)

January 27, 2006

Study Record Updates

Last Update Posted (Estimate)

December 16, 2013

Last Update Submitted That Met QC Criteria

November 21, 2013

Last Verified

November 1, 2013

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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