Trial Outcomes & Findings for Assessment of Endogenous Oxalate Synthesis (NCT NCT05229952)

NCT ID: NCT05229952

Last Updated: 2025-05-13

Results Overview

Daily oxalate synthesis rate (mg/day) determined by the 13c2-oxalate infusion method

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 23 participants
• Primary outcome timeframe: day 5
• Results posted on: 2025-05-13

Participant Flow

Participant milestones

Measure	Constant Infusion of 13C2-oxalate Subjects who have passed screening, will consume a low-oxalate, normal calcium controlled diet for 5 days total. On Days 3 and 4, subjects will collect two 24-hour urines. On Day 5, they will receive a carbon 13 oxalate infusion which will occur at a constant rate for 6 hours, in the fasted state, following a priming dose. Hourly urine and twice hourly blood samples will be collected during the 6 hours. Meals will be resumed at the end of the infusion and timed urine collections will take place at home until the next day. A DXA scan will be performed to assess body composition at another date. Low-oxalate controlled diet: Participants will consume a diet that is controlled in its contents of protein, carbohydrates, fat, calcium, oxalate, vitamin C and sodium for 5 days. Participants will be asked not to take any dietary supplements, exercise strenuously, or consume food or drink that is not provided to them. Primed, continuous intravenous infusion of 13C2-oxalate: Participants will receive a continuous intravenous administration of carbon-13 oxalate, a naturally occurring form of oxalate, over the course of several hours until steady-state is achieved, using an IV catheter, while remaining fasting.
Overall Study STARTED	23
Overall Study COMPLETED	23
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Assessment of Endogenous Oxalate Synthesis

Baseline characteristics by cohort

Measure	Constant Infusion of 13C2-oxalate n=23 Participants Subjects who have passed screening, will consume a low-oxalate, normal calcium controlled diet for 5 days total. On Days 3 and 4, subjects will collect two 24-hour urines. On Day 5, they will receive a carbon 13 oxalate infusion which will occur at a constant rate for 6 hours, in the fasted state, following a priming dose. Hourly urine and twice hourly blood samples will be collected during the 6 hours. Meals will be resumed at the end of the infusion and timed urine collections will take place at home until the next day. A DXA scan will be performed to assess body composition at another date. Low-oxalate controlled diet: Participants will consume a diet that is controlled in its contents of protein, carbohydrates, fat, calcium, oxalate, vitamin C and sodium for 5 days. Participants will be asked not to take any dietary supplements, exercise strenuously, or consume food or drink that is not provided to them. Primed, continuous intravenous infusion of 13C2-oxalate: Participants will receive a continuous intravenous administration of carbon-13 oxalate, a naturally occurring form of oxalate, over the course of several hours until steady-state is achieved, using an IV catheter, while remaining fasting.
Age, Categorical <=18 years	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	23 Participants n=5 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants
Age, Continuous	41 years STANDARD_DEVIATION 11 • n=5 Participants
Sex: Female, Male Female	14 Participants n=5 Participants
Sex: Female, Male Male	9 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	21 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	1 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants
Race (NIH/OMB) Asian	1 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	10 Participants n=5 Participants
Race (NIH/OMB) White	12 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Region of Enrollment United States	23 participants n=5 Participants
Body mass index	31 kg/m2 STANDARD_DEVIATION 6 • n=5 Participants

PRIMARY outcome

Timeframe: day 5

Daily oxalate synthesis rate (mg/day) determined by the 13c2-oxalate infusion method

Outcome measures

Measure

Constant Infusion of 13C2-oxalate n=23 Participants Subjects who have passed screening, will consume a low-oxalate, normal calcium controlled diet for 5 days total. On Days 3 and 4, subjects will collect two 24-hour urines. On Day 5, they will receive a carbon 13 oxalate infusion which will occur at a constant rate for 6 hours, in the fasted state, following a priming dose. Hourly urine and twice hourly blood samples will be collected during the 6 hours. Meals will be resumed at the end of the infusion and timed urine collections will take place at home until the next day. A DXA scan will be performed to assess body composition at another date. Low-oxalate controlled diet: Participants will consume a diet that is controlled in its contents of protein, carbohydrates, fat, calcium, oxalate, vitamin C and sodium for 5 days. Participants will be asked not to take any dietary supplements, exercise strenuously, or consume food or drink that is not provided to them. Primed, continuous intravenous infusion of 13C2-oxalate: Participants will receive a continuous intravenous administration of carbon-13 oxalate, a naturally occurring form of oxalate, over the course of several hours until steady-state is achieved, using an IV catheter, while remaining fasting.

Endogenous Oxalate Synthesis Rate

17 mg/day Standard Deviation 4

SECONDARY outcome

Timeframe: day 3-4

24-hr urinary oxalate excretion (mg/day) after equilibration on the low-oxalate controlled diet, measured by ion chromatography coupled with mass spectrometry.

Outcome measures

Measure

Constant Infusion of 13C2-oxalate n=23 Participants Subjects who have passed screening, will consume a low-oxalate, normal calcium controlled diet for 5 days total. On Days 3 and 4, subjects will collect two 24-hour urines. On Day 5, they will receive a carbon 13 oxalate infusion which will occur at a constant rate for 6 hours, in the fasted state, following a priming dose. Hourly urine and twice hourly blood samples will be collected during the 6 hours. Meals will be resumed at the end of the infusion and timed urine collections will take place at home until the next day. A DXA scan will be performed to assess body composition at another date. Low-oxalate controlled diet: Participants will consume a diet that is controlled in its contents of protein, carbohydrates, fat, calcium, oxalate, vitamin C and sodium for 5 days. Participants will be asked not to take any dietary supplements, exercise strenuously, or consume food or drink that is not provided to them. Primed, continuous intravenous infusion of 13C2-oxalate: Participants will receive a continuous intravenous administration of carbon-13 oxalate, a naturally occurring form of oxalate, over the course of several hours until steady-state is achieved, using an IV catheter, while remaining fasting.

Urinary Oxalate Excretion

20 mg/day Standard Deviation 4

SECONDARY outcome

Timeframe: day 3-4

24-hr urinary creatinine excretion (g/day) after equilibration on the low-oxalate controlled diet.

Outcome measures

Measure

Constant Infusion of 13C2-oxalate n=23 Participants Subjects who have passed screening, will consume a low-oxalate, normal calcium controlled diet for 5 days total. On Days 3 and 4, subjects will collect two 24-hour urines. On Day 5, they will receive a carbon 13 oxalate infusion which will occur at a constant rate for 6 hours, in the fasted state, following a priming dose. Hourly urine and twice hourly blood samples will be collected during the 6 hours. Meals will be resumed at the end of the infusion and timed urine collections will take place at home until the next day. A DXA scan will be performed to assess body composition at another date. Low-oxalate controlled diet: Participants will consume a diet that is controlled in its contents of protein, carbohydrates, fat, calcium, oxalate, vitamin C and sodium for 5 days. Participants will be asked not to take any dietary supplements, exercise strenuously, or consume food or drink that is not provided to them. Primed, continuous intravenous infusion of 13C2-oxalate: Participants will receive a continuous intravenous administration of carbon-13 oxalate, a naturally occurring form of oxalate, over the course of several hours until steady-state is achieved, using an IV catheter, while remaining fasting.

Urinary Creatinine Excretion

1.6 g/day Standard Deviation 0.5

Adverse Events

Constant Infusion of 13C2-oxalate

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr Sonia Fargue

University of Alabama at Birmingham

Phone: 2059756932

Email: sfargue@uab.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place