Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT02125721 |
Other study ID # |
16-00108 |
Secondary ID |
1U54DK083908 |
Status |
Completed |
Phase |
Phase 4
|
First received |
|
Last updated |
|
Start date |
June 2012 |
Est. completion date |
December 2017 |
Study information
Verified date |
July 2021 |
Source |
NYU Langone Health |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
The purpose of this study is to evaluate the effect of escalating doses of cystine biding
thiol drugs, including tiopronin and d-penicillamine, on the urinary cystine capacity, which
is a measure of the amount of cystine in the urine, in patients with cystinuria. The overall
goal will be to help guide therapy and ultimately minimize unnecessary side effects caused by
larger doses.
Description:
Cystinuria is a rare genetic cause of kidney stones that leads to significant morbidity due
to the recurrent nature of the disease. As a result, a significant part of treatment is
focused on prevention of stone formation. Current methods of prevention include increasing
fluid intake, dietary modifications, alkali therapy, and cystine binding thiol drugs (CBTDs),
which help increase the solubility of cystine in the urine. At present, the dosing of CBTDs
is empiric, and not titrated to a specific measured effect. Our primary objective will be to
measure the effect of increasing doses of CBTDs on cystine capacity. The investigators
predict that higher dosages of these medications will lead to a more positive urinary cystine
capacity, or the ability of urine to take up more cystine (and therefore decreased risk of
stone formation). However, the dose at which increasing dosages of the medications cease to
provide additional benefit is unknown. The investigators will directly measure the cystine
capacity in the urine in response to increasing doses of medications to determine if there is
a dose at which the maximum benefit of the drug exists.
This is a cross-over trial of escalating doses. There will be four parts to the study. In the
first part, subjects will stop taking CBTDs for 7 days, and perform a 24-hour urine
collection on day 7. In part 2, they will take their usual CBTD (either tiopronin or
d-penicillamine) 1 gram per day for 7 days. They will perform another 24-hour urine
collection on day 7 of this study period. In part 3, they will take their usual CBTD at 2
grams per day for 7 days and in part 4 they will take their CBTD at 3 grams per day for 7
days. Again, they will perform 24-hour urine collections on day 7 of each period. The order
in which the parts of the study are performed will be randomized for each subject. The mean
cystine capacities in each part of the study will be compared to determine the effect of drug
dosage on urinary cystine capacity.