Trial results for the Phase 2 study (NCT04818034) investigating dapagliflozin for cystine stone formation in patients with cystinuria were posted on ClinicalTrials.gov on 2025-10-08. The preliminary study, which enrolled 10 participants, found no statistically significant effect of dapagliflozin on 24hr urine cystine concentration, with a p-value of 0.965.
Background
Cystinuria is an inherited autosomal recessive kidney disorder characterized by the inability to reabsorb cystine from urine. This leads to supersaturation of cystine, crystal precipitation, and stone formation in the kidney, causing obstruction, infection, and chronic kidney disease. These cystine stones present a significant health challenge due to frequent recurrence of painful symptoms and a lack of effective treatments. Dapagliflozin is a sodium-glucose cotransporter (SGLT) 2 inhibitor.
Trial design
The study (NCT04818034), titled "The Effect of Sodium-glucose Cotransporter (SGLT) 2 Inhibitors on Cystine Stone Formation: A Preliminary Study," was a Phase 2 trial with an enrollment of 10 participants diagnosed with Cystinuria. The intervention investigated was dapagliflozin. The study aimed to measure the effect of SGLT-2 inhibitor therapy on cystine production in the urine.
Key results
For the outcome "24hr Urine Measurements of the Effect of SGLT-2 Inhibitor Therapy on Cystine Production in Urine in Patients With Cystinuria," the "Study Drug" group showed a mean 24hr urine cystine concentration of 999.3 mg with a Standard Deviation of 1.1.
A paired t-test analysis yielded a p-value of 0.965 (96.0% CI). This indicates no statistically significant difference in 24hr urine cystine concentration.
What this means
The results from this Phase 2 preliminary study suggest that dapagliflozin did not have a statistically significant impact on 24hr urine cystine concentration in the 10 participants with cystinuria. The p-value of 0.965 indicates that the observed change was not statistically different from what might be expected by chance. Given the small sample size, these findings provide initial data but do not support a role for dapagliflozin in reducing cystine production in this patient population based on this study's parameters.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT04818034, titled "The Effect of Sodium-glucose Cotransporter (SGLT) 2 Inhibitors on Cystine Stone Formation: A Preliminary Study," were posted on 2025-10-08 on clinicaltrials.gov.