Urine protein:creatinine ratio vs 24-hour urine protein for proteinuria management: analysis from the phase 3 REFLECT study of lenvatinib vs sorafenib in hepatocellular carcinoma.

BACKGROUND Proteinuria monitoring is required in patients receiving lenvatinib, however, current methodology involves burdensome overnight urine collection. METHODS To determine whether the simpler urine protein:creatinine ratio (UPCR) calculated from spot urine samples could be accurately used for proteinuria monitoring in patients receiving lenvatinib, we evaluated the correlation between UPCR and 24-hour urine protein results from the phase 3 REFLECT study. Paired data (323 tests, 154 patients) were analysed. RESULTS Regression analysis showed a statistically significant correlation between UPCR and 24-hour urine protein (R2: 0.75; P < 2 × 10-16). A UPCR cut-off value of 2.4 had 96.9% sensitivity, 82.5% specificity for delineating between grade 2 and 3 proteinuria. Using this UPCR cut-off value to determine the need for further testing could reduce the need for 24-hour urine collection in ~74% of patients. CONCLUSION Incorporation of UPCR into the current algorithm for proteinuria management can enable optimisation of lenvatinib treatment, while minimising patient inconvenience. CLINICAL TRIAL REGISTRATION NCT01761266.