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 (R-2: 0.75; P < 2 x 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 similar to 74% of patients. CONCLUSION: Incorporation of UPCR into the current algorithm for proteinuria management can enable optimisation of lenvatinib treatment, while minimising patient inconvenience.