#1891 Evaluating the safety and effectiveness of Tolvaptan for management of adult Korean ADPKD patients (ESSENTIAL study): final report

Abstract

Abstract Background and Aims Tolvaptan, a selective vasopressin V2 receptor antagonist, was first approved by Korean FDA in 2015 as a treatment option in autosomal dominant polycystic kidney disease (ADPKD). In order to prescribe Tolvaptan safely and effectively, we designed the phase 4 clinical trial among Korean ADPKD patients with chronic kidney disease (CKD) stage 1-3. Method Korean patients aged 19 to 50 with rapidly progressing ADPKD were enrolled in the study. The dose titration was performed every one week for a total of 4 weeks. The patient was prescribed Tolvaptan with the maximum tolerable dose up to 120 mg per day. A total duration of Tolvaptan prescription was 24 months. The primary outcome was the incidence of treatment emergent adverse events (TEAE) including drug-induced liver injury (DILI). The secondary outcomes were the annual mean percent change of total kidney volume (TKV) and the annual mean change of estimated glomerular filtration rate (eGFR). Results A total of 117 patients were included in the analysis. Mean age was 38.7 ± 8.4 years old and male were predominant (58.1%). The average TKV was 2066 ± 1094 mL and mean eGFR was 79.7 ± 27.7 mL/min/1.73 m2. Mean duration of Tolvaptan exposure was 1.7 ± 0.6 years and the average daily dose of Tolvaptan was 94.4 ± 24.1 mg/day. A total of 489 treatment-emergent adverse events (TEAE) occurred in 106 (90.6%) patients during study duration. The drug-induced liver injury and aquaresis-related adverse events were two most common adverse events. A total of 17 DILI cases (14.5%) occurred during the study period and mostly within 18-month period. However, liver enzymes were normalized after drug discontinuation The patients with previous history of liver disease as well as those who were prescribed higher dose of Tolvaptan demonstrated higher frequency of DILI. Mean growth rate of TKV after Tolvaptan treatment was 4.5 ± 0.5% and mean eGFR decline rate was -3.0 ± 0.39 mL/min/1.73 m2/year. Comparing with the predicted value from calculation, Tolvaptan attenuated both TKV growth and eGFR decline rate. Conclusion This study is the first post-marketing survey assessing the safety and efficacy of Tolvaptan in Korean ADPKD patients. The incidence of DILI was higher than the previous studies and especially in those with liver disease and higher Tolvaptan prescription dose. While Tolvaptan can effectively reduce TKV and attenuate eGFR decline, the clinicians should be aware of higher frequency of DILI among Korean population.