Kidney Function Trajectories with Tolvaptan in ADPKD Patients with CKD-G5

Introduction: Improvement of estimated glomerular filtration rate (eGFR) slope has been established using tolvaptan in patients with Autosomal Dominant Polycystic Kidney Disease (ADPKD). In Japan, the therapeutic dose of tolvaptan (60–120 mg/d) must be discontinued at chronic kidney disease stage G5 (CKD-G5), eGFR < 15 ml/min per 1.73 m². However, low-dose tolvaptan (≤ 15 mg/d) can be continued in CKD-G5 patients with heart failure complicated by kidney failure. Methods: This was a Japanese nation-wide, multicenter, retrospective observational study. Between May 2014 and September 2019, 110 patients with ADPKD developed CKD-G5 were included (data: previous 10 years). Participants were categorized into 3 groups: the tolvaptan continued group (received tolvaptan before CKD-G5 and reduced the dose to ≤ 15 mg at CKD-G5, N = 14), the tolvaptan discontinued group (received tolvaptan before CKD-G5 but discontinued at CKD-G5, N = 13), and the non-tolvaptan group (never received tolvaptan, N = 83). Results: The eGFR slope remained stable before and during CKD-G5 in the non-tolvaptan group. In the tolvaptan discontinued group, the eGFR slope was accelerated from before (−3.3 [−4.3, −2.5] ml/min per 1.73 m²/yr) to during CKD-G5 (−5.3 [−6.7, −3.8]). However, in the tolvaptan continued group, the eGFR slope did not change from before (−3.9 [−5.4, −2.6]) to during CKD-G5 (−3.8 [−5.4, −3.4]). Compared with the tolvaptan continued group, the eGFR slope worsened significantly from before to during CKD-G5 in the tolvaptan discontinued group (P = .006). Conclusion: Continuation of low-dose tolvaptan may be effective in suppressing kidney function deterioration in ADPKD patients with CKD-G5. A clinical trial is needed to evaluate its efficacy and safety.