Preservation of kidney function irrelevant of total kidney volume growth rate with tolvaptan treatment in patients with autosomal dominant polycystic kidney disease

BACKGROUND: Tolvaptan slowed the rates of total kidney volume (TKV) growth and renal function decline over a 3-year period in patients with autosomal dominant polycystic kidney disease (ADPKD) enrolled in the Tolvaptan Efficacy and Safety in Management of Autosomal Dominant Polycystic Kidney Disease and Its Outcomes (TEMPO) 3:4 trial (NCT00428948). In this post hoc analysis of Japanese patients from TEMPO 3:4, we evaluated whether the effects of tolvaptan on TKV and on renal function are interrelated. METHODS: One hundred and forty-seven Japanese patients from TEMPO 3:4 were included in this analysis (placebo, n = 55; tolvaptan, n = 92). Tolvaptan-treated patients were stratified into the responder group (n = 37), defined as tolvaptan-treated patients with a net decrease in TKV from baseline to year 3, and the non-responder group (n = 55), defined as tolvaptan-treated patients with a net increase in TKV. RESULTS: Mean changes during follow-up in the placebo, responder, and non-responder groups were 16.99%, − 8.33%, and 13.95%, respectively, for TKV and − 12.61, − 8.47, and − 8.58 mL/min/1.73 m(2), respectively, for estimated glomerular filtration rate (eGFR). Compared with the placebo group, eGFR decline was significantly slowed in both the responder and non-responder groups (P < 0.05). CONCLUSION: Tolvaptan was effective in slowing eGFR decline, regardless of TKV response, over 3 years in patients with ADPKD in Japan. Treatment with tolvaptan may have beneficial effects on slowing of renal function decline even in patients who have not experienced a reduction in the rate of TKV growth by treatment with tolvaptan. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10157-020-02009-0.