Long-term outcomes of longitudinal efficacy study with tolvaptan in autosomal dominant polycystic kidney disease

Background: The effects of long-term and uninterrupted tolvaptan treatment on autosomal dominant polycystic kidney disease are unclear. Therefore, an over 3-years continuous treatment study was performed. Methods: From the Kyorin University Cohort, 299 patients were surveyed and 179 patients were indicated for tolvaptan having a total kidney volume (TKV) ≥750 ml, TKV slope ≥5%/year and estimated glomerular filtration rate (eGFR) ≥15 mL/min/1.73m. Among 179 patients, 118 patients consented to the study. Results: Retrospective preand prospective on-treatment periods were a median of 1.8 and 4.0 years, respectively. During 5 treatment-years, the log10(TKV) slope per year decreased from the pre-treatment period (P<0.0001) and the estimated height-adjusted TKV growth rate (eHTKV-, %/year) decreased from baseline (P<0.0001). The decline in eGFR improved in females (P<0.0001), but not in males (P=0.6321). During 5 treatment-years, eGFR remained significantly better in the group with a percent decrease in eHTKV- from baseline to the first treatment-year ≥ the median (2.94%) than in the group with a decrease <2.94%. The free-water clearance was higher in males than in females irrespective of treatment. Conclusions: The TKV growth rate decreased over 4 years with tolvaptan in both sexes. Jo urn al Pr -pr oo f