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

Area of Science:

• Nephrology
• Pharmacology
• Genetics

Background:

• Tolvaptan improves estimated glomerular filtration rate (eGFR) slope in Autosomal Dominant Polycystic Kidney Disease (ADPKD).
• In Japan, high-dose tolvaptan is discontinued at chronic kidney disease stage G5 (CKD-G5).
• Low-dose tolvaptan may be continued in CKD-G5 patients with heart failure and kidney failure.

Purpose of the Study:

• To investigate the effect of continuing low-dose tolvaptan on kidney function in ADPKD patients who reach CKD-G5.
• To compare the eGFR slope in ADPKD patients who continued, discontinued, or never received tolvaptan at CKD-G5.

Main Methods:

• A Japanese nationwide, multicenter, retrospective observational study.
• 110 ADPKD patients who developed CKD-G5 were included.
• Patients were categorized into: tolvaptan continued (≤15 mg/d at CKD-G5), tolvaptan discontinued, and non-tolvaptan groups.

Main Results:

• The eGFR slope remained stable in the non-tolvaptan group.
• The eGFR slope accelerated during CKD-G5 in the tolvaptan discontinued group compared to before.
• The eGFR slope remained stable from before to during CKD-G5 in the tolvaptan continued group.

Conclusions:

• Continuation of low-dose tolvaptan may preserve kidney function in ADPKD patients with CKD-G5.
• Discontinuing tolvaptan at CKD-G5 significantly worsened the eGFR slope.
• A clinical trial is warranted to confirm the efficacy and safety of continued low-dose tolvaptan.