A phase 2 study on the treatment of hyperkalemia in patients with chronic kidney disease suggests that the selective potassium trap, ZS-9, is safe and efficient

Study answer

What this study found

ZS-9 produced dose-dependent reductions in serum potassium. Primary efficacy endpoint (rate of s-K+ decline in the first 48 h) reached significance for 3 g (P=0.048) and 10 g (P<0.001) vs placebo; 10 g yielded a mean decrease of 0.92 ± 0.52 mEq/L at 38 h (P<0.001). On day 2, 24-h urinary potassium excretion declined by 15.8 vs 8.9 mEq/24 h for 10 g vs placebo (P<0.001). AEs were generally mild; no serious AEs occurred; mild constipation observed with 3 g. Serum potassium remained below placebo for up to 3.5 days after last dose. Serum bicarbonate rose modestly with 10 g. Conclusion: ZS-9 is…

Study & population

Phase 2 randomized, double-blind, placebo-controlled multicenter dose-escalation trial; 90 adults with stable Stage 3 CKD and hyperkalemia (serum K+ 5.0–6.0 mEq/L).

Intervention

ZS-9 (sodium zirconium cyclosilicate) oral suspension; per-dose options: 0.3 g, 3 g, or 10 g; taken three times daily with meals; initial 2-day treatment (six doses) to normalize serum potassium; if serum potassium remains ≥5.0 mEq/L, additional doses on day 3 or day 4 (up to 12 doses over 4 days).

Key limitation

Small sample size per arm; short acute treatment duration (2 days with up to 3.5 days of follow-up); limited to stable Stage 3 CKD; not studied in more severe CKD or longer-term maintenance; dietary potassium content not measured; long-term safety and efficacy not established; potential sponsor involvement.

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Original abstract