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Kidney Week

Abstract: FR-PO254

Efficacy and Safety of Patiromer by Baseline Serum Potassium Level <6.0 vs. ≥6.0 mEq/L: Pooled Results of Three Studies

Session Information

Category: Diabetic Kidney Disease

  • 602 Diabetic Kidney Disease: Clinical


  • Weir, Matthew R., University of Maryland School of Medicine, Baltimore, Maryland, United States
  • Mayo, Martha, Relypsa, Inc., a Vifor Pharma Group Company, Redwood City, California, United States
  • Yuan, Jinwei, Relypsa, Inc., a Vifor Pharma Group Company, Redwood City, California, United States
  • Conrad, Ansgar, Relypsa, Inc., a Vifor Pharma Group Company, Redwood City, California, United States
  • Rafique, Zubaid, Baylor College of Medicine, Houston, Texas, United States

Patiromer (PAT) is a sodium-free non-absorbed potassium (K+) binder that uses calcium as the counter-exchange ion. In this post-hoc analysis, we assessed the efficacy and safety of PAT by baseline severity of hyperkalemia (HK).


We analyzed pooled data (patients with starting dose up to 25.2 g/day) through week 4 from 3 trials of PAT (AMETHYST-DN, OPAL-HK, TOURMALINE). Patients who took ≥1 PAT dose and had ≥1 post-baseline serum K+ measurement (sK+) were included, stratified according to sK+ ≥6.0 mEq/L and sK+ <6.0 mEq/L, and assessed for sK+ change from baseline at week 4, sK+ over time, and % with any sK+ measurement in target range (3.8–5.0 mEq/L).


623 patients were evaluated; 53 had baseline sK+ ≥6.0 mEq/L and 570 had baseline sK+ <6.0 mEq/L. Mean (SD) baseline eGFR was 33.0 (16.6) and 40.2 (19.2) mL/min/1.73m2 in those with sK+ ≥6.0 and <6.0 mEq/L, respectively. >90% of patients in both groups were taking RAASi. Mean sK+ was reduced to <5.5 mEq/L at Day 3 (48 hours after the first dose) in both subgroups (Figure). 97% of patients with sK+ <6.0 mEq/L and 93% with sK+ ≥6.0 mEq/L achieved any sK+ measurement in the target range through week 4. Mean (95% CI) reductions from baseline at week 4 were -0.67 (-0.71, -0.63) and -1.67 (-1.91, -1.43) mEq/L in the sK+ <6.0 and sK+ ≥6.0 mEq/L subgroups, respectively. Adverse events (AEs) were reported in 31% of patients with sK+ <6.0 mEq/L and 43% with sK+ ≥6.0 mEq/L, with PAT-related AEs (most commonly constipation and diarrhea) reported in 13% and 19%, respectively.


Patiromer was effective and well-tolerated in patients with mild/moderate HK and severe HK. Regardless of the severity of HK, treatment with patiromer lowered sK+ to 3.8–5.0 mEq/L in >93% of patients in 4 weeks. A higher rate of constipation occurred in the sK+ ≥6.0 mEq/L subgroup and may be related to the fact that these patients appear to have worse overall health (e.g. lower eGFR).

Serum K+ Over 4 Weeks by Baseline Serum K+ <6.0 vs ≥6.0 mEq/L: Pooled Analysis Across 3 Trials


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