A Two-Part, Single-Blind, Phase 3 Study Evaluating the Efficacy and Safety of Patiromer for the Treatment of Hyperkalemia (OPAL)

There were two parts in the study, Part A and Part B. Part A was an assessment of 4 weeks of dosing with patiromer in the treatment of hyperkalemia; Part B was a randomized, placebo-controlled, 8-week assessment of the withdrawal of patiromer in participants with a baseline serum potassium at the beginning of Part A ≥ 5.5 mEq/L who responded to the 4 weeks of treatment with patiromer during Part A. All participants received patiromer during Part A; Part B participants were randomized to continue patiromer or switch to placebo. Total study participation was up to 14 weeks (including up to 2 weeks of follow up). The dose of patiromer could be titrated based on participant's serum potassium response.