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

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: A Two-Part, Single-Blind, Phase 3 Study Evaluating the Efficacy and Safety of Patiromer for the Treatment of Hyperkalemia

Brief Summary: The purpose of this study was to evaluate the efficacy and safety of patiromer (investigational drug) in the treatment of hyperkalemia (high serum potassium). The study also evaluated the effect of withdrawing patiromer treatment and assessed whether chronic treatment with patiromer prevented the recurrence of hyperkalemia. The safety of patiromer treatment was also evaluated.

Detailed Summary:

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.


Sponsor: Relypsa, Inc.

Current Primary Outcome:

  • Change in Serum Potassium From Part A Baseline to Part A Week 4 [ Time Frame: Part A Baseline to Part A Week 4 ]
    The primary analysis endpoint is the change from Baseline at Week 4. The estimate of the change at Week 4 is from a repeated measures model, which includes data from Weeks 1, 2, 3 and 4. The analysis includes all intent to treat participants who had a serum potassium result at baseline and at least one weekly post-baseline visit (i.e. Part A Week 1 or later) and excludes six participants who had no result collected after Day 3).
  • Change in Serum Potassium From Part B Baseline [ Time Frame: Part B Baseline to Part B Week 4 or first local laboratory serum potassium < 3.8 mEq/L or ≥ 5.5 mEq/L ]

    Change in Serum Potassium from Part B Baseline to either:

    Part B Week 4 visit, if the participant's serum potassium remained ≥ 3.8 mEq/L and < 5.5 mEq/L up to the Part B Week 4 visit or the earliest Part B visit at which the participant's serum potassium was < 3.8 mEq/L or ≥ 5.5 mEq/L.



Original Primary Outcome:

  • Part A: Change in serum potassium from Baseline to Week 4 [ Time Frame: Week 4 ]
  • Part B: Change from baseline serum potassium [ Time Frame: Up to 4 weeks ]

    Change in Serum Potassium from Part B Baseline to either:

    • Week 4, for subjects whose local serum potassium remains in the range of 3.8 to < 5.5 mEq/L (milliequivalents)up to Week 4;or
    • When the subject first has a local serum potassium <3.8 mEq/L or ≥ 5.5 mEq/L


Current Secondary Outcome:

  • Proportion of Participants With Serum Potassium Levels in the Target Range of 3.8 to < 5.1 mEq/L at Part A Week 4 [ Time Frame: Week 4 ]
  • Proportion of Participants With Serum Potassium That Was ≥ 5.5 mEq/L in Part B [ Time Frame: Part B Baseline to Part B Week 8 ]
  • Proportion of Participants With Serum Potassium ≥ 5.1 mEq/L in Part B [ Time Frame: Part B Baseline to Part B Week 8 ]


Original Secondary Outcome:

  • Part A: Serum potassium level in the range of 3.8 to < 5.1 mEq/L [ Time Frame: Week 4 ]
  • Part B: Having a serum K+ value ≥ 5.5 mEq/L [ Time Frame: 8 weeks ]
  • Part B: Having a serum K+ value ≥ 5.1 mEq/L [ Time Frame: 8 weeks ]


Information By: Relypsa, Inc.

Dates:
Date Received: March 12, 2013
Date Started: February 2013
Date Completion:
Last Updated: March 11, 2016
Last Verified: March 2016