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A Phase 3 Study of Tenapanor to Treat Hyperphosphatemia in ESRD Patients on Dialysis

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ClinicalTrials.gov Identifier: NCT03427125
Recruitment Status : Completed
First Posted : February 9, 2018
Last Update Posted : August 25, 2020
Information provided by (Responsible Party):

Brief Summary:
This Phase 3, 26-week, open label study with a 12-week, placebo-controlled, randomized withdrawal period followed by an open label long term safety extension will evaluate the safety and efficacy of tenapanor to treat hyperphosphatemia in end-stage renal disease (ESRD) on hemodialysis and peritoneal dialysis.

Condition or disease Intervention/treatment Phase
Hyperphosphatemia Drug: Tenapanor Drug: Placebo Drug: Sevelamer Carbonate Phase 3

Detailed Description:

The study consists of a screening visit, a phosphate binder-free washout period of up to 4 weeks, a 26-week treatment period, an up to 12-week placebo-controlled, randomized withdrawal period, during which patients are randomized 1:1 to either remain on their tenapanor treatment or placebo, followed by an open label safety extension period for a total treatment period of up to 52 weeks. An active control group, for safety analysis only, will receive sevelamer carbonate, open label, for the entire 52-week study period

Depending on increase in serum phosphate (s-P) levels, subjects can be randomized 2 or 3 weeks after being taken off their phosphate lowering medication.

Subjects who qualify to enroll in the study will be randomized 3:1 to either receive tenapanor at a dose of 30 mg bid or sevelamer carbonate.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 564 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary Purpose: Treatment
Official Title: A 26-Wk, Phase 3, Open Label Study With a 12-Wk, Placebo-Controlled, Randomized Withdrawal Period Followed by an Open Label Long Term Safety Extension to Evaluate the Safety and Efficacy of Tenapanor to Treat Hyperphosphatemia in ESRD Patients on Dialysis
Actual Study Start Date : January 8, 2018
Actual Primary Completion Date : November 15, 2019
Actual Study Completion Date : February 27, 2020

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Tenapanor 10 mg, 20 mg, 30 mg BID
During the 26-week open label part, all enrolled subjects will receive 30 mg BID doses of tenapanor. Investigators may decrease or increase the dose in 10 mg increments to a minimum of 10 g BIDor a maximum of 30 mg BID
Drug: Tenapanor
Active Drug
Other Name: RDX5791, AZD1722

Placebo Comparator: Placebo
Drug: Placebo
Inactive Drug

Active Comparator: Sevelamer Carbonate
Subjects randomized into the active control group, for safety analysis, will receive sevelamer carbonate, open label, for the entire 52-week study period. Sevelamer carbonate will be dosed based on package insert instructions (standard of care)
Drug: Sevelamer Carbonate
Active control
Other Name: Renvela

Primary Outcome Measures :
  1. Change in serum phosphorus levels during placebo controlled randomized withdrawal period in the responder population [ Time Frame: 12 weeks (randomized withdrawal period) ]
    Placebo adjusted change in serum phosphorus from the beginning to the end of the randomized withdrawal period in patients with at least a 1.2 mg/dL decrease in serum phosphorus (responder population) during the first 26 weeks of the study

Secondary Outcome Measures :
  1. Change in serum phosphorus levels during placebo controlled randomized withdrawal period in the ITT Population [ Time Frame: 12 weeks (randomized withdrawal period) ]
    Placebo Adjusted Change in Serum Phosphorus from the beginning to the end of the Randomized Withdrawal Period in all patients

  2. Change in serum phosphorus from Baseline [ Time Frame: 26 weeks (open label treatment period) ]
    change from baseline (post washout) to end of 26 week period

  3. Effect of Tenapanor on serum FGF23 levels [ Time Frame: 52 weeks ]
    Change from baseline to end of different treatment periods

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 80 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Females must be non-pregnant, non-lactating, and either be post-menopausal for at least 12 months, have documentation of irreversible surgical sterilization, or confirm the use of one of the acceptable contraceptive methods
  • Males must agree to avoid fathering a child and agree to use an appropriate method of contraception
  • Chronic maintenance hemodialysis 3x a week for at least 3 months
  • Chronic maintenance peritoneal dialysis for a minimum of 6 months
  • Kt/V ≥ 1.2 at most recent measurement prior to screening
  • Prescribed and taking at least 3 doses of phosphate binder per day
  • Serum phosphorus levels should be between 4.0 and 8.0 mg/dL at screening
  • Unchanged dose of vitamin D or calcimimetics for the last 4 weeks prior to screening
  • For enrollment in the study after at least 2 weeks of wash-out, subjects must have serum phosphorus levels of at least 6.0 mg/dL but not more than 10.0 mg/dL and have had an increase of at least 1.5 mg/dL versus pre-wash out value after 2 or 3 weeks wash-out of phosphate binders

Exclusion Criteria:

  • Severe hyperphosphatemia defined as serum phosphorus greater than 10.0 mg/dL on phosphate-binders at any time point during clinical routine monitoring for the 3 preceding months before screening visit
  • Serum/plasma parathyroid hormone >1200 pg/mL
  • Clinical signs of hypovolemia at enrollment
  • History of IBD or IBS-D
  • Scheduled for living donor kidney transplant, change to peritoneal dialysis, home HD or plans to relocate to another center during the study period
  • Positive serology with evidence of significant hepatic impairment or WBC elevation according to the Investigator
  • Life expectancy <6 months
  • Previous exposure to tenapanor

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03427125

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United States, New York
Site 529
Bronx, New York, United States, 10461
United States, North Carolina
Wake Forest School of Medicine
Winston-Salem, North Carolina, United States, 27157
Sponsors and Collaborators
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
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Responsible Party: Ardelyx
ClinicalTrials.gov Identifier: NCT03427125    
Other Study ID Numbers: TEN-02-301
First Posted: February 9, 2018    Key Record Dates
Last Update Posted: August 25, 2020
Last Verified: August 2020

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
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Phosphorus Metabolism Disorders
Metabolic Diseases
Chelating Agents
Sequestering Agents
Molecular Mechanisms of Pharmacological Action