Study to Evaluate the Efficacy of Tenapanor as Adjunctive Therapy to Phosphate Binder Therapy

Trial end date:
Target enrollment:
Participant gender:
This is a randomized, double-blind, placebo-controlled study to evaluate the effect of tenapanor on change in s-P levels when tenapanor is administered orally, twice daily for 28 days as adjunctive therapy to ESRD subjects with hyperphosphatemia on stable phosphate binder therapy.
Phase 2/Phase 3
Accepts Healthy Volunteers?
Lead Sponsor:
Calcium acetate
Calcium Carbonate
Calcium, Dietary
Inclusion Criteria:

- Signed and dated informed consent prior to any study specific procedures.

- Males or females aged 18 to 80 years, inclusive, at Screening

- Females must be non-pregnant, non-lactating and either be post-menopausal for at least
-2 months, have documentation of irreversible surgical sterilization, use of
acceptable -contraceptive method, or sexual abstinence, or a sterile sexual partner
from Screening -until 30 days after the last subject visit.

- Males must agree to avoid fathering a child (or donating sperm), and therefore be
either sterile (documented) or agree to use approved methods of contraception, from
the time of enrollment until 30 days after end of study.

- Chronic maintenance hemodialysis (HD) 3x/week for at least 3 months or chronic
maintenance peritoneal dialysis (PD) for a minimum of 6 months.

- If receiving active vitamin D or calcimimetics, the dose should have been unchanged
for the last 4 weeks prior to Screening.

- Kt/V ≥1.2 at most recent measurement prior to Screening.

- Prescribed and taking phosphate binder medication at least 3 times per day, and the
prescribed dose should have been unchanged during the last 4 weeks prior to Screening.

- Serum phosphorus levels must be ≥5.5 and ≤10.0 mg/dL at Screening and the end of the
run-in period, analyzed at the central laboratory used in the study.

Exclusion Criteria:

- Severe hyperphosphatemia defined as having an s-P level >10.0 mg/dL on
phosphate-binders at any time point during routine clinical monitoring for the 3
preceding months before Screening.

- Serum/plasma parathyroid hormone >1200 pg/mL.

- Clinical signs of hypovolemia at Screening as judged by the Investigator.

- History of inflammatory bowel disease (IBD) or irritable bowel syndrome with diarrhea

- Scheduled for living donor kidney transplant or plans to relocate to another center
during the study period.

- Use of an investigational agent within 30 days prior to Screening.

- Involvement in the planning and/or conduct of the study (applies to both
Ardelyx/Contract Research Organization (CRO) staff and/or staff at the study site).

- If, in the opinion of the Investigator, the subject is unable or unwilling to fulfill
the requirements of the protocol or has a condition which would render the results