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Safety, Tolerability, and Pharmacodynamics of RDX5791 in Healthy Volunteers

Phase 1
Completed
Conditions
Healthy
Interventions
Drug: Placebo
Registration Number
NCT02796131
Lead Sponsor
Ardelyx
Brief Summary

A Phase 1, single-center, randomized, double-blind, placebo-controlled study to evaluate the safety, tolerabiltiy, and pharmacodynamics of different multiple dose regimens of RDX5791 in healthy volunteers.

Detailed Description

The starting doses for this study are based on the results from the multiple ascending-dose study performed on RDX5791 (Protocol RDX5791-101). Subjects will be screened within 3 weeks of check in to the CPU. Each cohort of 15 subjects (12 RDX5791, 3 placebo) will check in to the CPU on Day -5 before dinner. Each subject will receive a diet standardized for Na+ content while in the CPU. Subjects will receive doses of RDX5791 with approximately 240 mL of non-carbonated water on Days 1 to 7 (just prior to meals, depending on QD, bid, or tid regimens). Subjects will be provided standardized meals within 10 minutes after dosing. Doses can be administered with breakfast, lunch, or dinner.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
105
Inclusion Criteria
  • Body mass index between 18 and 29.9 kg/m², inclusive
  • No clinically significant abnormalities in medical history
  • Females must be non-pregnant, non-lactating, and either postmenopausal for at least 12 months or have agreed to use an effective form of contraception from the time of signing the informed consent until 45 days after end of study
  • Men must be either sterile, abstinent, or agreed to use an approved method of contraception from check-in until 45 days after final study visit
Exclusion Criteria
  • Diagnosis or treatment of any clinically symptomatic biochemical or structural abnormality of the GI tract
  • Any surgery on the small intestine or colon, excluding appendectomy
  • Loose stools (Bristol Stool Form Score of 6 or 7) ≥2 days in the past 7 days
  • Hepatic dysfunction ([ALT] or [AST]) >1.5 times the upper limit of normal or renal impairment
  • Any evidence of or treatment of malignancy, excluding non-melanomatous malignancies of the skin
  • Use of diuretic medications, medications that are known to affect stool consistency and/or GI motility
  • Use of an investigational agent within 30 days prior to Day -2
  • Positive virology, alcohol, or drugs of abuse test during screening
  • Use of any prescription medication within 7 days before admission to the CPU
  • Have had significant blood loss (>450 mL) or have donated 1 or more units of blood or plasma within 8 weeks prior to study entry

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
30 mg tidRDX579130 mg of RDX5791 administered three times daily PO (90 mg total dose/day).
60 mg bidPlacebo60 mg of RDX5791 administered two times daily (120 mg total dose/day).
30 mg bidRDX579130 mg of RDX5791 administered twice daily PO (60 mg total dose/day).
30 mg QDRDX579130 mg of RDX5791 administered once daily (30 mg total dose/day).
Escalating dose bidPlacebo15 mg or 30 mg or 45 mg of RDX5791 administered two times daily (30, 60, or 90 mg total dose/day respectively). The stopping criteria for the dose escalation is based on Bristol Stool Score and AEs.
30 mg tidPlacebo30 mg of RDX5791 administered three times daily PO (90 mg total dose/day).
60 mg bidRDX579160 mg of RDX5791 administered two times daily (120 mg total dose/day).
15 mg bidRDX579115 mg of RDX5791 administered two times daily (30 mg total dose/day).
15 mg bidPlacebo15 mg of RDX5791 administered two times daily (30 mg total dose/day).
30 mg bidPlacebo30 mg of RDX5791 administered twice daily PO (60 mg total dose/day).
30 mg QDPlacebo30 mg of RDX5791 administered once daily (30 mg total dose/day).
30 mg bid with psylliumPlacebo30 mg of RDX5791 administered two times daily (60 mg total dose/day) with psyllium taken up to three times per day (maximum of 15 g psyllium/day).
Escalating dose bidRDX579115 mg or 30 mg or 45 mg of RDX5791 administered two times daily (30, 60, or 90 mg total dose/day respectively). The stopping criteria for the dose escalation is based on Bristol Stool Score and AEs.
30 mg bid with psylliumRDX579130 mg of RDX5791 administered two times daily (60 mg total dose/day) with psyllium taken up to three times per day (maximum of 15 g psyllium/day).
Primary Outcome Measures
NameTimeMethod
Safety of different dosing regimens of RDX57917 Days

Safety assessments will be based on adverse events, clinical laboratory tests, vital signs, ECG, and physical exams.

Secondary Outcome Measures
NameTimeMethod
Pharmacodynamics of different dosing regimens of RDX57917 Days

Pharmacodynamics of different dosing regimens of RDX5791 will be assessed by bowel movement timing, consistency, frequency, and by urine and stool sodium (Na+) excretion.

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