Recruiting

Phase 2

AP306A Study to Evaluate Safety, Tolerability and Efficacy of AP306 at Fixed Doses in Dialysis Participants With Hyperphosphatemia

Sponsor:

R1 Therapeutics

Code:

NCT06712654

Conditions

Hyperphosphatemia

Chronic Kidney Disease Requiring Chronic Dialysis

End Stage Renal Disease on Dialysis

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

AP306 75 mg BID

AP306 125 mg BID

AP306 150 mg BID

AP306 75 mg TID

AP306 100 mg TID

Study Details

Brief summary:

This study is being conducted to characterize the safety, tolerability, and efficacy of AP306 at fixed doses in adults with hyperphosphatemia receiving maintenance hemodialysis.

Conditions

Hyperphosphatemia

Chronic Kidney Disease Requiring Chronic Dialysis

End Stage Renal Disease on Dialysis

Study ID

NCT06712654

Start date

Jun 1, 2026

Status verified date

Jun, 2026

Completion date

Mar 31, 2027

Anticipated

Primary completion date

Feb 28, 2027

Anticipated

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Important Inclusion Criteria:

Signs a written informed consent form (ICF) and is willing to comply with all study requirements in the study
Receiving a stable hemodialysis (including hemodialysis, hemodiafiltration, and hemoadsorption) regimen, which is defined as a frequency of three times per week for at least 12 weeks before signing the ICF, and does not plan to change in the study
Who has a blood phosphate level within the study-required range
Who has a dialysis adequacy, assessed by single pooled Kt/V (SpKt/V, estimated with blood urea) ≥1.20, at screening or any documented value ≥1.20 within 12 weeks prior to signing the ICF
If the participant is receiving etelcalcetide, their doses must be unchanged for at least 4 weeks prior to signing the ICF
If the participant is receiving any of the following therapies, their doses are stable for at least 14 days prior to signing the ICF: phosphate-lowering products other than tenapanor or phosphate binders, active vitamin D and analogs, cinacalcet, calcitonin, and P-glycoprotein inhibitors
Agreement to use highly effective contraception for women of childbearing potentially and non-sterile sexually active males throughout the study and for 90 days after the final dose of study drug

Important Exclusion Criteria:

Pregnant or breastfeeding
Scheduled for a living donor kidney transplant in the next 6 months, planned change to peritoneal dialysis or home hemodialysis in the study; planned relocation to another dialysis center in the study
Any history of a non-pharmacological parathyroid intervention within 6 months prior to the ICF sign off, or planned parathyroid intervention in the study
Blood calcium or blood intact parathyroid hormone abnormality
Adequate organ and bone marrow function
Acute hepatitis or significant chronic liver disease
Any clinically significant GI disorders within 4 weeks prior to signing the ICF; or any history of gastrectomy; or any GI tract surgery (excluding appendectomy and polypectomy), within 12 weeks of signing the ICF
Uncontrolled hypertension
Hospitalization for cardiac or cardiocerebrovascular disease within 24 weeks prior to signing the ICF
Significant abnormalities of QT interval and heart rhythm on an electrocardiograph (ECG) test
Any clinically significant active infection or infestation or any treatment with systemic antimicrobial treatment within 2 weeks prior to signing the ICF
History or presence of malignancy within 3 years prior to signing the ICF, except basal cell skin cancer, in-situ carcinoma of the cervix, and in-situ prostate cancer
Taking moderate or strong cytochrome P450 (CYP) 3A inhibitors within 2 weeks or 5 half-lives, whichever is longer, prior to signing the ICF (topical use is allowed)
Treatment with any investigational medication or medical device within 30 days prior to signing the ICF
Life expectancy less than 12 months

Study Design

Enrollment

168 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Cohort 1

experimental: Cohort 2

experimental: Cohort 3

experimental: Cohort 4

experimental: Cohort 5

experimental: Cohort 6

placebo comparator: Cohort 7

Interventions

AP306 75 mg BID

AP306 75 mg by mouth, twice daily (150 mg/day). Placebo given once daily. Treatment given daily for 8 weeks.

AP306 125 mg BID

AP306 125 mg by mouth, twice daily (250 mg/day). Placebo given once daily. Treatment given daily for 8 weeks.

AP306 150 mg BID

AP306 150 mg by mouth, twice daily (300 mg/day). Placebo given once daily. Treatment given daily for 8 weeks.

AP306 75 mg TID

AP306 75 mg by mouth, three times daily (225 mg/day). Treatment given daily for 8 weeks.

AP306 100 mg TID

AP306 100 mg by mouth, three times daily (300 mg/day). Treatment given daily for 8 weeks.

AP306 125 mg TID

AP306 125 mg by mouth, three times daily (375 mg/day). Treatment given daily for 8 weeks.

Placebo

Placebo given by mouth, three times daily. Treatment given daily for 8 weeks.

Primary outcome measure

To investigate the ability of AP306 at different fixed doses to lower serum phosphate in participants with hyperphosphatemia receiving maintenance hemodialysis [ Time Frame: 8 weeks ]

Central Contacts and Locations

Central contacts

Clinical Trials Information

(844) 697-3339 ClinicalTrials@r1therapeutics.com

Locations

Apogee Clinical Research, LLC

Recruiting

Huntsville, Alabama, United States, 35801

California Institute of Renal Research

Recruiting

Chula Vista, California, United States, 91910

Academic Medical Research Institute

Recruiting

Los Angeles, California, United States, 90022

North America Research Institute

Recruiting

San Dimas, California, United States, 91773

Colorado Kidney Care

Recruiting

Denver, Colorado, United States, 80220

DaVita Clinical Research

Recruiting

Middlebury, Connecticut, United States, 06762

PACT Kidney Care

Recruiting

Orange, Connecticut, United States, 06477

US Renal Care - Fort Myers South

Recruiting

Fort Myers, Florida, United States, 33912

Nephrology & Hypertension Specialists

Recruiting

Dalton, Georgia, United States, 30720

St. Clair Nephrology Research

Recruiting

Shelby, Michigan, United States, 48315

DaVita Clinical Research Edina

Recruiting

Edina, Minnesota, United States, 55435

Johnson County Clinical Trials

Recruiting

Kansas City, Missouri, United States, 64111

DaVita Clinical Research

Recruiting

Las Vegas, Nevada, United States, 89107

R1 Therapeutics Clinical Trial Site

Recruiting

Albuquerque, New Mexico, United States, 87109

NY Kidney & Hypertension Medicine

Recruiting

Ridgewood, New York, United States, 11385

US Renal Care - Alexis

Recruiting

Toledo, Ohio, United States, 43613

Sunbeam Research

Recruiting

Greenville, Texas, United States, 75402

DaVita Clinical Research

Recruiting

Houston, Texas, United States, 77054

Gamma Medical Research

Recruiting

McAllen, Texas, United States, 78503

US Renal Care - South San Antonio

Recruiting

San Antonio, Texas, United States, 35801

US Renal Care - Westover Hills

Recruiting

San Antonio, Texas, United States, 78251

DaVita Clinical Research San Antonio

Recruiting

San Antonio, Texas, United States, 78258

US Renal Care

Recruiting

Waxahachie, Texas, United States, 75165

DaVita Clinical Research Norfolk

Recruiting

Norfolk, Virginia, United States, 23502

More Information

Sponsor

R1 Therapeutics

Last update posted

Aug 26, 2026

Last verified

Jun, 2026

Keywords

AP306
AP-306
EOS789
pan-phosphate transporter inhibitor

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-19. This information was provided to ClinicalTrials.gov by R1 Therapeutics on 2026-08-26.