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

A Phase 2b, Randomized, Double-Blind, Placebo-Controlled, Multicenter Study to Evaluate the Safety, Tolerability, and Serum Phosphate Lowering Effect of Fixed Dose AP306 in Participants With Hyperphosphatemia Receiving Maintenance Hemodialysis

Status
Recruiting
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06712654
Enrollment
168
Registered
2024-12-02
Start date
2026-06-01
Completion date
2027-03-31
Last updated
2026-08-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Chronic Kidney Disease Requiring Chronic Dialysis, End Stage Renal Disease on Dialysis, Hyperphosphatemia

Keywords

AP306, AP-306, EOS789, pan-phosphate transporter inhibitor

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.

Detailed description

Hyperphosphatemia, one of the most common complications of advanced chronic kidney disease, becomes increasingly prevalent as kidney function declines and is found almost universally in patients with end-stage kidney disease requiring dialysis. Hyperphosphatemia is an independent risk factor for cardiovascular outcomes, fractures, and mortality in patients with chronic kidney disease, especially in patients receiving dialysis. AP306 is a pan-phosphate transporter inhibitor that may stop phosphate absorption in the gut, controlling hyperphosphatemia. This is a randomized, double-blind, placebo-controlled, study to characterize the safety, tolerability, and efficacy of AP306 given daily for 8 weeks at fixed doses in adults with hyperphosphatemia receiving maintenance hemodialysis.

Interventions

DRUGAP306 75 mg BID

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

DRUGAP306 125 mg BID

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

DRUGAP306 150 mg BID

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

DRUGAP306 75 mg TID

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

DRUGAP306 100 mg TID

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

DRUGAP306 125 mg TID

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

DRUGPlacebo

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

Sponsors

R1 Therapeutics
Lead SponsorINDUSTRY
Alebund Pharmaceuticals
CollaboratorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

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

Design outcomes

Primary

MeasureTime frameDescription
To investigate the ability of AP306 at different fixed doses to lower serum phosphate in participants with hyperphosphatemia receiving maintenance hemodialysis8 weeksThe change in serum phosphate from baseline to the end of treatment or before the initiation of rescue therapy, or before the interruption of study drug due to serum phosphate \<2.5 mg/dL (0.81 mmol/L)

Secondary

MeasureTime frameDescription
To assess the proportion of participants with serum phosphate in the target range8 weeksAchievement of serum phosphate concentrations within the target range (between 3.5 and 5.5 mg/dL \[1.13 and 1.78 mmol/L\], inclusive) at any time during the Treatment Period
To assess the change in serum phosphate from baseline to the end of the Treatment Period8 weeksThe change in serum phosphate from baseline to the end of Treatment Week 8.
To assess the time to response on serum phosphate reduction8 weeks* The change in serum phosphate over time * The time to the first occurrence of serum phosphate ≤5.5 mg/dL (1.78 mmol/L) and ≤4.5 mg/dL (1.45 mmol/L)

Countries

China, United States

Contacts

CONTACTClinical Trials Information
ClinicalTrials@r1therapeutics.com(844) 697-3339

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 27, 2026