HyperphosphatemiaPhase 2NCT06712654
A Study to Evaluate Safety, Tolerability and Efficacy of AP306 at Fixed Doses in Dialysis Participants With Hyperphosphatemia
A Phase 2 study testing AP306 75 mg BID, AP306 125 mg BID and AP306 150 mg BID in people with Hyperphosphatemia and Chronic Kidney Disease Requiring Chronic Dialysis, run by R1 Therapeutics at 31 sites in 2 countries.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Hyperphosphatemia, Chronic Kidney Disease Requiring Chronic Dialysis, End Stage Renal Disease on Dialysis
- What is being tested?
- AP306 75 mg BID, AP306 125 mg BID and AP306 150 mg BID
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 168 participants
- Where
- 31 sitesin 2 countries
- Study dates
- 1 Jun 2026to 31 Mar 2027
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
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
Trial locations and contacts
31 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
31 sites in 2 countries
United States24 sites, 24 recruiting
- Recruiting
R1 Therapeutics Clinical Trial Site
Albuquerque, New Mexico, 87109
- Recruiting
California Institute of Renal Research
Chula Vista, California, 91910
- Recruiting
Nephrology & Hypertension Specialists
Dalton, Georgia, 30720
- Recruiting
Colorado Kidney Care
Denver, Colorado, 80220
- Recruiting
DaVita Clinical Research Edina
Edina, Minnesota, 55435
- Recruiting
US Renal Care - Fort Myers South
Fort Myers, Florida, 33912
- Recruiting
Sunbeam Research
Greenville, Texas, 75402
- Recruiting
DaVita Clinical Research
Houston, Texas, 77054
- Recruiting
Apogee Clinical Research, LLC
Huntsville, Alabama, 35801
- Recruiting
Johnson County Clinical Trials
Kansas City, Missouri, 64111
- Recruiting
DaVita Clinical Research
Las Vegas, Nevada, 89107
- Recruiting
Academic Medical Research Institute
Los Angeles, California, 90022
- Recruiting
Gamma Medical Research
McAllen, Texas, 78503
- Recruiting
DaVita Clinical Research
Middlebury, Connecticut, 06762
- Recruiting
DaVita Clinical Research Norfolk
Norfolk, Virginia, 23502
- Recruiting
PACT Kidney Care
Orange, Connecticut, 06477
- Recruiting
NY Kidney & Hypertension Medicine
Ridgewood, New York, 11385
- Recruiting
US Renal Care - South San Antonio
San Antonio, Texas, 35801
- Recruiting
US Renal Care - Westover Hills
San Antonio, Texas, 78251
- Recruiting
DaVita Clinical Research San Antonio
San Antonio, Texas, 78258
- Recruiting
North America Research Institute
San Dimas, California, 91773
- Recruiting
St. Clair Nephrology Research
Shelby, Michigan, 48315
- Recruiting
US Renal Care - Alexis
Toledo, Ohio, 43613
- Recruiting
US Renal Care
Waxahachie, Texas, 75165
China7 sites, 7 recruiting
- Recruiting
Peking University First Hospital
Beijing, Beijing Municipality, 100035
- Recruiting
Peking University People's Hospital
Beijing, Beijing Municipality, 100044
- Recruiting
Sichuan Provincial People's Hospital
Chengdu, Sichuan, 610072
- Recruiting
The Second Affiliated Hospital of Nanjing Medical University
Nanjing, Jiangsu, 210003
- Recruiting
Zhongda Hospital Southeast University
Nanjing, Jiangsu, 210009
- Recruiting
Shanghai Jiao Tong University School of Medicine, Renji Hospital
Shanghai, Shanghai Municipality, 201112
- Recruiting
Zhengzhou University-First Affiliated Hospital
Zhengzhou, Henan, 450003
About this study
Official title: 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
This study is being conducted to characterize the safety, tolerability, and efficacy of AP306 at fixed doses in adults with hyperphosphatemia receiving maintenance hemodialysis.
Read the 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.
- Conditions
- Hyperphosphatemia, Chronic Kidney Disease Requiring Chronic Dialysis, End Stage Renal Disease on Dialysis
- Being tested
- AP306 75 mg BID, AP306 125 mg BID, AP306 150 mg BID, AP306 75 mg TID, AP306 100 mg TID
- Keywords
- AP306, AP-306, EOS789, pan-phosphate transporter inhibitor
- Medical subject headings
- Hyperphosphatemia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AP306 75 mg BIDDrug
AP306 75 mg by mouth, twice daily (150 mg/day). Placebo given once daily. Treatment given daily for 8 weeks.
AP306 125 mg BIDDrug
AP306 125 mg by mouth, twice daily (250 mg/day). Placebo given once daily. Treatment given daily for 8 weeks.
AP306 150 mg BIDDrug
AP306 150 mg by mouth, twice daily (300 mg/day). Placebo given once daily. Treatment given daily for 8 weeks.
AP306 75 mg TIDDrug
AP306 75 mg by mouth, three times daily (225 mg/day). Treatment given daily for 8 weeks.
AP306 100 mg TIDDrug
AP306 100 mg by mouth, three times daily (300 mg/day). Treatment given daily for 8 weeks.
AP306 125 mg TIDDrug
AP306 125 mg by mouth, three times daily (375 mg/day). Treatment given daily for 8 weeks.
PlaceboDrug
Placebo given by mouth, three times daily. Treatment given daily for 8 weeks.
| Study group | Role | What they receive |
|---|---|---|
| Cohort 1 | Experimental | Not described Receives: Drug: AP306 75 mg BID |
| Cohort 2 | Experimental | Not described Receives: Drug: AP306 125 mg BID |
| Cohort 3 | Experimental | Not described Receives: Drug: AP306 150 mg BID |
| Cohort 4 | Experimental | Not described Receives: Drug: AP306 75 mg TID |
| Cohort 5 | Experimental | Not described Receives: Drug: AP306 100 mg TID |
| Cohort 6 | Experimental | Not described Receives: Drug: AP306 125 mg TID |
| Cohort 7 | Placebo comparator | Not described Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
To investigate the ability of AP306 at different fixed doses to lower serum phosphate in participants with hyperphosphatemia receiving maintenance hemodialysis
The 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)
Measured: 8 weeks
Secondary outcomes (3)
To assess the proportion of participants with serum phosphate in the target range
Achievement 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
Measured: 8 weeks
To assess the change in serum phosphate from baseline to the end of the Treatment Period
The change in serum phosphate from baseline to the end of Treatment Week 8.
Measured: 8 weeks
To assess the time to response on serum phosphate reduction
- 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)
Measured: 8 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Dec 2024
- Study start1 Jun 2026
- Primary completion28 Feb 2027 (estimated)
- Study completion31 Mar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HyperphosphatemiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 168 participants (estimated)
Sponsor and investigators
- Lead sponsor
- R1 Therapeutics
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Alebund Pharmaceuticals
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06712654
- Sponsor's protocol ID
- AP306-HP-202
- Status last verified
- Jun 2026
- First submitted
- 27 Nov 2024
- Last updated
- 26 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 26 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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
- ClinicalTrials.gov ID
- NCT06712654
- Acronym / sponsor ID
- AP306-HP-202
- Conditions
- Hyperphosphatemia, Chronic Kidney Disease Requiring Chronic Dialysis, End Stage Renal Disease on Dialysis
- Keywords
- AP306, AP-306, EOS789, pan-phosphate transporter inhibitor
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 168 participants (estimated)
- Lead sponsor
- R1 TherapeuticsIndustry (pharma, biotech, devices)
- Collaborators
- Alebund Pharmaceuticals
- Study start
- 1 Jun 2026 (actual)
- Primary completion
- 28 Feb 2027 (estimated)
- Study completion
- 31 Mar 2027 (estimated)
- First posted
- 2 Dec 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 7
| Arm | Type | Receives |
|---|---|---|
| Cohort 1 | Experimental | Drug: AP306 75 mg BID |
| Cohort 2 | Experimental | Drug: AP306 125 mg BID |
| Cohort 3 | Experimental | Drug: AP306 150 mg BID |
| Cohort 4 | Experimental | Drug: AP306 75 mg TID |
| Cohort 5 | Experimental | Drug: AP306 100 mg TID |
| Cohort 6 | Experimental | Drug: AP306 125 mg TID |
| Cohort 7 | Placebo comparator | Drug: Placebo |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| AP306 75 mg BIDAP306 75 mg by mouth, twice daily (150 mg/day). Placebo given once daily. Treatment given daily for 8 weeks. | Drug | Cohort 1 |
| AP306 125 mg BIDAP306 125 mg by mouth, twice daily (250 mg/day). Placebo given once daily. Treatment given daily for 8 weeks. | Drug | Cohort 2 |
| AP306 150 mg BIDAP306 150 mg by mouth, twice daily (300 mg/day). Placebo given once daily. Treatment given daily for 8 weeks. | Drug | Cohort 3 |
| AP306 75 mg TIDAP306 75 mg by mouth, three times daily (225 mg/day). Treatment given daily for 8 weeks. | Drug | Cohort 4 |
| AP306 100 mg TIDAP306 100 mg by mouth, three times daily (300 mg/day). Treatment given daily for 8 weeks. | Drug | Cohort 5 |
| AP306 125 mg TIDAP306 125 mg by mouth, three times daily (375 mg/day). Treatment given daily for 8 weeks. | Drug | Cohort 6 |
| PlaceboPlacebo given by mouth, three times daily. Treatment given daily for 8 weeks. | Drug | Cohort 7 |
Primary outcome
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
The 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)
3 secondary outcomes
To assess the proportion of participants with serum phosphate in the target range
Time frame: 8 weeks
To assess the change in serum phosphate from baseline to the end of the Treatment Period
Time frame: 8 weeks
To assess the time to response on serum phosphate reduction
Time frame: 8 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Aug 2026.
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Pragmatic Randomised Trial of High Or Standard PHosphAte Targets in End-stage Kidney Disease (PHOSPHATE)
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
31 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing AP306 75 mg BID, AP306 125 mg BID and AP306 150 mg BID in people with Hyperphosphatemia and Chronic Kidney Disease Requiring Chronic Dialysis, run by R1 Therapeutics at 31 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 26 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 31 sites in United States, China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Clinical Trials Information ((844) 697-3339, ClinicalTrials@r1therapeutics.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the 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). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Aug 2026.