HyperphosphatemiaPhase 3RESPOND-2NCT06933472
A Study of a Novel Iron-based Phosphate Binder AP301 in Patients With Hyperphosphatemia in the U.S. and China
A Phase 3 study testing AP301 and AP301 Low Dose in people with Hyperphosphatemia and Chronic Kidney Disease, Receiving Dialysis, run by Alebund Pharmaceuticals at 42 sites in 2 countries.
Trial summary
The goal of this clinical trial is to learn if AP301 could work in the patients receiving maintenance dialysis with elevated blood phosphate. The main questions it aims to answer are: Does AP301 lower blood phosphate levels? Does AP301 works on serum calcium level, calcium times phosphate level, and intact parathyroid… Read more about this study
- Who is it for?
- Ages 12 years and older
- Conditions the study is for
- Hyperphosphatemia, Chronic Kidney Disease, Receiving Dialysis, ESRD (End-Stage Renal Disease)
- What is being tested?
- AP301 and AP301 Low Dose
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 264 participants
- Where
- 42 sitesin 2 countries
- Study dates
- 13 Jun 2025to 10 Jan 2027
- Phase
- Phase 3
- 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 12 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Provision of signed and dated ICF
- Age ≥ 12 years when signing the ICF
- Patients on dialysis for ≥ 3 months before signing the ICF and throughout the study
- For HD patients, spKt/V ≥ 1.2; for PD patients, total Kt/V ≥ 1.7/week
- Patients who receive phosphate-lowering drugs over 4 weeks and their serum phosphate level is:
- Screening: 1.13 mmol/L (3.5 mg/dL) ≤ serum phosphate < 2.58 mmol/L (8.0 mg/dL)
- After washout: 1.94 mmol/L (6.0 mg/dL) ≤ serum phosphate < 3.23 mmol/L (10.0 mg/dL)
Who cannot join
- History or plan of kidney transplantation
- History or plan of parathyroid intervention 6 months before signing the ICF
- Serum calcium < 1.9 mmol/L (7.6 mg/dL) or > 2.75 mmol/L (11 mg/dL) at screening
- Serum intact parathyroid hormone > 127 pmol/L (1200 pg/mL) at screening
- Presence of clinically significant gastrointestinal (GI) disorder
- History of gastrectomy or duodenectomy, or GI surgery within 3 months before signing the ICF
- Known allergic to any ingredient of AP301, or known history of severe allergies leading to emergency medical care
- Female who are breastfeeding
Trial locations and contacts
42 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
42 sites in 2 countries
China23 sites, 23 recruiting
- Recruiting
Peking University First Hospital
Beijing, Beijing Municipality, 100035
Yuqing Chen, M.D., cyq@bjmu.edu.cn
- Recruiting
Beijing Tsinghua Chang Gung Hospital
Beijing, Beijing Municipality, 102218
Yuehong Li, M.D., liyuehong0616@163.com
- Recruiting
Peking University International Hospital
Beijing, Beijing Municipality, 102218
Jiaxiang Ding, M.D., dingjiaxiang@pkuih.edu.cn
- Recruiting
Central South University-The Third Xiangya Hospital
Changsha, Hunan, 410013
Hao Zhang, M.D., zhanghaoliaoqin@163.com
- Recruiting
Sichuan Provincial People's Hospital
Chengdu, Sichuan, 610072
Li Wang, M.D., scwangli62@163.com
- Recruiting
Jiangxi Provincial People's Hospital
Nanchang, Jiangxi, 330006
Aimin Zhong, M.D., aiminzhong@126.com
- Recruiting
Southeast University-Zhongda Hospital
Nanjing, Jiangsu, 210009
Xiaoliang Zhang, M.D., tonyxlz@163.com
- Recruiting
Jiangsu Province Hospital (The First Affiliated Hospital with Nanjing Medical University)
Nanjing, Jiangsu, 210029
Huijuan Mao, M.D., huijuanmao@126.com
- Recruiting
Nantong University-Affiliated Hospital
Nantong, Jiangsu, 226001
Houyong Dai, M.D., daihy520@126.com
- Recruiting
Qingdao University-The Affiliated Hospital
Qingdao, Shandong, 266000
Yan Xu, M.D., xuyanqyfy@126.com
- Recruiting
Shanghai Jiao Tong University School of Medicine (SJTUSM)-Renji Hospital
Shanghai, Shanghai Municipality, 200000
Leyi Gu, M.D., guleyi@aliyun.com
- Recruiting
Fudan University-Zhongshan Hospital
Shanghai, Shanghai Municipality, 200032
Xiaoqiang Ding, M.D., ding.xiaoqiang@zs-hospital.sh.cn
- Recruiting
Fudan University-Huashan Hospital
Shanghai, Shanghai Municipality, 200040
Jing Chen, M.D., chenjing1998@fudan.edu.cn
- Not yet recruiting
Children's Hospital of Fudan University
Shanghai, Shanghai Municipality, 200080
Qian Shen, M.D., shenqian@shmu.edu.cn
- Recruiting
Shanghai Tongren Hospital
Shanghai, Shanghai Municipality, 200336
Xiaoxia Wang, M.D., ouyang1985@sjtu.edu.cn
- Recruiting
Huazhong University of Science and Technology-Tongji Medical College - Wuhan Union Hospital
Wuhan, Hubei, 430022
Chun Zhang, M.D., drzhangchun@126.com
- Recruiting
Wuhan University People's Hospital
Wuhan, Hubei, 430060
Ming Shi, M.D., shikidney@qq.com
- Recruiting
Nanjing Medical University-Wuxi People's Hospital (Wuxi No.1 People's Hospital)
Wuxi, Jiangsu, 214023
Zhijian Zhang, M.D., zzjwxyy@163.com
- Recruiting
The First Affiliated Hospital of Xiamen University
Xiamen, Fujian, 361003
Leping Shao, M.D., lepingshao@163.com
- Recruiting
Subei People's Hospital
Yangzhou, Jiangsu, 225002
Guangyu Bi, M.D., biguangyu@yeah.net
- Recruiting
Yantai Yuhuangding Hospital
Yantai, Shandong, 264099
Peng Li, M.D., lipengsdyt@163.com
- Recruiting
Henan Provincial People's Hospital
Zhengzhou, Henan, 450003
Fengmin Shao, M.D., fengminshao@126.com
- Recruiting
Zhengzhou University-First Affiliated Hospital
Zhengzhou, Henan, 450003
Pei Wang, M.D., wangpei146@hotmail.com
United States19 sites, 19 recruiting
- Recruiting
Renal Associates Of Baton Rouge, LLC
Baton Rouge, Louisiana, 70808
Michael Roppollo, M.D., mroppolo@renalassociates.com
- Recruiting
US Renal Care - West Cheektowaga
Cheektowaga, New York, 14215
Imad Ahmed, M.D., imad16th@yahoo.com
- Recruiting
Nephrology Associates, P.C. - Columbus
Columbus, Mississippi, 38801
Angela Riley, M.D., ariley@nakidneydocs.com
- Recruiting
Dallas Renal Group - Dallas
Dallas, Texas, 75237
Ajay Kallam, M.D., akallam@dallasrenalgroup.com
- Recruiting
Nephrology & Hypertension Specialists
Dalton, Georgia, 30720
Frank Newby, M.D., dnewby@kidneydocs.net
- Recruiting
US Renal Care - Fort Myers South
Fort Myers, Florida, 33912
Mary Mouracade, M.D., mmouracade@associatesnephrology.com
- Recruiting
US Renal Care - Bluebonnet
Fort Worth, Texas, 76110
Raju Patil, M.D., rpatil@fortworthrenal.com
- Recruiting
High Desert Nephrology Association - US Renal Care
Gallup, New Mexico, 87301
Ayodele Erinle, M.D., Aerinle@hdnakidney.com
- Recruiting
Renal Consultants Medical Group
Granada Hills, California, 91344
Dayan Gandhi, M.D., drg@renalconsultants.com
- Recruiting
Rocky Mountain Kidney Care - Lone Tree
Lone Tree, Colorado, 80124
Geoffrey Block, M.D., geoff.block@usrenalcare.com
- Recruiting
Gamma Medical Research
McAllen, Texas, 78503
Roberto Manllo-Karim, rmangoo@gmail.com
- Recruiting
PACT Kidney Care - Orange
Orange, Connecticut, 06477
Peter Chuang, M.D., pchuang@pactmd.com
- Recruiting
NY Kidney & Hypertension Medicine
Ridgewood, New York, 11385
Jodumutt Bhat, M.D., jbhat@atlanticdialysis.com
- Recruiting
US Renal Care - South San Antonio
San Antonio, Texas, 78211
Carolina Arias, M.D., carias@texaskidneycare.com
- Recruiting
US Renal Care - Hill Country
San Antonio, Texas, 78251
Varshasb Broumand, M.D., vbroumand@texaskidneycare.com
- Recruiting
North America Research Institute - San Dimas
San Dimas, California, 91773
Nitin Bhasin, M.D., nbhasin@nariresearch.com
- Recruiting
North America Research Institute - San Dimas
San Dimas, California, 91773
Aamir Jamal, M.D., ajamal@nariresearch.com
- Recruiting
US Renal Care - Alexis
Toledo, Ohio, 43613
Ramy Fayad, M.D., ramyfayad@hotmail.com
- Recruiting
Nephrology & Hypertension Associates Ltd - Tupelo
Tupelo, Mississippi, 38801
Thomas Wooldridge, M.D., TDWooldridgeResearch@gmail.com
About this study
Official title: A Randomized, Double-Blind, Multi-Regional, Phase 3 Study to Evaluate the Efficacy and Safety of AP301 on Serum Phosphorus Control in Chronic Kidney Disease Patients Receiving Maintenance Dialysis With Hyperphosphatemia
The goal of this clinical trial is to learn if AP301 could work in the patients receiving maintenance dialysis with elevated blood phosphate. The main questions it aims to answer are:
- Does AP301 lower blood phosphate levels?
- Does AP301 works on serum calcium level, calcium times phosphate level, and intact parathyroid hormone level?
- What discomfort or medical problem do the patients have when taking AP301?
- Does AP301 improve quality of life in Chinese patients?
Read more
The researchers will compare AP301 to an ineffective comparator (a look-alike substance that contains low dose AP301) to see if AP301 works to treat elevated blood phosphate.
In the study, the patients will experience the following stages in a chronicle order:
- Stop all using blood phosphate-lowering drugs,
- Take AP301 or the comparator three times a day for 8 weeks,
- Take AP301 three times a day for 24 weeks, and
- Take AP301 or the comparator three times a day for 3 weeks.
In the first 32 weeks, the dose of AP301 will be adjusted upwards or downwards based on the patient's blood phosphate level and the study doctor's judgment.
If the participant has a blood phosphate level above or below a certain level, they may receive additional treatment to lower the blood phosphate level.
- Conditions
- Hyperphosphatemia, Chronic Kidney Disease, Receiving Dialysis, ESRD (End-Stage Renal Disease), Dialysis
- Being tested
- AP301, AP301 Low Dose
- Keywords
- Hyperphosphatemia, AP301, Dialysis, ESKD
- Medical subject headings
- Hyperphosphatemia, Renal Insufficiency, Chronic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AP301Drug
Three times a day, administered orally with three meals at a daily dose level from 2.7g to 9.0g
AP301 Low DoseDrug
Three times a day, administered orally with three meals at a daily dose level from 0.075g to 0.25g
| Study group | Role | What they receive |
|---|---|---|
| AP301 | Experimental | A blood phosphate-lowering medication containing iron Receives: Drug: AP301 |
| AP301 Low Dose | Experimental | A blood phosphate-lowering medication containing iron, but with a low dose considered as ineffective Receives: Drug: AP301 Low Dose |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in serum phosphate concentrations in the AP301 and the AP301 low dose groups
The amount of phosphate in the blood will be measured with a standard laboratory test. The change in phosphate levels will be compared between the group receiving AP301 and the group receiving AP301 low dose.
Measured: From Baseline to the end of Week 8
Secondary outcomes (5)
Chang in serum phosphate concentrations in the AP301 maintenance dose and the AP301 low dose groups
The amount of phosphate in the blood will be measured with a standard laboratory test. The change in phosphate levels will be compared between the group receiving AP301 maintenance dose and the group receiving AP301 low dose.
Measured: From the beginning of Week 33 to the end of Week 35
Change in serum phosphate concentrations over time throughout the study
Measured: From Baseline to the end of Week 35
Change in serum calcium (Ca) and intact parathyroid hormone levels over time
The amount of calcium and intact parathyroid hormone (iPTH) in the blood will be measured with standard laboratory tests.
Measured: From Baseline to the end of Week 35
Number of adverse events
Measured: From Baseline to Follow-up (Up to 37 weeks)
Change in QT intervals measured by 12-lead electrocardiagram test over time
The duration of QT intervals will be measured with a standard 12-lead electrocardiagram test.
Measured: From Baseline to the end of Week 35
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Apr 2025
- Study start13 Jun 2025
- Primary completion20 Jun 2026 (estimated)
- Study completion10 Jan 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 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 264 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Alebund Pharmaceuticals
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Fortrea
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06933472
- Sponsor's protocol ID
- AP301-HP-03
- Acronym
- RESPOND-2
- Status last verified
- Jun 2025
- First submitted
- 19 Mar 2025
- Last updated
- 29 Jan 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 29 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized, Double-Blind, Multi-Regional, Phase 3 Study to Evaluate the Efficacy and Safety of AP301 on Serum Phosphorus Control in Chronic Kidney Disease Patients Receiving Maintenance Dialysis With Hyperphosphatemia
- ClinicalTrials.gov ID
- NCT06933472
- Acronym / sponsor ID
- RESPOND-2 / AP301-HP-03
- Conditions
- Hyperphosphatemia, Chronic Kidney Disease, Receiving Dialysis, ESRD (End-Stage Renal Disease), Dialysis
- Keywords
- Hyperphosphatemia, AP301, Dialysis, ESKD
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 264 participants (estimated)
- Lead sponsor
- Alebund PharmaceuticalsIndustry (pharma, biotech, devices)
- Collaborators
- Fortrea
- Study start
- 13 Jun 2025 (actual)
- Primary completion
- 20 Jun 2026 (estimated)
- Study completion
- 10 Jan 2027 (estimated)
- First posted
- 18 Apr 2025 (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.
The goal of this clinical trial is to learn if AP301 could work in the patients receiving maintenance dialysis with elevated blood phosphate. The main questions it aims to answer are:
- Does AP301 lower blood phosphate levels?
- Does AP301 works on serum calcium level, calcium times phosphate level, and intact parathyroid hormone level?
- What discomfort or medical problem do the patients have when taking AP301?
- Does AP301 improve quality of life in Chinese patients?
The researchers will compare AP301 to an ineffective comparator (a look-alike substance that contains low dose AP301) to see if AP301 works to treat elevated blood phosphate.
In the study, the patients will experience the following stages in a chronicle order:
- Stop all using blood phosphate-lowering drugs,
- Take AP301 or the comparator three times a day for 8 weeks,
- Take AP301 three times a day for 24 weeks, and
- Take AP301 or the comparator three times a day for 3 weeks.
In the first 32 weeks, the dose of AP301 will be adjusted upwards or downwards based on the patient's blood phosphate level and the study doctor's judgment.
If the participant has a blood phosphate level above or below a certain level, they may receive additional treatment to lower the blood phosphate level.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| AP301 | Experimental | Drug: AP301A blood phosphate-lowering medication containing iron |
| AP301 Low Dose | Experimental | Drug: AP301 Low DoseA blood phosphate-lowering medication containing iron, but with a low dose considered as ineffective |
Who may qualify
- Ages
- 12 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (7 listed)
- Provision of signed and dated ICF
- Age ≥ 12 years when signing the ICF
- Patients on dialysis for ≥ 3 months before signing the ICF and throughout the study
- For HD patients, spKt/V ≥ 1.2; for PD patients, total Kt/V ≥ 1.7/week
- Patients who receive phosphate-lowering drugs over 4 weeks and their serum phosphate level is:
Key exclusion criteria (8 listed)
- History or plan of kidney transplantation
- History or plan of parathyroid intervention 6 months before signing the ICF
- Serum calcium < 1.9 mmol/L (7.6 mg/dL) or > 2.75 mmol/L (11 mg/dL) at screening
- Serum intact parathyroid hormone > 127 pmol/L (1200 pg/mL) at screening
- Presence of clinically significant gastrointestinal (GI) disorder
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 |
|---|---|---|
| AP301Three times a day, administered orally with three meals at a daily dose level from 2.7g to 9.0g | Drug | AP301 |
| AP301 Low DoseThree times a day, administered orally with three meals at a daily dose level from 0.075g to 0.25g | Drug | AP301 Low Dose |
Primary outcome
Change in serum phosphate concentrations in the AP301 and the AP301 low dose groups
Time frame: From Baseline to the end of Week 8
The amount of phosphate in the blood will be measured with a standard laboratory test. The change in phosphate levels will be compared between the group receiving AP301 and the group receiving AP301 low dose.
5 secondary outcomes
Chang in serum phosphate concentrations in the AP301 maintenance dose and the AP301 low dose groups
Time frame: From the beginning of Week 33 to the end of Week 35
Change in serum phosphate concentrations over time throughout the study
Time frame: From Baseline to the end of Week 35
Change in serum calcium (Ca) and intact parathyroid hormone levels over time
Time frame: From Baseline to the end of Week 35
Number of adverse events
Time frame: From Baseline to Follow-up (Up to 37 weeks)
Change in QT intervals measured by 12-lead electrocardiagram test over time
Time frame: From Baseline to the end of Week 35
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 29 Jan 2026.
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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.
42 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing AP301 and AP301 Low Dose in people with Hyperphosphatemia and Chronic Kidney Disease, Receiving Dialysis, run by Alebund Pharmaceuticals at 42 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?
The sponsor lists 7 inclusion and 8 exclusion criteria. 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 29 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 42 sites in China, United States. 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. 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 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
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 Weifeng Zhang, M.D. (+8618602184576, weifeng.zhang@alebund.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in serum phosphate concentrations in the AP301 and the AP301 low dose groups (time frame: From Baseline to the end of Week 8). 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 29 Jan 2026.