End-Stage Kidney Disease (ESKD)Phase 1NCT07759167
Study of 3 Monoclonal Antibodies (REGN9933, REGN7508, and REGN9533) in Adult Participants With End-Stage Kidney Disease on Hemodialysis
A Phase 1 study testing REGN9933, REGN7508 and REGN9533 in people with End-Stage Kidney Disease (ESKD), run by Regeneron Pharmaceuticals at 1 site in Belgium.
Trial summary
This study will evaluate three Investigational Medicinal Products (IMPs) called REGN9933, REGN7508, and REGN9533. The study is focused on participants with End-Stage Kidney Disease (ESKD) treated with hemodialysis and standard anticoagulant treatment, such as heparin, to reduce the risk of blood clots as they can lead… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- End-Stage Kidney Disease (ESKD)
- What is being tested?
- REGN9933, REGN7508 and REGN9533
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 36 participants
- Where
- 1 siteBelgium
- Study dates
- 17 Sep 2026to 2 Apr 2027
- Phase
- Phase 1
- 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
Who may be able to join
- Has ESKD and has regular adherence receiving HD 3 times per week as described in the protocol
- Is receiving heparin (standard of care) anticoagulation, with no history of intolerability, during each dialysis session
- Has adequate vascular access
- Is clinically stable with no hospitalizations in the past 30 days prior to first screening visit as described in the protocol
Who cannot join
- Has history of major bleeding (International Society on Thrombosis and Haemostasis [ISTH]) criteria) within the past 3 months prior to the first screening visit as described in the protocol
- Has known bleeding conditions (eg, Hemophilia A, B or C, von Willebrand's disease) hemorrhagic tumor sites, or other conditions with a high risk for bleeding (eg, hepatic disease associated with coagulopathy)
- Current use of oral anticoagulants (eg, warfarin, Direct Oral Anti-Coagulant [DOACs]) or dual antiplatelet therapy for clinical indication
- Heart failure as classified by New York Heart Association (NYHA) class III or IV
- Has a sustained uncontrolled hypertension as described in the protocol
- Note: Other protocol-defined Inclusion/ Exclusion criteria apply
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium1 site, 1 recruiting
- Recruiting
Universitair Ziekenhuis (UZ) Gent/ Ghent University Hospital
Ghent, Oost-Vlaanderen, 9000
About this study
Official title: A Master Protocol for a Phase 1b Double-Blind, Randomized Study to Assess the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of REGN9933 and REGN7508, Factor XI Monoclonal Antibodies, and REGN9533, a Factor XII Monoclonal Antibody, in Participants With End-Stage Kidney Disease on Hemodialysis
This study will evaluate three Investigational Medicinal Products (IMPs) called REGN9933, REGN7508, and REGN9533.
The study is focused on participants with End-Stage Kidney Disease (ESKD) treated with hemodialysis and standard anticoagulant treatment, such as heparin, to reduce the risk of blood clots as they can lead to serious health problems or be life-threatening. Because participants with ESKD who have hemodialysis have a higher risk of bleeding, the IMPs could be a meaningful new therapeutic option.
Read more
The main aim of the study is to see what side effects may happen from taking REGN9933, REGN7508, or REGN9533.
The study is looking at several other research questions, including:
- How much IMP is in the blood at different times and
- If the IMPs affect the ability of the blood to clot normally
- Conditions
- End-Stage Kidney Disease (ESKD)
- Being tested
- REGN9933, REGN7508, REGN9533, Heparin
- Keywords
- Hemodialysis (HD), Thrombosis, Bleeding, Blood clots, Chronic Kidney Disease (CKD)
- Medical subject headings
- Kidney Failure, Chronic, Thrombosis, Hemorrhage, Renal Insufficiency, Chronic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
REGN9933Drug
Also called amrecibart
Administered per the protocol
REGN7508Drug
Also called cenvacibart
Administered per the protocol
REGN9533Drug
Administered per the protocol
HeparinDrug
Administered per the protocol
| Study group | Role | What they receive |
|---|---|---|
| REGN9933 | Experimental | Not described Receives: Drug: REGN9933; Drug: Heparin |
| REGN7508 | Experimental | Not described Receives: Drug: REGN7508; Drug: Heparin |
| REGN9533 | Experimental | Not described Receives: Drug: REGN9533; Drug: Heparin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Occurrence of Treatment-Emergent Adverse Events (TEAEs)
Measured: Up to approximately 78 days
Severity of TEAEs
Measured: Up to approximately 78 days
Secondary outcomes (5)
Concentrations of REGN9933
Measured: Up to approximately 78 days
Concentrations of REGN7508
Measured: Up to approximately 78 days
Concentrations of REGN9533
Measured: Up to approximately 78 days
Change in activated Partial Thromboplastin Time (aPTT)
Measured: From baseline up to approximately 78 days
Change in Prothrombin Time (PT)
Measured: From baseline up to approximately 78 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Aug 2026
- Study start17 Sep 2026
- Primary completion2 Apr 2027 (estimated)
- Study completion2 Apr 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for End-Stage Kidney Disease (ESKD)Studies of the same condition, open and under way.
- More trials run by Regeneron PharmaceuticalsThe sponsor's other registered studies.
- 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 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 36 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Regeneron Pharmaceuticals
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Clinical Trial Management, Study director, Regeneron Pharmaceuticals
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07759167
- Sponsor's protocol ID
- R9533-HD-2576
- Other IDs
- 2026-525844-14-00
- Status last verified
- Sep 2026
- First submitted
- 6 Aug 2026
- Last updated
- 6 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing.
Study at a glance
From the registry record, last updated by the sponsor on 6 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Master Protocol for a Phase 1b Double-Blind, Randomized Study to Assess the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of REGN9933 and REGN7508, Factor XI Monoclonal Antibodies, and REGN9533, a Factor XII Monoclonal Antibody, in Participants With End-Stage Kidney Disease on Hemodialysis
- ClinicalTrials.gov ID
- NCT07759167
- Acronym / sponsor ID
- R9533-HD-2576
- Conditions
- End-Stage Kidney Disease (ESKD)
- Keywords
- Hemodialysis (HD), Thrombosis, Bleeding, Blood clots, Chronic Kidney Disease (CKD)
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 36 participants (estimated)
- Lead sponsor
- Regeneron PharmaceuticalsIndustry (pharma, biotech, devices)
- Study start
- 17 Sep 2026 (actual)
- Primary completion
- 2 Apr 2027 (estimated)
- Study completion
- 2 Apr 2027 (estimated)
- First posted
- 12 Aug 2026 (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 will evaluate three Investigational Medicinal Products (IMPs) called REGN9933, REGN7508, and REGN9533.
The study is focused on participants with End-Stage Kidney Disease (ESKD) treated with hemodialysis and standard anticoagulant treatment, such as heparin, to reduce the risk of blood clots as they can lead to serious health problems or be life-threatening. Because participants with ESKD who have hemodialysis have a higher risk of bleeding, the IMPs could be a meaningful new therapeutic option.
The main aim of the study is to see what side effects may happen from taking REGN9933, REGN7508, or REGN9533.
The study is looking at several other research questions, including:
- How much IMP is in the blood at different times and
- If the IMPs affect the ability of the blood to clot normally
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| REGN9933 | Experimental | Drug: REGN9933, Drug: Heparin |
| REGN7508 | Experimental | Drug: REGN7508, Drug: Heparin |
| REGN9533 | Experimental | Drug: REGN9533, Drug: Heparin |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Has ESKD and has regular adherence receiving HD 3 times per week as described in the protocol
- Is receiving heparin (standard of care) anticoagulation, with no history of intolerability, during each dialysis session
- Has adequate vascular access
- Is clinically stable with no hospitalizations in the past 30 days prior to first screening visit as described in the protocol
Key exclusion criteria (6 listed)
- Has history of major bleeding (International Society on Thrombosis and Haemostasis [ISTH]) criteria) within the past 3 months prior to the first screening visit as described in the protocol
- Has known bleeding conditions (eg, Hemophilia A, B or C, von Willebrand's disease) hemorrhagic tumor sites, or other conditions with a high risk for bleeding (eg, hepatic disease associated with coagulopathy)
- Current use of oral anticoagulants (eg, warfarin, Direct Oral Anti-Coagulant [DOACs]) or dual antiplatelet therapy for clinical indication
- Heart failure as classified by New York Heart Association (NYHA) class III or IV
- Has a sustained uncontrolled hypertension as described in the protocol
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 |
|---|---|---|
| REGN9933Also: amrecibartAdministered per the protocol | Drug | REGN9933 |
| REGN7508Also: cenvacibartAdministered per the protocol | Drug | REGN7508 |
| REGN9533Administered per the protocol | Drug | REGN9533 |
| HeparinAdministered per the protocol | Drug | REGN7508, REGN9533, REGN9933 |
Primary outcome
Occurrence of Treatment-Emergent Adverse Events (TEAEs)
Time frame: Up to approximately 78 days
Severity of TEAEs
Time frame: Up to approximately 78 days
5 secondary outcomes
Concentrations of REGN9933
Time frame: Up to approximately 78 days
Concentrations of REGN7508
Time frame: Up to approximately 78 days
Concentrations of REGN9533
Time frame: Up to approximately 78 days
Change in activated Partial Thromboplastin Time (aPTT)
Time frame: From baseline up to approximately 78 days
Change in Prothrombin Time (PT)
Time frame: From baseline up to approximately 78 days
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 6 Oct 2026.
- Individual participant dataSharing planned: Yes. All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing.
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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.
Clinical Trial Management study director
Regeneron Pharmaceuticals
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing REGN9933, REGN7508 and REGN9533 in people with End-Stage Kidney Disease (ESKD), run by Regeneron Pharmaceuticals at 1 site in Belgium.
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 4 inclusion and 6 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 6 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. 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 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
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 Administrator (844-734-6643, clinicaltrials@regeneron.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Occurrence of Treatment-Emergent Adverse Events (TEAEs) (time frame: Up to approximately 78 days). The study lists 2 primary outcomes in all. 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 6 Oct 2026.