Antibody-mediated RejectionPhase 2ShamrockNCT06503731
A Study to Evaluate the Safety and Tolerability of Efgartigimod PH20 SC Given by Prefilled Syringe in Kidney Transplant Recipients With Antibody-Mediated Rejection (AMR)
A Phase 2 study testing Efgartigimod PH20 SC - prefilled syringe in people with Antibody-mediated Rejection, run by argenx at 23 sites in 8 countries.
Trial summary
The purpose of this study is to assess the safety, tolerability, and efficacy of efgartigimod PH20 SC given by a prefilled syringe in participants with Antibody-Mediated Rejection (AMR) after kidney transplantation. After a screening period of up to 6 weeks, eligible participants will be randomized in a 1:1:1 ratio. Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Antibody-mediated Rejection
- What is being tested?
- Efgartigimod PH20 SC - prefilled syringe
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 33 participants
- Where
- 23 sitesin 8 countries
- Study dates
- 30 Aug 2024to Nov 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 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- The participant is within the ages of 18 and 80 years old
- The participant had a kidney transplant (living or deceased donor) at least 6 months before the study
- The participant has received a diagnosis of active or chronic active antibody-mediated rejection (AMR) with detectable donor-specific antibodies at time of the study
- A participant may be allowed into the study if they receive the following medications:
- Received mycophenolate mofetil for at least 20 weeks before the study
- Has remained on a stable dose of mycophenolate mofetil and tacrolimus for at least 4 weeks before being allowed to participate in the study
- Has remained on tacrolimus doses between 5 to 10 ng/mL at least 4 weeks before being allowed to participate in the study
- Steroid dose was between 0 to 10 mg per day of prednisone (or dose equivalent) for at least 4 weeks before being allowed to participate in the study
Who cannot join
- Confirmed T-cell or mixed rejection at time of the study
- Recent change in immunosuppressive therapy agents
- Any other medical condition that, in the investigator's opinion, would interfere with the results of the study or put the participant at undue risk
- Pregnant or lactating state or intention to become pregnant during the study
- The complete list of criteria can be found in the protocol
Trial locations and contacts
23 sites in 8 countries.
23 sites in 8 countries
United States8 sites
University of Alabama at Birmingham (UAB) Hospital
Birmingham, Alabama, 35233
University of Chicago Medical Center
Chicago, Illinois, 60615
The Ohio State University Wexner Medical Center
Columbus, Ohio, 43210
Duke University Hospital
Durham, North Carolina, 27705
Cedars-Sinai Medical Center
Los Angeles, California, 90048
University of Nebraska Medical Center
Omaha, Nebraska, 68198
Virginia Commonwealth University (VCU) Medical Center Hume-Lee Transplant Center
Richmond, Virginia, 23298
University of Washington Medical Center
Seattle, Washington, 98195
Spain4 sites
Hospital Del Mar
Barcelona, 08003
Hospital Universitario Vall d'Hebron
Barcelona, 08035
Hospital Universitario de Bellvitge
Barcelona, 08907
Hospital Universitario Miguel Servet
Zaragoza, 50009
France3 sites
Centre Hospitalier Universitaire (CHU) de Bordeaux - Hôpital Pellegrin
Bordeaux, 33076
Centre Hospitalier Universitaire (CHU) de Grenoble Alpes - Hôpital Michallon
La Tronche, 38700
Centre Hospitalier Universitaire (CHU) de Toulouse - Hôpital de Rangueil
Toulouse, 31059
Germany3 sites
Charité - Universitätsmedizin Berlin
Berlin, 13353
Universitaetsklinikum Carl Gustav Carus Dresden
Dresden, 01307
Universitätsklinikum Hamburg-Eppendorf
Hamburg, 20246
Belgium2 sites
Universitair Ziekenhuis (UZ) Gent
Ghent, 9000
Universitair Ziekenhuis Leuven (UZ Leuven) - Campus Gasthuisberg
Leuven, 3000
Austria1 site
Allgemeines Krankenhaus der Stadt Wien (AKH Wien) - Medizinischer Universitätscampus
Vienna, 1090
Czechia1 site
Institut klinicke a experimentalni mediciny (IKEM)
Prague, 140-21
About this study
Official title: A Global, Multicenter, Randomized, Double-Blinded, Placebo-Controlled, Phase 2 Study to Evaluate the Safety, Tolerability, and Efficacy of Efgartigimod PH20 SC Administered by a Prefilled Syringe in Kidney Transplant Recipients With Antibody-Mediated Rejection
The purpose of this study is to assess the safety, tolerability, and efficacy of efgartigimod PH20 SC given by a prefilled syringe in participants with Antibody-Mediated Rejection (AMR) after kidney transplantation.
After a screening period of up to 6 weeks, eligible participants will be randomized in a 1:1:1 ratio. The study drug will be administered subcutaneously while patients remain on their standard background immunosuppression therapy (tacrolimus, mycophenolate mofetil, steroids) during the treatment period (48 weeks). At the end of the treatment period, the participants will enter an observational/follow-up period (approximately 24 weeks). The participants will be in the study for up to 78 weeks.
- Conditions
- Antibody-mediated Rejection
- Being tested
- Efgartigimod PH20 SC - prefilled syringe, Placebo PH20 SC - prefilled syringe
- Keywords
- Active AMR, Chronic active AMR, Late AMR
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Efgartigimod PH20 SC - prefilled syringeCombination product
Subcutaneous efgartigimod PH20 SC given by prefilled syringe
Placebo PH20 SC - prefilled syringeOther
Subcutaneous placebo PH20 SC given by prefilled syringe
| Study group | Role | What they receive |
|---|---|---|
| Treatment arm 1 | Experimental | Participants receiving Efgartigimod PH20 SC on top of optimized standard background immunosuppression therapy (tacrolimus, mycophenolate mofetil, and optionally steroids) Receives: Combination Product: Efgartigimod PH20 SC - prefilled syringe |
| Treatment arm 2 | Experimental | Participants receiving Efgartigimod PH20 SC on top of optimized standard background immunosuppression therapy (tacrolimus, mycophenolate mofetil, and optionally steroids) up to week 24 followed by placebo PH20 SC on top of optimized standard background immunosuppression therapy from weeks 24 to 48 Receives: Combination Product: Efgartigimod PH20 SC - prefilled syringe; Other: Placebo PH20 SC - prefilled syringe |
| Treatment arm 3 | Placebo comparator | Participants receiving Placebo PH20 SC on top of optimized standard background immunosuppression therapy (tacrolimus, mycophenolate mofetil, and optionally steroids) Receives: Other: Placebo PH20 SC - prefilled syringe |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of Adverse Events (AEs)
Measured: Up to 78 weeks
Percentage of participants with permanent treatment discontinuation due to adverse events (AEs)
Measured: Up to 48 weeks
Secondary outcomes (10)
Changes from baseline (slope) of the estimated glomerular filtration rate (eGFR)
Measured: Up to 72 weeks
Histological changes in kidney biopsy
Measured: Up to 72 weeks
Urine protein creatinine ratio (UPCR)
Measured: Up to 72 weeks
Graft and participant survival
Measured: Up to 72 weeks
Proportion of participants with biopsy-proven histologic resolution (BPHR) over time
Measured: Up to 72 weeks
Changes from baseline in AMR/MVI index score over time
MVI: microvascular inflammation. AMR/MVI score is a continuous index derived from Banff histological lesions (g, ptc, cg, and C4d positivity) and used to quantify the intensity of microvascular inflammation linked to AMR. It aims to describe where a biopsy lies along the spectrum from no rejection to probable AMR to complete AMR/MVI, providing a more granular measure of disease severity than dichotomous Banff categories.
Measured: Up to 72 weeks
Percentage change from baseline in total IgG levels in serum over time
Measured: Up to 60 weeks
Efgartigimod serum concentration-time profile and PK parameter Ctrough
Measured: Up to 48 weeks
Incidence of antidrug antibodies (ADA) against efgartigimod in serum over time
Measured: Up to 72 weeks
Incidence of antibodies against rHuPH20 in plasma over time
Measured: Up to 72 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jul 2024
- Study start30 Aug 2024
- Primary completionNov 2027 (estimated)
- Study completionNov 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Antibody-mediated RejectionStudies of the same condition, open and under way.
- More trials run by argenxThe 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 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 33 participants (actual)
Sponsor and investigators
- Lead sponsor
- argenx
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06503731
- Sponsor's protocol ID
- ARGX-113-2302
- Other IDs
- 2023-508180-72-00, 2023
- Acronym
- Shamrock
- Status last verified
- Jul 2026
- First submitted
- 10 Jul 2024
- Last updated
- 2 Jul 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Global, Multicenter, Randomized, Double-Blinded, Placebo-Controlled, Phase 2 Study to Evaluate the Safety, Tolerability, and Efficacy of Efgartigimod PH20 SC Administered by a Prefilled Syringe in Kidney Transplant Recipients With Antibody-Mediated Rejection
- ClinicalTrials.gov ID
- NCT06503731
- Acronym / sponsor ID
- Shamrock / ARGX-113-2302
- Conditions
- Antibody-mediated Rejection
- Keywords
- Active AMR, Chronic active AMR, Late AMR
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 33 participants (actual)
- Lead sponsor
- argenxIndustry (pharma, biotech, devices)
- Study start
- 30 Aug 2024 (actual)
- Primary completion
- Nov 2027 (estimated)
- Study completion
- Nov 2027 (estimated)
- First posted
- 16 Jul 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.
The purpose of this study is to assess the safety, tolerability, and efficacy of efgartigimod PH20 SC given by a prefilled syringe in participants with Antibody-Mediated Rejection (AMR) after kidney transplantation.
After a screening period of up to 6 weeks, eligible participants will be randomized in a 1:1:1 ratio. The study drug will be administered subcutaneously while patients remain on their standard background immunosuppression therapy (tacrolimus, mycophenolate mofetil, steroids) during the treatment period (48 weeks). At the end of the treatment period, the participants will enter an observational/follow-up period (approximately 24 weeks). The participants will be in the study for up to 78 weeks.
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 |
|---|---|---|
| Treatment arm 1 | Experimental | Combination Product: Efgartigimod PH20 SC - prefilled syringeParticipants receiving Efgartigimod PH20 SC on top of optimized standard background immunosuppression therapy (tacrolimus, mycophenolate mofetil, and optionally steroids) |
| Treatment arm 2 | Experimental | Combination Product: Efgartigimod PH20 SC - prefilled syringe, Other: Placebo PH20 SC - prefilled syringeParticipants receiving Efgartigimod PH20 SC on top of optimized standard background immunosuppression therapy (tacrolimus, mycophenolate mofetil, and optionally steroids) up to week 24 followed by placebo PH20 SC on top of optimized standard background immunosuppression therapy from weeks 24 to 48 |
| Treatment arm 3 | Placebo comparator | Other: Placebo PH20 SC - prefilled syringeParticipants receiving Placebo PH20 SC on top of optimized standard background immunosuppression therapy (tacrolimus, mycophenolate mofetil, and optionally steroids) |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- The participant is within the ages of 18 and 80 years old
- The participant had a kidney transplant (living or deceased donor) at least 6 months before the study
- The participant has received a diagnosis of active or chronic active antibody-mediated rejection (AMR) with detectable donor-specific antibodies at time of the study
- A participant may be allowed into the study if they receive the following medications:
Key exclusion criteria (5 listed)
- Confirmed T-cell or mixed rejection at time of the study
- Recent change in immunosuppressive therapy agents
- Any other medical condition that, in the investigator's opinion, would interfere with the results of the study or put the participant at undue risk
- Pregnant or lactating state or intention to become pregnant during the study
- The complete list of criteria can be found 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 |
|---|---|---|
| Efgartigimod PH20 SC - prefilled syringeSubcutaneous efgartigimod PH20 SC given by prefilled syringe | Combination product | Treatment arm 1, Treatment arm 2 |
| Placebo PH20 SC - prefilled syringeSubcutaneous placebo PH20 SC given by prefilled syringe | Other | Treatment arm 2, Treatment arm 3 |
Primary outcome
Incidence of Adverse Events (AEs)
Time frame: Up to 78 weeks
Percentage of participants with permanent treatment discontinuation due to adverse events (AEs)
Time frame: Up to 48 weeks
10 secondary outcomes
Changes from baseline (slope) of the estimated glomerular filtration rate (eGFR)
Time frame: Up to 72 weeks
Histological changes in kidney biopsy
Time frame: Up to 72 weeks
Urine protein creatinine ratio (UPCR)
Time frame: Up to 72 weeks
Graft and participant survival
Time frame: Up to 72 weeks
Proportion of participants with biopsy-proven histologic resolution (BPHR) over time
Time frame: Up to 72 weeks
Changes from baseline in AMR/MVI index score over time
Time frame: Up to 72 weeks
Percentage change from baseline in total IgG levels in serum over time
Time frame: Up to 60 weeks
Efgartigimod serum concentration-time profile and PK parameter Ctrough
Time frame: Up to 48 weeks
Incidence of antidrug antibodies (ADA) against efgartigimod in serum over time
Time frame: Up to 72 weeks
Incidence of antibodies against rHuPH20 in plasma over time
Time frame: Up to 72 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 2 Jul 2026.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
23 sites in 8 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Efgartigimod PH20 SC - prefilled syringe in people with Antibody-mediated Rejection, run by argenx at 23 sites in 8 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 8 inclusion and 5 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: under way, not looking for participants, as of the sponsor's last update on 2 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 23 sites in United States, Spain, France, Germany, Belgium and 3 more countries. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of Adverse Events (AEs) (time frame: Up to 78 weeks). 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 2 Jul 2026.