Antibody-mediated RejectionPhase 3NCT07444489
A Study to Learn More About the Long-Term Safety and Effects of Felzartamab Infusions in Adults With Kidney Transplants Who Have Antibody-Mediated Rejection (AMR) or Microvascular Inflammation (MVI) (TRANSCEND/TRANSPIRE LTE)
A Phase 3 study testing Felzartamab in people with Antibody-mediated Rejection and Microvascular Inflammation, run by Biogen at 14 sites in United States.
Trial summary
In this study, researchers will learn more about a drug called felzartamab in people who have received a kidney transplant and then developed antibody-mediated rejection (AMR) or microvascular inflammation (MVI). Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Antibody-mediated Rejection, Microvascular Inflammation
- What is being tested?
- Felzartamab
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 201 participants
- Where
- 14 sitesUnited States
- Study dates
- 16 Apr 2026to 31 Dec 2031
- 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 18 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Have completed the parent study Week 52 visit or will be completing Week 52 visit procedures (for participants who sign consent before reaching the Week 52 visit).
- Have received at least one dose of felzartamab in the parent studies, and had the following disposition status in the parent study:
- Ongoing Treatment: Did not discontinue felzartamab treatment in the parent study and received a dose at the Week 44 visit.
- Treatment Interrupted: Did not discontinue felzartamab treatment in the parent study and did not receive a dose at the Week 44 visit.
- Off Treatment, On Study: Discontinued felzartamab treatment in the parent study and were not withdrawn from the study.
- Participants who discontinued study treatment prior to receiving any doses of felzartamab in the parent study (i.e., those in the placebo group who discontinued before receiving felzartamab) are not eligible for enrollment in this substudy.
- For participants enrolling into this study who have not discontinued felzartamab treatment in the parent study only: The Investigator has determined that the participant could benefit from continued felzartamab treatment.
Who cannot join
- Met a treatment discontinuation criterion in the parent study but treatment was not discontinued (for example, because the criterion was met after the last dose of felzartamab in the parent study).
- Note: Other protocol-defined inclusion/exclusion criteria apply.
Trial locations and contacts
14 sites in 1 country. Contact the study team or a site near you to ask about taking part.
14 sites in 1 country
United States14 sites
Cleveland Clinic
Cleveland, Ohio, 44195
The Ohio State University
Columbus, Ohio, 43210
Keck Medical Center of USC
Los Angeles, California, 90033
Cedars-Sinai Medical Center
Los Angeles, California, 90048
UCLA College of Medicine
Los Angeles, California, 90095
Medical College of Wisconsin
Milwaukee, Wisconsin, 53226
University of Nebraska Medical Center (UNMC) - Nebraska Medicine - Nebraska Medical Center
Omaha, Nebraska, 68198-3040
Penn Medicine - Hospital of the University of Pennsylvania
Philadelphia, Pennsylvania, 19104
Virginia Commonwealth University
Richmond, Virginia, 23298
Mayo Clinic
Rochester, Minnesota, 55905
California Pacific Medical Center (Sutter Health)
San Francisco, California, 94115
University of Washington Medical Center
Seattle, Washington, 98195
Washington University School of Medicine
St Louis, Missouri, 63110
Cooperman Barnabas Medical Center
West Orange, New Jersey, 07039
About this study
Official title: An Open-Label Long-Term Extension Study of Felzartamab in Participants With Antibody-Mediated Rejection or Microvascular Inflammation Previously Enrolled in TRANSCEND or TRANSPIRE
In this study, researchers will learn more about a drug called felzartamab in people who have received a kidney transplant and then developed antibody-mediated rejection (AMR) or microvascular inflammation (MVI). AMR happens when the body's immune system creates donor-specific antibodies (DSAs) that attack the transplanted kidney. In late AMR, this typically happens more than 6 months after the kidney transplant. MVI is a condition where the small blood vessels in the transplanted kidney become inflamed. MVI can happen with or without DSAs. Both AMR and MVI can cause the transplanted kidney to stop working properly.
Two earlier studies looked at felzartamab in kidney transplant recipients. Study 299AR301 (TRANSCEND) (NCT06685757) included participants with AMR. Study 299AR201 (TRANSPIRE) (NCT07219043) included participants with MVI.
Read more
This study, 299AR302-299AR301 LTE, is a long-term extension of both of these "parent" studies. Participants who join this study will have the opportunity to receive felzartamab for up to 4 more years after completing their parent study.
The goal of this study is to learn more about the long-term safety and effects of felzartamab in people with kidney transplants. This study is part of a group of studies looking at long-term felzartamab use in people with organ transplants. This study is a substudy of the main study 299AR302.
The main question researchers will answer relate to safety. Namely, how many participants have adverse events during the study and how lab test results change over time. Adverse events are health problems that may or may not be caused by the study drug.
Researchers will perform kidney biopsies to track kidney health. Researchers will also study how felzartamab affects kidney inflammation, kidney function, immune activity, and overall health.
The study will be done as follows:
- Participants who complete the final visit of the treatment period in one of the parent studies can enroll in this study. This includes participants who stopped receiving felzartamab early but still attended their final visits.
- Participants who did not stop receiving felzartamab in their parent study will continue to receive felzartamab for up to 4 more years in this study. Participants may also stop felzartamab during this study at any time.
- Participants who stopped receiving felzartamab in their parent study will only attend study visits for health monitoring- they will not receive felzartamab.
- Felzartamab will be given as an intravenous (IV) infusion, which is a slow injection into a vein using a needle.
- Participants receiving felzartamab may have up to 27 study visits over 200 weeks with an additional safety follow-up visit after their final dose.
- Participants who are not receiving felzartamab may have up to 9 study visits over 200 weeks.
Read the detailed description
The primary objective of this study is to evaluate the long-term safety of felzartamab. The secondary objectives of this study are to describe the ongoing efficacy of felzartamab on biopsy-proven histologic response (BPHR), microvascular inflammation (MVI) and graft function; and to evaluate pharmacokinetics (PK) and immunogenicity of felzartamab.
- Being tested
- Felzartamab
- Keywords
- AMR, Felzartamab, Kidney Transplant, Kidney Transplant Rejection
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
FelzartamabDrug
Also called MOR202, MOR03087, TJ202, HIB202
Administered IV
| Study group | Role | What they receive |
|---|---|---|
| Felzartamab: Long-Term Extension Treatment | Experimental | Participants will receive multiple IV doses of felzartamab. Receives: Drug: Felzartamab |
| Felzartamab: Off-Treatment Observation | Experimental | Participants who were off treatment but still continued participating in the respective parent study at the time of enrollment into the LTE or who have discontinued felzatamab treatment after receiving one or more doses in this substudy will be encouraged to continue being followed off-treatment. Receives: Drug: Felzartamab |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants With Adverse Events (AEs), Serious Adverse Events (SAEs), and Adverse Events of Special Interest (AESI)
Measured: From first dose of study drug up to end of study follow-up (Up to Week 204)
Number of Participants who Discontinue Treatment due to an AE
Measured: From first dose of study drug up to end of study follow-up (Up to Week 204)
Number of Participants with Clinically Significant Laboratory, Vital Signs and Electrocardiograms (ECGs) Abnormalities
Measured: From first dose of study drug up to end of trial visit (up to Week 200)
Secondary outcomes (9)
Percentage of Participants Achieving Biopsy-proven Histologic Resolution (BPHR)
Measured: Up to Week 200
Microvascular Inflammation (MVI) Score
Measured: Up to Week 200
Percentage of Participants Achieving an MVI Score of 0 by Each Biopsy Timepoint
Measured: Up to Week 200
Change from Baseline in Estimated Glomerular Filtration Rate (eGFR)
Measured: Baseline, Week 200
Change From Baseline in Proteinuria
Measured: Baseline, Week 200
Time to All-cause Allograft Loss
Measured: Up to Week 200
Time to Death Censored Allograft Loss
Measured: Up to Week 204
Felzartamab Serum Concentration
Measured: At Week 200
Number of Participants with Anti-drug Antibodies (ADAs) Against Felzartamab
Measured: At Week 200
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Mar 2026
- Study start16 Apr 2026
- Primary completion31 Dec 2031 (estimated)
- Study completion31 Dec 2031 (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 BiogenThe 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 3
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 201 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Biogen
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Biogen
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07444489
- Sponsor's protocol ID
- 299AR302-299AR301-LTE
- Status last verified
- Oct 2026
- First submitted
- 26 Feb 2026
- Last updated
- 9 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: In accordance with Biogen's Clinical Trial Transparency and Data Sharing Policy on https://www.biogentrialtransparency.com/
Study at a glance
From the registry record, last updated by the sponsor on 9 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-Label Long-Term Extension Study of Felzartamab in Participants With Antibody-Mediated Rejection or Microvascular Inflammation Previously Enrolled in TRANSCEND or TRANSPIRE
- ClinicalTrials.gov ID
- NCT07444489
- Acronym / sponsor ID
- 299AR302-299AR301-LTE
- Keywords
- AMR, Felzartamab, Kidney Transplant, Kidney Transplant Rejection
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 201 participants (estimated)
- Lead sponsor
- BiogenIndustry (pharma, biotech, devices)
- Study start
- 16 Apr 2026 (actual)
- Primary completion
- 31 Dec 2031 (estimated)
- Study completion
- 31 Dec 2031 (estimated)
- First posted
- 3 Mar 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.
In this study, researchers will learn more about a drug called felzartamab in people who have received a kidney transplant and then developed antibody-mediated rejection (AMR) or microvascular inflammation (MVI). AMR happens when the body's immune system creates donor-specific antibodies (DSAs) that attack the transplanted kidney. In late AMR, this typically happens more than 6 months after the kidney transplant. MVI is a condition where the small blood vessels in the transplanted kidney become inflamed. MVI can happen with or without DSAs. Both AMR and MVI can cause the transplanted kidney to stop working properly.
Two earlier studies looked at felzartamab in kidney transplant recipients. Study 299AR301 (TRANSCEND) (NCT06685757) included participants with AMR. Study 299AR201 (TRANSPIRE) (NCT07219043) included participants with MVI.
This study, 299AR302-299AR301 LTE, is a long-term extension of both of these "parent" studies. Participants who join this study will have the opportunity to receive felzartamab for up to 4 more years after completing their parent study.
The goal of this study is to learn more about the long-term safety and effects of felzartamab in people with kidney transplants. This study is part of a group of studies looking at long-term felzartamab use in people with organ transplants. This study is a substudy of the main study 299AR302.
The main question researchers will answer relate to safety. Namely, how many participants have adverse events during the study and how lab test results change over time. Adverse events are health problems that may or may not be caused by the study drug.
Researchers will perform kidney biopsies to track kidney health. Researchers will also study how felzartamab affects kidney inflammation, kidney function, immune activity, and overall health.
The study will be done as follows:
- Participants who complete the final visit of the treatment period in one of the parent studies can enroll in this study. This includes participants who stopped receiving felzartamab early but still attended their final visits.
- Participants who did not stop receiving felzartamab in their parent study will continue to receive felzartamab for up to 4 more years in this study. Participants may also stop felzartamab during this study at any time.
- Participants who stopped receiving felzartamab in their parent study will only attend study visits for health monitoring- they will not receive felzartamab.
- Felzartamab will be given as an intravenous (IV) infusion, which is a slow injection into a vein using a needle.
- Participants receiving felzartamab may have up to 27 study visits over 200 weeks with an additional safety follow-up visit after their final dose.
- Participants who are not receiving felzartamab may have up to 9 study visits over 200 weeks.
Detailed description
The primary objective of this study is to evaluate the long-term safety of felzartamab. The secondary objectives of this study are to describe the ongoing efficacy of felzartamab on biopsy-proven histologic response (BPHR), microvascular inflammation (MVI) and graft function; and to evaluate pharmacokinetics (PK) and immunogenicity of felzartamab.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Felzartamab: Long-Term Extension Treatment | Experimental | Drug: FelzartamabParticipants will receive multiple IV doses of felzartamab. |
| Felzartamab: Off-Treatment Observation | Experimental | Drug: FelzartamabParticipants who were off treatment but still continued participating in the respective parent study at the time of enrollment into the LTE or who have discontinued felzatamab treatment after receiving one or more doses in this substudy will be encouraged to continue being followed off-treatment. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Have completed the parent study Week 52 visit or will be completing Week 52 visit procedures (for participants who sign consent before reaching the Week 52 visit).
- Have received at least one dose of felzartamab in the parent studies, and had the following disposition status in the parent study:
- Participants who discontinued study treatment prior to receiving any doses of felzartamab in the parent study (i.e., those in the placebo group who discontinued before receiving felzartamab) are not eligible for enrollment in this substudy.
- For participants enrolling into this study who have not discontinued felzartamab treatment in the parent study only: The Investigator has determined that the participant could benefit from continued felzartamab treatment.
Key exclusion criteria (2 listed)
- Met a treatment discontinuation criterion in the parent study but treatment was not discontinued (for example, because the criterion was met after the last dose of felzartamab in the parent study).
- Note: Other protocol-defined inclusion/exclusion criteria apply.
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 |
|---|---|---|
| FelzartamabAlso: MOR202, MOR03087, TJ202, HIB202Administered IV | Drug | Felzartamab: Long-Term Extension Treatment, Felzartamab: Off-Treatment Observation |
Primary outcome
Number of Participants With Adverse Events (AEs), Serious Adverse Events (SAEs), and Adverse Events of Special Interest (AESI)
Time frame: From first dose of study drug up to end of study follow-up (Up to Week 204)
Number of Participants who Discontinue Treatment due to an AE
Time frame: From first dose of study drug up to end of study follow-up (Up to Week 204)
Number of Participants with Clinically Significant Laboratory, Vital Signs and Electrocardiograms (ECGs) Abnormalities
Time frame: From first dose of study drug up to end of trial visit (up to Week 200)
9 secondary outcomes
Percentage of Participants Achieving Biopsy-proven Histologic Resolution (BPHR)
Time frame: Up to Week 200
Microvascular Inflammation (MVI) Score
Time frame: Up to Week 200
Percentage of Participants Achieving an MVI Score of 0 by Each Biopsy Timepoint
Time frame: Up to Week 200
Change from Baseline in Estimated Glomerular Filtration Rate (eGFR)
Time frame: Baseline, Week 200
Change From Baseline in Proteinuria
Time frame: Baseline, Week 200
Time to All-cause Allograft Loss
Time frame: Up to Week 200
Time to Death Censored Allograft Loss
Time frame: Up to Week 204
Felzartamab Serum Concentration
Time frame: At Week 200
Number of Participants with Anti-drug Antibodies (ADAs) Against Felzartamab
Time frame: At Week 200
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 9 Oct 2026.
- Individual participant dataSharing planned: Yes. In accordance with Biogen's Clinical Trial Transparency and Data Sharing Policy on https://www.biogentrialtransparency.com/
Related trials for Antibody-mediated Rejection
RecruitingPhase 1
Syk Inhibition in MItigating Lung Allograft Rejection (SIMILAR): A Trial to Evaluate the Safety and Tolerability of Fostamatinib in Lung Transplant Patients With Donor-Specific Antibodies
Lung Transplantation
RecruitingPhase 1
Treatment of Antibody-Mediated Rejection (ABMR) With CarBel
Kidney Transplant Rejection
Not yet recruitingPhase 2
A Study of Mezagitamab in Adults With Late Antibody-Mediated Rejection (AMR) After a Kidney Transplant
Antibody-Mediated Rejection (AMR)
RecruitingPhase 1
A Phase 1 Clinical Trial of Siltuximab for the Treatment of Antibody-Mediated Rejection After Lung Transplantation
Antibody Mediated Rejection of Lung Transplant
Active, not recruitingPhase 2
BIVV020 (SAR445088) in Prevention and Treatment of Antibody-mediated Rejection (AMR)
Transplant Rejection
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.
Medical Director study director
Biogen
14 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Felzartamab in people with Antibody-mediated Rejection and Microvascular Inflammation, run by Biogen at 14 sites in United States.
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 2 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: enrolling by invitation, as of the sponsor's last update on 9 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 14 sites in 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?
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?
Number of Participants With Adverse Events (AEs), Serious Adverse Events (SAEs), and Adverse Events of Special Interest (AESI) (time frame: From first dose of study drug up to end of study follow-up (Up to Week 204)). The study lists 3 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 9 Oct 2026.