NCT07219043 · Biogen
A Study to Learn About the Effects of Felzartamab Infusions in Adults With Kidney Transplants Who Have Late Isolated Microvascular Inflammation
(TRANSPIRE)
What this study is about
In this study, researchers will learn more about a drug called felzartamab in people who have received a kidney transplant and later developed a condition called microvascular inflammation (MVI). MVI is a type of injury to small blood vessels in the transplanted kidney and may be a sign of rejection by the body. It can lead to serious kidney problems over time.
View original scientific description
In this study, researchers will learn more about a drug called felzartamab in people who have received a kidney transplant and later developed a condition called microvascular inflammation (MVI). MVI is a type of injury to small blood vessels in the transplanted kidney and may be a sign of rejection by the body. It can lead to serious kidney problems over time. In many cases, MVI is caused by antibodies that attack the transplanted kidney. But in some people, MVI happens without these antibodies. This type of MVI is called isolated MVI. There are currently no approved treatments for isolated MVI. The main goal of the study is to learn about the effect felzartamab has on inflammation in the transplanted kidney. The main question researchers want to answer is: • How many participants have no signs of active inflammation in the transplanted kidney after 24 weeks of treatment with felzartamab? Researchers will also study how felzartamab affects kidney function, immune activity, and overall health. They will monitor safety through kidney biopsies, lab tests, and by recording adverse events throughout the study. Adverse events are health problems that may or may not be caused by the study drug. The study will be done in 2 parts as follows: * Participants will be randomly assigned to receive either felzartamab or a placebo. A placebo looks like the study drug but contains no real medicine. * In Part A, participants will receive their assigned drug for 24 weeks. Neither the researchers nor the participants will know who is receiving felzartamab or placebo. * Part B will last another 28 weeks. All participants will receive felzartamab and both participants and researchers will know this. * All treatments will be given by intravenous (IV) infusion at the study site. * Participants will have kidney biopsies at the start of the study, at Week 24, and at Week 52 to help measure changes in inflammation. * Participants will stay in the study for about 1 year.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- MVI (MVI ≥2), donor specific antibody (DSA)-negative that is either complement activation (C4d) negative or C4d positive (biopsy-confirmed) without T cell-mediated rejection (TCMR) per central reading, as defined by the Banff 2022 criteria.
- Biopsy must be within 3 months (preferably within 1 month) prior to randomization and meet adequate criteria (option a preferred over option b):
- Adequate: 10 or more non-sclerotic/evaluable glomeruli and two muscular arteries
- Minimally Adequate: at least 7 non-sclerotic/evaluable glomeruli and one muscular artery
- For participants who received any prior treatment for antibody-mediated rejection (AMR), MVI, or TCMR as outlined in
Exclusion criteria
- Criterion 5, the biopsy must be performed at least 6 weeks after completing (or stopping) prior treatment.
- Kidney transplant at least 6 months prior to Screening visit (recipients of either living or deceased donors).
- DSA: Human leukocyte antigen (HLA) Class I and II antigen-specific DSA-negative (preformed and de novo DSA) as determined by the local laboratory's definition of positivity using single-antigen bead-based assays within 3 months prior to randomization. Key Exclusion Criteria:
- Transplant: Blood type (ABO)-incompatible transplant.
- History of multiple organ transplants including en bloc and dual kidney transplants.
- Presence of HLA donor-specific antibodies.
- Acute, rapid decline in renal function, defined as a participant likely to require renal replacement therapy within the next 30 days as determined by the Investigator.
- Prior AMR or TCMR treatment (with the exception of corticosteroids) within 3 months prior to randomization is excluded as listed below. Participants who received any of these treatments between 3 and 6 months prior to randomization must have both a renal biopsy (IC3) and DSA testing at least 6 weeks after completing (or stopping) treatment in order to confirm continuing MVI≥2 and DSA negative status and to determine eligibility:
- Intravenous or subcutaneous immunoglobulin (IVIg or subcutaneous immunoglobulin \[SCIg\]) or plasma exchange (PLEX).
- Complement system inhibitors (e.g., eculizumab).
- Proteasome inhibitors (e.g., bortezomib).
- The anti-interleukin-6 receptor (anti-IL-6R) tocilizumab.
- Any B cell-depleting therapy (including anti-CD20 agents \[e.g., rituximab\]) within 3 months prior to randomization.
- Any other investigational agent within 3 months or 5 half-lives (whichever is longer) of randomization. Note: Other protocol-defined Inclusion/Exclusion criteria may apply.
Where
- Loma Linda, California
- Los Angeles, California
- Orange, California
- San Francisco, California
- Kansas City, Kansas
- Ann Arbor, Michigan
- Rochester, Minnesota
- St Louis, Missouri
- Omaha, Nebraska
- West Orange, New Jersey
- Durham, North Carolina
- Cleveland, Ohio
And 6 more locations — see the full list below.
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 7, 2026 · Source of record for eligibility and locations