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NCT Number: NCT07689149

Safety and Efficacy of BiTE in Desensitization Therapy for Highly Sensitized Kidney Transplant Candidates With cPRA ≥ 90%

This study is a prospective, open-label, two-arm exploratory clinical trial aimed at evaluating the safety and efficacy of Bispecific T-cell Engager (BiTE) therapies in refractory, highly sensitized kidney transplant candidates. Patients with end-stage renal disease (ESRD) who have a calculated panel reactive antibody (cPRA) ≥ 90% and have waited for a transplant for over 5 years, despite receiving standard desensitization therapies (e.g., IVIG, plasmapheresis, rituximab), will be enrolled.

A total of 20 participants will be randomized in a 1:1 ratio to receive either Blinatumomab (a CD19×CD3 BiTE) or Teclistamab (a BCMA×CD3 BiTE). The primary objective is to evaluate the desensitization response rate, defined as the reduction of cPRA to < 20% or by ≥ 50% from baseline, assessed at multiple time points up to 1 year post-treatment. Secondary objectives include assessing the safety profile (such as the incidence of Cytokine Release Syndrome [CRS] and neurotoxicity), the extent of CD19+ B cell depletion, and the proportion of participants who successfully undergo kidney transplantation within 1 year.

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Key information

Conditions

Kidney Transplantation Recipients HLA Sensitization

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

About this study

Background:

Kidney transplantation is the optimal treatment for end-stage renal disease (ESRD). However, highly sensitized patients with a calculated panel reactive antibody (cPRA) ≥ 90% face significant barriers to finding a compatible donor and have a higher risk of antibody-mediated rejection (AMR). Standard desensitization protocols, primarily utilizing intravenous immunoglobulin (IVIG) and plasmapheresis (PLEX), often fail to achieve long-term reductions in human leukocyte antigen (HLA) antibodies because they do not adequately deplete memory B cells and long-lived plasma cells. Bispecific T-cell Engagers (BiTEs) such as Blinatumomab (CD19×CD3) and Teclistamab (BCMA×CD3) directly recruit endogenous T cells to eliminate B cells and plasma cells, respectively. This study investigates whether these targeted therapies can provide a deeper and more sustained desensitization for refractory transplant candidates, bridging them to a successful transplant.

Study Design:

This is a single-center, prospective, non-blinded, two-arm exploratory trial conducted at West China Hospital, Sichuan University. Twenty eligible patients will be enrolled and randomly assigned (1:1) via block randomization (block size of 4) to either the Blinatumomab arm or the Teclistamab arm.

Interventions:

Arm 1 (Blinatumomab): Administered intravenously. Cycle 1 consists of 9 µg/day for 4 consecutive days (Days 1-4). Following a 7-day interval, Cycle 2 consists of 9 µg/day for another 4 consecutive days (Days 12-15).

Arm 2 (Teclistamab): Administered subcutaneously using a step-up dosing schedule to mitigate Cytokine Release Syndrome (CRS) risk. Cycle 1 involves 0.06 mg/kg on Day 1 and 0.3 mg/kg on Day 2. Following a 7-day interval, Cycle 2 involves a target dose of 1.5 mg/kg on Day 10.

Study Objectives & Endpoints:

Primary Endpoint: Desensitization response rate evaluated at 1, 2, 3, 6, and 12 months post-treatment. A positive response is defined as a reduction of cPRA from >90% to <20% (or a ≥50% decrease from baseline), or the conversion of positive HLA antibodies to negative, or a ≥50% reduction in Mean Fluorescence Intensity (MFI) to a predefined threshold.

Secondary Endpoints:

Safety and tolerability, including the incidence and severity of CRS, Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS), infections, and neutropenia.

Changes in peripheral blood lymphocyte subsets, with a specific focus on CD19+ B cell depletion and recovery trends.

Duration of sustained low cPRA levels. Proportion of patients receiving a kidney transplant within 1 year.

Safety Monitoring:

Given the mechanism of action of BiTEs, strict monitoring for adverse events like CRS and ICANS is integrated into the protocol, utilizing ASTCT consensus grading standards. Treatment algorithms for managing severe events (e.g., using tocilizumab or corticosteroids) are predefined. An independent Data and Safety Monitoring Board (DSMB) consisting of multidisciplinary experts will oversee the study. The protocol includes strict stopping rules for severe toxicities, such as ≥ Grade 3 CRS/ICANS refractory to standard treatment, severe infections, or treatment-related mortality, to ensure patient safety throughout the trial.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Male or female participants aged 18 to 65 years.
  • Diagnosis of end-stage kidney disease and being evaluated for or awaiting kidney transplantation.
  • Calculated panel-reactive antibody level (cPRA) ≥90% and a kidney transplant waiting time of ≥5 years.
  • Previous treatment with a conventional desensitization regimen based on intravenous immunoglobulin and/or plasma exchange, with or without rituximab, with traceable medical records.
  • Persistent cPRA ≥90% or unacceptable HLA antibodies after conventional desensitization, resulting in failure to meet the immunological criteria for kidney transplantation.
  • Adequate nonrenal organ function to tolerate the study treatment, including left ventricular ejection fraction >50%, resting oxygen saturation >94%, AST and ALT <3 times the upper limit of normal, total bilirubin <34.2 μmol/L, and no active infection.
  • Ability to understand the study procedures, provide written informed consent, and comply with study treatment and follow-up requirements.

Exclusion criteria

  • Inability to understand or comply with the study protocol or follow-up schedule.
  • Known or suspected hereditary complement deficiency.
  • Clinically significant central nervous system disease, including epilepsy, psychotic disorder, organic brain syndrome, cerebrovascular accident, encephalitis, central nervous system vasculitis, or cranial neuropathy requiring intervention.
  • AST, ALT, or GGT >3 times the upper limit of normal, or alkaline phosphatase or total bilirubin >1.5 times the upper limit of normal.
  • Acute myocardial infarction or unstable angina within 6 months before screening, severe cardiac arrhythmia, or New York Heart Association class III or IV heart failure.
  • Uncontrolled acute or chronic disease unrelated to end-stage kidney disease that may impair tolerance to study treatment.
  • Active or uncontrolled infection requiring systemic treatment.
  • Human immunodeficiency virus infection or uncontrolled active hepatitis B or hepatitis C infection.
  • Participation in another interventional clinical study within 3 months before screening or planned concurrent participation in another interventional study.
  • Previous treatment with another T-cell engager or bispecific T-cell-redirecting therapy.
  • Known severe hypersensitivity to blinatumomab, teclistamab, or any of their excipients.
  • Active malignancy.
  • Pregnancy, breastfeeding, or planned pregnancy during the study period.
  • Previous bone marrow transplantation, hematopoietic stem cell transplantation, or solid-organ transplantation other than kidney transplantation.
  • Receipt of a live vaccine within 30 days before screening or planned receipt of a live vaccine during study treatment.
  • Any other clinically significant condition that, in the investigator's judgment, may increase participant risk, interfere with study procedures, or affect safety or efficacy assessments.

Treatment and study plan

BiTE (CD19 x CD3 Bispecific Antibody)

Drug

Blinatumomab is a CD19×CD3 bispecific T-cell engager (BiTE) administered via intravenous infusion. This intervention utilizes a specific low-dose, short-course exploratory regimen tailored for non-oncology kidney transplant candidates to safely deplete B cells and reduce HLA antibodies. The treatment consists of two cycles separated by a 7-day interval. In Cycle 1 (Days 1-4), patients receive a continuous infusion of 9 µg/day for 4 consecutive days, with a total target dose of 35 µg for the cycle. Following the 7-day interval, Cycle 2 (Days 12-15) is administered with the identical regimen of 9 µg/day for 4 consecutive days.

BiTE (BCMA x CD3 Bispecific Antibody)

Drug

Teclistamab is a BCMA×CD3 bispecific T-cell engager (BiTE) administered via subcutaneous injection. To mitigate the early risk of cytokine release syndrome (CRS), this intervention employs a strictly defined step-up dosing schedule. The treatment involves two cycles separated by a 7-day interval. Cycle 1 (Days 1-2) begins with a step-up dose of 0.06 mg/kg on Day 1, followed by 0.3 mg/kg on Day 2. After the 7-day interval, Cycle 2 (Days 10-11) is initiated, during which a target dose of 1.5 mg/kg is administered on Day 10.

Primary outcomes

  1. Percentage of participants achieving the predefined composite desensitization response

    Time frame: At baseline and at 1, 2, 3, 6, and 12 months after treatment

    A composite desensitization response is defined as meeting at least one of the following criteria:

    • cPRA decreases to <20%;
    • cPRA decreases by ≥50% from baseline;
    • a previously positive HLA antibody becomes negative, defined as an MFI <1,000; or
    • the MFI of a persistent HLA antibody decreases by ≥50% from baseline or reaches the prespecified threshold.

    The number and percentage of participants achieving the composite response will be reported at Months 1, 2, 3, 6, and 12 after treatment.

    (HLA class I and II antibodies and their mean fluorescence intensity will be assessed using a single-antigen bead assay. Calculated panel-reactive antibody levels will be determined based on the unacceptable HLA antigen profile. At each prespecified assessment timepoint, participants will be classified as responders or nonresponders, and the percentage of responders will be reported.)

Secondary outcomes

  1. Percentage reduction from baseline in calculated panel-reactive antibody level

    Time frame: At baseline and at 1, 2, 3, 6, and 12 months after treatment

    Percentage reduction will be calculated as:

    (Baseline cPRA - cPRA at the assessment timepoint) / baseline cPRA × 100%. A positive value indicates a reduction, whereas a negative value indicates an increase.HLA antibodies will be assessed using a single-antigen bead assay, and cPRA will be calculated based on unacceptable HLA antigens. The percentage reduction from baseline will be calculated at each assessment timepoint.

  2. Absolute change from baseline in calculated panel-reactive antibody level

    Time frame: At baseline and at 1, 2, 3, 6, and 12 months after treatment

    Absolute change will be calculated as cPRA at the assessment timepoint minus baseline cPRA. A negative value indicates a reduction from baseline. Results will be reported separately at Months 1, 2, 3, 6, and 12.

    HLA antibody specificities will be determined using a single-antigen bead assay. cPRA will be calculated based on prespecified unacceptable HLA antigens and the HLA antigen frequencies of the reference donor population. The absolute difference between cPRA at each assessment and baseline cPRA will be calculated.

  3. Change from baseline in the maximum mean fluorescence intensity of unacceptable HLA class I antibodies

    Time frame: At baseline and at 1, 2, 3, 6, and 12 months after treatment

    The change will be calculated as the maximum MFI at each assessment minus the baseline maximum MFI. A negative value indicates a reduction in HLA class I antibody strength. Maximum MFI will be used as the prespecified participant-level summary when multiple antibody specificities are present.

    HLA-A, HLA-B, and HLA-C antibodies will be measured using a single-antigen bead assay. For each participant, the highest MFI among all baseline unacceptable HLA class I antibody specificities will be identified, and the MFI of the same antibody specificity will be followed at each assessment.

  4. Change from baseline in the maximum mean fluorescence intensity of unacceptable HLA class II antibodies

    Time frame: At baseline and at 1, 2, 3, 6, and 12 months after treatment

    Change will be calculated as the maximum MFI at each assessment minus the baseline maximum MFI. A negative value indicates a reduction in antibody strength.

    HLA-DR, HLA-DQ, and HLA-DP antibodies will be measured using a single-antigen bead assay. The highest MFI among all baseline unacceptable HLA class II antibody specificities will be identified for each participant, and the same antibody specificity will be followed over time.

  5. Number of participants receiving kidney transplantation within 12 months after treatment

    Time frame: Within 12 months after the first administration of study treatment

    The number of participants who undergo kidney transplantation within 12 months after the first administration of study treatment will be reported. Participants who receive a donor offer or matching assessment without undergoing transplantation will not be counted.

    Kidney transplantation will be confirmed using transplant waiting-list records, donor-matching information, crossmatch results, hospitalization records, and operative records.

  6. Change from baseline in peripheral blood CD19-positive B-cell absolute count

    Time frame: At baseline, at protocol-specified assessments during treatment, and at 1, 2, 3, 6, and 12 months after treatment

    Change will be calculated as the CD19-positive B-cell absolute count at each assessment minus the baseline count. The magnitude of B-cell reduction, nadir, and recovery pattern will be evaluated.

    Peripheral blood CD19-positive B-cell absolute counts will be measured using multiparameter flow cytometry.

  7. Number of participants achieving peripheral blood CD19-positive B-cell depletion

    Time frame: During treatment and at 1, 2, 3, 6, and 12 months after treatment

    CD19-positive B-cell depletion is defined as an absolute peripheral blood CD19-positive B-cell count <10 cells/μL. The number of participants meeting the depletion criterion at each assessment will be reported.

    Peripheral blood CD19-positive B-cell absolute counts will be measured using multiparameter flow cytometry.

  8. Change from baseline in peripheral blood CD3-positive T-cell absolute count

    Time frame: At baseline, during treatment, and at 1, 2, 3, 6, and 12 months after treatment

    Change will be calculated as the CD3-positive T-cell absolute count at each assessment minus the baseline count.

    Peripheral blood CD3-positive T-cell absolute counts will be measured using multiparameter flow cytometry.

  9. Change from baseline in peripheral blood CD4-positive T-cell absolute count

    Time frame: At baseline, during treatment, and at 1, 2, 3, 6, and 12 months after treatment

    Change from baseline in the CD4-positive T-cell absolute count will be calculated at each assessment.

    Peripheral blood CD4-positive T-cell absolute counts will be measured using multiparameter flow cytometry.

  10. Change from baseline in peripheral blood CD8-positive T-cell absolute count

    Time frame: At baseline, during treatment, and at 1, 2, 3, 6, and 12 months after treatment

    Change from baseline in the CD8-positive T-cell absolute count will be calculated at each assessment.

    Peripheral blood CD8-positive T-cell absolute counts will be measured using multiparameter flow cytometry.

  11. Change from baseline in peripheral blood CD3-negative CD16-positive and/or CD56-positive natural killer cell absolute count

    Time frame: At baseline, during treatment, and at 1, 2, 3, 6, and 12 months after treatment

    Change from baseline in natural killer cell absolute count will be calculated at each assessment.

    Peripheral blood CD3-negative CD16-positive and/or CD56-positive natural killer cell absolute counts will be measured using multiparameter flow cytometry.

  12. Number of participants with cytokine release syndrome as assessed by the ASTCT consensus grading criteria

    Time frame: From the first dose through 30 days after the last dose

    The number of participants experiencing at least one CRS event will be reported. Each participant will be summarized according to the maximum CRS grade experienced during the study. Time to onset, duration, management, and outcome will also be recorded.

    CRS will be diagnosed and graded according to the ASTCT consensus grading criteria based on fever, hypotension, vasopressor requirement, and oxygen requirement.

  13. Number of participants with immune effector cell-associated neurotoxicity syndrome as assessed by the ASTCT consensus grading criteria

    Time frame: From the first dose through 30 days after the last dose

    The number of participants experiencing at least one ICANS event will be reported. Each participant will be summarized according to the maximum ICANS grade, with clinical manifestations, onset, duration, management, and outcome recorded.

    ICANS will be assessed using neurological examination, the Immune Effector Cell-Associated Encephalopathy score, and electroencephalography or neuroimaging when clinically indicated. Events will be graded according to the ASTCT criteria.

  14. Number of participants with treatment-emergent infections

    Time frame: From the first dose through 12 months after treatment

    The number of participants experiencing at least one infection will be reported. Infection site, pathogen, maximum CTCAE grade, opportunistic infection status, requirement for intravenous anti-infective treatment or hospitalization, and outcome will be recorded.

    Infections will be identified based on clinical manifestations, physical examination, microbiological testing, culture, imaging, and laboratory findings, and will be graded according to CTCAE version 5.0.

  15. Number of participants with serious adverse events

    Time frame: From the first dose through 12 months after treatment

    Serious adverse events include events resulting in death, life-threatening events, hospitalization or prolonged hospitalization, persistent or significant disability, and other medically important serious events. The number of participants with at least one serious adverse event will be reported.

    Serious adverse events will be collected through participant reports, clinical observation, hospitalization records, physical examinations, and laboratory assessments and will be classified according to standard serious adverse event criteria.

  16. Number of participants with neutropenia as assessed by CTCAE version 5.0

    Time frame: From the first dose through 12 months after treatment

    The number of participants with at least one post-treatment absolute neutrophil count below the laboratory lower limit of normal will be reported. Each participant will be summarized according to the maximum CTCAE grade.

    Absolute neutrophil count will be measured using complete blood counts, and neutropenia will be graded according to CTCAE version 5.0.

Study contacts

Contact information is provided by the study sponsor or research team.

Chenliang Xu, Master of Clinical Medicine

CONTACT

[email protected]

+86 17208274528

Sponsors and collaborators

Lead sponsor

West China Hospital

Other

Registry information

Important dates

Study start
2026
Primary completion
2029
Study completion
2029
First posted
Jul 8, 2026
Registry last updated
Jul 8, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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