NCT06839456 · Children's Hospital of Philadelphia
Phase 1/2: CD45RA Depleted Stem Cell Addback to Prevent Viral or Fungal Infections Post TCRab/CD19 Depleted HSCT
What this study is about
The major morbidities of allogeneic hematopoietic stem cell transplant (HSCT) using donors that are not human leukocyte antigen (HLA) matched siblings are graft vs host disease (GVHD) and life- threatening infections.
View original scientific description
The major morbidities of allogeneic hematopoietic stem cell transplant (HSCT) using donors that are not human leukocyte antigen (HLA) matched siblings are graft vs host disease (GVHD) and life- threatening infections. T cell receptor alpha beta (TCRαβ) T lymphocyte depletion and CD19+ B lymphocyte depletion of alternative donor hematopoietic stem cell (HSC) grafts is effective in preventing GVHD, but immune reconstitution may be delayed, increasing the risk of infections. The central hypothesis of this study is that an addback of CD45RO memory T lymphocytes, derived from a fraction of the original donor peripheral stem cell product depleted of CD45RA naïve T lymphocytes, will accelerate immune reconstitution and help decrease the risk of infections in TCRab/CD19 depleted PSCT.
Interventions
DEVICE
Phase 1 Dose Level 1
Patients in the first dose level for the CD45RA depleted addback will receive 1 X 10\^6 CD45RO+ T cells/kg. Once all patients in this dose group have been evaluated for acute GVHD at day 100, then we will advance to the next dose level if indicated by safety analysis.
DEVICE
Phase 1 Dose Level 2
Patients in the second dose level for the CD45RA depleted addback will receive 2 X 10\^6 CD45RO+ T cells/kg. Once all patients in this dose group have been evaluated for acute GVHD at day 100, then we will advance to the next dose level if indicated by safety analysis.
DEVICE
Phase 1 Dose Level 3
Patients in the third and final dose level for the CD45RA depleted addback will receive 5 X 10\^6 CD45RO+ T cells/kg. All patients in this dose group will be evaluated for acute GVHD at day 100. Based on these findings, the maximum tolerated dose (MTD) will be determined. Once MTD for the addback cell dose has been determined in Phase 1, subjects with mismatched related donors will then enroll in Phase 2.
DEVICE
Phase 2 Maximum Tolerated Dose determined in Phase 1
Patients with mismatched related donors will receive the CD45RA depleted addback at the maximum tolerated dose determined in the Phase 1 portion of the study.
DEVICE
Phase 2 Established Dose from prior study, NCT03810196
Patients with unrelated donors will receive the CD45RA depleted addback at the dose 5 X 10\^6 CD45RO+ T cells.
Primary outcome measures
Evaluate number of patients with acute graft vs host disease (aGVHD)
Time frame: Up to 100 days post-transplantation
Safety evaluation assessment by cumulative incidence of acute graft vs host disease (reaction of donor immune cells against host tissues) to determine percentage of patients that develop grade 3-4 aGVHD.
Evaluate number of patients with chronic graft vs host disease (cGVHD)
Time frame: Up to 2 years post-transplantation
Safety evaluation assessment by cumulative incidence and severity of chronic GVHD (graft vs host disease that occurs more than 100 days after transplant) to determine percentage of patients that develop cGVHD.
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
- Disease for which allogeneic HSCT may be curative.
- Remission status of hematologic malignancies and additional disease-specific eligibility determinations will be according to standards of practice within the CHOP Cellular Immunotherapy and Transplant Program (CTTS).
- Patients must be 25 years of age and less
- Evaluation for organ and infectious status as per our CTTS standard operating procedure.
- Signed consent by parent/guardian or able to give consent if 18 years of age and older.
- Participants of childbearing potential must have a negative pregnancy test as per institutional SOP.
Exclusion criteria
- Patients who have performance score less than 60.
- No suitable donor available for mobilized peripheral stem cells.
- Patients with Hodgkin lymphoma or non-Burkitt, non-lymphoblastic lymphoma.
- Planned receipt of alemtuzumab during conditioning.
- Patients with an available 10/10 HLA matched sibling donor.
- Patients who do not meet institutional disease, organ or infectious criteria. Donor selection and eligibility:
- Unrelated donor meets National Marrow Donor Program criteria for donation.
- Related donor (at least haploidentical) willing and able to donate mobilized peripheral stem cells.
- HLA testing/matching
- HLA testing to be done by molecular methods for A, B, C, DRB1, DQB1
- Related donor: Must be ≥ 5/10 match
- Unrelated donor: 10/10 or 9/10 match
- KIR typing for haploidentical donor for hematologic malignancies
- Donor specific HLA antibodies (DSA) should be assessed for all subjects receiving an HLA mismatched graft (≤ 9/10).
- Donor must be willing to undergo granulocyte colony stimulating factor (GCSF) mobilization and peripheral blood stem cell collection
- Donors must be willing to sign consent to participate in this study.
Where
- Philadelphia, Pennsylvania
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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 Apr 15, 2026 · Source of record for eligibility and locations