NCT01189786 · Baylor College of Medicine
Ex Vivo T-Cell Depletion of Mobilized Peripheral Blood Stem Cells Via CD34-Selection
(EXCESS)
What this study is about
Participants are being asked to take part in this study because treatment of his or her disease requires a stem cell transplant. Stem cells or "mother" cells are the source of normal blood cells and lead to recovery of blood counts after bone marrow transplantation.
View original scientific description
Participants are being asked to take part in this study because treatment of his or her disease requires a stem cell transplant. Stem cells or "mother" cells are the source of normal blood cells and lead to recovery of blood counts after bone marrow transplantation. Unfortunately, there is not a perfectly matched stem cell donor (like a sister or brother) for the participant and his or her disease does not permit enough time to identify another donor (like someone from a registry list that is not his or her relative) or another suitable donor has not been identified. However, a close relative of the patient has been identified whose stem cells are not a perfect match, but can be used. Alternatively, the patient may have already received a stem cell transplant but have evidence of mixed chimerism, which means some of the patient's own bone marrow cells are present, rather than all of the donor's cells. This may lead to an increased risk of the disease coming back. Or, the patient may have all donor cells but his or her bone marrow is not working very well, which may lead to frequent blood or platelet (cells that help in clotting blood) transfusions or infection. Regardless of the reason, it may be necessary to isolate stem cells from a haploidentical (half-match) donor in order to provide bone marrow function. Because the stem cells from the donor are only half-matched to the participant, the risk of graft-versus-host disease (GvHD) is very high. GvHD is a complication after transplant caused by donor T cells (graft) that attack the transplant recipient, and this complication can cause death after transplant. Thus, it is important that the donor's blood cells are treated to minimize cells that are most likely to attack the host's tissues. This is done by using a special device to capture the CD34+ stem cells from the donor's stem cell product prior to giving the cells to the host. This method minimizes the donor T cells, which are responsible for causing GvHD. Purpose: In an effort to lower the occurrences and severity of graft-versus-host disease in patients and to lower the rate of transplant failure, investigators would like to specially treat the donor's blood cells to minimize the cells that are most likely to attack the patient's tissues.
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
- for Stem Cell Transplant WITH Conditioning (COHORT 1)
- Patient requiring allogeneic SCT
- Age between birth and 70 years
- Patient and/or responsible person able to understand and sign consent
Exclusion criteria
- for Stem Cell Transplant WITH Conditioning (COHORT 1)
- Active, acute GvHD \> grade II or extensive, chronic GvHD
- Severe life, threatening infection
- Pulmonary dysfunction (FEV1, FVC or DLCO 40% of predicted or 3 SD below normal)
- Cardiac dysfunction (LVSF less than 25%)
- Psychiatric disturbance
- Lansky or Karnofsky score \< 50%
- The presence of severe hepatic disease (direct bilirubin \>3x upper limit of normal and AST \> 5x upper limit of normal).
- Creatinine \> 3x normal
- Known HIV Positivity
- Pregnancy Inclusion Criteria for CD34+ Topoff WITHOUT conditioning (COHORT 2)
- Allogeneic SCT Recipient requiring additional cellular therapy
- Age between birth and 70 years
- Patient and/or responsible person able to understand and sign consent
- At least ONE of the following must be answered YES for a patient to be eligible to receive CD34+ topoff:
- Evidence of mixed chimerisms (less than 95% donor cells)
- Evidence of poor bone marrow function (bone marrow cellularity less than 50% with at least one cytopenia)
- Relapsed or persistent disease Exclusion criteria for CD34+ Topoff WITHOUT conditioning (COHORT 2)
- Active, acute GvHD \> grade II or extensive, chronic GvHD
- Severe life, threatening infection
- Known HIV positivity
- Pregnancy Inclusion Criteria for CD34+ Topoff WITH conditioning (COHORT 3)
- Allogeneic SCT Recipient requiring additional cellular therapy
- Age between birth and 70 years
- Patient and/or responsible person able to understand and sign consent
- At least ONE of the following must be answered YES for a patient to be eligible to receive CD34+ topoff:
- Evidence of mixed chimerisms (less than 95% donor cells)
- Evidence of poor bone marrow function (bone marrow cellularity less than 50% with at least one cytopenia)
- Relapsed or persistent disease Exclusion criteria for CD34+ Topoff WITH Conditioning (COHORT 3)
- Active, acute GVHD \> grade II or extensive, chronic GvHD
- Severe life, threatening infection
- Pulmonary disfunction (FEV1, FVC or DLCO 40% of predicted or 3 SD below normal)
- Cardiac dysfunction (LVSF less than 25%)
- Psychiatric disturbance
- Lansky or Karnofsky score \< 50%
- The presence of severe hepatic disease (direct bilirubin \> 3x upper limit of normal and AST \> 5x upper limit of normal)
- Creatinine \> 3x normal
- Known HIV positivity
Where
- Houston, Texas
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 Dec 3, 2025 · Source of record for eligibility and locations