NCT03311503 · David Williams
Phase I/II Trial of Lentiviral Gene Transfer for SCID-X1 with Low Dose Targeted Busulfan Conditioning
What this study is about
This is a phase I/II open label multi-center study in which patients will receive low dose targeted busulfan followed by infusion of autologous CD34+ selected bone marrow or mobilized peripheral blood cells transduced with the G2SCID vector.
View original scientific description
This is a phase I/II open label multi-center study in which patients will receive low dose targeted busulfan followed by infusion of autologous CD34+ selected bone marrow or mobilized peripheral blood cells transduced with the G2SCID vector. Subjects will be enrolled over 3 years and be followed for 2 years post-infusion on this protocol, then followed long-term on a separate long-term follow-up protocol. Enrollment of subjects will be agreed upon by representatives of both sites.
Interventions
BIOLOGICAL
autologous CD34+ cell transduced with G2SCID vector
single infusion of autologous CD34+ cells transduced with the self-inactivating (SIN) lentiviral vector G2SCID
Primary outcome measures
The primary objective is to measure event free survival
Time frame: 1 year post infusion
Events will include death, infusion of unmanipulated back-up product for failure of hematopoietic recovery, and allogeneic transplant performed for poor immune reconstitution
T cell reconstitution
Time frame: 1 year post infusion
* CD3+ T cell count ≥300 cells/microliter in peripheral blood * Gene marking ≥0.1 copies/cell in sorted CD3+ T cells
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
- \- 1. Diagnosis of SCID-X1 based on immunophenotype and lack of T cell function (proliferation to PHA \<10% of the lower limit of normal for the laboratory) AND confirmed by a mutation in IL2RG 2. Lack of an HLA identical (A, B, C, DR, DQ) related donor 3. Age 5 years old or younger 4. Signed informed consent 5. Documentation of willingness to follow up for 15 years post-infusion as currently required by the FDA 6. If the patient has previously undergone allogeneic transplant, lack of donor T cell engraftment must be documented. 7\. Age at least 8 weeks by the time of busulfan administration
Exclusion criteria
- Patients with an active, therapy-resistant infection. Infections that are known to be highly morbid in SCID patients will be considered active and therapy-resistant if the infectious agent is repeatedly isolated despite a minimum of 2 weeks of appropriate therapy and is associated with significant organ dysfunction (including but not limited to abnorma
Where
- Los Angeles, California
- Atlanta, Georgia
- Boston, Massachusetts
- Cincinnati, Ohio
Related conditions & keywords
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 11, 2025 · Source of record for eligibility and locations