A Phase 1 interventional study of Filgrastim and Plerixafor in Bone Marrow Failure Syndrome, sponsored by St. Jude Children's Research Hospital. Not yet recruiting at 1 site in United States. Open to participants aged 18 Years to 25 Years. Per ClinicalTrials.gov, last updated 2026-08-31.
Sponsored by St. Jude Children's Research Hospital · Phase 1, Interventional, and Other
The purpose of this study is to investigate mobilization and collection of HSPCs in patients with bone marrow failure syndromes (BMFS) using granulocyte-colony stimulating factor (otherwise known as Filgrastim) with plerixafor to demonstrate safety and feasibility of collecting HSPCs to advance gene therapy.
Primary objective:
- To characterize the safety of Filgrastim plus plerixafor in participants with bone marrow failure syndromes as determined by the incidence of adverse events (AEs).
Secondary Objectives:
This is a phase I, open-label, single-center study to evaluate the safety of Filgrastim plus plerixafor stem cell mobilization and apheresis in patients with BMFS. This study will include a screening period with labs, physical examination, and bone marrow evaluation at least 6 months prior to mobilization and apheresis, an intervention period that includes mobilization and apheresis of patient HSPCs, and outpatient follow-up within 7-10 days after intervention. Study staff will follow up with the participant via telephone approximately 30 days after mobilization and apheresis. A bone marrow evaluation will be done within 6 months post-intervention.
The following hematological parameters need to be met (regardless of transfusion or growth factor support)
Exclusion Criteria:
Participants in this study will receive a twice daily dose of Filgrastim (GCSF) (5 mcg/kg BID) SQ starting on day 1 for 5 days followed by a single dose of SQ plerixafor (0.24 mg/kg) on day 5 followed by collection of CD34+ HSPCs via apheresis. A portion of cells collected from the participant will be stored as backup to be used toward future gene therapy endeavors. The remaining cells will be donated for research studies
Drug: Filgrastim · Drug: Plerixafor · Procedure: Leukapheresis
Administered twice daily dose starting on day 1 for 5 days.
Administered on day 5 via IV.
Peripheral venous access or through a central venous catheter approximately 4-5 hours after the dose of plerixafor is given.
Incidence of treatment-emergent adverse events following filgrastim plus plerixafor administration
Safety will be assessed by the incidence, type, and severity of adverse events occurring after administration of filgrastim plus plerixafor in participants with bone marrow failure syndromes.
Time frame: From initiation of drug administration through Day +7 to +10 follow-up
Number of participants achieving peripheral blood CD34+ counts ≥5 cells/µL
Feasibility of hematopoietic stem and progenitor cell mobilization will be assessed by peripheral blood CD34+ cell counts measured after plerixafor administration and prior to or during apheresis.
Time frame: From initiation of plerixafor administration through completion of apheresis, or 6 hours after drug administration if apheresis is not performed
Peripheral blood CD34+ kinetics following filgrastim plus plerixafor administration
Peripheral blood CD34+ cell counts will be measured after plerixafor administration and prior to or during apheresis.
Time frame: After plerixafor administration through completion of apheresis, or 6 hours after drug administration if apheresis is not performed
Observed CD34+ cell yield after 1 blood volume apheresis
CD34+ cell yield (CD34+ cells/kg) collected after processing 1 blood volume during apheresis following filgrastim plus plerixafor administration.
Time frame: At completion of 1 blood volume apheresis on Day 5
Estimated total CD34+ cell yield from projected full-volume apheresis
Estimated total CD34+ cell yield (CD34+ cells/kg) projected from the observed yield after processing 1 blood volume during apheresis.
Time frame: At completion of 1 blood volume apheresis on Day 5
Plan to share: Yes — Individual participant de-identified datasets containing the variables analyzed in the published article will be made available (related to the study primary or secondary objectives contained in the publication). Supporting documents such as the protocol, statistical analyses plan, and informed consent are available through the CTG website for the specific study. Data used to generate the published article will be made available at the time of article publication. Investigators who seek access to individual level de-identified data will contact the computing team in the Department of Biostatistics (ClinTrialDataRequest@stjude.org) who will respond to the data request.
Supporting information: Study protocol, Sap, Icf
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Bone Marrow Failure Disorders→
St. Jude Children's Research Hospital