Conditions: Leukemia Solid Tumors
Keywords: Recurrent or Refractory Leukemia or Solid Tumors in Pediatrics
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 9
Healthy volunteers: no

Brief summary:
This study will assess the feasibility of utilizing a reduced intensity conditioning regimen, in the setting of haploidentical transplantation, for patients with recurrent acute lymphoblastic leukemia (ALL), AML and high risk or refractory solid tumors. In addition, the feasibility and safety of administering post-transplant NK cell infusions will be evaluated. Data obtained from this study will help determine the efficacy of allogeneic HSCT in the treatment of pediatric sarcomas and add to the small body of literature utilizing haploidentical HSCT to treat acute leukemia in pediatric patients. This study will also further elucidate the role of NK cells in mediating a graft vs. tumor effect in allogeneic HSCT. The main benefit to society is that this study will explore a novel therapy for children with highly refractory cancer who are felt to be incurable with conventional approaches. If feasibility is demonstrated, and there is evidence of anti-tumor activity, then this will open up a new area of clinical research to better define the efficacy of this approach for specific childhood malignancies.

Detailed description:

Arms:
arm 1: patients will undergo a standard pre-transplant evaluation, but will also have blood drawn to evaluate their HLA class I killer immunoglobulin-like receptor (KIR) ligand typing. Parents will undergo KIR genotyping and phenotyping, and a donor will be selected based on which parent shows the greatest degree of KIR receptor-ligand mismatching. Once the donor has been selected he/she will undergo a peripheral blood stem cell (PBSC) collection utilizing G-CSF and GM-CSF for stem cell mobilization. The PBSC collection will be performed utilizing standard procedures. The PBSC will then be processed in the UW BMT Laboratory in order to deplete the graft of T cells. This will be accomplished using the CliniMACS cell separation system. T cell depletion is a standard procedure for patients receiving haploidentical stem cell grafts. The resulting stem cell product will be analyzed for T cell, stem cell and NK cell content.

Interventions: intervention 1: Clinimacs Cell Separation System intervention 2: conditioning chemotherapy intervention 3: DLI
Intervention descriptions: intervention 1: Depletion of T-cells intervention 2: Methylprednisolone, Equine ATG, Cyclosporine, Fludarabine, Melphalan, Thiotepa and Rituximab. intervention 3: NK Cell selected DLI

Protocol document: