Outcome of allogeneic peripheral blood stem cell transplantation using matched sibling donors in patients with high-risk hematological diseases

Long-term outcomes in patients with high-risk myeloid malignancies following matched related donor hematopoietic cell transplantation with myeloablative conditioning of BU, etoposide and CY

Patients with high-risk or advanced myeloid malignancies have limited effective treatment options. These include high-dose therapy followed by allogeneic hematopoietic cell transplantation (HCT). We report a single-institution, long-term follow-up of 96 patients, median age 50 (range, 20-60) years, who received HLA-matched related HCT between 1992 and 2007. All patients were treated with a uniform preparatory regimen intended to enhance the widely used regimen of BU and CY that included: BU 16.0 mg/kg (days -8 to -5), etoposide 60 mg/kg (day -4), CY 60 mg/kg (day -2) with GVHD prophylaxis of CsA or FK506 and prednisone. Disease status at transplantation was high-risk AML (n=41), CML in second chronic phase or blast crisis (n=8), myelofibrosis and myeloproliferative disorders (n=8), and myelodysplasia (n=39). Thirty-six percent (n=35) of patients received BM whereas 64% (n=61) received G-CSF-mobilized PBPC. With a median follow-up of 5.6 years (range, 1.6-14.6 years) actuarial 5-year OS was 32% (95% CI 22-42) and 5-year EFS was 31% (95% CI 21-41). Relapse rate was 24% (95% CI 15-33) at 2 and 5 years. Nonrelapse mortality was 29% (95% CI 20-38) at day 100 and 38% (95% CI 29-47) at 1 year. Cumulative incidence of acute (grade II-IV) and extensive chronic GVHD was 27% (95% CI 18-36) and 29% (95% CI 18-40), respectively. There was no statistically significant difference in OS (31 vs 32%, P=0.89) or relapse rates (17 vs 28%, P=0.22) for recipients of BM vs PBPC, respectively. These results confirm that patients with high-risk or advanced myeloid malignancies can achieve long-term survival following myeloablative allogeneic HCT with aggressive conditioning.

Completely mismatched allogeneic CD3/CD28 cross-linked Th1 memory cells elicit anti-leukemia effects in unconditioned hosts without GVHD toxicity

Fully allogeneic CD3/CD28 cross-linked Th1 cells were found to elicit host-mediated anti-leukemia effects without GVHD toxicity. Mice inoculated with a lethal dose of BCL1 leukemia demonstrated significantly enhanced survival after allogeneic Th1 treatment. Cure rates of 12.5% with a single allogeneic cell infusion and 31.25% with multiple infusions were demonstrated. Cured mice were able to reject rechallenge with a lethal dose of tumor without further treatment. These results suggest that use of intentionally mis-matched, Th1 memory cells infused with cross-linked CD3/CD28 could represent a novel clinical approach to eliciting potent anti-tumor effects in patients without conditioning and without GVHD toxicity.

Diverse clinical applications using advantages of allogeneic peripheral blood stem cell transplantation

The diverse clinical applications of allogeneic peripheral blood stem cells based on use of their advantages are summarized. It is apparent that more stem cells and T-lymphocytes can be harvested by mobilization treatment with cytokines from healthy donors in allogeneic peripheral blood stem cell transplantation (PBSCT) than in bone marrow transplantation. It is also clear that a stronger graft-versus-tumor effect can be induced with allogeneic PBSCT than with bone marrow transplantation. One merit of allogeneic PBSCT is that it allows clinicians to design diverse clinical applications. It would appear that allogeneic PBSCT may be preferable in special clinical settings, such as advanced hematological malignancies, situations requiring a strong graft-versus-tumor effect, nonmyeloablative stem cell transplantation, and situations requiring a megadose of stem cells. Cytokine-primed peripheral blood stem cells can also be used for adoptive immunotherapy, such as a nonprimed donor lymphocyte infusion.