Myeloablative conditioning associated with hazardous immediate and late complications is considered as a mandatory first step in preparation for allogeneic blood or marrow transplantation (allogeneic BMT) for the treatment of malignant hematologic disorders and genetic diseases. Immune-mediated graft-versus-leukemia (GVL) effects constitute the major benefit of allogeneic BMT. Therefore, we have introduced the use of relatively nonmyeloablative conditioning before allogeneic BMT aiming for establishing host-versus-graft tolerance for engraftment of donor immunohematopoietic cells for induction of GVL effects to displace residual malignant or genetically abnormal host cells. Our preliminary data in 26 patients with standard indications for allogeneic BMT, including acute leukemia (n = 10); chronic leukemia (n = 8), non-Hodgkin's lymphoma (n = 2), myelodysplastic syndrome (n = 1), multiple myeloma (n = 1), and genetic diseases (n = 4) suggest that nonmyeloablative conditioning including fludarabine, anti–T-lymphocyte globulin, and low-dose busulfan (8 mg/kg) is extremely well tolerated, with no severe procedure-related toxicity. Granulocyte colony-stimulating factor mobilized blood stem cell transplantation with standard dose of cyclosporin A as the sole anti-graft-versus-host disease (GVHD) prophylaxis resulted in stable partial (n = 9) or complete (n = 17) chimerism. In 9 patients absolute neutrophil count (ANC) did not decrease to below 0.1 × 109/L whereas 2 patients never experienced ANC <0.5 × 109/L. ANC ≥ 0.5 × 109/L was accomplished within 10 to 32 (median, 15) days. Platelet counts did not decrease to below 20 × 109/L in 4 patients requiring no platelet support at all; overall platelet counts >20 × 109/L were achieved within 0 to 35 (median 12) days. Fourteen patients experienced no GVHD at all; severe GVHD (grades 3 and 4) was the single major complication and the cause of death in 4 patients, occurring after early discontinuation of cyclosporine A. Relapse was reversed by allogeneic cell therapy in 2/3 cases, currently with no residual host DNA (male) by cytogenetic analysis and polymerase chain reaction. To date, with an observation period extending over 1 year (median 8 months), 22 of 26 patients (85%) treated by allogeneic nonmyeloablative stem cell transplantation are alive, and 21 (81%) are disease-free. The actuarial probability of disease-free survival at 14 months is 77.5% (95% confidence interval, 53% to 90%). Successful eradication of malignant and genetically abnormal host hematopoietic cells by allogeneic nonmyeloablative stem cell transplantation represents a potential new approach for safer treatment of a large variety of clinical syndromes with an indication for allogeneic BMT. Transient mixed chimerism which may protect the host from severe acute GVHD may be successfully reversed postallogeneic BMT with graded increments of donor lymphocyte infusions, thus resulting in eradication of malignant or genetically abnormal progenitor cells of host origin.

Precision medicine focuses on DNA abnormalities, but not all tumors have tractable genomic alterations. The WINTHER trial () navigated patients to therapy on the basis of fresh biopsy-derived DNA sequencing (arm A; 236 gene panel) or RNA expression (arm B; comparing tumor to normal). The clinical management committee (investigators from five countries) recommended therapies, prioritizing genomic matches; physicians determined the therapy given. Matching scores were calculated post-hoc for each patient, according to drugs received: for DNA, the number of alterations matched divided by the total alteration number; for RNA, expression-matched drug ranks. Overall, 303 patients consented; 107 (35%; 69 in arm A and 38 in arm B) were evaluable for therapy. The median number of previous therapies was three. The most common diagnoses were colon, head and neck, and lung cancers. Among the 107 patients, the rate of stable disease ≥6 months and partial or complete response was 26.2% (arm A: 23.2%; arm B: 31.6% (P=0.37)). The patient proportion with WINTHER versus previous therapy progression-free survival ratio of >1.5 was 22.4%, which did not meet the pre-specified primary end point. Fewer previous therapies, better performance status and higher matching score correlated with longer progression-free survival (all P<0.05, multivariate). Our study shows that genomic and transcriptomic profiling are both useful for improving therapy recommendations and patient outcome, and expands personalized cancer treatment.

Myeloablative conditioning associated with hazardous immediate and late complications is considered as a mandatory first step in preparation for allogeneic blood or marrow transplantation (allogeneic BMT) for the treatment of malignant hematologic disorders and genetic diseases. Immune-mediated graft-versus-leukemia (GVL) effects constitute the major benefit of allogeneic BMT. Therefore, we have introduced the use of relatively nonmyeloablative conditioning before allogeneic BMT aiming for establishing host-versus-graft tolerance for engraftment of donor immunohematopoietic cells for induction of GVL effects to displace residual malignant or genetically abnormal host cells. Our preliminary data in 26 patients with standard indications for allogeneic BMT, including acute leukemia (n = 10); chronic leukemia (n = 8), non-Hodgkin's lymphoma (n = 2), myelodysplastic syndrome (n = 1), multiple myeloma (n = 1), and genetic diseases (n = 4) suggest that nonmyeloablative conditioning including fludarabine, anti–T-lymphocyte globulin, and low-dose busulfan (8 mg/kg) is extremely well tolerated, with no severe procedure-related toxicity. Granulocyte colony-stimulating factor mobilized blood stem cell transplantation with standard dose of cyclosporin A as the sole anti-graft-versus-host disease (GVHD) prophylaxis resulted in stable partial (n = 9) or complete (n = 17) chimerism. In 9 patients absolute neutrophil count (ANC) did not decrease to below 0.1 × 109/L whereas 2 patients never experienced ANC <0.5 × 109/L. ANC ≥ 0.5 × 109/L was accomplished within 10 to 32 (median, 15) days. Platelet counts did not decrease to below 20 × 109/L in 4 patients requiring no platelet support at all; overall platelet counts >20 × 109/L were achieved within 0 to 35 (median 12) days. Fourteen patients experienced no GVHD at all; severe GVHD (grades 3 and 4) was the single major complication and the cause of death in 4 patients, occurring after early discontinuation of cyclosporine A. Relapse was reversed by allogeneic cell therapy in 2/3 cases, currently with no residual host DNA (male) by cytogenetic analysis and polymerase chain reaction. To date, with an observation period extending over 1 year (median 8 months), 22 of 26 patients (85%) treated by allogeneic nonmyeloablative stem cell transplantation are alive, and 21 (81%) are disease-free. The actuarial probability of disease-free survival at 14 months is 77.5% (95% confidence interval, 53% to 90%). Successful eradication of malignant and genetically abnormal host hematopoietic cells by allogeneic nonmyeloablative stem cell transplantation represents a potential new approach for safer treatment of a large variety of clinical syndromes with an indication for allogeneic BMT. Transient mixed chimerism which may protect the host from severe acute GVHD may be successfully reversed postallogeneic BMT with graded increments of donor lymphocyte infusions, thus resulting in eradication of malignant or genetically abnormal progenitor cells of host origin.

Reduced-intensity or nonmyeloablative stem cell transplantation (NST) is designed to induce host-versus-graft tolerance by engraftment of donor stem cells. The rationale behind NST is to induce optimal graft-versus-leukemia (GVL) effects for elimination of all malignant cells by donor alloreactive immunocompetent cells as an alternative to standard high-dose myeloablative chemoradiotherapy. NST based on the use of fludarabine, low-dose busulfan, and anti-T-lymphocyte globulin (ATG) was employed in 24 patients aged 3 to 63 years with chronic myeloid leukemia (CML) in first chronic phase (CP). Graft-versus-host disease (GVHD) prophylaxis consisted of low-dose cyclosporine (CSP), in some cases with low-dose methotrexate. Early discontinuation of CSP was attempted in cases of mixed chimerism in an attempt to amplify GVL effects. All 24 patients showed rapid 3-lineage engraftment, mostly without complete aplasia; 6 patients did not require transfusion of any blood products. NST was associated with minimal procedure-related toxicity. The incidence of acute GVHD (grade I or higher) was 54%; however, this incidence increased following CSP withdrawal. After a follow-up of up to 70 months (median, 42 months), 21 of 24 patients remained alive and disease free. The GVL effects induced by donor immunocompetent lymphocytes eradicated all host hematopoietic cells, as evidenced by molecular testing. The Kaplan-Meier probability of survival and disease-free survival at 5 years is 85% +/- 8% (95% confidence interval, 70%-100%). NST may successfully replace myeloablative stem cell transplantation, providing a safer, well-tolerated therapeutic option for all patients with CML in first CP with a matched donor. However, this conclusion must be tested in a prospective randomized clinical trial.

Allogeneic bone marrow transplantation (BMT) is the only effective treatment for hematologic malignancies resistant to conventional chemotherapy. Until recently, no cure existed for patients who relapsed post-BMT. We present our long-term observations on remission induction, after relapse post-BMT, by allogeneic cell therapy (allo-CT) and the feasibility of remission induction in allo-CT-resistant patients by activation of antileukemia effector cells with recombinant human interleukin-2 (rhIL-2) in vitro and in vivo. The longest observation of successful allo-CT (event-free survival, greater than 8 years) was made in a patient with resistant pre-B lymphoblastic leukemia who received infusions with graded increments of donor (female) peripheral blood lymphocytes (PBL) as soon as bulky hematologic and extramedullary relapse was noticed early post-BMT. The patient is currently without evidence of residual host (male) cells as determined by polymerase chain reaction (PCR). Of 17 patients with acute and chronic leukemia in relapse after BMT, 10 were reinduced into complete remission. Four patients with cytogenetic relapse responded to allo-CT alone, while five of six patients with overt hematologic relapse responded only after additional activation of donor with rhIL-2. Allo-CT can, therefore, successfully reverse chemoradiotherapy-resistant relapse of both acute and chronic leukemia. Moreover, in patients resistant to donor lymphocyte infusion, remission can be accomplished by additionally activating donor PBL in vitro and/or in vivo with rhIL-2. Based on our observations, after BMT, allo-CT should be considered the treatment of choice for patients with hematologic malignancies resistant to conventional anticancer modalities. Allogeneic activated cell therapy (allo ACT) should be considered for patients with tumor cells resistant to allo-CT. Although allo-CT, followed if indicated by allo-ACT, can be effective for patients with overt hematologic relapse, reversal of persistent minimal residual disease or documented molecular/cytogenetic relapse early after BMT may also be considered as a possible indication for allo-CT.

Imatinib mesylate (IM), a small molecule that is a selective inhibitor of the ABL, platelet derived growth factor receptor (PDGFR-R) and stem cell ligand receptor (c-kit) tyrosine kinases

Reduced intensity conditioning has been suggested as a desirable therapeutic modality for the treatment of patients with malignant and nonmalignant indications, but it seems particularly attractive for patients with Fanconi anemia due to their increased sensitivity to chemoradiotherapy. Between November 1996 and September 2003, 7 patients (1 male and 6 female; age range, 3-31 years; median age, 9.5) were conditioned with a fludarabine-based protocol for stem cell transplantation without radiation. In vivo T-cell depletion was accomplished with anti-thymocytic globulin or Campath-1H (alemtuzumab). Graft-versus-host disease prophylaxis consisted of low-dose cyclosporine alone. Eight transplantations were carried out for 7 patients using bone marrow, peripheral blood, and/or cord blood as sources of stem cells. All patients received transplants from HLA-A, -B, -C, and -DR matched donors, 5 from family members and 2 from matched unrelated donors. One patient did not engraft her first matched unrelated donor and underwent a second transplantation from another matched unrelated donor, after which she engrafted well. All 7 patients are alive and well, fully reconstituted with donor cells, and with 100% performance status. In conclusion, fludarabine-based preparative protocols are well tolerated, facilitate rapid engraftment with minimal toxicity, and should be considered an essential component of choice for patients with Fanconi anemia.

SummaryWe reviewed our experience in the treatment of 13 patients with severe acquired aplastic anaemia, using a newly developed non-myeloablative regimen consisting of fludarabine (total dose 180 mg/m 2 ), cyclophosphamide (total dose 120 mg/kg), and antithymocyte globulin (total dose 40 mg/kg). All except one patient received multiple transfusions and had failed prior immunosuppressive treatment. Twelve out of 13 patients achieved sustained engraftment. One patient was not evaluable for engraftment because of early death on day +10. None of the patients developed graft failure. Mucositis of mild-to-moderate severity was the only observed regimen-related toxicity. The cumulative incidence of acute graft-versus-host disease (GvHD) grade II-IV and III-IV was 8AE3% and 0%, respectively. With a median follow-up period of 45 months, the 5-year overall survival probability was 84%. Eight out of 11 surviving patients have been followed for more than 1 year and only one developed limited chronic GvHD. All patients enjoy a normal life style, with a Karnofsky score of 100%, and all except three, followed for 3, 5 and 6 months respectively, are free of any immunosuppressive medication. The results of this study look promising, while prospective clinical trials may be required to confirm the benefits of this regimen as an alternative to existing protocols.