ALBERT

Description: More alternative donor stem cell transplantation (SCT) has been performed in recent years in China due to lack of HLA identical siblings. Higher risk for developing acute graft-versus-host disease (aGVHD) has been seen in patients who receive haploidentical stem cell transplantation (haplo-SCT) compared with identical sibling SCT patients (Lu DP et al, Blood2006; 107: 3065). In a murine model, we have first demonstrated that the animals transplanted with three mixed bone marrow (A+B+C to A) were survived longer due to milder aGVHD compared with the mice transplanted with single allogeneic bone marrow (B to A). In current clinical trial, we examine whether cord blood (CB) as the third party cells could reduce aGVHD in haplo-SCT setting under the same principle investigator in two hospitals. Between January 2006 and April 2008, total 133 haplo-SCT patients with hematological malignancies were enrolled. The patients with advanced diseases were excluded. All patients received unmanipulated blood and marrow transplant after BUCy2 or CyTBI plus antithymocyte globulin (ATG, Genzyme 10mg/kg) as preconditioning. Cyclosporine, short-term Methotrexate, and Mycophenolate mofetil were employed for GVHD prophylaxis. Fifty-six patients received one unit of HLA 3–6/6 matched CB one day before SCT as CB group, and 77 cases did not receive CB as control group. The main clinical characteristics in both groups are comparable. All patients in both groups achieved full donor chimerism. Low levels of CB chimerism were detected in a few patients at early stage after SCT. No long-term CB engraftment was found. The cumulative incidences of grade II to IV aGVHD were 16.4% versus 38.4% (p=0.008) in CB group, control group respectively. The cumulative incidences of grades III to IV aGVHD for CB group versus control group were 9.2% versus 22.4% with p=0.043. The incidences of 100-day treatment-related mortality were 1.8% versus 10.4% (p=0.053) for CB group, control group respectively. Our preliminary clinical study has shown that CB as the third party cells could significantly reduce the incidences of aGVHD, especially for severe aGVHD, and also treatment-related mortality in haplo-SCT. The mechanism of this strategy need to be further investigated.

Description: Abstract 4095 Poster Board III-1030 The clinical outcomes of refractory/recurrent leukemia that salvaged by allogeneic hematopoietic cell transplantation (HCT) is usually poor. It is crucial for the management of those high-risk patients with appropriate conditioning regimens that balance the efficacy and safety well and with enhanced anti-leukemia effect post-HCT. Our previous study has shown that donor's dendritic cell-primed cytokine-induced killer cells (DC-CIK) is a safe and effective therapy in the management of early leukemia recurrence after allogeneic HCT, which fail to or ineligible for current standard treatment. Objective In present clinical study, we examine the efficacy of refractory/recurrent myelogenous leukemia salvaged by allogeneic HCT and prophylactic immunotherapy. Methods From September 2006 to May 2008, 30 patients with refractory/recurrent myelogenous leukemia (AML 29, CML-BC 1) were enrolled. The median age was 32 (12 to 55) years old. The median blasts in bone marrow were 36% (20% to 87%) prior to conditioning. The grafts were from HLA identical siblings (5), unrelated donors (7), and haploidentical family members (18). Conditioning regiments were individualized according to patients' status as following. Generally, the regimen with high-dose cytarabine plus BUCY2 was used (13 cases). The patients with impaired organ function received above regimen except with fludarabine instead of cyclophosphamide (11 cases). For the recipients with 〉 40% blasts in bone marrow, melphalan (2 cases) or aclarubicin (1 case) was added into the regimen or FLAG followed by reduced-intensified BUCY2 (3 cases) was employed in order to reduce leukemia burden. Cyclosporine A, methotrexate and mycophenolate mofetil were administrated for GVHD prophylaxis. To prevent leukemia relapse, immunosuppressants were tapered off early post-HCT. Prophylactic immunotherapy including cellular (DLI, DC-CIK, NK cells), and humoral (IL-2, IFN-a, thymosin) was used selectively in the patients who had no GVHD 120 days after HCT. Results The median mononuclear cells in the graft were 7.36 (3.49 to 11.5) ×108/kg. The median CD34+ cells were 4.06 (1.57 to 11.4) ×106/kg. The median CD3+ cells were 1.42 (0.75 to 3.61) ×108/kg. Twenty-nine patients attained sustained engraftment. One died of multi-organ failure before hematopoietic reconstitution. The median time for white blood cells 〉 1.0 × 109/L, and platelets 〉 20 × 109/L was 14 (10 to 21) days, 15 (12 to 26) days, respectively. Thirteen patients developed acute GVHD (grade I in 5, grade II in 7, and grade III in 1). Thirteen patients developed chronic GVHD after immunosuppressants' reduction or withdrawal. In addition, 13 patients received prophylactic immunotherapy due to lack of chronic GVHD 120 days post-HCT, then 7 of 13 developed chronic GVHD. With the median follow-up of 15 (3 to 35) months, two (6.7%) patients with AML had hematological recurrence. One patient attained durable complete remission again after treatment with chemotherapy followed by immunotherapy with DLI, DC-CIK, and NK cells. Five (16.7%) patients died (infections in 2, hematological relapse in 1, chronic GVHD in 1, and multi-organ failure in 1). 25 of 30 (83.3%) patients have been in continuous complete remission since salvaged HCT. Conclusion Our preliminary clinical results have shown that the combination of salvaged allogeneic HCT and prophylactic immunotherapy is a promising modality for the treatment of myelogenous leukemia in refractory/recurrent status, even with high leukemia burden. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 228 Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is an important alternative option for patients with hematological malignancies who need urgent transplant but without HLA matched either sibling or unrelated donor (Dao-Pei Lu et al., Blood 2006; 107:3065). Each patient usually has several haploidentical family members who could be selected as a donor. To determine the principal of donor selection among all available related haploidentical candidates, the clinical outcomes of a large series of haplo-HSCT in our hospital are analyzed. From April 2002 to April 2010, consecutive 440 patients with hematological malignancies who underwent haplo-HSCT were included. The median age of patients was 23 (3-59) years old. The diagnosis included AML (39.8%), ALL (35.9%), MDS (3.6%), CML (16.1%), and others (4.6%). Transplants at CR1 or CML-CP1, ≥CR2 or CML-CP2/AP, and advanced disease (refractory/relapsed acute leukemia or CML-BC) were 33.4%, 40.9% and 25.7%. HLA mismatched at 1, 2, 3 loci was 13.2 %, 27.5%, 59.3%, respectively. Transplants in sex-matched donor-recipient pair, female donor to male recipient, and male donor to female recipient were 55.1%, 33.0% and 13.9%. Major clinical characteristics among these three arms were similar. All patients received unmanipulated combined marrow and peripheral blood stem cells for transplant after BUCy2/CyTBI plus ATG conditioning. Fludarabine was substituted for cyclophosphamide in some patients due to impaired organ function. Prophylaxis and treatment of GVHD were reported previously. Steady hematopoietic reconstitution was seen in 98.6% of recipients. The cumulative incidences of grade II to IV acute GVHD and chronic GVHD were 32.6%, 61.3%, respectively. 100-day mortality was 10.5%. With the median follow-up of 32 (3-99) months, 2-year and 5-year overall survival (OS) rates for patients who were in different disease status were 57.9% and 52.9%. Univariate and multivariate analysis all showed that disease status before transplant, CD34+ cell dosage infused and sex-matched or not between donor and recipient but not HLA disparity and age were pivotal impact factors on survival. Two-year OS of transplants in sex-matched donor-recipient pair, female donor to male recipient, male donor to female recipient were 65.5%, 55.3%, 37.6, respectively (p=0.000). No significant differences were found on OS of transplants among haploidentical donors from sibling or parent or offspring or other relatives. In conclusion, our clinical results from a large series of transplants demonstrate that haplo-HSCT in sex-matched donor-recipient pair has survival advantage. Therefore, in haplo-HSCT, sex-matched donor should be the first choice, if not available, then female donor to male recipient could be the second option. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 4295 Syngeneic blood and marrow transplantation (BMT) has been applied in the treatment of many malignant or nonmalignant hematologic disorders with no or minimal and transient graft-versus-host disease (GVHD), much less transplant-related mortality (TRM) in contrast to allogeneic BMT, and lower relapse rate compared with autologous BMT. However, limited data in a single BMT center is not sufficient for statistical analysis. To evaluate the clinical outcomes of syngeneic BMT, CSBMT has performed a cooperative survey among BMT centers in mainland, Taiwan, and Hong Kong. From January 1964 to May 2009, 94 transplants from syngeneic donors have been performed in 32 BMT centers. The median age was 20 (1.5 to 51) years old. The diagnosis included AML (29 cases), SAA (26 cases), ALL (17 cases), CML (12 cases), lymphoma (3 cases), MDS (4 cases), neuroblastoma (2 cases), and large granular lymphocytosis (1 case). The main conditioning regimens were CYTBI or BUCY for malignant diseases, none or CY plus ATG for SAA. Bone marrow (BM, 34) or peripheral blood (PB, 49) or both BM and PB (11) as grafts were used. Five patients (SAA 2, AML 3) underwent the same donor's syngeneic BMT twice. One patient with large granular lymphocytosis and 1 case with SAA underwent the same donor's syngeneic BMT thrice. The median follow-up time was 28 months (1 month to 45 years). The median time for white blood cells 〉 1.0 × 109/L, and platelets 〉 20 × 109/L was 11 (2-30) days, 13 (0-122) days, respectively. Two patients (2.1%) had grade I acute GVHD (aGVHD), and 4 cases (4.3%) had grade II aGVHD. However, only one patient's specimen was consulted by pathologist. All aGVHD was controlled easily with low-dose steroid. No chronic GVHD was noted. Three-year disease-free survival (DFS) for the patients with nonmalignant disorders was 88.5%. Among them, the longest survivor was living and well for 45 years after transplant. Three-year DFS for the patients with malignant diseases was 62.9%. The overall survival rates at 3 years were 87.9%, and 69.5% for nonmalignant, and malignant diseases, respectively. 22 of 94 patients died after BMT (nonmalignant 3, malignant 19). The only cause of death for the patients with nonmalignant disorders was rejection. Relapse was the main cause of death in patients with malignancies (17/19). TRM was 2.1%. In conclusion, syngeneic BMT is a safe and effective therapeutic option for both nonmalignant and malignant hematologic disorders. Syngeneic donor, if available, should be the first choice in all cases of AA and hematological malignancies in general. The longest survivor of 45 years post-BMT is presented in this series. The good results and advantage of syngeneic BMT cast light on the potential utility of stored autologous placental-cord blood which is shared by the identical twin through the same placenta. Disclosures: No relevant conflicts of interest to declare.