Reduced-intensity Conditioning Allogeneic Hematopoietic Cell Transplantation Research Articles

The impact of beta-blocker use at the time of hematopoietic cell transplantation on the development of acute and chronic graft-versus-host disease

Sympathetic nervous system activation plays a role in the development of acute and chronic graft-versus-host disease (GVHD) following allogeneic hematopoietic cell transplantation (HCT). The primary objective was to compare the cause-specific hazard of grade II-IV and III-IV acute GVHD (aGVHD) and chronic GVHD (cGVHD) in the context of ß-blocker use and type (selective vs. non-selective). Secondary objectives included overall survival (OS), relapse-free survival (RFS), and cumulative incidence of relapse, non-relapse mortality (NRM), and grade II-IV and III-IV aGVHD and cGVHD. The current study included 151 patients ages 18 and older diagnosed with hematological malignancies who underwent reduced intensity conditioning allogeneic HCT from HLA matched related or unrelated donors between January 2014 and 2017. 31 patients were on a ß-blocker of which 71% were on a selective ß-blocker. The incidence of aGVHD was not different among groups. Results show a non-significant trend in the association between ß-blocker use and reduction in the risk of developing cGVHD (cause-specific hazard ratio 0.49, p = 0.060), with no negative impact on survival or relapse. The current data are supportive of a potential ß-adrenergic influence on the pathogenesis of GVHD, consistent with the inflammatory etiology of GVHD and the anti-inflammatory effects of ß-adrenergic antagonists.

Dasatinib and dexamethasone followed by hematopoietic cell transplantation for adults with Ph-positive ALL

AbstractPost-remission strategies after dasatinib-corticosteroid induction in adult Philadelphia chromosome (Ph)–positive acute lymphoblastic leukemia (ALL) are not well studied. We evaluated dasatinib and dexamethasone induction then protocol-defined post-remission therapies, including hematopoietic cell transplantation (HCT). Adults (N = 65) with Ph-positive ALL received dasatinib-dexamethasone induction, methotrexate-based central nervous system (CNS) prophylaxis, reduced-intensity conditioning (RIC) allogeneic HCT, autologous HCT, or chemotherapy alone, and dasatinib-based maintenance. Key end points were disease-free survival (DFS) and overall survival (OS). The median age was 60 years (range, 22-87 years). The complete remission rate was 98.5%. With a median follow-up of 59 months, 5-year DFS and OS were 37% (median, 30 months) and 48% (median, 56 months), respectively. For patients receiving RIC allogeneic HCT, autologous HCT, or chemotherapy, 5-year DFS were 49%, 29%, and 34%, and 5-year OS were 62%, 57%, and 46%, respectively. Complete molecular response rate after CNS prophylaxis was 40%. Relative to the p190 isoform, p210 had shorter DFS (median 10 vs 34 months, P = .002) and OS (median 16 months vs not reached, P = .05). Relapse occurred in 25% of allogeneic HCT, 57% of autologous HCT, and 36% of chemotherapy patients. T315I mutation was detected in 6 of 8 marrow relapses. Dasatinib CNS concentrations were low. Dasatinib-dexamethasone followed by RIC allogeneic HCT, autologous HCT, or chemotherapy was feasible and efficacious, especially with RIC allogeneic HCT. Future studies should address the major causes of failure: T315I mutation, the p210 BCR-ABL1 isoform, and CNS relapse. This study was registered at www.clinicaltrials.gov as #NCT01256398.

Long-term results of reduced-intensity conditioning allogeneic hematopoietic cell transplantation for older patients with acute myeloid leukemia: a retrospective analysis of 10-year follow-up data.

The long-term outcomes of allogeneic hematopoietic cell transplantation (HCT) with reduced-intensity conditioning (RIC) remain inconclusive. To address this issue, we conducted a nationwide registry-based study of patients with acute myeloid leukemia (AML) age 50 years or older who underwent allogeneic HCT in complete remission using RIC (n = 284) or myeloablative conditioning (MAC, n = 190) between 2002 and 2007. The median follow-up period for surviving patients was 10.1 years for RIC recipients and 10.4 years for MAC recipients. The 10-year probabilities of overall survival, relapse, and non-relapse mortality were 36.4%, 30.0%, and 35.7% for RIC recipients, and 39.8%, 26.3%, and 35.5% for MAC recipients, respectively. Multivariate analysis revealed that the conditioning intensity did not affect overall mortality (P = 0.184), relapse (P = 0.904), or non-relapse mortality (P = 0.387). For the 218 patients qualifying for propensity score-matched pairing (109 pairs), RIC was found to be associated with similar survival (P = 0.095) and relapse (P = 0.467), and significantly lower non-relapse mortality (P = 0.046) compared with MAC. Our results confirm the long-term efficacy of RIC allogeneic HCT for older patients with AML and mitigate concerns over an increase in late relapse.

Prognostic Score and Cytogenetic Risk Classification for Chronic Lymphocytic Leukemia Patients: Center for International Blood and Marrow Transplant Research Report.

To develop a prognostic model and cytogenetic risk classification for previously treated patients with chronic lymphocytic leukemia (CLL) undergoing reduced intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (HCT). We performed a retrospective analysis of outcomes of 606 patients with CLL who underwent RIC allogeneic HCT between 2008 and 2014 reported to the Center for International Blood and Marrow Transplant Research. On the basis of multivariable models, disease status, comorbidity index, lymphocyte count, and white blood cell count at HCT were selected for the development of prognostic model. Using the prognostic score, we stratified patients into low-, intermediate-, high-, and very-high-risk [4-year progression-free survival (PFS) 58%, 42%, 33%, and 25%, respectively, P < 0.0001; 4-year overall survival (OS) 70%, 57%, 54%, and 38%, respectively, P < 0.0001]. We also evaluated karyotypic abnormalities together with del(17p) and found that del(17p) or ≥5 abnormalities showed inferior PFS. Using a multivariable model, we classified cytogenetic risk into low, intermediate, and high (P < 0.0001). When the prognostic score and cytogenetic risk were combined, patients with low prognostic score and low cytogenetic risk had prolonged PFS (61% at 4 years) and OS (75% at 4 years). In this large cohort of patients with previously treated CLL who underwent RIC HCT, we developed a robust prognostic scoring system of HCT outcomes and a novel cytogenetic-based risk stratification system. These prognostic models can be used for counseling patients, comparing data across studies, and providing a benchmark for future interventions. For future study, we will further validate these models for patients receiving targeted therapies prior to HCT.

Impact of Chronic Graft-Versus-Host Disease on Long-Term Outcomes of Reduced-Intensity Conditioning Allogeneic Hematopoietic Cell Transplantation for Adults with High-Risk Acute Lymphoblastic Leukemia in First Remission

Background : The role of reduced-intensity conditioning allogeneic hematopoietic cell transplantation (RIC-HCT) in adult acute lymphoblastic leukemia (ALL) remains unclear because the interpretation of transplantation outcome is mainly limited by the small sample size, short follow-up duration, various regimens for conditioning and graft-versus-host disease (GVHD) prophylaxis, and the heterogeneity of the criteria used to select patients for RIC-HCT. Previously, we conducted a phase 2 trial of RIC-HCT in adults with high-risk ALL who were ineligible for myeloablative conditioning and showed the potential role of this strategy, especially in patients in first complete remission (CR1). Here, we report the long-term outcomes of RIC-HCT by analyzing 122 consecutive adults with high-risk ALL in CR1, particularly focusing on the prognostic relevance of chronic GVHD.Methods: During the period between 2000 and 2014, 122 patients in CR1 (median age, 52 years [range, 15-65 years]; 54 Ph-negative ALL and 68 Ph-positive ALL) were given an identical RIC regimen consisting of fludarabine (150 mg/m2 in total) and melphalan (140 mg/m2in total). The indications for RIC-HCT were advanced age (≥50 years; n=79; 64.8%) and comorbid conditions (n=43; 35.2%). Graft sources were peripheral blood stem cells (n=118; 66 matched sibling donor, 23 matched unrelated donor, 29 mismatched unrelated donor) and bone marrow (n=4; 1 matched sibling donor, 1 matched unrelated donor, 2 mismatched unrelated donor). The median time to transplantation was 155.5 days (range, 103-291 days). GVHD prophylaxis was attempted by administering calcineurin inhibitors (cyclosporine for sibling donor transplants, tacrolimus for unrelated donor transplants) plus methotrexate. Antithymocyte globulin was administered to the patients who received mismatched unrelated donor grafts. If residual leukemia was detected in the absence of GVHD at 3 months after transplantation, calcineurin inhibitors were rapidly discontinued.Results: The median time for neutrophil and platelet recovery was 12 days (range, 8-30 days) and 13 days (range, 5-60 days) after RIC-HCT. Sixty-two patients developed acute GVHD (53 grade II, 5 grade III, 4 grade IV). The cumulative incidence of acute GVHD at 1 year was 50.8% (42.6% for Ph-negative and 57.4% for Ph-positive, P=0.152). Except for 11 patients with early deaths within 100 days, 77 developed chronic GVHD (30 mild, 29 moderate, 18 severe), resulting in a 5-year cumulative incidence of 63.6% (69.1% for Ph-negative ALL and 58.8% for Ph-positive ALL, P=0.319). The median time to onset of chronic GVHD was 140 days (range, 37-843 days) after transplantation. Cytomegalovirus reactivation >10,000 copies/mL was observed in 40.2% (44.4% for Ph-negative ALL and 36.8% for Ph-positive ALL, P=0.447). After a median follow-up duration of 57.9 months (range, 17.7-206.8 months), the 5-year cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) were 27.5% (23.9% for Ph-negative ALL and 30.2% for Ph-positive ALL) and 19.0% (17.4% for Ph-negative ALL and 20.3% for Ph-positive ALL), respectively, and the 5-year disease-free survival (DFS) and overall survival (OS) rates were 53.5% (58.4% for Ph-negative ALL and 49.7% for Ph-positive ALL) and 59.8% (60.2% for Ph-negative ALL and 59.3% for Ph-positive ALL). In multivariate analysis, the presence of chronic GVHD lowered CIR (HR, 0.23; 95% CI, 0.10-0.48; P<0.001), but severe chronic GVHD increased NRM (HR, 8.76; 95% CI, 3.39-22.6; P<0.001). Thus, the presence of mild to moderate chronic GVHD was closely related to better outcomes in terms of DFS (HR, 0.45; 95% CI, 0.32-0.64; P<0.001) and OS (HR, 0.44; 95% CI, 0.30-0.64; P<0.001) in all patients as well as in both subgroups of patients. In Ph-positive ALL subgroup of patients, patients without achievement of major molecular response until the time of transplantation had also significantly higher CIR (HR, 7.42; 95% CI, 3.04-18.10; P<0.001) and poorer DFS (HR, 3.47; 95% CI, 1.48-8.14; P=0.004) and OS (HR, 2.58; 95% CI, 1.03-6.47; P=0.043).Conclusion: Our long-term follow-up data with a uniform treatment strategy suggest that RIC-HCT is a valid alternative choice for providing a long-term disease control for adult high-risk ALL patients in CR1. Minimal residual disease-based treatment strategies to reduce leukemia cell burden before HCT and to enhance the graft-versus-leukemia effect are needed in the future. DisclosuresKim:ILYANG: Consultancy, Honoraria, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Lee:Alexion Pharmaceuticals, Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

A Phase II Study of Dasatinib and Dexamethasone As Primary Therapy Followed By Hematopoietic Cell Transplantation for Adults with Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia: CALGB Study 10701 (Alliance)

Background:Potent inhibitors of BCR-ABL1have improved remission results and altered post-remission therapy for Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). Dasatinib plus dexamethasone followed by hematopoietic cell transplantation (HCT) promises high response rates, reduced toxicity, and durable remissions.Methods:We conducted a Phase II trial at 17 U.S. centers with the primary objective being to estimate the 3-year overall survival and disease-free survival of patients with Ph+ ALL treated with dasatinib and dexamethasone for remission induction and intensification, central nervous system (CNS) prophylaxis, consolidation with reduced-intensity conditioning (RIC) allogeneic HCT, autologous HCT, or etoposide and cytarabine, and dasatinib-based maintenance. Eligible patients had untreated Ph+ ALL, were ≥18 years old, and had normal cardiac function. Induction (Course I) used dasatinib 140 mg oral daily and dexamethasone 10 mg/m2/day oral or intravenous (IV) days 1-7. For patients with ≤20% blasts in the Course I, Day 15 bone marrow biopsy, intensification (course II) continued daily dasatinib with another 7 days of dexamethasone. Those with >20% lymphoblasts also received vincristine (VCR) and daunorubicin (DNR). Patients (n=3) not in CR/CRi after Course II received a second induction (Course III) with dasatinib, cyclophosphamide, VCR, DNR, and dexamethasone. After Course II or III, CNS prophylaxis (Course IV) consisted of IV VCR and IV, oral, and intrathecal methotrexate (MTX). Dasatinib was restarted at serum [MTX] <0.05 microM. Course V consisted of HCT or chemotherapy. Patients aged 18-70 years with an HLA-matched donor underwent RIC allogeneic HCT; otherwise they underwent autologous HCT. Allogeneic HCT conditioning used fludarabine 30 mg/m2/day IV day -7 through -3, alemtuzumab 20 mg/day IV day -7 through -3, and melphalan 140 mg/m2 once on day -2. GVHD prophylaxis with tacrolimus began day -2. Patients undergoing autologous HCT received etoposide 10 mg/kg/day (age >65 years, 5 mg/kg/day) continuous IV for 4 days and cytarabine 2 g/m2 (age >65 years, 1 g/m2) IV every 12 hours for 8 doses (EA) then G-CSF for mobilization. Autologous HCT conditioning used melphalan 100 mg/m2/day on days -2 and -1. Patients >70 years or unable to undergo HCT received EA alone. Dasatinib maintenance (Course VI) began on day 30 of Course V and continued for 12 months and until 2 consecutively negative bone marrow BCR-ABL1RT-PCR assays 3 months apart or until relapse. Dasatinib levels were measured on day 15 of induction.Results:Sixty-six patients enrolled from 12/15/2010 to 11/14/2014; 65 received dasatinib and are evaluable. Median age was 60 years (22-87); 49% were male. Median presenting WBC count was 23.1 x 103/ul (0.3-453.6). No deaths occurred during induction or intensification. CR or CRi occurred 31 patients (48%) by Day 15 of induction and in 62 patients overall (95%; CR 86%). Median dasatinib levels in serum and CSF on Day 15 of induction were 30.3 ng/mL (<3-308) and 0.29 ng/mL (<0.2-1.37), respectively suggesting approximately 1% of plasma dasatinib penetrates into the CSF, less than the unbound fraction (6%). Fifty-four patients started Course IV, 38 Course V, and 37 Course VI. Fourteen patients continue on protocol therapy. Of 38 patients receiving Course V, 22 had allogeneic HCT, 6 had autologous HCT, and 10 had EA chemotherapy. Median age of allogeneic HCT recipients was 61 years (31-69). Robust autologous stem cell mobilization was observed [median CD34+ cell count, 90 x 106/kg (31-166, n=6)]. Dasatinib maintenance was feasible after allogeneic HCT, autologous HCT, and chemotherapy alone with no missed doses in 59%, 83%, and 63% of cycles, respectively. Ten patients have relapsed with one isolated CNS relapse. No relapses have occurred after allogeneic HCT with 3 relapses after autologous HCT and one after Course V EA alone. Median follow up for survivors is 22.8 months (longest, 51 months). There have been 23 deaths: 5 treatment-related (4 after allogeneic HCT, 1 after course V EA), 16 disease-related and 2 unrelated.Conclusions:Dasatinib with dexamethasone yields CR rates comparable to those reported with tyrosine kinase inhibitors combined with conventional chemotherapy. Post-remission therapy with reduced-intensity allogeneic HCT, autologous HCT, or chemotherapy followed by dasatinib maintenance is feasible. Survival follow up is maturing. DisclosuresStock:Sigma-Tau: Honoraria, Research Funding; Royalties for a chapter in Up to Date: Patents & Royalties; ADC Therapeutics: Honoraria; Amgen: Honoraria; Gilead Sciences: Honoraria. Beumer:Bristol-Myers Squibb: Research Funding. Stone:Abbvie: Consultancy, Membership on an entity’s Board of Directors or advisory committees; Pfizer: Consultancy; Juno Therapeutics: Consultancy; Karyopharm: Consultancy; Sunesis Pharmaceuticals: Consultancy; Agios: Consultancy; Amgen: Consultancy; Celator: Consultancy; Celgene: Consultancy, Membership on an entity’s Board of Directors or advisory committees; Novartis: Consultancy; Jansen: Consultancy; Merck: Consultancy; ONO: Consultancy; Roche: Consultancy; Seattle Genetics: Consultancy; Xenetic Biosciences: Consultancy. Larson:Bristol-Myers Squibb: Consultancy; Astellas: Consultancy, Research Funding.

Reduced-intensity conditioning allogeneic hematopoietic-cell transplantation for older patients with acute myeloid leukemia.

Elderly patients (>60 years) with acute myeloid leukemia have a poor prognosis with a chemotherapy-alone approach. Allogeneic hematopoietic-cell transplantation (HCT) can improve overall survival (OS). However, myeloablative regimens can have unacceptably high transplant-related mortality (TRM) in an unselected group of older patients. Reduced-intensity conditioning (RIC) or nonmyeloablative (NMA) conditioning regimens preserve the graft-versus-leukemia effects but reduce TRM. NMA regimens result in minimal cytopenia and may not require stem cell support for restoring hematopoiesis. RIC regimens, intermediate in intensity between NMA and myeloablative regimens, can cause prolonged myelosuppresion and usually require stem cell support. A few retrospective and prospective studies suggest a possibility of lower risk of relapse with myeloablative HCT in fit older patients with lower HCT comorbidity index; however, RIC and NMA HCTs have an important role in less-fit patients and those with significant comorbidities because of lower TRM. Whether early tapering of immunosuppression, monitoring of minimal residual disease, and post-transplant maintenance therapy can improve the outcomes of RIC and NMA HCT in elderly patients will require prospective trials.

Comparison of Reduced-Intensity Hematopoietic Cell Transplantation with Chemotherapy in Patients Age 60-70 Years with Acute Myelogenous Leukemia in First Remission

We compared the outcomes of patients age 60-70 years with acute myelogenous leukemia receiving reduced-intensity allogeneic hematopoietic cell transplantation (HCT) in first remission (CR1) reported to the Center for International Blood and Marrow Research (n = 94) with the outcomes in patients treated with induction and postremission chemotherapy on Cancer and Leukemia Group B protocols (n = 96). All patients included had been in CR1 for at least 4 months. The HCT recipients were slightly younger than the chemotherapy patients (median age, 63 years vs 65 years; P < .001), but there were no significant between-group differences in the proportion with therapy-related leukemia or in different cytogenetic risk groups. Time from diagnosis to CR1 was longer for the HCT recipients (median, 44 days vs 38 days; P = .031). Allogeneic HCT was associated with significantly lower risk of relapse (32% vs 81% at 3 years; P < .001), higher nonrelapse mortality (36% vs 4% at 3 years; P < .001), and longer leukemia-free survival (32%vs15% at 3years; P = .001). Although overall survival was longer for HCT recipients, the difference was not statistically significant (37% vs 25% at 3 years; P = .08). Our findings suggest that reduced-intensity conditioning allogeneic HCT in patients age 60-70 with acute myelogenous leukemia in CR1 reduces relapse and improves leukemia-free survival. Strategies that reduce nonrelapse mortality may yield significant improvements in overall survival.

A Retrospective Review of Response to Donor Leukocyte Infusions In Adults with Acute Myeloid Leukemia After Reduced Intensity Conditioned Allogeneic Hematopoietic Cell Transplantation.

AbstractAbstract 4512Relapse remains the most common cause of death after allogeneic hematopoietic cell transplantation (HCT), and occurs in 40% of all hematologic malignancy patients. Reduced intensity conditioning (RIC) of acute myeloid leukemia (AML) patients for HCT has been adopted as a means to reduce treatment related mortality and graft-versus-host disease (GvHD) after transplantation. The trade off of this approach has been an increased relapse risk. There is limited data on the use of donor leukocyte infusion (DLI) for AML relapse after RIC HCT. We conducted a single center retrospective review of the outcomes of DLI in adults with AML after RIC allogeneic HCT. We hypothesized that DLI given for disease relapse or graft hypoplasia would improve overall survival in patients. A database of patients undergoing hematopoietic cell transplantation (HCT) from 1997 – 2007 were screened and eligible if they had undergone a fludarabine based conditioning regimen. 33 charts were initially selected for review (16 undergoing leukocyte infusion and 17 not undergoing leukocyte infusion). 3 patients in the DLI cohort were excluded because they had undergone a second transplant and 11 patients in the non-DLI cohort were excluded for no evidence of relapse. A cohort of 13 DLI patients and 6 non-DLI controls were included in the analysis. The median age of patients undergoing DLI was 52 (69% males). 8% of recipients had evidence of graft-versus-host disease (GvHD) prior to DLI and 61% were reported to have GvHD after DLI. 46% of transplant recipients had evidence of disease at the time of RIC HCT. 92% of DLI recipients received DLI for disease relapse and all underwent treatment with either chemotherapy or radiation prior to DLI. Those patients receiving DLI had prolonged survival compared to the non-DLI cohort (Wilcoxon chi-square = 4.212, p=0.04). Variables that statistically predicted overall survival in the DLI treated cohort were disease after DLI (Log rank chi-square = 12.636, p=0.002), chronic GvHD after DLI (Log Rank chi-sqare = 3.932, p=0.047), undergoing a HLA matched transplant (Log rank chi-square 5.017, p=0.025) and CMV positive recipient (Log rank chi-square = 4.562, p=0.033). Other variables that were not significant in predicting survival after DLI included: acute or chronic GvHD before DLI, disease specific treatment before DLI, gender, cytokines at the time of transplant or DLI, total number of DLI's, recipient lymphocyte count pre-DLI, immunosuppression at the time of DLI, CD3 dose, leukemic burden measured by blast percentage on bone marrow biopsy pre-DLI, and cytogenetic risk group. We conclude that DLI improves survival for relapsed AML patients after RIC HCT. The risk for GvHD is significant but no patients experienced life threatening GvHD in this cohort. Interestingly, complete HLA matched transplant recipients had improved survival after DLI over mismatched transplant recipients undergoing DLI. Limited by the small sample size, we did not have enough power to conduct multiple regression analysis. In the future we plan to model predictors of overall survival, progression free survival and GvHD after DLI in a larger cohort including myeloablative conditioning in adult patients with AML. Disclosures:Schroeder:Genzyme: Research Funding; Celgene: Research Funding; NIH/NHLBI 5K12HL08710703: Research Funding. Westervelt:Novartis: Honoraria; Celgene: Honoraria, Speakers Bureau. DiPersio:Genzyme: Honoraria. Vij:Novartis: Honoraria; Eisai: Speakers Bureau.

Improved Outcomes Using Tacrolimus/Sirolimus for Graft-versus-Host Disease Prophylaxis with a Reduced-Intensity Conditioning Regimen for Allogeneic Hematopoietic Cell Transplant as treatment of Myelofibrosis

Allogeneic hematopoietic cell transplantation (HCT) using reduced-intensity conditioning (RIC) regimens is a potentially curative treatment for patients (patients) with myelofibrosis (MF), as we and others have reported. Nonrelapse mortality (NRM) from graft-versus-host disease (GVHD) and other complications has limited the success of this approach. As part of an ongoing prospective research study at City of Hope, a combination of tacrolimus/sirolimus +/- methotrexate (MTX) for GVHD prophylaxis has become the standard treatment for our allogeneic HCT patients. In this report, we present results for 23 consecutive patients, including extended follow up for 9 patients previously reported who received cyclosporine (CsA)/mycophenolate moffetil (MMF)+/-MTX, and the current series of 14 patients who received tacrolimus/sirolimus+/-MTX, and evaluate the impact of the GVHD prophylaxis regimen on the outcomes. Median follow-up for alive patients was 29.0 months (9.5-97.0). The estimated 2-year overall survival (OS) for the CsA/MMF cohort was 55.6% (confidence interval 36.0, 71.3), and for the tacrolimus/sirolimus cohort it was 92.9% (63.3, 98.8) (P=.047). The probability of grade III or IV acute GVHD (aGVHD) was 60% for the CsA/MMF patients, and 10% for the tacrolimus/sirolimus group (P=.0102). No significant differences were seen for grade II to IV aGVHD in the 2 groups. We conclude that the combination of tacrolimus/sirolimus+/-MTX for GVHD prophylaxis in the setting of RIC HCT for MF appears to reduce the incidence of severe aGVHD and NRM, and leads to improved OS compared to CSA/MMF+/-MTX.

Prolonged Survival in Adults with Acute Lymphoblastic Leukemia (ALL) Following Reduced Intensity Conditioning and Allogeneic Transplantation

Reduced intensity conditioning (RIC) and allogeneic hematopoietic cell transplantation (HCT) for adult patients with ALL may improve the tolerance and outcomes following allografting. We studied 22 consecutive patients (2001–2008) who received RIC HCT. Indications for RIC regimens included: age > 55 years (for matched related donor [MRD], >45 years for unrelated or umbilical cord [UCB]), Karnofsky index <80%, impaired organ function or prior autologous/allogeneic HCT. The median age was 49 years (24–68), median diagnostic WBC 20×109/L (1.4–248) and median comorbidity index of 3 (range: 0–8) at HCT. All patients had high risk disease, including 14 patients (64%) with Ph+ ALL, 10 patients (46%) in 2nd or subsequent remission. Five patients (23%) were treated with tyrosine kinase inhibitors pre-HCT. Uniform conditioning (Cyclophosphamide 50 mg/kg; Flu 200 mg/m2; total body irradiation (TBI) 200cGy, n=21) and graft versus host disease (GvHD) prophylaxis (Cyclosporin/MMF) was followed by MRD (n=4) or UCB donor (n=18) grafts. All patients had sustained donor neutrophil engraftment (median 10 days, range 0–28) and reached 100% donor chimerism at median day 23 post-transplantation (range 14–99 days). At 3 years, treatment related morality relapse and overall survival (OS) were 27% (95% confidence interval [CI]: 9–45%), 36% (95% CI: 14–58%) and 50% (95% CI: 27–73%), respectively. There were no relapses beyond 2 years. After a median follow-up of 33 months (range 5–77) the cumulative incidence of acute II–IV, III–IV and chronic graft versus host disease were 55%, 20% and 45%. Lower TRM for HCT in CR1 vs ≥ CR2 (8% vs. 50%; p<0.04) led to improved 3 year OS in the CR1 cohort (81% vs. 15% (p<0.01)). HCT using either MRD or UCB resulted in similar risks of GVHD, relapse and OS. These data suggest that RIC allogeneic HCT using either related or UCB donors for adults with ALL can result in modest TRM, and only limited risks of relapse and promising leukemia-free survival. Further study, especially for patients in CR1, will better define the utility of this approach for patients unsuited for more intensive, myeloablative conditioning.

Allogeneic Hematopoietic Cell Transplantation following Reduced Intensity Conditioning for Treatment of Myelofibrosis

This report describes our experience with reduced intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (HCT) using matched sibling and unrelated donors (MUDs) for treatment of myelofibrosis (MF). Nine patients with MF (median age, 54 years) were treated with RIC allogeneic HCT using MUDs for 7 of the 9 patients and sibling donors for 2 patients. By the Lille classification, 4 patients were characterized as having high risk, 4 as having intermediate risk, and 1 as having low risk. The RIC regimen consisted of fludarabine and a single dose of total body irradiation for the first patient and fludarabine/melphalan for the remaining 8 patients. Granulocyte colony-stimulating factor-primed peripheral blood stem cells (PBSCs) were used for all but 1 patient who received a total of 3 products because of graft failure, of which 2 were bone marrow cells and the third was PBSCs. Prophylaxis against graft-versus-host disease consisted of cyclosporin/mycophenolate with or without methotrexate. Seven patients were successfully engrafted with white blood cells, with an absolute neutrophil count ≥500 by a median of day +15 (range, 10-21 days). At the time of final fluorescence in situ hybridization and/or short tandem repeat analysis, 8 of 9 patients were chimeric, with 96%-100% donor cells and/or DNA. Five of the 9 patients were alive at the time of final contact, with a median follow-up of 32.2 months for the living patients. Overall survival probability at 1 year was 55.6% (95% confidence interval, 31.3%-77.4%). These results suggest that RIC MUD HCT using PBSCs can be an effective treatment for older patients with MF.