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Despite low nonrelapse mortality (NRM) at day 100 after allogeneic hematopoietic cell transplantation (HCT), NRM at 1 year remains substantial. In this study, we retrospectively analyzed 199 patients who were treated on a phase II clinical trial assessing safety and efficacy of myeloablative fractionated busulfan and fludarabine conditioning regimen for hematologic malignancies. The goal of the study was to identify factors associated with NRM occurring between days 101 and 365 post-HCT and generate a hypothesis for future studies to reduce the risk of NRM at 1 year. We found that a vast majority (83%) of patients who experienced NRM between days 101 and 365 had prior grade II-IV acute graft-versus-host disease (GVHD), which was the leading cause of death either by itself (33.3%) or complicated by infections (37.5%). In multivariate analysis, grade II-IV acute GVHD (hazard ratio (HR) 2.9, 95% confidence interval (CI) 1.3–6.6, p = 0.01) was the only significant predictor of NRM between days 101 and 365. Measures to reduce the risk of acute GVHD could lower the risk of NRM at 1 year and improve overall survival.

Pretransplant conditioning with Fludarabine (Flu)-Busulfan (Bu) is safe, but clofarabine (Clo) has improved antileukemic activity. Hypothesis: Flu+Clo-Bu (FCB) yields superior progression-free survival (PFS) after allogeneic transplantation. We randomized 250 AML/MDS patients aged 3–70, Karnofsky Score ≥80, with matched donors, to FCB (n = 120) or Flu-Bu (n = 130), stratifying complete remission (CR) vs. No CR, (NCR). HCT-CI scores varied, from 0 to 10. All evaluable patients engrafted. Median follow-up was 66 months (interquartile range: 58–80). Three-year relapse incidence (RI), 25% with FCB, vs. 39% with Flu-Bu (p = 0.018), offset by higher non-relapse mortality, 22.6% (95%CI: 16–30.2%) vs. 12.3% (95%CI: 6.5–19%). Three-year PFS was 52% (95%CI: 44–62%) (FCB), vs. 48% (95%CI: 41–58%) (Flu-Bu). FCB benefited CR patients less, NCR patients age ≤ 60 had 3-year 34% RI (95%CI: 19–49%) (FCB) vs. 56% (95%CI: 38–70%) after Flu-Bu (p = 0.037). NCR patients >60 years had 3-year RI 10.0% (FCB), vs. 56.0%, after Flu-Bu (p = 0.003). Bayesian regression analysis including treatment-covariate interactions showed FCB superiority in NCR patients with low HCT-CI (0–2). Serious adverse event profiles were similar for the regimens. Conditioning with FCB did not improve PFS overall, but improved disease control in NCR patients, mandating confirmatory trials. Remission status and HCT-CI should be considered when using FCB.

Busulfan is used in myeloablative schemes for hematopoietic stem cell transplantation (HSCT), with monitoring of dosage through the area under the curve (AUC) of the drug plasma concentration (µMol min). In this study, we compared the complete pharmacokinetics of busulfan administered orally (Bu-Oral) and intravenously (Bu-IV). We evaluated 40 patients who underwent HSCT with different types of conditioning regimens. After one dose, in the Bu-Oral group (n = 21), the median AUC was 1174 µMol min (799-4000), reaching a median of 4440 µMol min (3428-7181.5) during conditioning in 24 h. In the Bu-IV group (n = 19), it was 1244.8 µMol min (1001.2-2021), reaching 5598.0 µMol min (3102-8818) during conditioning in 24 h. Measuring plasma concentration of Bu in patients undergoing HSCT is important, regardless of the formulation, and the inclusion of a pre-HSCT test can predict the optimal dose during conditioning. Pharmacokinetics of the oral administration of busulfan, as well as clearance, are extremely variable, and this can potentially compromise the clinical results of the treatment since it makes it difficult to predict clinical results.

Despite low nonrelapse mortality (NRM) at day 100 after allogeneic hematopoietic cell transplantation (HCT), NRM at 1 year remains substantial. In this study, we retrospectively analyzed 199 patients who were treated on a phase II clinical trial assessing safety and efficacy of myeloablative fractionated busulfan and fludarabine conditioning regimen for hematologic malignancies. The goal of the study was to identify factors associated with NRM occurring between days 101 and 365 post-HCT and generate a hypothesis for future studies to reduce the risk of NRM at 1 year. We found that a vast majority (83%) of patients who experienced NRM between days 101 and 365 had prior grade II-IV acute graft-versus-host disease (GVHD), which was the leading cause of death either by itself (33.3%) or complicated by infections (37.5%). In multivariate analysis, grade II-IV acute GVHD (hazard ratio (HR) 2.9, 95% confidence interval (CI) 1.3-6.6, p = 0.01) was the only significant predictor of NRM between days 101 and 365. Measures to reduce the risk of acute GVHD could lower the risk of NRM at 1 year and improve overall survival.

Relapse is the major cause of mortality in patients with acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Effective preventive intervention in high-risk AML may be crucial. In this study, we investigated the clinical efficacy and safety of low dose decitabine (DAC) as part of a modified Busulfan-Cyclophosphamide (Bu-Cy) regimen for high-risk AML patients undergoing allo-HSCT to reduce relapse rate. Fifty-nine patients received DAC (20 mg/m2/d, i.v.) for 5 days, followed by modified Bu-Cy (DAC group). A matched-pair control (CON) group of 177 patients (matched 1:3) received modified Bu-Cy only. The differences were more substantial among patients with active disease: 2-year OS, 80.7% (DAC) versus 43.5% (CON), P = 0.011 and 2-year LFS, 64.9% (DAC) versus 39.2% (CON), P = 0.024. Median time to relapse was 8 months (DAC) versus 5 months (CON) for the entire groups and 6.5 months (DAC) versus 3.5 months (CON) for patients with active disease. In summary, our data indicated that the conditioning regimen containing low dose DAC may confer a survival advantage in high-risk AML patients with active disease undergoing allo-HSCT, and a prospective randomized trial is warranted to confirm these observations.

Outcomes after allogeneic stem-cell transplantation (AHSCT) are influenced by both disease- and patient-related factors. Here, we developed a novel prognostic model, hematopoietic cell transplant-composite risk (HCT-CR), by combining the refined disease risk index (DRI-R) and hematopoietic stem-cell transplant comorbidity/age index (HCT-CI/Age) to predict post-transplant survival for patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). The analysis included 942 AML/MDS patients treated with AHSCT. Patients were stratified into 4 HCT-CR risk groups: Low-risk—patients with low/intermediate DRI-R and HCT-CI/Age ≤3 (N = 272); Intermediate-risk—patients with low/intermediate DRI-R and HCT-CI/Age >3 (N = 168); High-risk—patients with high/very high DRI-R and HCT-CI/Age ≤3 (N = 284); and Very high-risk—patients with high/very high DRI-R and HCT-CI/Age >3 (N = 184). Compared with the low-risk group, intermediate, high, and very high-risk groups had a significantly increased risk of death [adjusted HR of 1.37 (P

We hypothesized that IV Busulfan (Bu) dosing could be safely intensified through pharmacokinetic (PK-) dose guidance to minimize the inter-patient variability in systemic exposure (SE) associated with body-sized dosing, and this should improve outcome of AML/MDS patients undergoing allogeneic stem cell transplantation (allo-HSCT). To test this hypothesis, we treated 218 patients (median age 50.7 years, male/female 50/50%) with fludarabine (Flu) 40 mg/m2 once daily ×4, each dose followed by IV Bu, randomized to 130 mg/m2 (N=107) or PK-guided to average daily SE, AUC of 6,000 µM-min (N=111), stratified for remission-status, and allo-grafting from HLA-matched donors. Toxicity and graft vs. host disease (GvHD) rates in the groups were similar; the risk of relapse or treatment-related mortality remained higher in the fixed-dose group throughout the 80-month observation period. Further, PK-guidance yielded safer disease-control, leading to improved overall and progression-free survival, most prominently in MDS-patients and in AML-patients not in remission at allo-HSCT. We conclude that AML/MDS patients receiving pretransplant conditioning treatment with our 4-day regimen may benefit significantly from PK-guided Bu-dosing. This could be considered an alternative to fixed dose delivery since it provides the benefit of precise dose delivery to a predetermined SE without increasing risk(s) of serious toxicity and/or GvHD.

Thalassemia free survival after allogeneic stem cell transplantation (SCT) is about 80–90% with either matched related or unrelated donors. However, the probability of finding a HLA-compatible donor is less than 50%. We explored the use of a mismatched related (“Haplo-”) donor. All patients received two courses of pre-transplant immunosuppression therapy (PTIS) with fludarabine (Flu) and dexamethasone (Dxm) to facilitate engraftment. After two courses of PTIS, a reduced-toxicity conditioning regimen of rabbit anti-thymocyte globulin (ATG), Flu, and IV Busulfan (Bu) was given followed by T-cell replete peripheral blood progenitor cells (PBPC). GVHD prophylaxis consisted of cyclophosphamide (Cy) on days SCT +3 and +4 (Post-Cy), and on day SCT +5 tacrolimus or sirolimus was started together with a short course of mycophenolate mofetil. Thirty-one patients underwent haplo-SCT. Their median age was ten years (range, 2 to 20 years). Twenty-nine patients engrafted with 100% donor chimerism. Two of three patients with high titers of donor-specific anti-HLA antibodies suffered primary graft failure. Median time to neutrophil engraftment was 14 days (range, 11 to 18 days). Five patients developed mild to moderate, reversible veno-occlusive disease, while nine patients developed acute GVHD grade II, that quickly responded to steroid therapy. Only five patients developed limited chronic GVHD. Projected overall and event-free survival rates at two years are 95% and 94%, respectively. The median follow up time is 12 months (range; 7 to 33 months). This haplo-SCT protocol may yield excellent outcomes for thalassemia patients, and provide a treatment option for patients lacking a HLA-matched donor.

Conditioning regimens contribute significantly to outcomes following allogeneic stem cell transplantation (allo-SCT). Reduced-intensity conditioning (RIC) regimens provide lower toxicity at the cost of reduced efficacy compared with myeloablative conditioning (MAC) regimens. However, because pre-transplant prognostic variables often determine the conditioning regimen, studies of RIC vs. MAC have been inconclusive. We present a retrospective analysis of 242 acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) patients, 112 of whom were in 56 pairs matched using propensity scores, to account for variation that may confound clinical outcomes. The uniform conditioning regimens consisted of fludarabine with pharmacokinetic (PK)-guided intravenous busulfan (Bu). The RIC and MAC regimens were dosed at the average daily area under the concentration-vs-time curve (AUC) of 4000 µMol min and 5000–6000 µMol min, or total course AUC of 16,000 µMol min and 20,000–24,000 µMol min, respectively; PK-guided dosing removes overlap in systemic Bu exposure. When patients’ data were propensity-matched, there was a trend toward significantly increased full donor chimerism and decreased chronic graft vs. host disease in RIC, and no significant differences in progression free survival and overall survival between RIC and MAC. Our results also elucidate the efficacy of PK-guided-dosing in the setting of allo-SCT for AML and MDS.

Pretransplant conditioning with fludarabine and IV busulfan, reduced toxicity and increased safety without compromising antitumor efficacy and overall treatment effect?

We investigated the administration of intravenous (i.v.) busulfan (Bu) combined with melphalan (Mel) in patients with acute lymphoblastic leukemia (ALL) undergoing allogeneic hematopoietic stem cell transplantation (SCT). Forty-seven patients with median age 33 years (range 20–61) received a matched sibling (n=27) or matched unrelated donor transplant (n=20) for ALL in first complete remission (n=26), second complete remission (n=13), or with more advanced disease (n=8). Bu was infused daily for 4 days, either at fixed dose 130 mg/m2 (5 patients) or using pharmacokinetic dose adjustment (42 patients), to target an average daily AUC of 5,000 uMol-min, determined by a test dose of i.v. Bu at 32 mg/m2. This was followed by a rest day, then two daily doses of Mel at 70 mg/m2. Stem cells were infused on the following day. The 2-year overall survival (OS), progression-free survival (PFS), and non-relapse mortality (NRM) rates were 35% (95% confidence interval [CI] 23%–51%), 31% (95% CI 21%–48%), and 37% (95% CI 23%–50%), respectively. Acute non-relapse mortality (NRM) at 100 days was favorable at 12% (95%CI 5%–24%); however, the 2-year NRM was significantly higher for patients older than 40 years, 58% vs. 20%, mainly due to graft versus host disease.

The copper chelator tetraethylenepentamine (TEPA; StemEx) was shown to attenuate the differentiation of ex vivo cultured hematopoietic cells resulting in preferential expansion of early progenitors. A phase I/II trial was performed to test the feasibility and safety of transplantation of CD133+ cord blood (CB) hematopoietic progenitors cultured in media containing stem cell factor, FLT-3 ligand, interleukin-6, thrombopoietin and TEPA. Ten patients with advanced hematological malignancies were transplanted with a CB unit originally frozen in two fractions. The smaller fraction was cultured ex vivo for 21 days and transplanted 24 h after infusion of the larger unmanipulated fraction. All but two units contained2 x 10(7) total nucleated cells (TNCs) per kilogram pre-expansion. All donor-recipient pairs were mismatched for one or two HLA loci. Nine patients were beyond first remission; median age and weight were 21 years and 68.5 kg. The average TNCs fold expansion was 219 (range, 2-620). Mean increase of CD34+ cell count was 6 (over the CD34+ cell content in the entire unit). Despite the low TNCs per kilogram infused (median=1.8 x 10(7)/kg), nine patients engrafted. Median time to neutrophil and platelet engraftment was 30 (range, 16-46) and 48 (range, 35-105) days. There were no cases of grades 3-4 acute graft-versus-host disease (GVHD) and 100-day survival was 90%. This strategy is feasible.

Nine patients with advanced Hodgkin's lymphoma (HL) who had undergone allogeneic stem cell transplantation (allo-SCT) received donor leukocyte infusions (DLIs) for treatment of persistent or progressive disease (PD). A total of 15 DLIs were performed, with four patients receiving more than one DLI. In four patients, prior salvage chemotherapy was administered. The median CD3+ cell dose administered was 77.5 x 10(6)/kg (range 5-285). GVHD developed in all but one patient. The response rate was 4/9 (44%). Three of these four responders developed GVHD and 3/4 had received chemotherapy. No correlation was observed between CD3+ cell dose infused and disease response. At the latest follow-up, three patients are alive and six have expired (PD n=3, nonrelapse mortality n=3). The median response duration was 7 months (range 4-9), with one response currently ongoing. These data suggest that DLIs for immunotherapy of recurrent HL have significant activity, although they frequently leads to GVHD. The small sample size does not allow any conclusion as to whether chemotherapy administration increases the chance of response. The CD3 cell dose infused does not seem to correlate with disease response.

Our purpose was to study the risk factors associated with disease progression after high-dose chemotherapy followed by autologous stem cell transplantation in patients with recurrent or refractory Hodgkin's lymphoma (HL). We analyzed the long-term outcome of 184 patients with recurrent or refractory HL who underwent autologous hematopoietic stem cell transplantation. At the time of transplantation, 82 patients were in first relapse or second remission, 46 patients were refractory to the primary induction chemotherapy, and 56 patients were beyond first relapse or second remission. In 64 patients, the disease had proved refractory to the chemotherapy regimen administered immediately prior to transplantation. The median follow-up of patients who were alive and free of disease at the time of this report was 8.9 years (range, 0.1-19.0 years). At 10 years, the overall and disease-free survival rates were 34% (95% CI 27-42) and 29% (95% CI 22-36) respectively. The major cause of treatment failure was disease relapse. Chemotherapy resistance prior to transplantation, advanced stage, and higher number of chemotherapy regimens administered prior to transplantation were adverse prognostic factors for disease progression. We conclude that autologous transplantation is an effective salvage treatment for recurrent HL.

Relapse after allogeneic progenitor cell transplant is associated with a poor prognosis for patients with advanced leukemia, with few curative options available. Use of novel chemotherapeutic agents with limited toxicity is warranted. We investigated the role of decitabine, a pyrimidine analogue with significant anti-leukemic effect and limited toxicity, in this setting. Fourteen patients with advanced acute leukemia or transformed chronic myelogenous leukemia (CML) who had failed previous allogeneic transplant were treated. Decitabine at doses of 100 mg/m2 to 150 mg/m2 given every 12 h for 5 days was followed by infusion of stem cells from the original donor 2 to 5 days after the completion of chemotherapy. Dose of decitabine was escalated in cohorts of three patients based on the modified Fibonacci scheme. The primary study end-point was assessment of the toxicity of the regimen with secondary endpoints of response and survival. Eight patients responded with either a complete remission or partial hematological remission (absence of blasts in peripheral blood and bone marrow but with platelet count

The study was designed to evaluate the efficacy and safety of an intensive, tri-alkylator conditioning regimen, consisting of thiotepa, busulfan and cyclophosphamide (TBC), prior to autologous hematopoietic cell transplantation in patients with multiple myeloma (MM) and to analyze factors associated with outcome. One hundred and twenty patients with MM received high-dose chemotherapy with TBC followed by autologous bone marrow (n = 24) or peripheral blood stem cell (PBSC) transplantation (n = 96). Fifty-four patients had chemosensitive disease and 66 had refractory disease at the time of transplantation. The overall response rate was 81% and the complete remission (CR) rate was 26%. Patients with chemosensitive disease had a CR rate of 52% vs 5% for patients with refractory disease. Multivariable analysis determined disease status at transplant as the factor most likely associated with long survival. Estimated median survival was 48, 35 and 9 months for patients with chemosensitive, primary refractory or disease in refractory relapse, respectively. Short interval from diagnosis to transplant among patients with primary refractory disease and younger age were also favorable prognostic factors for survival. Patients with refractory disease pre-transplant who achieved remission criteria rapidly after treatment had a worse outcome than the slow responders. Treatment-related mortality with the introduction of PBSC and better supportive care was 4.8%. In conclusion, TBC is an effective and relatively well-tolerated intensive conditioning regimen in patients with MM. A more favorable outcome was observed in patients with chemosensitive disease and with early treatment for primary refractory disease. TBC merits further study in these subgroups and comparison with alternative regimens in prospective studies is warranted.

Thirty-six adults with chronic myelogenous leukemia (CML) in second or greater chronic phase, accelerated phase, or blast crisis underwent marrow or blood stem cell transplantation from an HLA-matched sibling using high-dose thiotepa, busulfan and cyclophosphamide (TBC) as the preparative regimen. All evaluable patients engrafted and had complete donor chimerism. One patient failed to clear meningeal leukemia, and one patient had one of 30 metaphases positive for the Philadelphia chromosome at 2 months post transplant. The remainder of the patients studied had eradication of CML documented by cytogenetics and/or Southern blot for BCR gene rearrangement, and 13 of 15 patients studied became negative for the BCR gene rearrangement by polymerase chain reaction. Three-year relapse rate is 42% (95% CI, 19-64%). The relapse rate was significantly lower for patients transplanted without blast crisis (9% vs 100%, P < 0.001). Eight (22%, 95% CI, 10-39%) patients had severe or fatal veno-occlusive disease (VOD). Elevated liver enzymes within 1 month prior to transplantation and transplantation using marrow were significantly associated with the occurrence of VOD. Three-year survival is 28% (95% CI, 13-43%). Survival was significantly higher for patients transplanted without blast crisis (45% vs 0%, P = 0.01). TBC is an effective preparative regimen for CML in accelerated phase but not refractory blast crisis, and it should be used with caution in patients with prior hepatopathy who have an increased risk of severe VOD.

Cytomegalovirus (CMV) disease can be prevented by administration of ganciclovir prophylactically post-transplant. However, up to 30% of patients discontinue use of ganciclovir as a result of profound neutropenia and may subsequently develop CMV infections while unprotected. To prevent reactivation of CMV, we administered foscarnet to 39 adults unable to receive ganciclovir due to delayed engraftment or ganciclovir-induced neutropenia. Twenty-four (62%) of the patients had received T cell-depleted marrow transplants. Foscarnet sodium 60 mg/kg i.v. daily was continued until the neutropenia resolved, at which time ganciclovir was resumed. CMV prophylaxis commenced at a median of 28 days following transplantation. Median time to initiation of foscarnet was day 60 post-transplant, and the median duration of treatment was 22 days. Foscarnet was well-tolerated. Six (15%) patients had CMV detected while receiving prophylaxis, and CMV-related mortality was 5%. Foscarnet is a safe and effective agent for prevention of CMV disease in allogeneic transplant recipients unable to receive ganciclovir.

Allogeneic bone marrow transplantation for advanced hematologic cancer is associated with a high risk of early treatment-related morbidity and mortality. To determine the short-term benefits of allogeneic blood stem cell transplants when compared to bone marrow transplants, we reviewed outcomes of 74 adults with advanced hematologic cancer transplanted from HLA-matched related donors after conditioning with thiotepa, busulfan and cyclophosphamide. There were three cohorts: group 1 received bone marrow transplants with cyclosporine (CsA) and methotrexate (MTX) for GVHD prophylaxis; group 2 received bone marrow transplants with CsA and methylprednisolone (MP); and group 3 received blood stem cells with CsA and MP. All patients received filgrastim post-transplant. Median times (range) to neutrophilsor = 0.5 x 10(9)/l were 17 (8-30), 9 (8-16) and 10 (8-13) days post-transplant, and to plateletsor = 20 x 10(9)/l were 28 (14-100+), 19 (13-100+) and 14 (9-86) days post-transplant for groups 1, 2 and 3, respectively (P0.05 only for group 1 vs group 3 for both outcomes). Blood stem cell recipients had the least regimen-related toxicity, fewest early deaths and earliest discharge. There was no significant difference in acute GVHD between the three groups. One hundred and eighty-day survivals (95% CI) were 53% (35-72%), 32% (10-53%), and 68% (49-87%) for groups 1, 2 and 3, respectively (P0.05 only for group 2 vs group 3). For allogeneic transplantation, use of blood stem cell grafts has substantial advantages over marrow grafts.

Pulmonary infiltrates frequently complicate hematopoietic SCT (HSCT). The utility of fiberoptic bronchoscopy (FOB) with bronchoalveolar lavage (BAL) in the evaluation of new pulmonary infiltrates, particularly as it relates to optimal timing of the procedure, is unclear. Based on this, we retrospectively reviewed 501 consecutive, adult, nonintubated patients who underwent 598 BALs for evaluation of new pulmonary infiltrates during the first 100 days following HSCT to determine whether diagnostic yields for infection, subsequent antimicrobial treatment modifications and patient outcomes differed following early vs late referrals for the procedure. The overall yield of BAL for clinically significant pathogens was 55%. Notably, the yield was 2.5-fold higher among FOBs performed within the first 4 days of presentation (early FOB) compared to those performed late, and highest (75%) when performed within 24 h of clinical presentation. Rates of FOB-guided adjustments in antimicrobial therapy (51%) did not differ significantly between early and late examinations. However, late FOB-related antibiotic adjustments were associated with 30-day pulmonary-associated deaths that were threefold higher (6 vs 18%, P=0.0351). Major FOB-related complications occurred in only three (0.6%) patients. We conclude that early referral for FOB in this patient setting is associated with higher diagnostic yields and may favorably impact survival.

Allogeneic hematopoietic progenitor cell transplantation (HPCT) remains an established curative approach for selected patients with chronic myelogenous leukemia (CML). Patients for whom an allogeneic donor cannot be found or who are unable to tolerate allotransplantation require post-Gleevec alternatives. Autologous HPCT causes less morbidity/mortality than allotransplantation but CML cells in the autograft pose a potential risk for post-transplant relapse. An effective purging method for eliminating leukemic cells without compromising normal reconstituting activity would make autotransplantation a more attractive strategy for selected CML patients. In previous studies, we and others have shown that primitive CML cells are selectively killed after brief treatments in vitro with Mafosfamide (Maf) or Gleevec. Additionally, cultured primitive CML cells differentiate much more rapidly than their normal counterparts resulting in a selective depletion of CML stem cells after 1–2 weeks. Here we report the development of a novel autograft purging strategy that combines the use of a brief exposure of CML cells to Gleevec plus Maf followed by extended culture without cytotoxic agents but with added recombinant cytokines that favor the maintenance of normal stem cells. Methods: CD34+ cells were isolated from the peripheral blood progenitor cell (PBPC) products of CML patients and normal donors, treated for 72 hrs with graded concentrations of Gleevec (0.5–1.0 uM) followed by 0, 30, 60 or 90 ug/ml of Maf for 30 min. Cells were then washed and cultured for 14 days in medium containing 10% FBS and 100 ng/ml each of stem cell factor (SCF), granulocyte colony-stimulating factor (G-CSF) and thrombopoietin (TPO). Following treatment, cells from each group were evaluated for total viable cells, BCR-ABL message by real time polymerase chain reaction (RT-PCR) assays and colony-forming unit-granulocyte macrophage (CFU-GM) content in methylcellulose assays. Results: BCR-ABL+ cells were eliminated in the CML PBPC products from patients in chronic phase (n=3), but not blast crisis (n=1) when treated with Gleevec (0.75 uM) and Maf (60 ug/ml) followed by 2 weeks in vitro with SCF+G-CSF+TPO. Residual Ph positive cells by RT PCR Patient/Disease stage Culture alone Drugs alone (Gleevec 0.75 or 1uM + Maf 60ug/ml) Culture + Drugs 1-chronic phase/Gleevec refractory Positive Positive Negative 2-chronic phase/Gleevec refractory Positive Positive Negative 3-chronic phase/Gleevec naïve Positive Negative Negative 4-blastic phase/Gleevec naïve Positive Positive Positive Treatment of CD34+ PBPCs from normal donors with 0.75 uM Gleevec + 60 ug/ml Maf reduced CFU-GMs to 15% of input controls immediately post drug-exposure but these recovered to 320% of input after the additional 2 weeks in culture. Conclusion: Triple purging of CML cells with Gleevec, Maf and 2 weeks of culture appears to eradicate chronic phase BCR-ABL+ cells while retaining most of the normal progenitor activity as assessed by in vitro clonogenic assays. This approach may be useful as a strategy for purging CML autografts for Gleevec-refractory patients and, pending confirmatory results from in vivo xenograft assays, will be tested in a clinical autotransplant trial.

The major cause of failure after allogeneic hematopoietic stem cell transplantation (HSCT) for acute myelogenous leukemia (AML) is disease relapse or progression. We analyzed the outcome of second HSCT for treatment of patients with relapsed, refractory AML/myelodysplastic syndrome (MDS) at our institution. A total of 72 patients were eligible for this analysis. In all, 25 (35%) patients received salvage chemotherapy prior to the second transplant procedure and only two (3%) patients were in complete remission at the time of the second transplant. A total of 20 patients (28%) had low leukemia burden as measured by the absence of peripheral blood blasts andor=5% blasts in the bone marrow at the time of the second transplant. Although, the overall median survival after the second transplant was 6 months, a subset of patients who had low leukemia burden at the time of the second transplant had a 5-year survival of 25 vs 12% in those with a high leukemia burden. Thus, a second transplant may offer the possibility of long-term disease control in a subset of patients who have a 'low bulk' disease at the time of transplantation.

A total of 40 patients with relapsed/refractory Hodgkin's disease (HD) underwent reduced-intensity conditioning (RIC) allogeneic stem cell transplantation (allo-SCT) from an HLA-identical sibling (n=20) or a matched unrelated donor (n=20). The median age was 31 years (range 18-58). Disease status at allo-SCT was refractory relapse (n=14) or sensitive relapse (n=26). The conditioning regimens were fludarabine-cyclophosphamide+/-antithymocyte globulin (n=14), a less intensive regimen, and fludarabine-melphalan (FM) (n=26), a more intensive one. The two groups had similar prognostic factors. The median time to neutrophil recovery (ie absolute neutrophil count/=500/microl) was 12 days (range 10-24). The median time to platelet recovery (ie platelet count/=20 000/microl) was 17 days (range 7-132). Day 100 and cumulative (18-month) transplant-related mortalities (TRMs) were 5 and 22%. Twenty-four patients (60%) are alive (14 in complete remission or complete remission, unconfirmed/uncertain) with a median follow-up of 13 months (4-78). In all, 16 patients expired (TRM n=8, disease progression n=8). FM patients had better overall survival (73 vs 39% at 18 months; P=0.03), and a trend towards better progression-free survival (37 vs 21% at 18 months; P=0.2). RIC allo-SCT is feasible in relapsed/refractory HD patients with a low TRM. The intensity of the preparative regimen affects survival.

We evaluated the 100-day mortality rates associated with busulfan-based myeloablative conditioning regimens based on data from 1812 chronic myelogenous leukemia patients who underwent allogeneic blood or marrow transplantation (allotx). In all, 47 patients received intravenous (i.v.) busulfan and cyclophosphamide (i.v.BuCy2) with allotx at MD Anderson Cancer Center (MDACC) during 1995-1999. The remaining 1765 patients, whose data were supplied by the International Bone Marrow Transplant Registry (IBMTR), received alternative preparative regimens, primarily Cy-total body irradiation ( approximately 45%) or oral BuCy ( approximately 35%) during 1997-1998. As patients were not randomized between conditioning regimens, the i.v.BuCy2-versus-alternative treatment effect is confounded with a possible center effect due to nontreatment differences associated with factors differing between MDACC and the IBMTR centers. Additional complications are that the i.v.BuCy2-MDACC patients all survived 100 days, and three prognostic subgroups were included. Bayesian sensitivity analyses were performed to assess treatment effect on the probability of 100-day mortality, over a range of possible MDACC-versus-IBMTR center effects. For these patients, the posterior probability that i.v.BuCy2 was superior to alternative conditioning regimens ranges from 0.54 to 0.99, depending on prognosis and the magnitude of the assumed center effect.

Six patients with advanced Hodgkin's disease in which multiple conventional treatments (median prior chemotherapy regimens: seven), radiation therapy, and a prior autologous stem cell transplantation (SCT) had failed underwent allogeneic SCT following a fludarabine-based conditioning regimen. Median age was 29 years (22–30). Median time to progression after autologous SCT was 6 months (4–21). Disease status at transplant was refractory relapse (n = 3) and sensitive relapse (n = 3). Cell source was filgrastim-mobilized peripheral blood stem cells from an HLA-identical sibling (n = 4) or matched unrelated donor marrow (n = 2). Conditioning regimens were fludarabine–cyclophosphamide–antithymocyte globulin (n = 4), fludarabine–melphalan (n = 1) and fludarabine–cytarabine–idarubicin (n = 1). Myeloid recovery was prompt, with an absolute neutrophil count ⩾500/μl on day 12 (11–15). Median platelet recovery to ⩾20000/μl was on day 9 (0–60). Chimerism studies on day 30 indicated 100% donor-derived hematopoiesis in 4/5 evaluable patients (4/4 non-progressors). All responders (3/3) have ongoing 100% donor-derived chimerism. Acute graft-versus-host disease (GVHD) was diagnosed in 4/6 evaluable patients. Chronic GVHD was present in 2/4 evaluable patients. There were no regimen-related deaths. Overall day 100 transplant-related mortality was 2/6 (33%). Three patients have expired and three are alive and progression-free with a median follow-up of 9 months (6–26) post transplant. We conclude that allogeneic stem cell transplantation with fludarabine-based preparative regimens is feasible in these high-risk, heavily pretreated HD patients. Bone Marrow Transplantation (2000) 26, 615–620.

Patients with acute leukemias relapsing within 1 year of an allogeneic BMT have a poor prognosis. We studied the use of melphalan 180 mg/m2 followed by allogeneic peripheral blood stem cells (PBSC) as salvage treatment for patients relapsing after related (n = 7) or matched unrelated transplants (n = 3). Diagnoses were AML (n = 4), ALL (n = 3), biphenotypic acute leukemia (n = 2) and CML in blast crisis (n = 1). Eight patients were beyond first relapse and none were in remission. The median time from previous transplant to relapse was 146 days (range 66–206). The melphalan dose was 90 mg/m2 intravenously on days −4 and −3 with pbsc infusion on day 0. gvhd prophylaxis consisted of cyclosporine and methylprednisolone. the median time to an absolute neutrophil count >0.5 × 109/l and to a platelet count >20 × 109/l was 11 and 13 days, respectively. All engrafting patients (n = 8) had 100% donor cells. Two patients died before day 30, but no other grade 3 or 4 toxicity occurred. Acute GVHD grades II–III occurred in two subjects, and chronic GVHD in four. Seven patients achieved CR, but relapsed at a median of 116 days (range 56–614). Leukemia was the cause of death in eight patients. Median survival was 149 days (range 6–614). This treatment produced responses in the majority of this poor prognosis group. However, durable remissions were not observed, and new treatments to consolidate the responses achieved in this setting are needed. This regimen could be considered for short-term disease control to facilitate donor lymphocyte infusion-based immunotherapy or other measures to prevent disease recurrence. Bone Marrow Transplantation (2000) 26, 333–338.

Thirty adults with leukemia or lymphoma transplanted with marrow or blood stem cells from 1-antigen mismatched related donors received tacrolimus and minidose methotrexate to prevent acute graft-versus-host disease (GVHD). The group had a median age of 42 years (range 18-56 years). Twenty-seven patients had advanced disease, and 13 were resistant to conventional therapy. Tacrolimus was administered at 0.03 mg/kg/day i.v. by continuous infusion from day -2, converted to oral at four times the i.v. dose following engraftment, and continued to day 180 post-transplant. Methotrexate 5 mg/m2 was given i.v. on days 1, 3, 6 and 11. Mild nephrotoxicity was common before day 100; 69% of patients had a doubling of creatinine, 56% had a peak creatinine greater than 2 mg/dl, and two patients were dialyzed. Other toxicities prior to day 100 thought to be related to tacrolimus included hypertension (45%), hyperkalemia (17%), hyperglycemia (14%), seizures (13%), headache (3%) and hemolytic uremic syndrome (3%). Grades 2-4 GVHD occurred in 59% (95% CI, 38-70%), and grades 3-4 GVHD in 17% (95% CI, 1-32%). Overall survival at 1 year was 29% (95% CI, 12-45%). We conclude that tacrolimus and minidose methotrexate is active post-transplant immunosuppression for patients with 1-antigen mismatched donors.

Donor lymphocyte infusions, by virtue of a graft-versus-tumor effect, have been shown to induce remissions in leukemia that recurs after allogeneic bone marrow transplantation. Similar effects have been postulated to contribute to the decreased recurrence rate observed after allogeneic transplantation in non-Hodgkin's lymphoma. This lower recurrence rate may be due to a variety of other mechanisms. We aimed to evaluate the role of graft-versus-lymphoma effects in patients in whom lymphomas recur after allogeneic transplantation. At the time of recurrence, immunosuppressive therapy was withheld. Patients with non-responding disease received an infusion of donor lymphocytes. Patients were observed for response and graft-versus-host disease. Disease in four of nine patients responded to withdrawal of immunosuppressive therapy. A minor response was observed in one of three recipients of donor lymphocyte infusions. Responses were observed among two patients with follicular lymphoma, one with large cell lymphoma and one with lymphoblastic lymphoma. A minor response was observed in a patient with prolymphocytic leukemia/lymphoma. We conclude that withdrawal of immunosuppressive therapy and donor lymphocyte infusion can induce durable remissions in patients with recurrent lymphoma after allogeneic transplantation.

We evaluated the response to and toxicity of allogeneic or autologous bone marrow transplantation (BMT) for patients with non-Hodgkin's lymphoma (NHL) who relapsed after autologous BMT. Since 1990, 172 patients have received autologous BMTs in NHL at the MD Anderson Cancer Center and 75 have relapsed. Twelve patients (median age, 42 years), with disease recurrence underwent either allogeneic BMT (eight patients) or a second autologous BMT (four patients). Ten patients received thiotepa, busulfan and cyclophosphamide as conditioning, one patient received cyclophosphamide and total body irradiation and one received BCNU, etoposide, Ara-c and melphalan. The median interval between the first and second transplants was 23.5 months (range 5-80 months). Three patients who underwent allogeneic BMT had refractory relapses, three had a responsive relapse and two were in complete response (CR) at the time of BMT. Five patients received peripheral blood stem cells and three patients, allogeneic bone marrow. Three patients are alive and disease-free at 25, 22 and 7 months after allogeneic BMT. Four patients died of treatment-related causes and one from disease recurrence. All four patients undergoing autologous BMT had responsive relapses. Three patients received peripheral blood stem cells and one patient bone marrow. Two patients are alive and disease-free at 12 and 30 months after autologous transplants. There were no treatment-related deaths; two patients died of disease recurrence. This retrospective study shows that in selected patients, allogeneic or autologous BMT is an effective salvage therapy for NHL which recurs after autologous BMT.