Second allogeneic haematopoietic stem cell transplantation in relapsed acute and chronic leukaemias for patients who underwent a first allogeneic bone marrow transplantation: a survey of the Société Française de Greffe de moelle (SFGM)

Although recurrent malignancy is the most frequent indication for second stem cell transplantation (2nd SCT), there are few reports that include sufficiently large numbers of patients to enable prognostic factor analysis. This retrospective study includes 150 patients who underwent a 2nd SCT for relapsed acute myeloblastic leukaemia (n = 61), acute lymphoblastic leukaemia (n = 47) or chronic myeloid leukaemia (n = 42) after a first allogeneic transplant (including 26 T-cell-depleted). The median interval between the first transplant and relapse, and between relapse and second transplant was 17 months and 5 months respectively. After the 2nd SCT, engraftment occurred in 93% of cases, 32% of patients developed acute graft-vs.-host disease (GVHD) >/= grade II and 38% chronic GVHD. The 5-year overall and disease-free survival were 32 +/- 8% and 30 +/- 8%, respectively, with a risk of relapse of 44 +/- 12% and a transplant-related mortality of 45 +/- 9%. In a multivariate analysis, five factors were associated with a better outcome after 2nd SCT: age < 16 years at second transplant; relapse occurring more than 12 months after the first transplant; transplantation from a female donor; absence of acute GVHD; and the occurrence of chronic GVHD. The best candidates for a second transplant are likely to be patients with acute leukaemia in remission before transplant, in whom the HLA-identical donor was female and who relapsed more than 1 year after the first transplant.     

Hematopoietic stem cell transplantation with busulfanthiotepa-cyclophosphamide conditioning for pediatric patients with high-risk acute lymphoblastic leukemia]

Twelve children with high-risk acute lymphoblastic leukemia underwent stem cell transplantation (SCT) with a conditioning regimen consisting of busulfan, cyclophosphamide and thiotepa. Eight of them underwent SCT while in complete remission (CR) and the other 4 while not in CR. Three children underwent HLA-matched related bone marrow transplantation (BMT), 7 HLA-matched unrelated BMT, 1 HLA one-locus-mismatched unrelated cord blood cell transplantation, and 1 autologous peripheral blood stem cell transplantation. Grade II-IV acute GVHD was observed in 3 of the 11 allo-SCT cases, while chronic GVHD was seen in 3 of 9 evaluable cases. None of the 12 cases showed thrombotic microangiopathy, and veno-occlusive disease (VOD) was observed in 3. Nine of the patients are alive and disease-free 6-45 months after diagnosis. The event-free survival rate at 3 years was 72.2% for the 12 patients, including 8 of the 9 who received SCT during CR, and 2 of the 4 who did so while not in CR. The other 3 patients died: 2 of disease progression and 1 of VOD with pneumonia. All of those who died had undergone unrelated BMT.     

Factors affecting the outcome of allogeneic bone marrow transplantation for adult patients with refractory or relapsed acute leukaemia

We evaluated the outcome of allogeneic bone marrow transplantation (BMT) for advanced acute myeloid leukaemia (AML) and acute lymphoblastic leukaemia (ALL) in 383 adult patients in nine Australian adult BMT centres between 1981 and 1997. The median overall survival for the group was 4.8 months, with an estimated 5-year survival of 18%. 28% of patients died of transplant-related toxicities within the first 100 d. Progressive disease was responsible for 48% of deaths. Multi-factor analysis demonstrated that AML (v ALL), disease status (second complete remission [CR2] v others), age (< 40 years) and duration of prior first complete remission (CR1) (> 6 months) were pre-transplant variables significantly associated with improved survival. Acute graft-versus-host disease (GVHD) of any grade reduced the rate of relapse in both AML and ALL, but only grades I-II were associated with improved survival. Both limited and extensive chronic GVHD were associated with increased survival. Only patients with AML in untreated first relapse or CR2, with a duration of CR1 > 6 months, or patients with T ALL, had a 5-year survival > 20%. Transplants for AML in induction failure or pre-B ALL in untreated first relapse or CR2 had an intermediate outcome, with 5-year survival of 10-20%. A 5-year survival of < 10% was observed for patients transplanted for ALL in induction failure or for pre-B ALL or AML in refractory first relapse or beyond CR2. These results suggest that for most adult patients with advanced acute leukaemia an allograft offers only a small chance of cure.     

Single center experience with total body irradiation and melphalan (TBI-MEL) myeloablative conditioning regimen for allogeneic stem cell transplantation (SCT) in patients with refractory hematologic malignancies

We retrospectively evaluated the tolerability and efficacy of fractionated total body irradiation (TBI) (1,200 cGy) and melphalan (MEL) (100–110 mg/m²) myeloablative conditioning in 48 patients with nonremission AML (n?=?14), ALL (n?=?10), NHL (n?=?18), and other refractory hematologic malignancies (n?=?6) who received allogeneic stem cell transplantation (SCT) between 2002 and 2011. Median age was 48 years (22 to 68); 14 out of 26 leukemia patients (54 %) had circulating blasts at transplant, 20 (50 %) evaluable patients had poor-risk cytogenetics, 12 (25 %) had prior SCT, and 10 (21 %) received stem cells from a mismatch donor. All patients received tacrolimus with or without methotrexate for GVHD prophylaxis. At the time of analysis, 13 patients (27 %) were alive and disease free. Engraftment was complete in all patients. The median time to ANC recovery (>500) was 12 days (range, 6–28). The most common grade III and IV toxicities were mucositis and infections. Eighteen patients (43 %) developed grade II–IV acute GVHD, and eight (26 %) had extensive chronic GVHD. Of 44 evaluable patients for response, 28 (64 %) achieved a complete remission (CR), and seven (15 %) had a partial remission after the transplant. With a median follow-up of 30 months (4 to 124 months) for surviving patients, the cumulative incidence of relapse was 45 % at 1 year, and the probability of overall survival (OS) at 5 years was 22.5 %. Multivariate analysis showed that platelet count (<80,000/mL) and lactic dehydrogenase (>500 IU/L) at SCT were associated with relapse. Age less than 53 years and CR after SCT were associated with better OS. Our data suggest that TBI-MEL can result in CR in two thirds, durable remission in one third, and 5-year survival in about one quarter of patients with nonremission hematologic malignancies. Further studies with TBI-MEL in standard risk transplant patients are warranted.     

A pilot study of prophylactic donor lymphocyte infusions to prevent relapse in adult acute lymphoblastic leukemias after allogeneic hematopoietic stem cell transplantation

The outcome of patients with acute lymphoblastic leukemia (ALL) receiving therapeutic donor lymphocyte infusions (DLIs) in relapse after stem cell transplantation (SCT) is poor. We analyzed the impact of prophylactic DLIs in ALL on chimerism and sustained complete remission (CR). Eighty-five patients with ALL were allografted between January 1998 and September 2004. Twenty-six of them received prophylactic DLIs and were included in this analysis. A total of 12 of 13 patients, who were treated with mixed chimerism (MC) converted to complete donor chimerism (92%) and 10 of 12 patients had persistent donor chimerism and sustained CR during subsequent follow-up. Overall, 18 of 26 patients developed graft-versus-host disease (GVHD) after DLIs (69%), acute GVHD in 46 and chronic GVHD in 62%. After a median follow-up of 42 months (14-72) after SCT, 18 of 26 patients (70%) are alive, 16 in CR. Probability of event-free survival (EFS) for patients treated with DLIs is 62%, and overall survival is 70% at 3 years. Our preliminary data support a graft-versus-leukemia effect of prophylactic DLIs able to induce stable donor chimerism and ongoing CR after SCT. As the accompanying GVHD rate was considerable, careful selection of patients for prophylactic DLIs is mandatory.     

Outcome of reduced-intensity allogeneic hematopoietic stem cell transplantation (RISCT) using antilymphocyte antibodies in patients with high-risk acute myeloid leukemia (AML)

Hemopoietic stem cell transplantation (SCT) with fully ablative conditioning is associated with an age-related increase in treatment-related mortality. It is therefore particularly unsuited to older individuals, who are most at risk of developing acute myeloid leukemia (AML). Reduced-intensity SCT (RISCT) may be of value in this group. We report 17 consecutive patients with high-risk AML whose median age was 58 years and who received stem cells from HLA-matched siblings (n=5), or alternative donors (n=12). We used lymphodepleting antibodies as a part of the reduced-intensity conditioning regimen to limit the risk of graft rejection and graft-versus-host disease (GVHD). All patients engrafted. One patient developed severe fatal GVHD, and two patients died of infection. At a median follow-up of 861 days (372-1957 days), seven patients are alive in remission, which includes two patients treated in relapse and five patients who lacked an MHC identical sibling donor. Both progression-free survival and overall survival are 40% (95% CI, 17-64%). Hence, RISCT using lymphodepleting antibodies may be of value for older patients with AML, even in those with active or high-risk disease, and even if they lack an MHC-identical sibling donor.     

Clinical impact of graft-versus-host disease against leukemias not in remission at the time of allogeneic hematopoietic stem cell transplantation from related donors. The Japan Society for Hematopoietic Cell Transplantation Working Party

Acute graft-versus-host disease (GVHD) increases post-transplant mortality and morbidity, but exerts a potent graft-versus-leukemia (GVL) effect. To clarify the impact of GVHD on outcome after transplant in aggressive diseases, patients with acute myeloid or lymphoblastic leukemia (AML, n = 366 or ALL, n = 255) in nonremission states, or chronic myelogenous leukemia (CML, n = 180) in accelerated phase (AP) or blastic crisis (BC), who received allogeneic hematopoietic stem cell transplantation (HSCT) from a related donor between 1991 and 2000, were analyzed. Significant improvement in overall and disease-free survival (DFS) was detected with grade I acute GVHD in AML (P = 0.0002 for overall survival and 0.0009 for DFS, respectively) and in CML (P = 0.0256 and 0.0366, respectively), while the trend towards improved survival was observed in ALL. Relapse rate was lower in grade I acute GVHD than in grade II in all three diseases, suggesting that treatment for grade II GVHD may compromise the GVL effect associated with GVHD. Chronic GVHD was found to suppress relapse in CML and ALL, but not in AML, although no improvement in survival was observed in any disease category. Our results suggest that treatment for grade II acute GVHD may need to be attenuated in transplant for refractory leukemias.     

Myeloablative allogeneic hematopoietic stem cell transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia in adults: significant roles of total body irradiation and chronic graft-versus-host disease

Disease-free survival in Philadelphia chromosome-positive ALL (Ph + ALL) is very poor, and allogeneic hematopoietic stem cell transplantation (allo-HSCT) is currently considered the only procedure with curative potential. To identify factors affecting transplant outcome, we analyzed the data from 197 Ph + ALL patients aged 16 years or older who had undergone allo-HSCT. The 5-year survival rates were 34% for patients in first complete remission (CR), 21% for those in second or subsequent CR, and 9% for those with active disease (P < 0.0001). Multivariate analysis showed four pre-transplant factors as significantly associated with better survival: younger age, CR at the time of transplantation, conditioning with total body irradiation, and HLA-identical sibling donor (P < 0.0001, P < 0.0001, P = 0.0301, P = 0.0412, respectively). Severe acute GVHD increased the risk of treatment-related mortality (TRM) without diminishing the risk of relapse, whereas chronic GVHD reduced the risk of relapse without increasing the risk of TRM. Thus, patients who developed extensive chronic GVHD had better survivals (P = 0.0217), and those who developed grade III-IV acute GVHD had worse survivals (P = 0.0023) than did the others.     

Prospective Trial of High-Dose Chemotherapy Followed by Infusions of Peripheral Blood Stem Cells and Dose-Escalated Donor Lymphocytes for Relapsed Leukemia after Allogeneic Stem Cell Transplantation

To determine whether induction of graft-versus-host disease (GVHD) improves the outcome of acute relapsed leukemia after stem cell transplantation (SCT), we used high-dose cytarabine (ara-C) followed by infusions of donor-derived buffy coats containing peripheral blood stem cells to treat 12 patients with relapsed leukemia. Donor lymphocyte infusion (DLI) was repeated at least twice over a 5-week interval for patients in whom grade II to IV acute GVHD did not develop after the first DLI. Grade II to IV acute GVHD developed in 4 (33%) of the patients. Chronic GVHD developed in 3 patients, 2 of whom had not experienced acute GVHD. Four (67%) of the 6 patients who developed grade II to IV acute and/or chronic GVHD after DLI responded, but none of the other 6 patients responded. Four (33%) of the patients (2 with acute myelogenous leukemia [AML] and 2 with acute lymphoblastic leukemia [ALL]) achieved complete remission lasting longer than 4 months after the first DLI, but 3 of them had relapses in bone sites. Of these 4 patients, 1 patient with AML and 2 with ALL were alive 8 to 27 months after DLI. These findings indicate that high-dose ara-C combined with megadose DLI may produce durable remission of acute leukemia that has relapsed after SCT when GVHD is induced. The low induction rate of GVHD and extramedullary relapse after remission is achieved with DLI are problems yet to be solved.     

Graft-versus-leukaemia effect in children: chronic GVHD has a significant impact on relapse and survival

To examine whether graft-versus-host-disease (GVHD) is associated with a graft-versus-leukaemia (GVL) effect that also influences the outcome of allogeneic stem cell transplantation (SCT) in childhood acute leukaemia, we evaluated all consecutive (n=169) children who had undergone SCT for ALL and AML at our centre. Median follow-up was 7 years. The 5-year probability of chronic GVHD was 34%. Median time to relapse was 24 months in children with chronic GVHD and 6 months in those without. The corresponding 5-year probabilities of relapse were 30 and 45% (P=0.01). The 5-year probability of survival was 54%. Patients with chronic GVHD had a significantly better survival, 77 vs 51% (P=0.01). In a Cox regression model, chronic GVHD independently decreased the risk of relapse (RR 0.44) and further predicted an increased chance of relapse-free survival (RR 1.7) and survival (RR 2.6). The impact of chronic GVHD on survival was most apparent in late-stage disease and in ALL. Acute GVHD was not an independent predictor for relapse or death in this study. This study is in support of a GVL effect in childhood leukaemia related to chronic GVHD, reducing the risk of relapse and improving survival.     

The graft-versus-leukaemia effect in haematopoietic stem cell transplantation using unrelated donors

We studied the graft-versus-leukaemia (GVL) effect in 185 patients with haematological malignancies who underwent unrelated donor haematopoietic stem cell transplantation (HSCT) at Huddinge University Hospital between May 1991 and June 2001. Ninety-five were in first CR/CP and 90 in later stages. Most (86%) of them had a HLA-A, -B and -DRbeta1 matched donor. Conditioning usually consisted of total body irradiation and cyclophosphamide, and GVHD prophylaxis of cyclosporine and methotrexate. In the multivariate risk-factor analysis of relapse, we found that disease stage beyond CR1/CP1 (P = 0.02), acute GVHD 0-I (P = 0.02), absence of chronic GVHD (P = 0.02) and ALL (P = 0.02) were independent risk factors for relapse. The incidence of relapse in those with acute GVHD grade II was 18% vs 46% in those with no or grade I (P = 0.04). In patients with or without chronic GVHD, the incidences of relapse were 32% and 48%, respectively (P < 0.01). The best RFS was seen in patients with chronic GVHD. No difference in RFS was seen in patients with no, mild or moderate acute GVHD. Risk factors for relapse after HSCT with unrelated donors were: acute lymphoblastic leukaemia, disease stage beyond CR1/CP1, absence of chronic GVHD and no, or mild acute GVHD. Overall and relapse-free survival were not improved by the occurrence of acute GVHD.     

Allogeneic stem cell transplantation: low immunoglobulin levels associated with decreased survival

The aim of this study was to evaluate the effects and kinetics of IgG levels after allogeneic stem cell transplantation (SCT). This study retrospectively examines 179 consecutive patients undergoing SCT between 1995 and 2002. Diagnoses included acute and chronic leukemia (n=136), solid tumors (n=11), other malignancies (n=16) and non-malignant diseases (n=16). Standard myeloablative conditioning was given to 146 patients, and 33 patients received reduced intensity conditioning. Serum samples for measurement of IgG levels were collected 3, 6 and 12 months after SCT, and then yearly. IgG levels increased after SCT throughout the study period. Factors that were associated with low IgG levels after SCT were acute graft-versus-host disease (GVHD), patient age < or =30 years, female donor-to-male recipient, not receiving anti-thymocyte globulin and type of GVHD prophylaxis. Compared to patients with moderately low or normal levels as measured twice during the first year after transplantation, patients with low IgG levels (<4 g/l) showed a decreased survival rate (54 vs 71%, P=0.04) and an increased incidence of transplant-related mortality (27 vs 9%, P<0.01). IgG levels generally increase after SCT. Persistent low levels of IgG are a risk factor for death after SCT.     

Donor compatibility and performance status affect outcome of allogeneic haematopoietic stem cell transplant in patients with relapsed or refractory acute myeloid leukaemia

We retrospectively analysed 78 patients with relapsed (n?=?38), primary refractory (n?=?34) or untreated (n?=?6) acute myeloid leukaemia (AML) who underwent allogeneic HSCT at our Institution between 2002 and 2011, to verify outcome and to identify factors that can affect long-term outcome. Myeloablative conditioning regimens were used in 48 patients (24 siblings, 24 matched unrelated donor (MUD)), while 30 patients (18 siblings, 12 MUD) received reduced-intensity conditioning. Acute graft versus host disease (GVHD) developed in 37 (47?%) patients, while chronic GVHD occurred in 19 of the 65 evaluable patients (29?%). With a median follow-up time of 5?years, 13 of 78 patients (17?%) are alive and in complete remission (CR), while 64 have died. Cause of death was disease recurrence in 37 patients (58?%), infection in ten patients (16?%) and GVHD in six (9?%). One-year non-relapse mortality was 35?%. In multivariate analysis, performance status ≥80?% WHO and a full-matched donor were associated with a better outcome: these two variables allowed for risk stratification, identifying three groups with significantly different survival after transplant (P?=?0.0001). Considering post-transplant variables, only CR at recovery and development of cGVHD were correlated with a longer survival. Our data confirm the capacity of allogeneic transplant to prolong survival in a significant proportion of extremely high-risk AML patients.     

Busulfan pharmacokinetics do not predict relapse in acute myeloid leukemia

The purpose of this study was to evaluate the influence of busulfan (BU) pharmacokinetics on survival, grades II-IV acute graft-versus-host disease (GVHD), non-relapse mortality (NRM) and relapse in a group composed of 45 children (<18 years) and seven adults with acute myeloid leukemia (AML) in first complete remission and undergoing hematopoietic stem cell transplantation (SCT). Fifty-two patients underwent autologous (n = 25) or allogeneic (n = 27) SCT. The median age was 8.9 years (range 0.6-53 years). Conditioning therapy consisted of BU and cyclophosphamide. Improved disease-free survival was found in those patients with a steady-state concentration of BU (CssBU) below the median (<578 mg/ml, P = 0.05), and the same trend was noted for overall survival (P = 0.07). This was secondary to a higher incidence of NRM in the group of patients with CssBU above the median (P = 0.06). There was no significant correlation with CssBU and relapse (P = 0.31). No association between CssBU and GVHD was found in allogeneic patients (P = 0.30). Relapse was evaluated among the subgroups of age (< or >10 years) and transplant type (allogeneic or autologous) with no statistically significant association observed among these factors. Multiple regression analysis for relapse revealed no significant correlation with CssBU above or below the median, age, or transplant type. In this study, CssBU below the median did not correlate with an inferior outcome for patients with AML. Pharmacokinetic dosing of BU may be important for prevention of NRM but does not appear to influence the risk of relapse in this largely pediatric population with AML.     

Stem cell transplantation in acute myelogenous leukemia in first remission: what are the options?

Most newly diagnosed patients with acute myeloid leukemia (AML) in first remission will relapse without additional consolidation therapy. The options for consolidation therapy include repeated cycles of high-dose cytosine arabinoside-based chemotherapy and autologous or allogeneic stem cell transplantation (SCT). Chemotherapy alone is associated with the highest risk of relapse, but it has the lowest treatment-related mortality (TRM). Allogeneic SCT has the lowest risk of relapse with the highest TRM, whereas autologous SCT has an intermediate risk of relapse and TRM. Cytogenetic status of patients with AML is the single most important prognostic factor. However, it is increasingly recognized that this factor alone is inadequate for risk stratification. Based on cytogenetic stratification, a good-risk group of patients in first complete remission (CR1) would benefit most from high-dose consolidation chemotherapy. The risks of a SCT outweigh the benefit in this group. In the unfavorable-risk group, an allogeneic sibling SCT in CR1 would be acceptable, whereas the outcomes with chemotherapy alone or with an autologous SCT are dismal. Based on minimal data, a matched-unrelated donor SCT for this group of patients should be recommended. In the intermediate-risk group, strategies are evolving and the use of additional prognosticators will help in decision making. Autologous or allogeneic sibling SCT is a reasonable option in a subset of patients within this group at a high risk of relapse. There are insufficient data to recommend a haploidentical or cord blood transplant for patients with AML in CR1.     

Pericardial effusion and cardiac tamponade in pediatric stem cell transplant recipients

Pericardial effusion and cardiac tamponade is a rarely reported complication following stem cell transplant (SCT). The incidence among pediatric SCT recipients is not well defined. To assess the frequency of clinically significant pericardial effusions, we retrospectively examined clinically significant cardiac effusions at our center. Between January of 1993 and August 2004, clinically significant pericardial effusions were identified in nine of 205 patients (4.4%). The median age at the time of transplant was 9 years (range 0.6-18 years) and seven received an allogeneic transplant. All nine had normal cardiac function prior to transplant. The effusion developed at a median of 30 days (range 18-210 days). All allogeneic recipients had acute or clinically extensive graft-versus-host disease (GVHD) at the time the effusion was diagnosed. Seven patients (78%) required pericardiocentesis or surgical creation of a pericardial window. No patient died as a complication of the effusion or the therapeutic procedures. Clinically significant pericardial effusions are more common than previously reported in pediatric SCT recipients. Acute and chronic GVHD is an associated factor.     

Relatively favorable outcome after allogeneic stem cell transplantation for BCR‐ABL1‐positive AML: A survey from the acute leukemia working party of the European Society for blood and marrow transplantation (EBMT)

The aim of the study was to assess the role of allogeneic stem cell transplantation (SCT) in patients diagnosed with BCR‐ABL1‐positive acute myeloid leukemia (AML). Fifty‐seven patients (median age, 48 years, range: 19‐67) with BCR‐ABL1 positive AML undergoing SCT were identified. The majority of the patients (70%) received a TKI before the transplant. At SCT 48 patients were in CR (45 in CR1), while 9 patients were transplanted in a more advanced stage of the disease. MRD was negative (BCR‐ABL1/ABL < 10⁴) at time of SCT in 36.1% (14/40). After SCT, 16 (61.5%) out of 26 patients with MRD positive at transplantation reached MRD negativity. After a median follow‐up of 6.3 years (0.7–14.2), NRM, RI, LFS, OS, and GRFS at 5 years were 18.1%, 37%, 44.2%, 53.8%, and 32.1%, respectively. The cumulative incidence of acute GvHD grade II‐IV was 16.4%, incidence of chronic GvHD 24.9%, and of extensive cGvHD 21.4%, respectively. In patients who received SCT in CR1, 5‐yr NRM, RI, LFS, OS, and GRFS were 15.9%, 36.4%, 46.5%, 59.4%, and 34.9%, respectively. Univariate analysis showed that age (<50 vs. ≥50 years) was associated with RI (5‐yr: 22.7 vs. 50%), LFS (5‐yr: 61.9 vs. 31.8%), and GRFS (5‐yr: 52.4 vs. 18.2%), whereas MRD‐negative status before SCT was associated with an improved GRFS (38.9 vs. 16.7%). We conclude that the outcome of patients <50 years of age with BCR‐ABL1‐positive AML receiving allogeneic SCT in CR is relatively favorable, possibly reflecting the beneficial effect of the use of TKI.     

Relapse risk and survival in patients with FLT3 mutated acute myeloid leukemia undergoing stem cell transplantation

In patients with AML with FMS‐like tyrosine kinase 3 (FLT3) mutations, the significance of minimal residual disease (MRD) detected by PCR before allogeneic stem cell transplantation (SCT) on outcomes after transplant remains unclear. We identified 200 patients with FLT3‐AML who underwent SCT at our institution. Disease status at transplant was: first or second complete remission (CR1/CR2, n = 119), high‐risk CR (third or subsequent CR, marrow hypoplasia, or incomplete count recovery) (CR‐HR, n = 31), and morphological evidence of active disease (AD, n = 50). The median follow‐up was 27 months, and the 2‐year overall and progression‐free survival were 43% and 41%, respectively. Relapse was highest in the AD group (85%) and the CR‐HR FLT3 MRD positive group (72%), followed by CR‐HR FLT3 MRD negative (58%), CR1/CR2 FLT3 MRD positive (39%), and lowest in the CR1/CR2 FLT3 MRD negative group (23%). On multivariate analysis, independent factors influencing the risk of relapse were detectable morphological disease and FLT3 MRD by PCR pre‐transplant. Factors that did not influence the relapse risk included: age, graft type, graft source, type of FLT3 mutation, or conditioning intensity. Morphologic and molecular remission status at the time of transplant were key predictors of disease relapse and survival in patients with FLT3‐AML.     

Alternative donor bone marrow transplant for children with Philadelphia chromosome ALL

Children with Philadelphia chromosome positive (Ph+) acute lymphocytic leukemia (ALL) have only a 20% event-free survival when treated with chemotherapy alone. Bone marrow transplant (BMT) for patients with matched siblings has been associated with significantly better long-term survival. We asked whether children who lack a matched sibling donor would do as well if an alternative donor was utilized. Between 1987 and 2002, we transplanted 29 children and adolescents using either an unrelated donor (23) or a mismatched family member (six). The conditioning regimen included cytosine-arabinoside, cyclophosphamide and total body irradiation. Graft-versus-host disease (GVHD) prophylaxis consisted of T-cell depletion (antibody T10B9 or OKT3 and complement) with post transplant cyclosporine (CSA). All patients engrafted. Four developed grades III-IV acute GVHD. Three of 24 evaluable patients developed extensive chronic GVHD. Two patients died of relapse (7%). Two long-term survivors (>6 years) died of malignant glioblastoma multiforme. Event-free survival at 3, 5, and 10 years is 56, 51, and 46%, respectively. Five of six patients in >CR2 or relapse at the time of transplant died. Our data should encourage the use of alternative donor transplants early in the course of disease for children with Ph+ ALL.     

Umbilical cord blood transplant from unrelated HLA-mismatched donors in children with high risk leukemia

In the last 3 years, 14 children with high-risk leukemia (11 ALL, 2 AML and 1 CML) underwent cord blood transplantation from unrelated HLA-mismatched donors at a median of 99 days from the start of search. Eight patients were transplanted in second CR, one in accelerated phase, three at relapse and two patients in first CR. Conditioning regimen (fractionated TBI, etoposide, CY and anti-lymphocyte serum) and prophylaxis of GVHD (CsA and 6-methylprednisolone) were identical for all patients. Neutrophils >0.5x10(9)/l were reached at a median of 33 days from transplant, but in four cases we observed an autologous hematopoietic reconstitution (three spontaneous, one after autologous BM rescue). Acute and chronic GVHD were observed in 10/14 and 3/8 evaluable cases, respectively. Three patients died of transplant-related toxicity and three patients relapsed. The probabilities of event-free, disease-free and overall survival were 50, 53 and 64%, respectively. Cord blood transplant from HLA-mismatched unrelated donor is a valid option for the treatment of children with high-risk leukemia. With our eligibility criteria, conditioning regimen and prophylaxis of graft-versus-host disease, the main obstacles to successful transplant were represented by graft failure and fatal acute GVHD.