Outcomes Following Bone Marrow Transplantation in Children With Accelerated Phase or Blast Crisis Chronic Myelogenous Leukemia in the Era of Tyrosine Kinase Inhibitors.

The management of chronic myelogenous leukemia (CML) in children changed dramatically with the introduction of tyrosine kinase inhibitors (TKIs). Unfortunately, outcomes for patients presenting in an advanced stage-accelerated phase or blast crisis CML-continues to be poor, requiring chemotherapy and allogeneic hematopoietic stem cell transplant (HSCT) to attempt cure. Integration of TKIs in the therapy of advanced CML is still an area of active investigation. There are little published data on TKI use in children with advanced stage CML. We performed a retrospective review of all children treated at our institution between January 1, 2010 and June 30, 2013, and identified 5 children, age 12 to 18 years, with advanced stage CML. All patients were treated with a TKI before HSCT and TKIs were restarted post-HSCT in 4/5 with a goal of continuing until 2 years posttransplant. At time of HSCT all were in a morphologic and cytogenetic remission; 1 patient had also achieved molecular remission. All patients are alive and in molecular remission at an average of 38 months (range, 14 to 51 mo) following transplant. Our experience indicates that TKIs are safe and well tolerated in children both pretransplant and posttransplant and may improve outcomes in this aggressive disease.

Hematopoietic stem cell transplantation for T315I-mutated chronic myelogenous leukemia.

BACKGROUND: The T315I mutation of BCR/ABL gene is known to produce complete resistance of chronic myelogenous leukemia (CML) to all currently available BCR/ABL inhibitors. The data suggesting poor median survival of these patients may indicate that they should be primary candidates for allogeneic stem cell transplantation (alloSCT). However, evidence on efficiency of this treatment modality in CML with T315I mutation is lacking. CASE REPORT: A 25-year-old patient was diagnosed with Philadelphia chromosome positive CML in accelerated phase. As he did not have an HLA-identical sibling or fully-matched unrelated bone marrow donor, treatment with low dose tyrosine kinase inhibitor - imatinib was initiated. Despite satisfactory hematological remission, he failed to achieve complete cytogenetic remission within the first year of treatment. Moreover, despite escalation of imatinib dosage, the disease relapsed after further 3 months of treatment. Molecular studies revealed T315I mutation of BCR/ABL gene. He responded poorly to interferon alpha (IFN-alpha) and we decided to perform alloSCT from a partially mismatched (8/10 HLA allele match) unrelated donor. The course of transplantation was complicated by staphylococcal sepsis, grade I skin acute GvHD and limited chronic skin GVHD. However, the goal of alloSCT was achieved and the patient remains in complete molecular remission at week +68 post-transplantation. CONCLUSIONS: The clinical course of this case supports the idea that allogeneic hematopoietic transplantation is a viable treatment option for patients with CML bearing T315I mutation.

Response to tyrosine kinase inhibitor therapy in patients with chronic myelogenous leukemia relapsing in chronic and advanced phase following allogeneic hematopoietic stem cell transplantation.

Tyrosine kinase inhibitors (TKI) have been used to treat relapse of chronic myelogenous leukemia (CML) after allogeneic stem cell transplant (HSCT), with responses seen predominantly in chronic phase (CP) patients. This study aimed to analyze the response to TKI therapy and overall survival for patients relapsing predominantly in advanced phase. We retrospectively reviewed 22 patients treated with imatinib (n=20) and/or dasatinib (n=6) for relapsed CML after HSCT; 8 patients were in CP, and 14 patients had advanced disease. Seven patients also received donor lymphocyte infusions. Hematologic, cytogenetic, and molecular responses were analyzed. Nineteen patients (86%) achieved complete hematologic response (CHR), 17 patients (77%) achieved complete cytogenetic response (CCR), and 14 patients (64%) achieved complete molecular response (CMR). In advanced phase patients, 11 (79%) achieved CHR, 10 (71%) CCR, and 8 (57%) achieved CMR. Grade 3 or 4 cytopenias occurred in 10 cases. With median follow-up of 31.5 months from relapse, 14 (64%) patients remain alive, 13 in CMR. In multivariate analysis, the achievement of CMR was significantly correlated with OS with an odds ratio of 20.5 (95% confidence interval 2.3-182) P=.007. TKI therapy is capable of inducing durable molecular responses for CML relapsing after HSCT, both in chronic and advanced phases. The achievement of CMR appears to be crucial in providing long-term disease control for these patients.

[Nonmyeloablative peripheral blood stem cell transplantation for chronic myeloid leukemia in chronic and accelerated phases].

The aim of this study was to investigate the effect of nonmyeloablative peripheral blood stem cell transplantation in treatment of chronic myeloid leukemia in chronic phase (CML-CP) and accelerated phase (CML-AP). 24 patients with CML including 16 in CML-CP and 8 in CML-AP were treated with nonmyeloablative conditioning regimen for peripheral blood stem cell transplantation (PBHSCT). The conditioning regimen included fludarabine (30 mg/m(2)x6 d), busulphan [4 mg/(kg.d)x2 d] and CTX [350 mg/(m2.d)x2 d] combined with or without Ara-C. The donors were HLA-identical (n=20) and 5/6 antigen-matched (n=4). The dynamic observation of hematopoietic recovery in all patients was carried out. The results indicated that all the patients were successfully engrafted. The mean time for increase of the number of neutrophils to more than 0.5x10(9)/L and platelet more than 20x10(9)/L were 13 days and 11.5 days respectively. Out of 12 patients, 9 patients showed complete donor chimerism and 3 patients showed mixed chimerism at 30 days after transplantation. At 180 days after transplantation, 18 survival patients showed complete donor chimerism. 18 patients remained alive after a median follow-up length of 24 months (4-48 months). 2 cases died of severe acute GVHD and 1 case died of chronic GVHD, 2 cases died of interstitial pneumonia and 1 case died of relapsed. In conclusions, nonmyeloablative peripheral blood stem cell transplantation is an effective therapeutic method for CML patients in chronic phase and accelerated phase.

Frequent methylation of p16INK4A and p14ARF genes implicated in the evolution of chronic myeloid leukaemia from its chronic to accelerated phase.

The frequency and mechanism of p16(INK4A) and p14(ARF) gene alterations were studied in cell samples from 30 patients with Philadelphia (Ph) chromosome-positive chronic myeloid leukaemia (CML), both at diagnosis and at the onset of the accelerated phase (AP) of the disease. No alterations in the p16(INK4A) or p14(ARF) genes were found in any of the chronic phase (CP) samples. DNA sequencing analyses detected p16(INK4A) or p14(ARF) mutations in 17 AP samples. All mutations were heterozygous without loss of the other allele. Aberrant methylation of the p16(INK4A) or p14(ARF) promoters was found in 14 of 30 AP samples. The most common situation was the simultaneous methylation of both promoters. Our data indicate that p16(INK4A) and p14(ARF) are primary targets for inactivation by promoter methylation in the acceleration of CML. Transcriptional silencing of the p16(INK4A) and p14(ARF) genes may be important in the conversion of CML from the CP to the AP.

Perspectives on the treatment of chronic phase and advanced phase CML and Philadelphia chromosome positive ALL(1).

Chronic myeloid leukaemia (CML) is a malignant disease of the bone marrow characterised by the presence of the Philadelphia (Ph) chromosome. About 20% of acute lymphoblastic leukaemia (ALL) patients also show this genetic abnormality. A new drug, imatinib (Glivec, Novartis Pharma AG, Basel, Switzerland, and formerly STI571) is having a profound effect on the treatment and management of all stages of CML and Philadelphia chromosome positive (Ph+) ALL. New treatment algorithms are being developed. Should imatinib replace or be combined with existing therapies? To address this question, we review the pros and cons of therapy with interferon-alpha (IFN-alpha), allogeneic transplantation, autologous transplantation, imatinib, and in the case of Ph+ ALL, chemotherapy and experimental approaches. Conservative and aggressive treatments will be discussed and new molecular methods of monitoring cytogenetic response and their significance will also be reviewed.

The usefulness of monitoring WT1 gene transcripts for the prediction and management of relapse following allogeneic stem cell transplantation in acute type leukemia.

In acute-type leukemia, no method for the prediction of relapse following allogeneic stem cell transplantation based on minimal residual disease (MRD) levels is established yet. In the present study, MRD in 72 cases of allogeneic transplantation for acute myeloid leukemia, acute lymphoid leukemia, and chronic myeloid leukemia (accelerated phase or blast crisis) was monitored frequently by quantitating the transcript of WT1 gene, a "panleukemic MRD marker," using reverse transcriptase-polymerase chain reaction. Based on the negativity of expression of chimeric genes, the background level of WT1 transcripts in bone marrow following allogeneic transplantation was significantly decreased compared with the level in healthy volunteers. The probability of relapse occurring within 40 days significantly increased step-by-step according to the increase in WT1 expression level (100% for 1.0 x 10(-2)-5.0 x 10(-2), 44.4% for 4.0 x 10(-3)-1.0 x 10(-2), 10.2% for 4.0 x 10(-4)-4.0 x 10(-3), and 0.8% for < 4.0 x 10(-4)) when WT1 level in K562 was defined as 1.0). WT1 levels in patients having relapse increased exponentially with a constant doubling time. The doubling time of the WT1 level in patients for whom the discontinuation of immunosuppressive agents or donor leukocyte infusion was effective was significantly longer than that for patients in whom it was not (P <.05). No patients with a short doubling time of WT1 transcripts (< 13 days) responded to these immunomodulation therapies. These findings strongly suggest that the WT1 assay is very useful for the prediction and management of relapse following allogeneic stem cell transplantation regardless of the presence of chimeric gene markers.

Blast crisis of chronic myeloid leukemia: diagnosis prompted by T(8;9).

T(8;9) is a relatively new translocation that has been reported in a few patients with chronic myeloid leukemia (CML) but never in acute myeloid leukemia (AML). We report here a patient who presented with AML with t(8; 9). He lacked the Philadelphia chromosome but tested positive for the gene by the polymerase chain reaction method. This confirmed the diagnosis of CML with blast crisis, and appropriate treatment could be instituted

Autologous hematopoietic stem cell transplantation in chronic myeloid leukemia with different clinical stages.

Seven patients with Philadelphia (Ph) chromosome-positive chronic myeloid leukemia (CML) were treated with an ICE-based regimen plus G-CSF with the aim of mobilizing and collecting Ph-negative peripheral stem cells in the setting of an autologous transplant program. Five patients had CML in the first chronic phase and 2 in the accelerated phase. All patients had been previously treated with interferon-alpha. Median value and ranges for harvested mononuclear cells, CD34+ cells and CFU-GM, respectively: 5.65 x 10(8)/kg (2.61-11.38); 1.48 x 10(6)/kg (0.216-3.5), and 3.43 x 10(4)/kg (0.243-11.6). FISH was the only useful method for detection of minimal residual disease on apheresis product showing <5% t(9;22) positive cells in 2 cases and <10% positive cells in 4 other cases. Four of seven autologous grafts have been transplanted to date. Busulfan conditioning was used in 1 case and TBI/Cy conditioning in 3 other cases. All patients are alive and well following transplantation and are on interferon-alpha therapy.

Patient cytomegalovirus seropositivity with or without reactivation is the most important prognostic factor for survival and treatment-related mortality in stem cell transplantation from unrelated donors using pretransplant in vivo T-cell depletion with anti-thymocyte globulin.

We evaluated the cytomegalovirus (CMV) serostatus as a risk factor for survival and treatment-related mortality (TRM) in 125 patients allografted from an unrelated donor between 1994 and 1999. All patients received pretransplant in vivo T-cell depletion using rabbit anti-thymocyte globulin (ATG). Only one patient had primary graft failure and severe grade III/IV graft-versus-host disease occurred in 14% of the patients. The overall survival (OS) at 3 years was 70% for CMV-negative patients (n = 76) and 29% in the seropositive cohort (n = 49) (P > 0.001). In multivariate analyses, CMV seropositivity remained an independent negative prognostic factor for OS (RR: 2.1; CI: 1.2-3.8; P = 0.014), apart from age > 20 years (RR: 2.74; CI: 1.2-3.8; P = 0.004) and late leucocyte engraftment (RR: 2.4; CI: 1.2-4.9; P = 0.015). The TRM for all patients was 27%. Despite monitoring for CMV antigenaemia and preemptive therapy with ganciclovir when reactivation occurred, seropositive patients had a three times higher risk of fatal treatment-related complications than seronegative patients. In multivariate analyses, CMV seropositivity remained the strongest independent negative factor for TRM (RR: 5.3; CI: 1.9-14.6; P = 0.002), followed by age > 20 years (RR: 4.8; CI: 1.3-18.1; P = 0.02) and delayed leucocyte engraftment (RR: 3.6; CI: 1.2-11; P = 0.02). The TRM was identical in seropositive patients with (n = 27) or without (n = 22) CMV reactivation (44% versus 50%). We conclude that CMV seropositivity, despite preemptive ganciclovir therapy and even without reactivation, is a major negative prognostic factor for survival as well as for TRM in unrelated stem cell transplantation using pretransplant in vivo T-cell depletion with ATG.

A successful cord blood transplant in a child with second accelerated phase chronic myeloid leukemia following lymphoid blast crisis.

We describe a 5-year-old girl with Ph(+) CML who received a cord blood transplant in a second accelerated phase after a very early lymphoid blast crisis. She was induced into CR by ALL-directed chemotherapy and then maintained with IFN-alpha2b together with weekly rotational chemotherapy. Nineteen months after diagnosis, her mother gave birth to an HLA-compatible sibling, whose cord blood was cryopreserved. The patient's second acceleration occurred 22 months after the CML diagnosis. The subsequent conditioning regimen included busulfan 16 mg/kg, Ara-C 12 g/m2 and melphalan 140 mg/m2. In order to prevent GVHD, CsA alone was administered, 3 mg/kg i.v. per day for a total of 40 days. The total number of nucleated cells infused was 0.8 x 108/kg, with CD34+ cells 1.8 x 106/kg and CFU-GM 1 x 104/kg. Engraftment occurred on day +35. Respiratory distress, severe VOD and grade II acute gastrointestinal GVHD complicated the post-transplant period. No chronic GVHD occurred. The girl is alive 23 months after transplantation with complete donor chimerism; both Ph chromosome and bcr/abl RNA are negative. Bone Marrow Transplantation (2000) 25, 213-215.

Philadelphia chromosome-negative engraftment after autologous transplantation with granulocyte-macrophage colony-stimulating factor for chronic myeloid leukemia.

Autologous bone marrow transplantation (BMT) has not been curative in chronic myeloid leukemia (CML), because of the inability to purge CML from the autograft and the absence of the allogeneic T cell-mediated antileukemic activity. However, recent advances demonstrate that normal progenitors can be selected from CML marrows by a variety of techniques, including isolation by their small size. Furthermore, we found that myeloid growth factors have a potent antileukemic effect against CML progenitors in vitro by inducing their terminal differentiation. Based on these data, we initiated a trial of autologous BMT in patients with high-risk CML. Autografts were processed in an attempt to enrich for normal progenitors, first by isolating small cells by counterflow centrifugal elutriation and then incubating them in granulocyte-macrophage colony-stimulating factor (GM-CSF) for 72 hours. After a conditioning regimen of busulfan and cyclophosphamide, all patients received GM-CSF daily for 2 months. The median age of the 13 patients in the trial was 45 years (range 17-56 years). The median duration of disease before BMT was 24 months (range 13-72 months). Eight patients were in chronic phase (CP), and five were in accelerated phase (AP). All patients failed to achieve a cytogenetic response to interferon-alpha and were 100% Philadelphia chromosome (Ph)+ before BMT. There were three transplant-related deaths, all AP patients. All of the remaining 10 patients engrafted with some degree of Ph- hematopoiesis; despite high-risk features, nine patients engrafted 100% Ph-. All patients relapsed cytogenetically at a median of 6 months (range 4-22 months). These results demonstrate that autologous BMT can consistently induce complete Ph- engraftment in CP patients. GM-CSF appears to produce a clinical antileukemic effect against CML after autologous BMT.

Complete remission of accelerated phase chronic myeloid leukemia by treatment with leukemia-reactive cytotoxic T lymphocytes.

Relapse of chronic myeloid leukemia (CML) in chronic phase after allogeneic stem cell transplantation (SCT) can be successfully treated by donor lymphocyte infusion (DLI). However, relapse of accelerated phase CML, blast crisis, or acute leukemia after allogeneic SCT are resistant to DLI in the majority of cases. In vitro-selected and expanded leukemia-reactive T-cell lines may be more effective in inducing an antileukemic response in vivo. To treat a patient with accelerated phase CML after allogeneic SCT, leukemia-reactive cytotoxic T-lymphocyte (CTL) lines were generated from her HLA-identical donor. Using a modification of a limiting dilution assay, T cells were isolated from the donor, selected based on their ability to inhibit the in vitro growth of CML progenitor cells, and subsequently expanded in vitro to generate CTL lines. Three CTL lines were generated that lysed the leukemic cells from the patient and inhibited the growth of leukemic progenitor cells. The CTL did not react with lymphocytes from donor or recipient and did not affect donor hematopoietic progenitor cells. The 3 leukemia-reactive CTL lines were infused at 5-week intervals at a cumulative dose of 3.2 x 10(9) CTL. Shortly after the third infusion, complete eradication of the leukemic cells was observed, as shown by cytogenetic analysis, fluorescence in situ hybridization, molecular analysis of BCR/ABL-mRNA, and chimerism studies. These results show that in vitro cultured leukemia-reactive CTL lines selected on their ability to inhibit the proliferation of leukemic progenitor cells in vitro can be successfully applied to treat accelerated phase CML after allogeneic SCT.