Allogeneic hematopoietic cell transplantation (allogeneic HCT) for treatment of pediatric Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL)

Reduced-intensity allogenic transplantation for children and adolescents with Philadelphia chromosome-positive acute lymphoblastic leukemia

Survival rates of patients with Philadelphia chromosome-positive ALL (Ph+ALL) have improved considerably with the introduction of tyrosine kinase inhibitors (TKI); however, hematopoietic stem cell transplantation (HSCT) continues to play an important role. Reduced-intensity conditioning (RIC) regimens have been widely applied particularly for older patients, but their validity for children and adolescents with Ph+ALL has not been investigated. In this study, data from patients receiving HSCT for de novo Ph+ALL in first or second remission at ages younger than 25 years and with a history of pre-HSCT TKI therapy were retrospectively collected through the nationwide registry in Japan. In 265 patients who received myeloablative conditioning (MAC) and 33 patients receiving RIC, 5-year leukemia-free survival (LFS) rates were 67.3% and 79.8%, respectively (p = 0.142). Multivariate analysis of LFS, focusing on patients with good performance status, identified RIC as a significant prognostic factor for LFS (hazard ratio 0.32, p = 0.032), as well as older age, higher leukocyte count at diagnosis, and disease with additional chromosomal abnormalities. These trends were similar when we focused on patients who received prophylactic post-HSCT TKI treatment, as 5-year LFS was 81.0% for MAC and 84.4% for RIC (p = 0.748). In summary, HSCT with RIC regimen showed at least comparable LFS to HSCT with MAC regimen, and RIC was an independent favorable prognostic factor on multivariate analysis adjusting potential prognostic factors. While patient numbers were limited, our data suggest that RIC may be safely applied in this group, particularly combined with prophylactic post-HSCT TKI maintenance therapy.

Experience of the Spanish Group for Hematopoietic Transplantation (GETMON-GETH) in allogenic Hematopoietic stem cell Transplantation in Philadelphia acute lymphoblastic leukemia

INTRODUCTION

Outcomes in patients diagnosed of acute lymphoblastic leukemia with Philadelphia chromosome (Ph-ALL) remains unfavourable compared to other subtypes of acute lymphoblastic leukemia despite improvements in drug treatments as well as advances in hematopoietic stem cell transplantation (HSCT).

PATIENTS AND METHODS

The role of allogeneic HSCT in Ph-ALL patients has been analysed through a multicentric study where data belonging to 70 patients diagnosed of this entity in different centers that received HSCT between years 1998 and 2014, were reported by the Grupo Español de Trasplante Hematopoyético (GETH).

RESULTS

The performance of HSCT from year 2004, in first complete remission (CR) status with thymoglobulin (ATG) based conditioning had a favorable impact on overall survival (OS). HSTC performance from year 2004, in first CR with ATG-based conditioning in addition to acute graft versus host disease (aGvHD) development, increased event free survival (EFS). Treatment with imatinib as well as undetectable minimal residual disease (MRD) prior to HSCT, combined with aGvHD, reduced risk of relapse (RR). Patient age less than 10 years when HSCT, first CR and ATG-based conditioning were associated to a lower transplant related mortality (TRM).

CONCLUSIONS

Patients that could achieve first CR that also received ATG-based conditioning had a better OS and EFS, so HSCT should be considered for this group of patients.

[Experience of the Spanish Group for Hematopoietic Transplantation (GETMON-GETH) in allogenic hematopoietic stem cell transplantation in Philadelphia acute lymphoblastic leukemia]

INTRODUCTION

Outcomes in patients diagnosed of acute lymphoblastic leukemia with Philadelphia chromosome (Ph-ALL) remains unfavourable compared to other subtypes of acute lymphoblastic leukemia despite improvements in drug treatments as well as advances in hematopoietic stem cell transplantation (HSCT).

PATIENTS AND METHODS

The role of allogeneic HSCT in Ph-ALL patients has been analysed through a multicentric study where data belonging to 70 patients diagnosed of this entity in different center that received HSCT between years 1998 and 2014, were reported by the Grupo Español de Trasplante Hematopoyético (GETH).

RESULTS

The performance of HSCT from year 2004, in first complete remission (CR) status with thymoglobulin (ATG) based conditioning had a favorable impact on overall survival (OS). HSTC performance from year 2004, in first CR with ATG-based conditioning in addition to acute graft versus host disease (aGvHD) development, increased event free survival (EFS). Treatment with imatinib as well as undetectable minimal residual disease (MRD) prior to HSCT, combined with aGvHD, reduced risk of relapse (RR). Patient age less than 10 years when HSCT, first CR and ATG-based conditioning were associated to a lower transplant related mortality (TRM).

CONCLUSIONS

Patients that could achieve first CR that also received ATG-based conditioning had a better OS and EFS, so HSCT should be considered for this group of patients.

Case Report: A Case With Philadelphia Chromosome Positive T-Cell Lymphoblastic Lymphoma and a Review of Literature

Philadelphia chromosome positive (Ph⁺) in T-lineage acute lymphoproliferative tumors is a rare event in both children and adults. In particular, it has not been reported in T-cell lymphoblastic lymphoma(T-LBL) yet. Here, we describe a patient with Ph⁺ T-LBL for both cytogenetic abnormality and BCR-ABL1 fusion transcript. Moreover, we review the published cases of Ph⁺ T-cell acute lymphoblastic leukemia (T-ALL) in the literature and summarize their clinical characteristics, management, and prognosis.

Imatinib treatment of paediatric Philadelphia chromosome-positive acute lymphoblastic leukaemia (EsPhALL2010): a prospective, intergroup, open-label, single-arm clinical trial

BACKGROUND

The EsPhALL2004 randomised trial showed a 10% advantage in disease-free survival for short, discontinuous use of imatinib after induction compared with no use of imatinib in patients with Philadelphia chromosome-positive acute lymphoblastic leukaemia receiving Berlin-Frankfurt-Münster chemotherapy and haemopoietic stem-cell transplantation (HSCT). Other contemporary studies showed an advantage from continuous protracted exposure to imatinib, challenging the indications to transplant. The EsPhALL2010 study was designed to assess whether imatinib given from day 15 of induction and continuously throughout chemotherapy led to a different outcome to that obtained in EsPhALL2004, despite decreasing the number of patients having HSCT.

METHODS

This prospective, intergroup, open-label, single-arm clinical trial (EsPhALL2010) was done at 11 study groups across Europe, Chile, and Hong Kong. Patients aged 1-17 years with the translocation t(9;22)(q34;q11) who were recruited into national front-line trials for acute lymphoblastic leukaemia were eligible for this trial. Patients with abnormal renal or hepatic function or an active systemic infection were ineligible. Patients received imatinib 300 mg/m² continuously from day 15 of induction during chemotherapy. Eligibility to HSCT depended on early morphological response and minimal residual disease. Imatinib was recommended throughout the first year after transplant. The co-primary endpoints were event-free survival and overall survival. All analyses were done in the intention-to-treat population. The trial is registered with the European Clinical Trials Database (EudraCT 2004-001647-30) and with ClinicalTrials.gov (NCT00287105) and is completed.

FINDINGS

158 patients were screened for eligibility, of whom 155 were enrolled between Jan 1, 2010, and Dec 31, 2014. 151 (97%) patients achieved first complete remission after induction and four after the consolidation phase, with 102 (66%) patients categorised as good risk and 53 (34%) as poor risk according to EsPhALL risk stratification criteria. 59 (38%) patients had HSCT during their first complete remission. 40 (26%) patients relapsed and 41 (26%) patients died during the study (25 [61%] during complete continuous remission, and 16 [39%] after relapse). The 5-year event-free survival was 57·0% (95% CI 48·5-64·6) and 5-year overall survival was 71·8% (63·5-78·5). 154 serious adverse events were reported in 80 (52%) of 155 patients. The most common toxicity was infection (61 [39%] patients, mostly bacterial); gastrointestinal disorders occurred in ten (6%) patients and osteonecrosis in eight (5%). Serious adverse events occurred mainly during high-risk blocks and delayed intensifications, including 14 fatal events (one in the consolidation phase, six in high-risk blocks, six in first delayed intensification, and one in second delayed intensification).

INTERPRETATION

Although HSCT was done in a smaller proportion of patients in EsPhALL2010 than in EsPhALL2004, event-free and overall survival were similar between the two studies. Our data suggest that imatinib given early and continuously with intensive chemotherapy might increase toxicity.

FUNDING

Projet Hospitalier de Recherche Clinique-Cancer and Novartis France; Bloodwise and Cancer Research UK; Ministry of Health, Czech Republic.

When Less Is Good, Is None Better? The Prognostic and Therapeutic Significance of Peri-Transplant Minimal Residual Disease Assessment in Pediatric Acute Lymphoblastic Leukemia

The measurement of minimal residual disease (MRD) in pediatric acute lymphoblastic leukemia (ALL) has become the most important prognostic tool of, and the backbone to, upfront risk stratification. While MRD assessment is the standard of care for assessing response and predicting outcomes for pediatric patients with ALL receiving chemotherapy, its use in allogeneic hematopoietic stem cell transplant (HSCT) has been less clearly defined. Herein, we discuss the importance of MRD assessment during the peri-HSCT period and its role in prognostication and management.

T-cell-rich HLA-haploidentical hematopoietic stem cell transplantation for relapsed/refractory pediatric Philadelphia chromosome-positive acute lymphoblastic leukemia without posttransplant tyrosine kinase inhibitor therapy

Intensive chemotherapy with tyrosine kinase inhibitor (TKI) improves the prognosis of patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-ALL). However, the prognosis of cases of relapsed or refractory Ph-ALL remains poor. Here, we aimed to assess the efficacy of T-cell-rich HLA-haploidentical hematopoietic stem cell transplantation (TCR-haplo-HSCT) in eight patients with relapsed or refractory pediatric Ph-ALL. Transplant-related mortality was observed in two patients. All patients discontinued TKI after receiving TCR-haplo-HSCT. The 3-year probability of overall survival and event-free survival was 75.0 and 62.5%, respectively. These results indicate the efficacy of TCR-haplo-HSCT for relapsed/refractory pediatric Ph-ALL.

Efficiency of allogeneic hematopoietic SCT from HLA fully-matched non-sibling relatives: a new prospect of exploiting extended family search

The best donors for hematopoietic SCT (HSCT) are fully-matched siblings. In patients without fully-matched siblings, HLA registries or cord blood banks are alternative strategies with some restrictions. Owing to the high rate of consanguineous marriage in our country, between 2006 and 2013, extended family searches were undertaken in Hematology-Oncology Research Center and Stem Cell Transplantation (HORCSCT), Tehran, Iran, in 523 HSCT candidates with parental consanguinity and no available HLA identical sibling. Fully-matched other-relative donors were found for 109 cases. We retrospectively studied the HSCT outcome in these patients. Median time to neutrophil engraftment was 13 days (range: 9-31days). In 83 patients, full chimerism and in 17 patients, mixed chimerism was achieved. Acute GvHD (aGvHD) grade II-IV appeared in 36 patients (33%). The frequency of aGvHD development in various familial subgroups was NS. Five patients expired before day+100. In the surviving 104 cases, chronic GvHD developed in 20 patients (19.2%). The distantly related subgroup had significantly a higher rate of cGvHD (P=0.04). The 2-year OS and disease-free survival (DFS) were 76.7±4.5% and 71.7±4.7%, respectively. No significant difference in OS (P=0.30) and DFS (P=0.80) was unraveled between various familial relationships. Our considerable rate of fully-matched non-sibling family members and the favorable outcome support the rationale for extended family search in regions where consanguineous marriage is widely practiced.

Prophylactic post-transplant dasatinib administration in a pediatric patient with Philadelphia chromosome-positive acute lymphoblastic leukemia

Philadelphia chromosome-positive acute lymphoblastic leukemia has a poor prognosis, even in pediatric patients. Although imatinib-containing chemotherapy can reportedly improve early event-free survival, allogeneic hematopoietic stem cell transplantation is still considered to be the main curative treatment option. Dasatinib, a novel abl tyrosine kinase inhibitor, is being used for the treatment of relapsed or refractory Philadelphia chromosome-positive acute lymphoblastic leukemia and is reported to have excellent efficacy. We used dasatinib after bone marrow transplantation prior to the anticipated relapse for the purpose of prophylaxis against relapse. After discontinuation of dasatinib administration, molecular remission has lasted for 7 months. Although preventive use of dasatinib is as yet uncommon, we consider that dasatinib may eradicate the minimal residual disease and prevent recurrence, and it is feasible to administer and appears to be safe. Further studies are needed to confirm our experience in this case.

Hematopoietic stem cell transplant versus chemotherapy plus tyrosine kinase inhibitor in the treatment of pediatric Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL)

BACKGROUND

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) remained until recently the molecular genetic abnormality associated with the worst outcome. Hematopoietic stem cell transplant (HSCT) was considered the treatment of choice, however, recent data have indicated that chemotherapy plus tyrosine kinase inhibitor (TKI) maybe an alternative effective therapy.

METHODS

We conducted a retrospective analysis of children (<18 years) with Ph+ ALL who were treated at King Hussein Cancer Center (KHCC) from January 2003 till December 2011.

RESULTS

Over a 9 year period, 411 children were diagnosed and treated for ALL at KHCC. Twenty three (6.6%) had Ph+ ALL; 16 males and 7 females. Median age at diagnosis was 9.5 years (range 1.67-17). The median white blood cell count was 58.6×10(3)/μL (range 1.6-459). Twelve patients underwent HSCT from a full matched related donor; and 10 were treated with intensive chemotherapy plus TKI (imatinib). Those who underwent HSCT were significantly older (P=0.004) and had a higher leukocyte count at diagnosis (P=0.53). After a median follow up of 42.2 months (range 12.7-107), the estimated 5 year event free survival (EFS) and overall survival (OS) were 75% and 91.6%, respectively, for those who underwent HSCT as primary therapy and 49.3% and 83.3%, respectively, for those treated with chemotherapy plus imatinib. There was no significant difference in EFS (P=0.98) or OS (P=1) between the two treatment modalities.

CONCLUSIONS

Our results indicate that chemotherapy plus TKI may be a reasonable treatment option for some children with Ph+ ALL.

Criteria for and outcomes of allogeneic haematopoietic stem cell transplant in children, adolescents and young adults with acute lymphoblastic leukaemia in first complete remission

Most children, adolescents and young adults with acute lymphoblastic leukaemia (ALL) in first complete remission (CR1) have an excellent prognosis with multi-agent chemotherapy in induction, consolidation, re-induction and maintenance therapy. However, there is a subset of patients with a more guarded prognosis using this approach, who may benefit from haematopoietic allogeneic stem cell transplantation (alloHSCT). Commonly used criteria for alloHSCT in children, adolescents and young adults with ALL in CR1 include: induction failure, poor cytogenetics, persistent minimal residual disease (MRD), age, immunophenotype, white blood cell count at diagnosis and rapidity of induction response. Two-year event-free survival following alloHSCT in patients with ALL in CR1 ranges from 50 to 80% depending on disease status, donor source, conditioning therapy, age and other risk factors. Future studies should focus on more precisely identifying poor-risk features, such as disease genomics and host pharmacogenomics, refining MRD measurements, improving unrelated donor matching, reducing MRD prior to alloHSCT, and developing post-alloHSCT humoral and cellular therapy approaches.

Administration of imatinib after allogeneic hematopoietic stem cell transplantation may improve disease-free survival for patients with Philadelphia chromosome-positive acute lymphobla stic leukemia

BACKGROUND

Maintenance therapy with imatinib during the post-transplant period has been used for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL); however, its efficacy has not been demonstrated. A study was designed to investigate the safety of imatinib and its efficacy in preventing hematological relapse and improving disease-free survival (DFS) when administered after allogeneic hematopoietic stem cell transplantation (allo-HCT).

METHODS

Patients with Ph + ALL that received allo-HCT were enrolled in the study. Real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was used to detect BCR-ABL transcript levels. Imatinib therapy was initiated if patient neutrophil counts were > 1.0 × 10(9)/L and platelet counts were > 50.0 × 10(9)/L, or if they displayed either elevated BCR-ABL transcript levels in two consecutive tests, or a BCR-ABL transcript level ≥ 10(-2) after initial engraftment. Patients receiving imatinib after relapse were assigned to the non-imatinib group. The imatinib treatment was scheduled for 3-12 months, until BCR-ABL transcript levels were negative at least for three consecutive tests or complete molecular remission was sustained for at least 3 months.

RESULTS

A total of 82 patients were enrolled. Sixty-two patients initiated imatinib therapy post-HCT. Imatinib therapy was initiated at a median time of 70 days post-HCT. Grade 3-4 adverse events (AEs) occurred in 17.7% of patients. Ten patients (16.1%) terminated imatinib therapy owing to AEs. Among the patients in imatinib and non-imatinib groups, the estimated 5-year relapse rate was 10.2% and 33.1% (p = 0.016), and the 5-year probability of DFS was 81.5% and 33.5% (p = 0.000) with the median follow-up of 31 months (range, 2.5-76 months) and 24.5 months (range, 4-72 months), respectively. Multivariate analysis identified imatinib maintenance therapy post-HCT as an independent prognostic factor for DFS (p = 0.000, hazard ratio [HR] =4.8) and OS (p = 0.000, HR = 6.2).

CONCLUSIONS

These results indicate that relapse rate can be reduced and DFS may be improved in Ph + ALL patients with imatinib maintenance therapy after HCT. BCR-ABLmonitoring by qRT-PCR can guide maintenance therapy with imatinib including initiation time and treatment duration after allo-HCT.

Role of cytotoxic therapy with hematopoietic stem cell transplantation in the treatment of pediatric acute lymphoblastic leukemia: update of the 2005 evidence-based review

Clinical research published since the first evidence-based review on the role of hematopoietic stem cell transplantation (SCT) in the treatment of pediatric acute lymphoblastic leukemia (ALL) is presented and critically evaluated in this update. Treatment recommendations are provided by an expert panel. Allogeneic SCT is recommended for children who: are in second complete remission (CR2) after experiencing an early marrow relapse for precursor-B ALL; experienced primary induction failure, but subsequently achieved a CR1; have T-lineage ALL in CR2; or have ALL in third or greater remission. Although the 2005 pediatric ALL evidence-based review (EBR) recommended allogeneic SCT for children with Philadelphia chromosome positive (Ph+) ALL in CR1, preliminary tyrosine kinase inhibitor (TKI) data demonstrate that early outcomes are comparable for allogeneic SCT and chemotherapy + imatinib. Based on the evidence, autologous SCT is not recommended for ALL in CR1. Allogeneic SCT is not recommended for: T-lineage ALL in CR1; mixed-lineage leukemia (MLL)+ ALL when it is the sole adverse risk factor; isolated central nervous system (CNS) relapse in precursor-B ALL. Based on expert opinion, allogeneic SCT may be considered for hypodiploid ALL and persistent minimal residual disease [corrected] (MRD) positivity in ALL in CR1 or greater, although these are areas that need further study. Treatment recommendations pertaining to various transplantation techniques are also provided, as are areas of needed future research.

Intermediate dose of imatinib in combination with chemotherapy followed by allogeneic stem cell transplantation improves early outcome in paediatric Philadelphia chromosome-positive acute lymphoblastic leukaemia (ALL): results of the Spanish Cooperative Group SHOP studies ALL-94, ALL-99 and ALL-2005

Philadelphia-chromosome acute lymphoblastic leukaemia (Ph+ ALL) is a subgroup of ALL with very high risk of treatment failure. We report here the results of the Sociedad Española de Hematología y Oncología Pediátricas (SEHOP/SHOP) in paediatric Ph+ ALL treated with intermediate-dose imatinib concurrent with intensive chemotherapy. The toxicities and outcome of these patients were compared with historical controls not receiving imatinib. Patients with Ph+ ALL aged 1-18years were enrolled in three consecutive ALL/SHOP trials (SHOP-94/SHOP-99/SHOP-2005). In the SHOP-2005 trial, imatinib (260mg/m(2) per day) was given on day-15 of induction. Allogeneic haematopoietic stem-cell transplantation (HSCT) from a matched related or unrelated donor was scheduled in first complete remission (CR1). Forty-three patients were evaluable (22 boys, median age 6·8years, range, 1·2-15). Sixteen received imatinib whereas 27 received similar chemotherapy without imatinib. Seventeen of 27 and 15 of 16 patients in the non-imatinib and imatinib cohort, respectively, underwent HSCT in CR1. With a median follow-up of 109 and 39months for the non-imatinib and imatinib cohorts, the 3-year event-free survival (EFS) was 29·6% and 78·7%, respectively (P=0·01). These results show that, compared to historical controls, intermediate dose of imatinib given concomitantly with chemotherapy and followed by allogeneic HSCT markedly improved early EFS in paediatric Ph+ ALL.

The treatment of neurodegenerative disorders using umbilical cord blood and menstrual blood-derived stem cells

Stem cell transplantation is a potentially important means of treatment for a number of disorders. Two different stem cell populations of interest are mononuclear umbilical cord blood cells and menstrual blood-derived stem cells. These cells are relatively easy to obtain, appear to be pluripotent, and are immunologically immature. These cells, particularly umbilical cord blood cells, have been studied as either single or multiple injections in a number of animal models of neurodegenerative disorders with some degree of success, including stroke, Alzheimer's disease, amyotrophic lateral sclerosis, and Sanfilippo syndrome type B. Evidence of anti-inflammatory effects and secretion of specific cytokines and growth factors that promote cell survival, rather than cell replacement, have been detected in both transplanted cells.

Recent advances in hematopoietic stem cell transplantation for childhood acute lymphoblastic leukemia

Hematopoietic stem cell transplantation has been an important treatment modality in the management of high-risk or relapsed childhood acute lymphoblastic leukemia. Analysis of its efficacy has been based mostly on stratification of patients by epidemiologic criteria such as disease status at transplantation, type of donor, and conditioning regimens used. The outcome has improved only marginally over the years, with the improvement attributable mainly to better supportive care. Leukemia recurrence remains a major cause of treatment failure. Recent investigations have focused on the biology of the underlying malignancy and on transplant alloreactivity. The results of these investigations may provide a better scientific approach to indications for transplantation, donor selection, and disease monitoring.