Prior treatment with the tyrosine kinase inhibitors dasatinib and nilotinib allows stem cell transplantation (SCT) in a less advanced disease phase and does not increase SCT Toxicity in patients with chronic myelogenous leukemia and philadelphia positive acute lymphoblastic leukemia

Outcomes and toxicity of allogeneic hematopoietic cell transplantation in chronic myeloid leukemia patients previously treated with second-generation tyrosine kinase inhibitors: a prospective non-interventional study from the Chronic Malignancy Working Party of the EBMT

Allogeneic hematopoietic cell transplantation (allo-HCT) remains a treatment option for patients with chronic myeloid leukemia (CML) who fail to respond to tyrosine kinase inhibitors (TKIs). While imatinib seems to have no adverse impact on outcomes after transplant, little is known on the effects of prior use of second-generation TKI (2GTKI). We present the results of a prospective non-interventional study performed by the EBMT on 383 consecutive CML patients previously treated with dasatinib or nilotinib undergoing allo-HCT from 2009 to 2013. The median age was 45 years (18-68). Disease status at transplant was CP1 in 139 patients (38%), AP or >CP1 in 163 (45%), and BC in 59 (16%). The choice of 2GTKI was: 40% dasatinib, 17% nilotinib, and 43% a sequential treatment of dasatinib and nilotinib with or without bosutinib/ponatinib. With a median follow-up of 37 months (1-77), 8% of patients developed either primary or secondary graft failure, 34% acute and 60% chronic GvHD. There were no differences in post-transplant complications between the three different 2GTKI subgroups. Non-relapse mortality was 18% and 24% at 12 months and at 5 years, respectively. Relapse incidence was 36%, overall survival 56% and relapse-free survival 40% at 5 years. No differences in post-transplant outcomes were found between the three different 2GTKI subgroups. This prospective study demonstrates the feasibility of allo-HCT in patients previously treated with 2GTKI with a post-transplant complications rate comparable to that of TKI-naive or imatinib-treated patients.

[Efficacy comparison of sequential treatment with first-line administration of second-generation and first-generation tyrosine kinase inhibitors in patients with Ph+ acute lymphoblastic leukemia followed by allogeneic hematopoietic stem cell transplantation]

Objective: To investigate the efficacy of sequential treatment with first-line administration of second-generation tyrosine kinase inhibitors (TKI) and first-generation TKI (imatinib) in patients with Ph⁺ acute lymphoblastic leukemia (Ph⁺ ALL) followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods: Retrospective analysis of clinical features and prognosis of 76 newly diagnosed Ph ⁺ALL patients from June 2011 to December 2015 treated by allo-HSCT combined with first-line administration of second-generation or first-generation TKI was performed and the efficacy compared. Results: Of 76 Ph⁺ ALL patients, first-generation TKI was administered in 57 cases, second-generation TKI in 19 cases, including 10 cases of nilotinib and 9 cases of dasatinib. There was no significant difference in age, WBC counts, additional chromosomal abnormalities, time form diagnosis to transplantation, transplantation type, conditioning regimen or TKI initiation time between the two groups. Complete remission (CR) rates at the fourth week of induction therapy in first-generation TKI group and second-generation TKI group was 93.0% and 94.7% (P=1.000), respectively. Major molecular response (MMR, BCR-ABL/ABL reduce 3 log) rates meanwhile were 46.0% and 40.0% (χ²=0.169, P=0.681). Relapse rates before transplantation were 14.0% and 10.5% (P=1.000). MMR rates before transplantation were 54.4% and 68.2% (χ²=1.152, P=0.283). The 2-year overall survival (OS) rates of first-generation and second-generation TKI group were 62.0% and 94.7% (χ²=5.765, P=0.016), 2-year event-free survival (EFS) rates were 46.3% and 84.2% (χ²=5.644, P=0.018), respectively. Univariate analysis showed that second-generation TKI could improve OS (HR=0.126, 95%CI 0.017-0.939, P=0.043). Multiple factors analysis showed that second-generation TKI (HR=0.267, 95%CI 0.081-0.873, P=0.029) and MMR before transplantation (HR=0.496, 95%CI 0.254-0.968, P=0.040) were good independent prognostic factors of EFS. Conclusions: There was significant difference in the efficacy of second-generation TKI and first-generation TKI for Ph⁺ ALL patients treated by allo-HSCT. First-line administration of second-generation TKI showed better efficacy than that of first-generation TKI for Ph⁺ ALL patients.

Clinical impact of pretransplant use of multiple tyrosine kinase inhibitors on the outcome of allogeneic hematopoietic stem cell transplantation for chronic myelogenous leukemia

Tyrosine kinase inhibitors (TKIs) are widely used to treat patients with chronic myelogenous leukemia in the chronic phase (CML-CP), and outcomes of TKI treatment for patients with CML-CP have been excellent. Since multiple TKIs are currently available, second-line or third-line TKI therapy is considered for patients who are intolerant of or resistant to the previous TKI treatment. Therefore, allogeneic hematopoietic stem cell transplantation (allo-HSCT) is considered only for patients with disease progression or for patients after treatment failure with multiple TKIs. To reflect the current clinical situation of patients with CML-CP, we tried to clarify whether prior TKI treatment affects the outcome of allo-HSCT. Data from 237 patients for whom the number of pretransplant TKIs varied from one to three were used for analysis. Before allo-HSCT, 153 patients were treated with one TKI, 49 patients were treated with two TKIs and 35 patients were treated with three TKIs. In addition to conventional risk factors, i.e., disease status at transplantation and patient's age, the use of three TKIs before transplantation was identified as a significant adverse factor for prognosis. Nonrelapse mortality rate was higher in patients treated with three TKIs than in patients treated with one or two TKIs. Our results suggest that allo-HSCT could be considered for young patients with CML-CP who manifest resistance to second-line TKI therapy and who have an appropriate donor.

New drugs and allogeneic hematopoietic stem cell transplantation for hematological malignancies: do they have a role in bridging, consolidating or conditioning transplantation treatment?

INTRODUCTION

Novel targeted therapies and monoclonal antibodies can be combined with allogeneic stem cell transplantation (allo-SCT) at different time-points: 1) before the transplant to reduce tumour burden, 2) as part of the conditioning in place of or in addition to conventional agents 3) after the transplant to allow long-term disease control. Areas covered: This review focuses on the current integration of new drugs with allo-SCT for the treatment of major hematological malignancies for which allo-SCT has been a widely-adopted therapy. Expert opinion: After having been used as single agent salvage treatments in relapsed patients after allo-SCT or in combination with donor lymphocyte infusions, many new drugs have also been safely employed before allo-SCT as a bridge to transplantation or after it as planned consolidation/maintenance. This era of new drugs has opened new important opportunities to 'smartly' combine 'targeted drugs and cell therapies' in new treatment paradigms that may lead to higher cure rates or longer disease control in patients with hematological malignancies.

Allogeneic stem cell transplantation in chronic myeloid leukemia patients: Single center experience

Chronic myeloid leukemia (CML) is a myeloproliferative disease which leads the unregulated growth of myeloid cells in the bone marrow. It is characterized by the presence of Philadelphia chromosome. Reciprocal translocation of the ABL gene from chromosome 9 to 22 t (9; 22) (q34; q11.2) generate a fusion gene (BCR-ABL). BCR-ABL protein had constitutive tyrosine kinase activity that is a primary cause of chronic phase of CML. Tyrosine kinase inhibitors (TKIs) are now considered standard therapy for patients with CML. Even though, successful treatment with the TKIs, allogeneic stem cell transplantation (ASCT) is still an important option for the treatment of CML, especially for patients who are resistant or intolerant to at least one second generation TKI or for patients with blastic phase. Today, we know that there is no evidence for increased transplant-related toxicity and negative impact of survival with pre-transplant TKIs. However, there are some controversies about timing of ASCT, the optimal conditioning regimens and donor source. Another important issue is that BCR-ABL signaling is not necessary for survival of CML stem cell and TKIs were not effective on these cells. So, ASCT may play a role to eliminate CML stem cells. In this article, we review the diagnosis, management and treatment of CML. Later, we present our center’s outcomes of ASCT for patients with CML and then, we discuss the place of ASCT in CML treatment in the TKIs era.

Diagnostic and treatment of adult Philadelphia chromosome-positive acute lymphoblastic leukemia

The outcome of adult patients with Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) has improved substantially with the introduction of tyrosine kinase inhibitors (TKIs). TKIs are now integral components of therapy for Ph+ ALL. The current consensus is that they improve patient outcomes compared with historical control patients treated with chemotherapy alone, and increase the number of patients able to receive stem cell transplant. New challenges have emerged with respect to induction of resistance mainly via Abelson tyrosine kinase mutations. Several novel kinase inhibitors with significantly more potent antileukemic activity are currently being developed. Furthermore novel immune therapies, which recruit or modify patient's own T cells to fight leukemic cells, are being developed and could find an important place in Ph+ ALL therapy by few years. In this article, we reviewed treatment approaches in adults with Ph+ ALL with a focus on TKIs and combined chemotherapy regimens.

Allogeneic transplantation for CML in the TKI era: striking the right balance

The management of chronic myeloid leukaemia (CML) has changed extensively over the past 15 years. Prior to the development of targeted therapies and in the absence of allogeneic haematopoetic stem-cell transplantation (HSCT), the median survival was 5-7 years. HSCT was quickly established as the standard of care for eligible patients through the 1980s and 1990s, when considerable advances were made in the optimization of conditioning regimens and supportive care. Exploiting a deeper understanding of the molecular basis of CML, the development of tyrosine kinase inhibitors (TKIs) in the late 1990s revolutionized the management of the disease. TKIs offer the prospect of long-term disease control with a simple oral therapy, and are the first-line treatment in the 21(st) century. The majority of patients treated with TKIs achieve excellent responses with sustained treatment, and some even continue to have undetectable or exceptionally low level disease upon TKI withdrawal; however, for an almost equal number of patients, an adequate response cannot be achieved with any of the currently available TKIs. For those patients who fail to respond adequately to TKIs, HSCT offers the best prospect of long-term survival.

Long-term efficacy and safety of bosutinib in patients with advanced leukemia following resistance/intolerance to imatinib and other tyrosine kinase inhibitors

Long-term efficacy and safety of bosutinib (≥4 years follow-up from last enrolled patient) were evaluated in an ongoing phase 1/2 study in the advanced leukemia cohort with prior treatment failure (accelerated-phase [AP, n = 79] chronic myeloid leukemia [CML], blast-phase [BP, n = 64] CML, acute lymphoblastic leukemia [ALL, n = 24]). Fourteen AP, 2 BP, and 1 ALL patient remained on bosutinib at 4 years (vs. 38, 8, 1 at 1 year); median (range) treatment durations: 10.2 (0.1-88.6), 2.8 (0.03-55.9), 0.97 (0.3-89.2) months. Among AP and BP patients, 57% and 28% newly attained or maintained baseline overall hematologic response (OHR); 40% and 37% attained/maintained major cytogenetic response (MCyR) by 4 years (most by 12 months). In responders at 1 versus 4 years, Kaplan-Meier (KM) probabilities of maintaining OHR were 78% versus 49% (AP) and 28% versus 19% (BP); KM probabilities of maintaining MCyR were 65% versus 49% (AP) and 21% versus 21% (BP). Most common AEs (AP, BP) were gastrointestinal (96%; 83%), primarily diarrhea (85%; 64%), which was typically low grade (maximum grade 1/2: 81%; 59%) and transient; no patient discontinued due to diarrhea. Serious AEs occurred in 44 (56%) AP and 37 (58%) BP patients, most commonly pneumonia (n = 9) for AP and pyrexia (n = 6) for BP; 11 and 13 died within 30 days of last dose (2 considered bosutinib-related [AP] per investigator). Responses were durable in ∼50% AP responders at 4 years (∼25% BP patients responded at year 1, suggesting possible bridge-to-transplant role in BP patients); toxicity was manageable.

Final report of a phase II study of imatinib mesylate with hyper-CVAD for the front-line treatment of adult patients with Philadelphia chromosome-positive acute lymphoblastic leukemia

We have previously reported on the efficacy and tolerability of hyper-CVAD regimen (cyclophosphamide, vincristine, Adriamycin, and dexamethasone) and imatinib followed by imatinib-based consolidation/maintenance therapy in 20 patients with newly diagnosed Philadelphia-positive acute lymphoblastic leukemia. Here, we present the 13-year follow up of our study. Fifty-four patients with newly diagnosed Philadelphia-positive acute lymphoblastic leukemia were enrolled: 39 (72%) with de novo disease, 6 (11%) whose disease was primary refractory after induction (without a tyrosine kinase inhibitor), and 9 (17%) in complete remission after one course of induction therapy (without tyrosine kinase inhibitor). Forty-two (93%) of the 45 patients treated for active disease achieved complete remission, one achieved complete remission with incomplete recovery of platelets, one achieved partial remission and one died during induction. Nineteen (35%) patients are alive and 18 are in complete remission. The 5-year overall survival rate for all patients was 43%. Significant negative predictors of overall survival were age over 60 years, p190 molecular transcript, and active disease at enrollment. Sixteen (30%) patients underwent allogeneic stem cell transplantation. Median overall survival was not significantly greater for patients who underwent transplant. Patients with residual molecular disease at three months had improved complete remission duration with transplant. The median time to hematologic recovery and severe toxicities with combination were not significantly different from those observed with conventional chemotherapy. Only one patient discontinued therapy due to toxicity. HyperCVAD chemotherapy and imatinib is an effective regimen for Philadelphia-positive acute lymphoblastic leukemia. Transplant may not be indicated in all patients with Philadelphia-positive acute lymphoblastic leukemia. (clinicaltrials.gov identifier: NCT00038610).

Phase 1/2 study of nilotinib prophylaxis after allogeneic stem cell transplantation in patients with advanced chronic myeloid leukemia or Philadelphia chromosome-positive acute lymphoblastic leukemia

BACKGROUND

Allogeneic stem cell transplantation (SCT) remains the standard treatment for advanced chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL). Relapsed disease is the major cause of treatment failure, especially when SCT is given in the setting of advanced disease. Tyrosine kinase inhibitors can be given after transplantation prophylactically or after the detection of minimal residual disease (MRD) to reduce the relapse risk.

METHODS

Posttransplant nilotinib was started after the achievement of sustained engraftment and the resolution of transplant-related toxicities. Nilotinib was continued until progression or unacceptable toxicity.

RESULTS

Twenty-two patients with advanced CML (n = 15) or Ph(+) ALL (n = 7) underwent SCT with human leukocyte antigen-matched siblings (n = 11), unrelated donors (n = 7), or alternative donors (n = 4). Sixteen patients were given prophylactic nilotinib maintenance, which was started at a median of 38 days after transplantation. Six patients stopped the treatment because of toxicities (mostly gastrointestinal and hepatic). After nilotinib maintenance, 11 patients achieved (n = 9) or maintained (n = 2) a complete molecular response (CMR), and only 1 of them later relapsed. Four of the 5 patients not achieving CMR relapsed. At a median follow-up of 46 months, 9 patients were alive, and 13 had died. The 2-year overall and progression-free survival rates were 55% (95% confidence interval [CI], 34%-75%) and 45% (95% CI, 25%-66%), respectively. Among the 16 nilotinib recipients, the rates were 69% (95% CI, 46%-92%) and 56% (95% CI, 32%-81%), respectively. The 2-year nonrelapse mortality and relapse rates for all patients were 32% (95% CI, 17%-58%) and 23% (95% CI, 11%-49%), respectively.

CONCLUSIONS

Nilotinib is relatively safe and effective prophylactic therapy for the prevention of relapse after SCT. It may control MRD and convert patients to CMR, which is associated with prolonged survival. These observations merit further study in larger scale studies.

Chronic myeloid leukemia-transplantation in the tyrosine kinase era

Allogeneic hematopoietic stem cell transplantation (HSCT) revolutionized the outlook for many patients with chronic myeloid leukemia (CML) in the 1980s. The introduction of the tyrosine kinase inhibitors (TKIs) nearly 15 years ago displaced HSCT as the first-line treatment for most CML patients. However, in the twenty-first century HSCT remains a viable treatment option for many patients with CML. This review focuses on the role of HSCT for CML in the TKI era, paying particular attention to patient selection and transplant outcome.

Impact of minimal residual disease on outcomes after umbilical cord blood transplantation for adults with Philadelphia-positive acute lymphoblastic leukaemia: an analysis on behalf of Eurocord, Cord Blood Committee and the Acute Leukaemia working party of the European group for Blood and Marrow Transplantation

The status of umbilical cord blood transplantation (UCBT) in adults with Philadelphia-positive acute lymphoblastic leukaemia (Ph+ALL) and the impact of minimal residual disease (MRD) before transplant are not well established. We analysed 98 patients receiving UCBT for Ph+ALL in first (CR1) or second (CR2) complete remission (CR1, n = 79; CR2, n = 19) with MRD available before UCBT (92% analysed by reverse transcription polymerase chain reaction). Median age was 38 years and median follow-up was 36 months; 63% of patients received myeloablative conditioning and 42% received double-unit UCBT. Eighty-three patients were treated with at least one tyrosine kinase inhibitor before UCBT. MRD was negative (-) in 39 and positive (+) in 59 patients. Three-year cumulative incidence of relapse was 34%; 45% in MRD+ and 16% in MRD- patients (P =0·013). Three-year cumulative incidence of non-relapse mortality was 31%; it was increased in patients older than 35 years (P = 0·02). Leukaemia-free survival (LFS) at 3 years was 36%; 27% in MRD+ and 49% in MRD- patients (P = 0·05), and 41% for CR1 and 14% for CR2 (P = 0·008). Multivariate analysis identified only CR1 as being associated with improved LFS. In conclusion, MRD+ before UCBT is associated with increased relapse. Strategies to decrease relapse in UCBT recipients with Ph+ALL and MRD+ are needed.

Treatment of Philadelphia-positive acute lymphoid leukemia

SUMMARY Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL) represents approximately 15–30% of ALL in adults and is characterized by the expression of the fusion protein BCR–ABL with oncogenic activity. Remission and survival rates were lower whereas relapse risk was increased in Ph+ compared with Philadelphia-negative ALL, until remarkable improvements in the management of Ph+ ALL were achieved through the introduction of tyrosine kinase inhibitors that reduce the activity of the BCR–ABL protein. However, in patients achieving complete remission, allogeneic hematopoietic stem cell transplantation is in most cases a mandatory therapeutic step because rate of relapses are still high. This review will illustrate the current therapeutic options for the management of Ph+ ALL and indicate how better curative options may stem from appropriate implementation of tyrosine kinase inhibitors and novel antitumoral agents.

Prognostic factors for outcomes of allogeneic stem cell transplantation in chronic phase chronic myeloid leukemia in the era of tyrosine kinase inhibitors

The aim of this study was to estimate the prognostic factors for the outcomes of chronic myeloid leukemia (CML) patients receiving allogeneic stem cell transplantation (SCT) in chronic phase (CP) in the era of tyrosine kinase inhibitors (TKIs). Ninety-seven patients who underwent allogeneic SCT in CP were analyzed. Forty-seven were TKI-naïve at the time of transplant, and 50 received TKI(s) treatment before transplantation. After a median follow-up of 115.8 months, the 4-year overall survival and event-free survival were 80.4 and 58.8%, respectively. Multivariate analysis showed that there were no differences in survival outcomes based on prior TKI therapy. Older age was a prognostic factor for higher treatment-related mortality (TRM), and the type of graft source and younger age were associated with relapse, but prior TKI therapy and disease status at the time of transplant were not associated with either TRM or relapse. Additionally, a major molecular response at 1 month and an MR(4.5) at 3 months were important predictors of favorable long-term outcomes. This study demonstrates the prognostic factors for the outcomes of allogeneic SCT in CP CML and shows that survival outcomes were not affected by the administration of long-term multi-TKI treatment prior to transplantation.

Philadelphia-positive acute lymphoblastic leukemia: current treatment options

The Philadelphia chromosome (Ph), t(9;22), is seen in about 20 % to 30 % of adults diagnosed with acute lymphoblastic leukemia (ALL). It has been associated with poorer prognosis compared with Ph-negative ALL. Tyrosine kinase inhibitors (TKIs) targeting the BCR-ABL oncogenic protein from this translocation have been incorporated into treatment regimens used to treat patients with Ph-positive ALL. Imatinib has been the most widely used TKI with several published trials showing it produced better outcomes when combined with chemotherapy. Dasatinib, a more potent inhibitor than imatinib, has also been evaluated with promising results. However, relapses still occur at a high rate, and allogeneic stem cell transplant is considered, so far, a better curative option in first remission. Additional strategies have also included incorporation of TKIs in the post-transplant setting and the use of newer third generation TKIs. This review provides an update on emerging therapies for adults with Ph-positive ALL.

Chronic myelogenous leukemia: role of stem cell transplant in the imatinib era

In the pre-tyrosine kinase (TKI) era, allogeneic stem cell transplant (allo-SCT) was the front-line treatment of choice for young patients with chronic myelogenous leukemia (CML). Today, imatinib is well established as front-line therapy for CML, with excellent long-term outcomes. This has changed the role of allo-SCT and the number of patients undergoing allo-SCT has declined dramatically. Allo-SCT is currently recommended for patients in accelerated/blast phase disease, those who have failed a second-generation TKI and those with TKI-resistant mutations such as T315I. The role of allo-SCT in the management of CML will require continual reappraisal as medical therapies continue to evolve.

Molecular diagnostics, targeted therapy, and the indication for allogeneic stem cell transplantation in acute lymphoblastic leukemia

In recent years, the panel of known molecular mutations in acute lymphoblastic leukemia (ALL) has been continuously increased. In Philadelphia-positive ALL, deletions of the IKZF1 gene were identified as prognostically adverse factors. These improved insights in the molecular background and the clinical heterogeneity of distinct cytogenetic subgroups may allow most differentiated therapeutic decisions, for example, with respect to the indication to allogeneic HSCT within genetically defined ALL subtypes. Quantitative real-time PCR allows highly sensitive monitoring of the minimal residual disease (MRD) load, either based on reciprocal gene fusions or immune gene rearrangements. Molecular diagnostics provided the basis for targeted therapy concepts, for example, combining the tyrosine kinase inhibitor imatinib with chemotherapy in patients with Philadelphia-positive ALL. Screening for BCR-ABL1 mutations in Philadelphia-positive ALL allows to identify patients who may benefit from second-generation tyrosine kinase inhibitors or from novel compounds targeting the T315I mutation. Considering the central role of the molecular techniques for the management of patients with ALL, efforts should be made to facilitate and harmonize immunophenotyping, cytogenetics, and molecular mutation screening. Furthermore, the potential of high-throughput sequencing should be evaluated for diagnosis and follow-up of patients with B-lineage ALL.

Molecular diagnostics, targeted therapy, and the indication for allogeneic stem cell transplantation in acute lymphoblastic leukemia

In recent years, the panel of known molecular mutations in acute lymphoblastic leukemia (ALL) has been continuously increased. In Philadelphia-positive ALL, deletions of the IKZF1 gene were identified as prognostically adverse factors. These improved insights in the molecular background and the clinical heterogeneity of distinct cytogenetic subgroups may allow most differentiated therapeutic decisions, for example, with respect to the indication to allogeneic HSCT within genetically defined ALL subtypes. Quantitative real-time PCR allows highly sensitive monitoring of the minimal residual disease (MRD) load, either based on reciprocal gene fusions or immune gene rearrangements. Molecular diagnostics provided the basis for targeted therapy concepts, for example, combining the tyrosine kinase inhibitor imatinib with chemotherapy in patients with Philadelphia-positive ALL. Screening for BCR-ABL1 mutations in Philadelphia-positive ALL allows to identify patients who may benefit from second-generation tyrosine kinase inhibitors or from novel compounds targeting the T315I mutation. Considering the central role of the molecular techniques for the management of patients with ALL, efforts should be made to facilitate and harmonize immunophenotyping, cytogenetics, and molecular mutation screening. Furthermore, the potential of high-throughput sequencing should be evaluated for diagnosis and follow-up of patients with B-lineage ALL.

Managing Philadelphia chromosome-positive acute lymphoblastic leukemia: role of tyrosine kinase inhibitors

Before the introduction of tyrosine kinase inhibitors, the prognosis for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia was poor. The treatment of choice, stem cell transplantation, is a potentially curative option, but it is available only for a minority of patients and is associated with significant risk of morbidity and mortality. Although imatinib is largely effective, a substantial proportion of patients become resistant or intolerant to it. The activity of imatinib may be enhanced by coadministration with chemotherapy; such treatment is effective in many patients. Dasatinib is established as a second-line treatment in patients with resistance to or intolerance of imatinib. Recent data suggest that dasatinib, either alone or in combination with chemotherapy, has utility as first-line therapy. Dasatinib is more potent than imatinib, is less susceptible to drug-resistance mechanisms, and has been shown to penetrate the blood-brain barrier, making it potentially effective for treating central nervous system disease. Patients who relapse during treatment with dasatinib frequently carry the T315I mutation of BCR-ABL. Future regimens combining dasatinib with an agent able to inhibit this mutation may further improve outcome.

NCCN Task Force report: tyrosine kinase inhibitor therapy selection in the management of patients with chronic myelogenous leukemia

The advent of imatinib has dramatically improved outcomes in patients with chronic myelogenous leukemia (CML). It has become the standard of care for all patients with newly diagnosed chronic-phase CML based on its successful induction of durable responses in most patients. However, its use is complicated by the development of resistance in some patients. Dose escalation might overcome this resistance if detected early. The second-generation tyrosine kinase inhibitors (TKIs) dasatinib and nilotinib provide effective therapeutic options for managing patients resistant or intolerant to imatinib. Recent studies have shown that dasatinib and nilotinib provide quicker and potentially better responses than standard-dose imatinib when used as a first-line treatment. The goal of therapy for patients with CML is the achievement of a complete cytogenetic response, and eventually a major molecular response, to prevent disease progression to accelerated or blast phase. Selecting the appropriate TKI depends on many factors, including disease phase, primary or secondary resistance to TKI, the agent's side effect profile and its relative effectiveness against BCR-ABL mutations, and the patient's tolerance to therapy. In October 2010, NCCN organized a task force consisting of a panel of experts from NCCN Member Institutions with expertise in the management of patients with CML to discuss these issues. This report provides recommendations regarding the selection of TKI therapy for the management of patients with CML based on the evaluation of available published clinical data and expert opinion among the task force members.

Challenges for allogeneic hematopoietic stem cell transplantation in chronic myeloid leukemia in the era of tyrosine kinase inhibitors

Following the introduction of the tyrosine kinase inhibitor (TKI) imatinib in the treatment of chronic myeloid leukemia (CML) patients, the allogeneic hematopoietic stem cell transplantation (HSCT) scene in CML has changed dramatically. The number of patients receiving HSCT in first chronic phase (CP) has declined rapidly, as allogeneic HSCT in CP is now performed in these patients only in case of failure or intolerance of TKIs. Second, those CML patients who undergo allogeneic HSCT represent a selection of high-risk patients due to more advanced disease with high rates of accelerated or blast phase (being associated with an increased relapse risk), advanced age and relevant co-morbidities. Efforts at meeting these special challenges are being developed: treatment with TKIs aims to improve the pre-transplant remission status before HSCT. Dose-reduced conditioning protocols were introduced to decrease transplant-related mortality in patients with co-morbidities or older age. In the post-transplant period, TKIs may be administered for prophylaxis and for treatment of post-transplant relapse. Still, the outcome of patients in advanced CML phases remains guarded, and requires an improvement in current transplant strategies.

Chronic myeloid leukemia: an update of concepts and management recommendations of European LeukemiaNet

PURPOSE

To review and update the European LeukemiaNet (ELN) recommendations for the management of chronic myeloid leukemia with imatinib and second-generation tyrosine kinase inhibitors (TKIs), including monitoring, response definition, and first- and second-line therapy.

METHODS

These recommendations are based on a critical and comprehensive review of the relevant papers up to February 2009 and the results of four consensus conferences held by the panel of experts appointed by ELN in 2008.

RESULTS

Cytogenetic monitoring was required at 3, 6, 12, and 18 months. Molecular monitoring was required every 3 months. On the basis of the degree and the timing of hematologic, cytogenetic, and molecular results, the response to first-line imatinib was defined as optimal, suboptimal, or failure, and the response to second-generation TKIs was defined as suboptimal or failure.

CONCLUSION

Initial treatment was confirmed as imatinib 400 mg daily. Imatinib should be continued indefinitely in optimal responders. Suboptimal responders may continue on imatinb, at the same or higher dose, or may be eligible for investigational therapy with second-generation TKIs. In instances of imatinib failure, second-generation TKIs are recommended, followed by allogeneic hematopoietic stem-cell transplantation only in instances of failure and, sometimes, suboptimal response, depending on transplantation risk.

Allogeneic hematopoietic stem cell transplantation (allo SCT) for chronic myeloid leukemia in the imatinib era: evaluation of its impact within a subgroup of the randomized German CML Study IV

The role of allogeneic stem cell transplantation in chronic myeloid leukemia is being reevaluated. Whereas drug treatment has been shown to be superior in first-line treatment, data on allogeneic hematopoietic stem cell transplantation (allo SCT) as second-line therapy after imatinib failure are scarce. Using an interim safety analysis of the randomized German CML Study IV designed to optimize imatinib therapy by combination, dose escalation, and transplantation, we here report on 84 patients who underwent consecutive transplantation according to predefined criteria (low European Group for Blood and Marrow Transplantation [EBMT] score, imatinib failure, and advanced disease). Three-year survival after transplantation of 56 patients in chronic phase was 91% (median follow-up: 30 months). Transplantation-related mortality was 8%. In a matched pair comparison of patients who received a transplant and those who did not, survival was not different. Three-year survival after transplantation of 28 patients in advanced phase was 59%. Eighty-eight percent of patients who received a transplant achieved complete molecular remissions. We conclude that allo SCT could become the preferred second-line option after imatinib failure for suitable patients with a donor. The study is registered at the National Institutes of Health, http://clinicaltrials.gov: NCT00055874.

Prolonged survival in adults with acute lymphoblastic leukemia after reduced-intensity conditioning with cord blood or sibling donor transplantation

Twenty-two adult acute lymphoblastic leukemia (ALL) patients (21 of 22 in complete remission [CR]) received reduced-intensity conditioning followed by allogeneic transplantation. All patients were high risk. After a uniform preparative regimen (fludarabine 40 mg/m(2) x 5, cyclophosphamide 50 mg/kg, 200 cGy total body irradiation), patients received either matched related (n=4) or umbilical cord (n=18) donor grafts. All patients reached neutrophil engraftment and 100% donor chimerism (median, days 10 and 23, respectively). Overall survival, treatment-related mortality (TRM) and relapse were 50% (95% confidence interval [CI], 27%-73%), 27% (95% CI, 9%-45%), and 36% (95% CI, 14%-58%) at 3 years, respectively. There were no relapses beyond 2 years. The cumulative incidence of acute and chronic graft-versus-host disease was 55% and 45%. Hematopoietic cell transplantation in CR1 (n=14) led to significantly less TRM (8%, P< .04) and improved overall survival (81%, P< .01). For adults with ALL in CR, reduced intensity conditioning allografting results in modest TRM, limited risk of relapse, and promising leukemia-free survival. Clinical trial numbers are NCT00365287, NCT00305682, and NCT00303719.