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

Comparison of long-term outcomes between imatinib and dasatinib prophylaxis after allogeneic stem cell transplantation in patients with Philadelphia-positive acute lymphoblastic leukemia: A multicenter retrospective study

BACKGROUND

Although the prognosis of Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL) has improved with the introduction of tyrosine kinase inhibitors (TKIs) and stem cell transplantation, prevention of relapse after transplantation remains a concern. The aim of this study was to compare the impact of TKI prophylaxis with imatinib and dasatinib on long-term outcomes after transplantation.

METHODS

Patients with Ph+ ALL who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) at first complete remission (CR1) and received TKI prophylaxis after allo-HSCT were included in this retrospective analysis. Two cohorts were established based on the choice of TKI prophylaxis: the imatinib (Ima) and dasatinib (Das) cohorts. The survival and safety outcomes of these cohorts were compared.

RESULTS

Ninety-one patients in the Ima cohort and 50 in the Das cohort were included. After a median follow-up of 50.6 months, the 5-year cumulative incidence of relapse, nonrelapse mortality rate, and overall survival in the Ima and Das cohorts were 16.1% and 12.5%, 5.2% and 9.8%, and 86.5% and 77.6%, respectively, with no statistical differences. The cumulative incidence of mild chronic graft-versus-host disease was higher in the Das cohort. The most common adverse event was neutropenia (64.7% vs. 69.5%). The Das cohort had a higher incidence of gastrointestinal bleeding (25.5% vs. 2.3%) and gastrointestinal reaction (48.9% vs. 31.4%) than the Ima cohort. The proportion of patients treated on schedule was significantly lower in the Das cohort than in the Ima cohort, and drug intolerance was the main reason for protocol violation.

CONCLUSIONS

For patients with Ph+ ALL undergoing allo-HSCT in CR1, imatinib prophylaxis achieved long-term outcomes similar to those of dasatinib.

The potential role of RNA sequencing in diagnosing unexplained insensitivity to conventional chemotherapy in pediatric patients with B-cell acute lymphoblastic leukemia

Pediatric B-cell acute lymphoblastic leukemia (B-ALL) is a highly heterogeneous disease. According to large-scale RNA sequencing (RNA-seq) data, B-ALL patients can be divided into more than 10 subgroups. However, many genomic defects associated with resistance mechanisms have not yet been identified. As an individual clinical tool for molecular diagnostic risk classification, RNA-seq and gene expression pattern-based therapy could be potential upcoming strategies. In this study, we retrospectively analyzed the RNA-seq gene expression profiles of 45 children whose molecular diagnostic classifications were inconsistent with the response to chemotherapy. The relationship between the transcriptome and chemotherapy response was analyzed. Fusion gene identification was conducted for the included patients who did not have known high-risk associated fusion genes or gene mutations. The most frequently detected fusion gene pair in the high-risk group was the DHRSX duplication, which is a novel finding. Fusions involving ABL1, LMNB2, NFATC1, PAX5, and TTYH3 at onset were more frequently detected in the high-risk group, while fusions involving LFNG, TTYH3, and NFATC1 were frequently detected in the relapse group. According to the pathways involved, the underlying drug resistance mechanism is related to DNA methylation, autophagy, and protein metabolism. Overall, the implementation of an RNA-seq diagnostic system will identify activated markers associated with chemotherapy response, and guide future treatment adjustments.

Novel strategies to prevent and overcome relapse after allogeneic hematopoietic cell transplantation in acute lymphoblastic leukemia

The outcome of B-cell acute lymphoblastic leukemia (B-ALL) has improved over time with the incorporation of multi-agent chemotherapy in the treatment landscape as well as the recent approval of immunotherapeutic agents allowing a larger proportion of patients to undergo allogeneic hematopoietic cell transplantation (allo-HCT) which is still considered a potential curative approach. However, relapse post-transplant is still occurring and constitutes a common cause of treatment failure in B-ALL. The present review aims to discuss the novel strategies and therapies used to prevent and overcome relapse post allo-HCT in patients with ALL, focusing on the role of tyrosine kinase inhibitors in Philadelphia chromosome positive B-ALL, the role of innovative agents such as blinatumomab and inotuzumab ozogamicin, and finally the role of cellular therapy.

Prophylactic or preemptive tyrosine kinase inhibitor therapy after allogeneic hematopoietic cell transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia

Prevention of disease relapse after allogeneic hematopoietic cell transplantation (allo-HCT) in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia remains a major concern. Maintenance therapy with tyrosine kinase inhibitors (TKIs) after allo-HCT has been used to reduce the incidence of relapse. Two main strategies are employed for using TKIs after allo-HCT: prophylactic TKI therapy, which is given before measurable residual disease (MRD) detection, and preemptive TKI therapy, which is given after MRD detection. These strategies both have advantages and disadvantages in terms of treatment efficacy, adverse events, adherence, and socioeconomic factors. In addition, many issues remain to be resolved because of the lack of large prospective studies on how to use TKIs after allo-HCT. These include indications for prophylactic and preemptive TKI therapy, timing of initiation, frequency of MRD monitoring, TKI selection, dose, and treatment duration. While the current available evidence is extremely limited, this article will discuss these issues after summarizing some representative and recent studies. It will also share a novel indicator that can be used to visualize the reversible transition between molecular relapse and remission by TKI therapy.

How I treat with maintenance therapy after allogeneic HCT

Disease relapse is the leading cause of failure for patients receiving allogeneic hematopoietic cell transplantation (allo-HCT). Maintenance therapy administered after allo-HCT is a promising strategy to reduce the incidence of relapse and enhance the curative potential of allo-HCT. Research investigations and clinical applications of this approach have greatly increased in recent years, with an expanding number of available therapeutic agents to introduce in the posttransplant setting. However, many questions and challenges remain regarding the feasibility and clinical impact of maintenance. In this article, we present four common case scenarios addressing select available therapeutic agents as a framework to review published data and ongoing studies and describe our current standard practice in the rapidly evolving field of maintenance therapy after allo-HCT.

Tyrosine Kinase Inhibitor-associated Cerebral Arterial Occlusive Disease Treated with High-flow Bypass Surgery: A Case Report

Nilotinib, one of the tyrosine kinase inhibitors, has been used to treat chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). Nilotinib-associated cerebral arterial occlusive disease, which is treated with medicine with/without bypass surgery or stenting, has been sporadically reported to occur. The mechanism of the nilotinib-associated cerebral disease has not been clarified and is still controversial. Here we present the case of a 39-year-old woman with Ph+ ALL treated with nilotinib, which led to symptomatic intracranial arterial stenosis. We performed high-flow bypass surgery and observed the arterial stenotic change in the stenotic portion intraoperatively, whose findings strongly supported the theory of atherosclerosis and seemed to be irreversible.

Treatment of Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia in Adults

Simple Summary

Outcome of patients with Philadelphia-chromosome positive acute lymphoblastic leukemia (Ph+ ALL) dramatically improved during the past 20 years with the advent of tyrosine kinase inhibitors and monoclonal antibodies. Their great efficacy in young and fit patients led to question our reliance on chemotherapy and allogeneic hematopoietic stem cell transplantation. Moreover, these well-tolerated treatments can be safely administrated even in the elderly that represent the majority of Ph+ ALL patient. This review will focus on the recent changes of paradigm in the management of Ph+ ALL patients and the development of novel therapeutic strategies.

Abstract

Philadelphia-chromosome positive acute lymphoblastic leukemia (Ph+ ALL) is the most common subtype of B-ALL in adults and its incidence increases with age. It is characterized by the presence of BCR-ABL oncoprotein that plays a central role in the leukemogenesis of Ph+ ALL. Ph+ ALL patients traditionally had dismal prognosis and long-term survivors were only observed among patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) in first complete remission (CR1). However, feasibility of allo-HSCT is limited in this elderly population. Fortunately, development of increasingly powerful tyrosine kinase inhibitors (TKIs) from the beginning of the 2000′s dramatically improved the prognosis of Ph+ ALL patients with complete response rates above 90%, deep molecular responses and prolonged survival, altogether with good tolerance. TKIs became the keystone of Ph+ ALL management and their great efficacy led to develop reduced-intensity chemotherapy backbones. Subsequent introduction of blinatumomab allowed going further with development of chemo free strategies. This review will focus on these amazing recent advances as well as novel therapeutic strategies in adult Ph+ ALL.

20-Year Steady Increase in Survival of Adult Patients with Relapsed Philadelphia-Positive Acute Lymphoblastic Leukemia Post Allogeneic Hematopoietic Cell Transplantation

PURPOSE

Relapse after allogeneic hematopoietic cell transplantation (allo-HCT) remains the first cause of transplant failure in patients with Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL). In other hematologic malignancies, therapeutic advances resulted in significant improvement over time in survival of patients relapsing after transplant.

EXPERIMENTAL DESIGN

We compared outcomes at European Society for Blood and Marrow Transplantation (EBMT) participating centers of 899 adult patients with Ph+ ALL who relapsed between 2000 and 2019 after allo-HCT performed in first complete remission. Median follow-up for alive patients was 56 months.

RESULTS

Overall, 116 patients relapsed between 2000 and 2004, 225 between 2005 and 2009, 294 between 2010 and 2014, and 264 between 2015 and 2019. Patient and transplant characteristics were similar over the four time periods except for a progressive increase in unrelated donors, peripheral blood stem cells, reduced intensity conditioning, and in vivo T-cell depletion and a progressive decrease in total body irradiation. The 2-year overall survival (OS) after relapse increased from 27.8% for patients relapsing between 2000 and 2004 to 54.8% for 2015 and 2019 (P = 0.001). A second allo-HCT within 2 years after relapse was performed in 13.9% of patients resulting in a 2-year OS of 35.9%. In multivariate analysis, OS from relapse was positively affected by a longer time from transplant to relapse and the year of relapse.

CONCLUSIONS

We observed a major progressive improvement in OS from posttransplant relapse for patients with Ph+ ALL over the years, likely multifactorial including transplant-related factors, posttransplant salvage, and improvement in supportive care. These large-scale real-world data can serve as a benchmark for future studies in this setting. See related commentary by Gale, p. 813.

Comparison of allogeneic hematopoietic stem cell transplantation and TKI combined with chemotherapy for adult philadelphia chromosome positive acute lymphoblastic leukemia: a systematic review and meta-analysis

OBJECTIVE

This study seeks to clarify whether allogeneic hematopoietic stem cell transplantation (allo-HSCT) is necessary for adult patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) in post-remission based on a comparison with tyrosine kinase inhibitor (TKI) combined with chemotherapy.

METHODS

We searched the Pubmed, Embase, and Web of Science databases and limited the date range for the studies from January 2010 to August 2020. A hazard ratio (HR) with a 95% confidence interval (CI) was employed to assess overall survival (OS) and relapse-free survival (RFS), and an odds ratio (OR) with a 95% CI was used to evaluate the ratio of non-relapsed mortality (NRM) and non-relapsed survival (NRS). All analyses were conducted with Stata software 16.0 and Revman 5.3.

RESULTS

Fifteen studies, totaling 959 patients, were included in our analysis. Among those patients, 473 underwent allo-HSCT, and 486 received TKI plus chemotherapy. The pooled results showed no difference in OS between outcomes for patients receiving TKI plus chemotherapy and those treated with allo-HSCT (HR = 0.76, 95% CI [0.51-1.12], p = 0.16). Patients undergoing allo-HSCT did better than those receiving TKI plus chemotherapy regarding RFS (HR = 0.48, 95% CI [0.37-0.63], p = 0.00), and NRS (OR = 2.64, 95% CI [1.25-5.57], p = 0.00). The NRM rate of the TKI plus chemotherapy group was significantly lower than the allo-HSCT group (OR = 2.33, 95% CI [1.51-3.59], p = 0.00).

CONCLUSION

TKI combined with chemotherapy can be considered a post-remission treatment option for adult Ph+ ALL patients who are ineligible for allo-HSCT. However, more prospective studies with large sample sizes should be carried out in the future.

A new pre-emptive TKIs strategy for preventing relapse based on BCR/ABL monitoring for Ph+ALL undergoing allo-HCT: a prospective clinical cohort study

Relapse is a major cause of treatment failure in Philadelphia-chromosome-positive acute lymphoblastic leukemia (Ph+ALL) undergoing allogeneic hematopoietic cell transplantation (allo-HCT). This study aimed to evaluate the effect of a new pre-emptive tyrosine kinase inhibitors (TKIs) strategy on relapse in Ph+ALL patients with complete remission undergoing allo-HCT. Pre-emptive TKIs initiation was based on BCR/ABL molecular monitoring. TKIs choice was based on BCR/ABL mutations. Donor lymphocyte infusion was recommended in those with poor response to TKIs. Prophylactic TKIs from historical data were as control. The primary endpoint was relapse. One hundred and sixty-seven Ph+ALL patients were enrolled in this study, including 103 in the pre-emptive group and 64 in the prophylactic group. The 3-year cumulative incidence of relapse was 11% and 31% in the pre-emptive and prophylactic groups (P = 0.001), respectively. The 3-year overall survival (OS) was 87% and 66% (P = 0.001), and leukemia-free survival (LFS) was 83% and 61% (P = 0.000), respectively, in the pre-emptive and prophylactic groups. Multivariate analysis showed that the pre-emptive strategy was the protective factor for relapse, OS, and LFS (P = 0.005, P = 0.005, and P = 0.003, respectively). Our data suggest that this new pre-emptive TKIs strategy based on BCR/ABL molecular monitoring might reduce relapse and improve survival for Ph+ALL patients undergoing allo-HCT. ClinicalTrials.Gov Identifier (NCT01883219).

Novel Indicators of Transplant Outcomes for PhALL: Current Molecular-Relapse-Free Survival

Molecular relapse after allogeneic hematopoietic cell transplantation (allo-HCT) has been thought to predict clinical relapse in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (PhALL). Tyrosine kinase inhibitor (TKI) administration after allo-HCT may dynamically change the status from molecular relapse to molecular remission, but these state changes cannot be accurately represented by conventional survival indicators such as relapse-free survival, where events are usually considered irreversible. We aimed to develop novel indicators of transplant outcomes for allo-HCT recipients with PhALL and to visualize current molecular-relapse-free survival (CMRFS) and current on-TKI status (CTKI), treating molecular relapse or TKI administration after allo-HCT as a reversible event. We retrospectively analyzed 286 patients with PhALL who received allo-HCT between 2000 and 2016 in order to develop the indicators. CMRFS was defined as the probability of molecular remission without clinical relapse or death at any time after allo-HCT. Similarly, CTKI was defined as the probability of TKI administration without clinical relapse or death at any time after allo-HCT. The 1- and 5-year CMRFS rates were 67% and 59%, respectively, whereas the 1- and 5-year conventional molecular relapse-free survival rates were 42% and 37%. The 1- and 5-year CTKI rates were 14% and 8%, respectively. In a post hoc analysis focusing on patients who had achieved a molecular complete remission within 6 weeks (n = 201), the 5-year CMRFS rate (71%) was similar to the 5-year conventional molecular relapse-free survival (molRFS) rate (70%) in the non-TKI group. On the other hand, the 5-year CMRFS rate in the TKI group was 61%, whereas the 5-year conventional molRFS rate was only 38%. CMRFS and CTKI might become useful indicators of transplant success in terms of survival, leukemia-free status, and treatment-free status at any time point. Future extension of these survival models to other clinical situations is warranted.

The role of ponatinib in adult BCR-ABL1 positive acute lymphoblastic leukemia after allogeneic transplantation: a real-life retrospective multicenter study

The experience of third-generation tyrosine kinase inhibitor ponatinib treatment in Philadelphia chromosome-positive acute lymphoblastic leukaemia (Ph'+ ALL) patients post-allogeneic transplantation is limited. We retrospectively collected data on 25 Ph'+ ALL patients who were started on ponatinib after allogeneic transplantation between July 2015 and July 2019 from nine transplantation centers in Italy. Ponatinib was given in prophylaxis in five (20%), as pre-emptive treatment in seven (28%), and as salvage therapy in thirteen (52%) patients. It was combined with donor leukocyte infusions in ten patients. Half of the patients (12/25) harbored T315I mutation of BCR/ABL1, while in the remaining mutational analysis was negative or not performed. Among the 20 patients who received ponatinib as pre-emptive/salvage treatment, complete molecular response was achieved in 15 (75%) patients. Estimated overall survival at 2-year post-initiation of treatment in the whole cohort was 65% (respectively 60%, 60%, and 78% for the prophylaxis, pre-emptive, and salvage therapy groups). In patients with T315I-positive mutational status, the estimated 2-year survival was 40%. Fourteen patients (56%) experienced toxicity, requiring temporary or definitive suspension of treatment. In conclusion, treatment of Ph'+ ALL patients with ponatinib after transplantation is effective, although the question of adequate drug dose and treatment duration remains unanswered.

Stopping tyrosine kinase inhibitors started after allogeneic HCT in patients with Philadelphia chromosome-positive leukemia

For patients with Philadelphia chromosome (Ph)-positive leukemia, there is no consensus regarding how long tyrosine kinase inhibitors (TKI) should be given or whether TKI could be stopped if TKI is administrated after allogeneic hematopoietic cell transplantation (allo-HCT). We analyzed relapse-free survival (RFS) in 92 allo-HCT patients who received TKI for >3 months after allo-HCT, and aimed to develop a novel indicator, called as current TKI- & relapse-free (cTRFree) achievement. TKI after allo-HCT was started as planned in 39 patients, based on measurable residual disease (MRD) in 53 at a median of 152 days after allo-HCT. There was no difference in post-TKI RFS between the planned and MRD-based starting groups (P = 0.69). Second-generation TKIs were associated with superior RFS in Ph-positive acute leukemia (HR 2.71, P = 0.031). TKI was stopped before relapse in 48 patients. Stopping TKI as a time-dependent covariate was not associated with subsequent hematological relapse (HR 1.18, P = 0.72). In the TKI-stop group, TKI administration for >6 months tended to be associated with superior RFS (HR = 0.30, P = 0.08). As an indicator of transplant success, cTRFree was 35% 5 years after starting TKI. TKI could be stopped for recipients with sustained undetectable MRD. However, further prospective studies will be required to establish clinical recommendations.

CML Chapter

The discovery of the tyrosine kinase inhibitor (TKI) imatinib in the early 2000's revolutionized the treatment and prognosis of patients with chronic myeloid leukemia (CML) [Hochhaus et al. in N Engl J Med 376:917-927, 2017]. The treatment of patients with CML has changed dramatically since the approval of imatinib and other TKIs. Before the TKI era, newly diagnosed patients would undergo HLA typing to try to identify a well-matched donor, and then proceed quickly to allogeneic hematopoietic cell transplantation (HCT). With the introduction of imatinib followed a few years later by dasatinib, nilotinib, then bosutinib, treatment approaches changed in a dramatic way. Transplantation is no longer an upfront treatment option for newly diagnosed CML patients, and in fact, it is very rarely used in the management of a patient with CML currently. The management of CML patients has been a model of personalized medicine or targeted therapy that is being emulated in the treatment of many other hematologic malignancies and solid tumors such as lung cancer [Soverini et al. in Mol Cancer 17:49, 2018]. The Philadelphia Chromosome (Ph) which leads to the formation of the BCR-ABL fusion gene and its product the BCR-ABL protein is the cause of CML. With effective targeting of this protein with the available TKIs, the disease is completely controllable if not curable for most patients. Life expectancy for patients with CML is essentially normal. Quality of life becomes an important goal including the potential for pregnancy, and ultimately the chance to discontinue all TKI therapy permanently. The three cases outlined below serve to highlight some of the important issues in the management of patients with CML in the post-TKI era.

Second- and third-generation tyrosine kinase inhibitors for Philadelphia-positive adult acute lymphoblastic leukemia relapsing post allogeneic stem cell transplantation-a registry study on behalf of the EBMT Acute Leukemia Working Party

Second- and third-generation tyrosine kinase inhibitors (TKI) play an important role in the treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL). However, data on feasibility and efficacy of using these drugs for persisting or relapsed Ph + ALL after allogeneic stem cell transplantation (alloSCT) are scarce. Based on the EBMT Acute Leukemia Working Party registry, we evaluated the use of second-/third-generation TKI in 140 patients with Ph + ALL, suffering from measurable residual disease (MRD, n = 6), molecular relapse (MRel, n = 23), or hematological relapse (HRel, n = 111) following alloSCT. Treatment included dasatinib in 104, nilotinib in 18, or ponatinib in 18 patients. Forty-nine patients received TKI monotherapy, while 91 received additional treatment. Toxicity of second-/third-generation TKI post alloSCT was comparable to pretransplant use and could be managed with dose reduction or temporary discontinuation. Response rates were 71% (overall) and 61% (following TKI monotherapy). For the entire cohort, 2- and 5-year overall survival (OS) was 49% and 33%, respectively. OS was comparable among patients treated for persisting MRD/MRel and HRel. Among patients treated with TKI monotherapy, 2- and 5-year OS was 38% and 33%, respectively. The data underscore that second-/third-generation TKI are important compounds for the management of active Ph + ALL post alloSCT.

Effect of Prophylactic Post-transplant Ponatinib Administration on Outcomes in Patients With Philadelphia Chromosome-positive Acute Lymphoblastic Leukemia

BACKGROUND

The objective of the present retrospective study was to evaluate the effect of ponatinib administration as maintenance therapy on the outcomes after allogeneic hematopoietic stem cell transplantation in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia.

PATIENTS AND METHODS

We retrospectively analyzed the data from 34 consecutive patients treated at our institution from January 2008 to June 2019. We had administered post-transplant tyrosine kinase inhibitors preemptively before December 2017. Thereafter, we had initiated the prophylactic use of post-transplant ponatinib. The initial ponatinib dose was 15 mg/d. Ponatinib plasma trough levels were measured using the liquid chromatography-tandem mass spectrometry method 8 days after the first administration and subsequently.

RESULTS

Nine patients received ponatinib maintenance. The 2-year overall survival and leukemia-free survival in the ponatinib maintenance group tended to be better than that in the non-ponatinib group (100% vs. 70.5%, P = .10; and 100% vs. 50.8%, P = .02, respectively). In the first 7 of the 9 consecutive patients, the median plasma concentration after ponatinib administration (15 mg/d) was 15.6 ng/mL (range, 4.8-23.3 ng/mL). Although the treatment schedule for 1 patient was altered because of adverse effects (elevation of serum amylase and neutropenia), ponatinib administration was continued for all the patients, except for 1 patient with molecular relapse. One patient developed a transient elevation of serum lipase. No patient presented with any arterial occlusive events.

CONCLUSION

Our results have indicated that the strategy of ponatinib maintenance after allogeneic hematopoietic stem cell transplantation is safe, efficacious, and promising.

Maintenance Strategies After Hematopoietic Cell Transplantation

Hematopoietic cell transplantation (HCT) is an essential component of potentially curative therapy for patients with hematologic malignancies. High-dose chemotherapy with autologous (auto) stem cell rescue is used to overcome chemoresistance in multiple myeloma, non-Hodgkin lymphoma, and Hodgkin lymphoma. Alternatively, poor-risk acute leukemias rely on the graft versus leukemia effect of allogeneic (allo) products. Long-term remissions are feasible with both auto- and allo-HCT; however, disease relapse is the leading cause of death after HCT for many patients. In recognition of this, novel therapies are being investigated in the upfront, relapsed/refractory, and post-HCT maintenance settings to deepen response and maintain disease control. To date, the most robust data to support this approach are in multiple myeloma, where post-transplant maintenance therapy has improved clinical outcomes. In Hodgkin lymphoma, patients with high-risk features may benefit from post-auto-HCT vedotin (BV) regardless of pre-HCT BV exposure. Apart from mantle cell lymphoma, where rituximab maintenance is generally accepted, post-auto-HCT maintenance in other forms of NHL is less established. In patients who undergo allo-HCT, the utilization of maintenance therapy is an important component of improving post-HCT outcomes, however, an individualized approach that considers patient factors such as residual toxicity from HCT, an immature graft with poor graft function, infection, and graft-versus-host disease create a complex environment for aggressive interventions. Initiation of directed agents in patients with identified mutations prior to allo-HCT, including FLT3 in acute myeloid leukemia and Philadelphia chromosome in acute lymphoid leukemia have generally improved post-HCT outcomes. Ongoing studies are exploring the safety and efficacy of additional maintenance strategies post-allo-HCT in an effort to further improve post-HCT outcomes.

Next-generation sequencing for BCR-ABL1 kinase domain mutations in adult patients with Philadelphia chromosome-positive acute lymphoblastic leukemia: A position paper

Emergence of clones carrying point mutations in the BCR‐ABL1 kinase domain (KD) is a common mechanism of resistance to tyrosine kinase inhibitor (TKI)‐based therapies in Philadelphia chromosome‐positive (Ph+) acute lymphoblastic leukemia (ALL). Sanger sequencing (SS) is the most frequently used method for diagnostic BCR‐ABL1 KD mutation screening, but it has some limitations—it is poorly sensitive and cannot robustly identify compound mutations. Next‐generation sequencing (NGS) may overcome these problems. NSG is increasingly available and has the potential to become the method of choice for diagnostic BCR‐ABL1 KD mutation screening. A group discussion within an ad hoc constituted Panel of Experts has produced a series of consensus‐based statements on the potential value of NGS testing before and during first‐line TKI‐based treatment, in relapsed/refractory cases, before and after allo‐stem cell transplantation, and on how NGS results may impact on therapeutic decisions. A set of minimal technical and methodological requirements for the analysis and the reporting of results has also been defined. The proposals herein reported may be used to guide the practical use of NGS for BCR‐ABL1 KD mutation testing in Ph+ ALL.

Hematopoietic stem cell transplantation for blood cancers in the era of precision medicine and immunotherapy

Hematopoietic stem cell transplantation (HCT) has been an integral component in the treatment of many hematologic malignancies. Since the development of HCT nearly 50 years ago, the role of this modality has evolved as newer treatment approaches have been developed and integrated into the standard of care. In the last decade, novel and highly active targeted therapies and immunotherapies have been approved for many hematologic malignancies, raising the question of whether HCT continues to retain its prominent role in the treatment paradigms of various hematologic malignancies. In this review, the authors have described the current role of autologous and allogeneic HCT in the treatment of patients with acute leukemias, aggressive B-cell lymphomas, and multiple myeloma and discussed how novel targeted therapies and immunotherapies have changed the potential need, timing, and goal of HCT in patients with these diseases.

Maintenance Tyrosine Kinase Inhibitors Following Allogeneic Hematopoietic Stem Cell Transplantation for Chronic Myelogenous Leukemia: A Center for International Blood and Marrow Transplant Research Study

It remains unknown whether the administration of tyrosine kinase inhibitors (TKIs) targeting BCR-ABL1 after allogeneic hematopoietic cell transplantation (HCT) is associated with improved outcomes for patients with chronic myelogenous leukemia (CML). In this registry study, we analyzed clinical outcomes of 390 adult patients with CML who underwent transplantation between 2007 and 2014 and received maintenance TKI following HCT (n = 89) compared with no TKI maintenance (n = 301), as reported to the Center for International Blood and Marrow Transplant Research. All patients received TKI therapy before HCT. The majority of patients had a disease status of first chronic phase at HCT (n = 240; 62%). The study was conducted as a landmark analysis, excluding patients who died, relapsed, had chronic graft-versus-host disease, or were censored before day +100 following HCT. Of the 89 patients who received TKI maintenance, 77 (87%) received a single TKI and the other 12 (13%) received multiple sequential TKIs. The most common TKIs used for maintenance were dasatinib (n = 50), imatinib (n = 27), and nilotinib (n = 27). As measured from day +100, the adjusted estimates for 5-year relapse (maintenance, 35% versus no maintenance, 26%; P = .11), leukemia-free survival (maintenance, 42% versus no maintenance, 44%; P = .65), or overall survival (maintenance, 61% versus no maintenance, 57%; P = .61) did not differ significantly between patients receiving TKI maintenance or no maintenance. These results remained unchanged in multivariate analysis and were not modified by disease status before transplantation. In conclusion, our data from this day +100 landmark analysis do not demonstrate a significant impact of maintenance TKI therapy on clinical outcomes. The optimal approach to TKI administration in the post-transplantation setting in patients with CML remains undetermined.

Myeloablative vs reduced-intensity conditioning allogeneic hematopoietic cell transplantation for chronic myeloid leukemia

Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative treatment of chronic myeloid leukemia (CML). Optimal conditioning intensity for allo-HCT for CML in the era of tyrosine kinase inhibitors (TKIs) is unknown. Using the Center for International Blood and Marrow Transplant Research database, we sought to determine whether reduced-intensity/nonmyeloablative conditioning (RIC) allo-HCT and myeloablative conditioning (MAC) result in similar outcomes in CML patients. We evaluated 1395 CML allo-HCT recipients between the ages of 18 and 60 years. The disease status at transplant was divided into the following categories: chronic phase 1, chronic phase 2 or greater, and accelerated phase. Patients in blast phase at transplant and alternative donor transplants were excluded. The primary outcome was overall survival (OS) after allo-HCT. MAC (n = 1204) and RIC allo-HCT recipients (n = 191) from 2007 to 2014 were included. Patient, disease, and transplantation characteristics were similar, with a few exceptions. Multivariable analysis showed no significant difference in OS between MAC and RIC groups. In addition, leukemia-free survival and nonrelapse mortality did not differ significantly between the 2 groups. Compared with MAC, the RIC group had a higher risk of early relapse after allo-HCT (hazard ratio [HR], 1.85; P = .001). The cumulative incidence of chronic graft-versus-host disease (cGVHD) was lower with RIC than with MAC (HR, 0.77; P = .02). RIC provides similar survival and lower cGVHD compared with MAC and therefore may be a reasonable alternative to MAC for CML patients in the TKI era.

Tyrosine kinase inhibitor prophylaxis after transplant for Philadelphia chromosome-positive acute lymphoblastic leukemia

Tyrosine kinase inhibitor (TKI) administration after allogeneic hematopoietic stem cell transplantation (HSCT) may carry a survival benefit in Philadelphia chromosome‐positive acute lymphoblastic leukemia (Ph+ ALL). Therefore, we investigated whether TKI prophylaxis for negative‐minimal residual disease (MRD) after HSCT would improve patient outcomes in this nationwide retrospective cohort study. We included patients with Ph+ ALL who underwent their first allogeneic HSCT between 2001 and 2016, received TKI before HSCT, and achieved negative‐MRD status within 180 days after HSCT. Of 850 patients for inclusion, 50 patients received TKI prophylaxis, mostly imatinib or dasatinib (median dose: 400 mg with imatinib and 40 mg with dasatinib). In a multivariate analysis, disease status at HSCT was the sole risk factor for relapse (hazard ratio, 3.58; P < .001 for positive‐MRD with complete remission [CR] and hazard ratio, 6.13; P < .001 for active disease). TKI prophylaxis was not associated with a decreased risk of relapse or superior overall survival in either the whole cohort or in the analysis limited to negative‐MRD or positive‐MRD with CR1 at HSCT. Meanwhile, TKI prophylaxis limited to dasatinib might be associated with a decreased risk of relapse (hazard ratio, 0.34; P = .140), unlike imatinib. Alternative strategies using new‐generation TKI for high‐risk patients are warranted to improve the outcomes after allogeneic HSCT.

Hematopoietic Cell Transplantation in the Treatment of Adult Acute Lymphoblastic Leukemia: Updated 2019 Evidence-Based Review from the American Society for Transplantation and Cellular Therapy

The role of hematopoietic cell transplantation (HCT) in adults with acute lymphoblastic leukemia (ALL) is reviewed and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the recommendations. A panel of ALL experts developed consensus on the treatment recommendations based on the evidence. Allogeneic HCT offers a survival benefit in selected patients with ALL, and this review summarizes the standard indications as well as the areas of controversy. There is now greater experience with pediatric-inspired chemotherapy regimens that has transformed upfront therapy for adult ALL, resulting in higher remission rates and overall survival. This in turn has increased the equipoise around decision making for ALL in first complete remission (CR1) when there is no measurable residual disease (MRD) at the end of induction and/or consolidation. Randomized studies are needed for adults with ALL to compare allogeneic HCT in CR1 with pediatric-inspired chemotherapy alone. Indications for transplantation in the evolving landscape of MRD assessments and novel targeted and immune therapeutics remain important areas of investigation.

Treatment Selection for Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia in the Era of Tyrosine Kinase Inhibitors

With the advent of tyrosine kinase inhibitors (TKIs), the treatment of Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) has entered a new era. The efficacy of TKIs compared with other ALL treatment options is emphasized by a rapid increase in the number of TKI clinical trials. Subsequently, the use of traditional approaches, such as combined chemotherapy and even allogeneic hematopoietic stem cell transplantation (allo-HSCT), for the treatment of ALL is being challenged in the clinic. In light of the increased use of TKIs in the clinic, several questions have been raised. First, is it necessary to use intensive chemotherapy during the induction course of therapy to achieve a minimal residual disease (MRD)-negative status? Must a patient reach a complete molecular response/major molecular response before receiving allo-HSCT? Does MRD status affect long-term survival after allo-HSCT? Is auto-HSCT an appropriate alternative for allo-HSCT in those Ph+ ALL patients who lack suitable donors? Here, we review the recent literature in an attempt to summarize the current status of TKI usage in the clinic, including several new therapeutic approaches, provide answers for the above questions, and speculate on the future direction of TKI utilization for the treatment of Ph+ ALL patients.

A phase 2 study of alpha interferon for molecularly measurable residual disease in chronic myeloid leukemia after allogeneic hematopoietic cell transplantation

CML therapy has improved dramatically with the development of tyrosine kinase inhibitors (TKIs). Prior to the TKI era, we conducted two trials of alpha-interferon (IFN) for post-transplant hematologic and cytogenetic relapse. The complete cytogenetic response rate was 33% and 57% respectively. This report describes a third trial in which 40 patients with molecular relapse between 6 and 12 months post-transplant were treated with IFN. The projected cytogenetic relapse at 4.5 years was 12.6% compared with 42% in the historical control group. Although this data may not apply to most patients with CML today due to the availability of multiple TKIs, the effectiveness of short term IFN in post-transplant molecular relapse is supported by long-term treatment-free-survival in 75% of patients after a median follow-up of 15.6 years. This report suggests that alpha-interferon is potentially useful in the rare patient who has post-transplant molecular relapse who does not tolerate, or is resistant to TKIs.

Allogeneic Stem Cell Transplantation for FLT3-Mutated Acute Myeloid Leukemia: In vivo T-Cell Depletion and Posttransplant Sorafenib Maintenance Improve Survival. A Retrospective Acute Leukemia Working Party-European Society for Blood and Marrow Transplant Study

Acute myeloid leukemia (AML) with FLT3-mutation carries a poor prognosis, and allogeneic stem cell transplantation (allo-SCT) is recommended at first complete remission (CR1). We assessed 462 adults (median age 50 years) with FLT3-mutated AML allografted between 2010 and 2015 from a matched related (40%), unrelated (49%), or haploidentical donor (11%). The median follow-up of alive patients was 39 months. Day-100 acute graft versus host disease (GVHD) grades II–IV and III–IV were encountered in 26% and 9%, whereas the 2-year incidence of chronic and extensive chronic GVHD were 34% and 16%, respectively. The 2-year incidences of relapse and nonrelapse mortality were 34% and 15%, respectively. The 2-year leukemia-free survival, overall survival (OS), and GVHD relapse-free survival (GRFS) were 51%, 59%, and 38%, respectively. In multivariate analysis, NPM1-mutation, transplantation in CR1, in vivo T-cell depletion, and posttransplant sorafenib improved OS, whereas more than one induction (late CR1) negatively affected OS. Similarly, NPM1-mutation, a haploidentical donor, T-cell depletion, and sorafenib maintenance improved GRFS, whereas late CR1 or persistent disease negatively affected it. In conclusion, FLT3-mutated AML remains a challenge even following allo-SCT. In vivo T-cell depletion and posttransplant sorafenib significantly improve OS and GRFS, and may be considered as standard of care.

Immunological effects of nilotinib prophylaxis after allogeneic stem cell transplantation in patients with advanced chronic myeloid leukemia or philadelphia chromosome-positive acute lymphoblastic leukemia

Allogeneic stem cell transplantation remains the standard treatment for resistant advanced chronic myeloid leukemia and Philadelphia chromosome–positive acute lymphoblastic leukemia. Relapse is the major cause of treatment failure in both diseases. Post-allo-SCT administration of TKIs could potentially reduce relapse rates, but concerns regarding their effect on immune reconstitution have been raised. We aimed to assess immune functions of 12 advanced CML and Ph+ ALL patients who received post-allo-SCT nilotinib. Lymphocyte subpopulations and their functional activities including T-cell response to mitogens, NK cytotoxic activity and thymic function, determined by quantification of the T cell receptor (TCR) excision circles (TREC) and TCR repertoire, were evaluated at several time points, including pre-nilotib-post-allo-SCT, and up to 365 days on nilotinib treatment. NK cells were the first to recover post allo-SCT. Concomitant to nilotinib administration, total lymphocyte counts and subpopulations gradually increased. CD8 T cells were rapidly reconstituted and continued to increase until day 180 post SCT, while CD4 T cells counts were low until 180−270 days post nilotinib treatment. T-cell response to mitogenic stimulation was not inhibited by nilotinib administration. Thymic activity, measured by TREC copies and surface membrane expression of 24 different TCR Vβ families, was evident in all patients at the end of follow-up after allo-SCT and nilotinib treatment. Finally, nilotinib did not inhibit NK cytotoxic activity. In conclusion, administration of nilotinib post allo-SCT, in attempt to reduce relapse rates or progression of Ph+ ALL and CML, did not jeopardize immune reconstitution or function following transplantation.

[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.

[Preventative and therapeutic relapse strategies after allogeneic hematopoietic stem cell transplantation: Guidelines from the Francophone society of bone marrow transplantation and cellular therapy (SFGM-TC)]

Disease relapse remains the first cause of mortality of hematological malignancies after allogeneic hematopoietic stem cell transplantation (allo-HCT). The risk of recurrence is elevated in patients with high-risk cytogenetic or molecular abnormalities, as well as when allo-HCT is performed in patients with refractory disease or with persistent molecular or radiological (PET-CT scan) residual disease. Within the frame of the 7th annual workshops of the francophone society for bone marrow transplantation and cellular therapy, the working group reviewed the literature in order to elaborate unified guidelines for the prevention and treatment of relapse after allo-HCT. For high risk AML and MDS, a post transplant maintenance strategy is possible, using hypomethylating agents or TKI anti-FLT3 when the target is present. For Philadelphia positive ALL, there was a consensus for the use of post-transplant TKI maintenance. For lymphomas, there are no strong data on the use of post-transplant maintenance, and hence a preemptive strategy is recommended based on modulation of immunosuppression, close follow-up of donor chimerism, and donor lymphocytes infusion. For multiple myeloma, even though the indication of allo-HCT is controversial, our recommendation is post transplant maintenance using bortezomib, due to its a good toxicity profile without increasing the risk of GVHD.

Combination therapeutics of Nilotinib and radiation in acute lymphoblastic leukemia as an effective method against drug-resistance

Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) is characterized by a very poor prognosis and a high likelihood of acquired chemo-resistance. Although tyrosine kinase inhibitor (TKI) therapy has improved clinical outcome, most ALL patients relapse following treatment with TKI due to the development of resistance. We developed an in vitro model of Nilotinib-resistant Ph+ leukemia cells to investigate whether low dose radiation (LDR) in combination with TKI therapy overcome chemo-resistance. Additionally, we developed a mathematical model, parameterized by cell viability experiments under Nilotinib treatment and LDR, to explain the cellular response to combination therapy. The addition of LDR significantly reduced drug resistance both in vitro and in computational model. Decreased expression level of phosphorylated AKT suggests that the combination treatment plays an important role in overcoming resistance through the AKT pathway. Model-predicted cellular responses to the combined therapy provide good agreement with experimental results. Augmentation of LDR and Nilotinib therapy seems to be beneficial to control Ph+ leukemia resistance and the quantitative model can determine optimal dosing schedule to enhance the effectiveness of the combination therapy.

High likelihood of evolution of resistance to therapy is common in most forms of leukemia. This issue persists for tyrosine kinase inhibitor drug treatments as well as other forms of therapies. In the current work, we suggest a combination therapy where Ph+ acute lymphoblastic leukemic cells are treated with low-dose radiation before chemotherapy (Nilotinib). Our in vitro results of the combined therapy accompanied with a mathematical model shows successful suppression of resistance to Nilotinib. The mathematical model shows a synergistic interaction between Nilotinib and low dose radiation in the chemo dose response function. Beside acute radiation we investigate low dose fractionated therapies with model predicted optimal dosing schedules.

US Intergroup Study of Chemotherapy Plus Dasatinib and Allogeneic Stem Cell Transplant in Philadelphia Chromosome Positive ALL

This multicenter trial was conducted to determine whether the addition of dasatinib to chemotherapy followed by an allogeneic hematopoietic cell transplant (HCT) in patients with Philadelphia chromosome positive (Ph+) acute lymphoblastic leukemia (ALL) was feasible. Patients ≥ 18 and ≤ 60 years of age with newly diagnosed Ph+ ALL received up to 8 cycles of alternating hyperCVAD and high dose cytarabine and methotrexate with dasatinib. Patients with an available matched sibling or unrelated donor underwent an allogeneic HCT in first complete remission (CR1) followed by daily dasatinib starting from day 100. Others received maintenance therapy with vincristine and prednisone for 2 years and dasatinib indefinitely. 97 patients (94 evaluable) with median age of 44 years (range, 20 - 60) and median WBC at presentation of 10 × 10⁹/L (range, 1 - 410 × 10⁹/L) were accrued. 83 (88%) patients achieved CR or CR with incomplete count recovery (CRi) and 41 underwent ASCT in CR1. Median follow-up is 36 months (range, 9 - 63). For the overall population, overall survival (OS), event-free survival (EFS), and relapse-free survival (RFS) at 3 years were 69%, 55%, and 62%, respectively. The 12-month RFS and OS after transplant were 71% and 87%, respectively. Landmark analysis at 175 days from the time of CR/CRi (longest time to HCT), showed statistically superior advantages for RFS and OS (p=0.038 and 0.037, respectively) for the transplanted patients. Addition of dasatinib to chemotherapy and HCT for younger patients with Ph+ ALL is feasible and warrants further testing.

Achieving Molecular Remission before Allogeneic Stem Cell Transplantation in Adult Patients with Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia: Impact on Relapse and Long-Term Outcome

Allogeneic stem cell transplantation (alloHSCT) in first complete remission (CR1) remains the consolidation therapy of choice in Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL). The prognostic value of measurable levels of minimal residual disease (MRD) at time of conditioning is a matter of debate. We analyzed the predictive relevance of MRD levels before transplantation on the clinical outcome of Ph+ ALL patients treated with chemotherapy and imatinib in 2 consecutive prospective clinical trials. MRD evaluation before transplantation was available for 65 of the 73 patients who underwent an alloHSCT in CR1. A complete or major molecular response at time of conditioning was achieved in 24 patients (37%), whereas 41 (63%) remained carriers of any other positive MRD level in the bone marrow. MRD negativity at time of conditioning was associated with a significant benefit in terms of risk of relapse at 5 years, with a relapse incidence of 8% compared with 39% for patients with MRD positivity (P = .007). However, thanks to the post-transplantation use of tyrosine kinase inhibitors (TKIs), disease-free survival was 58% versus 41% (P = .17) and overall survival was 58% versus 49% (P = .55) in MRD-negative compared with MRD-positive patients, respectively. The cumulative incidence of nonrelapse mortality was similar in the 2 groups. Achieving a complete molecular remission before transplantation reduces the risk of leukemia relapse even though TKIs may still rescue some patients relapsing after transplantation.

Use of tyrosine kinase inhibitors to prevent relapse after allogeneic hematopoietic stem cell transplantation for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia: A position statement of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a standard of care for patients with Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). The introduction of tyrosine kinase inhibitors (TKIs) to first-line therapy has improved overall outcomes; however, a significant proportion of patients still relapse after alloHSCT. Posttransplant TKI maintenance was demonstrated to reduce the risk of relapse in a large retrospective study and, therefore, should be considered a valuable option. This consensus paper, written on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation, presents an overview of clinical studies on the use of TKIs after alloHSCT and proposes practical recommendations regarding the choice of TKI, treatment timing, and dosage. It is hoped that these recommendations will become the state of art in this field and, more importantly, lead to a reduction of Ph-positive ALL relapse after alloHSCT. Cancer 2016;122:2941-2951. © 2016 American Cancer Society.

Chronic myeloid leukemia: reminiscences and dreams

With the deaths of Janet Rowley and John Goldman in December 2013, the world lost two pioneers in the field of chronic myeloid leukemia. In 1973, Janet Rowley, unraveled the cytogenetic anatomy of the Philadelphia chromosome, which subsequently led to the identification of the BCR-ABL1 fusion gene and its principal pathogenetic role in the development of chronic myeloid leukemia. This work was also of major importance to support the idea that cytogenetic changes were drivers of leukemogenesis. John Goldman originally made seminal contributions to the use of autologous and allogeneic stem cell transplantation from the late 1970s onwards. Then, in collaboration with Brian Druker, he led efforts to develop ABL1 tyrosine kinase inhibitors for the treatment of patients with chronic myeloid leukemia in the late 1990s. He also led the global efforts to develop and harmonize methodology for molecular monitoring, and was an indefatigable organizer of international conferences. These conferences brought together clinicians and scientists, and accelerated the adoption of new therapies. The abundance of praise, tributes and testimonies expressed by many serve to illustrate the indelible impressions these two passionate and affable scholars made on so many people's lives. This tribute provides an outline of the remarkable story of chronic myeloid leukemia, and in writing it, it is clear that the historical triumph of biomedical science over this leukemia cannot be considered without appreciating the work of both Janet Rowley and John Goldman.

Update on the management of Philadelphia chromosome positive chronic myelogenous leukemia: role of nilotinib

Chronic myelogenous leukemia (CML) is a pluripotent stem cell disease characterized by the presence of the Philadelphia chromosome and the bcr-abl gene. The discovery of tyrosine kinase inhibitors (TKIs) revolutionized therapy for CML, such that durable response, increased overall survival, and increased progression-free survival of patients in chronic phase CML is now possible. Due to resistance and intolerance to imatinib, there was need for development of second- and third-generation TKIs for the treatment of CML. This review examines the role of nilotinib, an oral second-generation TKI, in the treatment of Philadelphia positive CML. The pharmacology, efficacy, and safety of nilotinib are critically evaluated. Patient-related issues, including tolerance, drug interactions, and quality of life issues are also examined.

Clinical Perspectives on Targeting Therapies for Personalized Medicine

Expected benefits from new technology include more efficient patient selection for clinical trials, more cost-effective treatment pathways for patients and health services and a more profitable accelerated approach for drug developers. Regulatory authorities expect the pharmaceutical and biotechnology industries to accelerate their development of companion diagnostics and companion therapeutics toward the goal of safer and more effective personalized medicine, and expect health services to fund and prescribers to adopt these new therapeutic technologies.

This review discusses the importance of a range of new approaches to developing new and reprofiled medicines to treat common and serious diseases, and rare diseases: new network pharmacology approaches, adaptive trial designs with enriched populations more likely to respond safely to treatment, as assessed by companion diagnostics for response and toxicity risk and use of “real world” data.

Case studies are described of single and multiple protein drug targets in several important therapeutic areas. These case studies also illustrate the value and complexity of use of selective biomarkers of clinical response and risk of adverse drug effects, either singly or in combination.

Therapeutic benefits targeting B-cells in chronic graft-versus-host disease

Allogeneic hematopoietic cell transplantation (allo-HCT) can be a curative strategy for hematological diseases, and the indications for allo-HCT have broadened widely due to recent progress in supportive strategies. However, patients must overcome various complications and chronic graft-versus-host disease (cGVHD) remains the most common allo-HCT cause of long-term morbidity and mortality. cGVHD is difficult to biologically assess due to the heterogeneity of cGVHD symptoms, and the pathogenesis of cGVHD has yet to be established. Recent experimental model progress has suggested that B-cells play a critical role in cGVHD development. Consistent with these experimental results, some clinical studies investigating B-cell depletion and modulation of B-cell signaling pathways have decreased cGVHD incidence and provided some therapeutic benefit. However, randomized control studies are necessary to confirm the efficacy of B-cell targeting drugs for cGVHD. Here, we review the pathophysiology of cGVHD, especially focusing on the role of B-cell immunity, and discuss the efficacy of both B-cell depletion and modulation of B-cell signaling pathways in human cGVHD prevention, initial treatment, and salvage treatment.