Autologous transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia achieves outcomes similar to allogeneic transplantation: results of CALGB Study 10001 (Alliance)

Results of Cancer and Leukemia Group B 10102 (Alliance), a Phase 1/2 Study

BACKGROUND

Acute lymphoblastic leukemia (ALL) in adults is aggressive, with long-term outcomes impacted by treatment resistance and toxicity. CD52 is expressed in most cases of B- and T-lineage ALL. Alemtuzumab, a humanized immunoglobulin G1 monoclonal antibody that targets CD52, was identified as a potential agent to improve treatment efficacy without increasing toxicity.

METHODS

In this phase 1/2 study (Cancer and Leukemia Group B [CALGB] 10102, NCT00061945), a course of single-agent alemtuzumab was intercalated into CALGB 19802 backbone chemotherapy after the third course of intensive chemotherapy in those who were CD52+ at diagnosis. Phase 1 tested three dose levels of subcutaneous alemtuzumab (10, 20, and 30 mg 3 times weekly for 4 weeks/12 doses) and demonstrated that 30 mg was tolerable. Phase 2 established feasibility.

RESULTS

The study enrolled 295 evaluable patients (115 in phase 1, 180 in phase 2); 206 (69.8%) were CD52+. Among evaluable CD52+ patients, 43.7% (90/206) completed the first three treatment modules; 97.8% (88 of 90) were treated with alemtuzumab. Alemtuzumab was associated with cytomegalovirus viremia, which occurred in 23.3% (14 of 60) of patients during and 29.2% (19 of 65) after alemtuzumab treatment. With a median follow-up of 101.2 months, median overall survival (OS) was 26.3 months (3-year rate, 44%; 5-year rate, 36%; 10-year rate, 31%). Landmark analysis at the start of the fourth course of treatment demonstrated no difference in OS or disease-free survival between patients who did and who did not receive alemtuzumab.

CONCLUSION

Alemtuzumab was feasible to administer in adults with ALL receiving intensive chemotherapy, but was without evidence of benefit.

A critical review of management of allogeneic transplant-eligible adults with Ph+ acute lymphoblastic leukaemia

Acute lymphoblastic leukaemia (ALL) in 20%-30% of adult patients contains the Philadelphia (Ph+) chromosome. Historically, Ph+ ALL denoted a markedly inferior outcome and long-term survival in the absence of an allograft was uncommon. However, the advent of targeted therapy directed against the BCR::ABL1 fusion protein with various tyrosine kinase inhibitors (TKIs) has markedly improved the prognosis, resulting in a number of treatment controversies in allograft-eligible patients. Which is the best TKI to use in induction? What is the clinical relevance of the subdivision of Ph+ ALL into multilineage vs lymphoid types? Do all patients in first morphological complete remission (CR1) after induction and consolidation with chemotherapy/TKI require an allograft? If not, what risk factors predict a poor outcome without an allograft? Can chemotherapy-free approaches, such as blinatumomab in conjunction with more potent TKIs, obviate the need for an allograft in high-risk patients? What is the best strategy to deal with persistent or emerging minimal residual disease both pre- and post-transplant? Is maintenance TKI indicated in all patients post allograft? Can salvage therapy and a subsequent allograft cure patients who relapse after not being transplanted in CR1? This manuscript reviews the latest data influencing contemporary management and discusses these controversies.

Long-term outcome after autologous BCR::ABL1-negative peripheral blood stem cell transplantation in adults with Philadelphia-positive acute lymphoblastic leukemia: a comparative study

Not available.

Outcomes of allogeneic or autologous stem cell transplantation followed by maintenance chemotherapy in adult patient with B-ALL in CR1 with no detectable minimal residual disease

Autologous haematopoietic stem cell transplantation (auto-HSCT) as a treatment for B-cell acute lymphoblastic leukaemia (B-ALL) has been rigorously debated in recent years. We retrospectively analysed the outcomes of 355 adult patients with B-ALL in first complete remission who had received auto-HSCT or allogeneic HSCT (allo-HSCT) in our centre. The treatment efficacy was evaluated from a model stratified on the risk classification and minimal residue disease (MRD) status after three chemotherapy cycles. Auto-HSCT demonstrated comparable 3-year overall survival (OS) (72.7% vs. 68.5%, p = 0.441) and leukaemia-free survival rates (62.8% vs. 56.1%, p = 0.383) compared to allo-HSCT for patients with negative MRD, while the advantage of lower non-relapse mortality (1.5% vs. 25.1%, p < 0.001) was offset by a higher cumulative incidence of relapse (CIR) rates (35.7% vs. 18.9%, p = 0.018), especially in high-risk patients. For patients at high risk and with positive MRD, there was a lower trend of 3-year OS (50.0% vs. 66.0%, p = 0.078) and significantly higher CIR rates (71.4% vs. 39.1%, p = 0.018) in auto-HSCT. However, no significant interaction was observed in the tests. In conclusion, auto-HSCT appears to be an attractive treatment for patients with negative MRD after three chemotherapy cycles. For MRD-positive patients, allo-HSCT may be a more effective treatment.

Autologous peripheral blood stem cell transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia is safe but poses challenges for long-term maintenance of molecular remission: Results of the Auto-Ph17 study

Autologous hematopoietic stem cell transplantation (SCT) is not a standard treatment option for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL); however, its position has been reassessed since the introduction of tyrosine kinase inhibitors (TKIs). We prospectively analyzed the efficacy and safety of autologous peripheral blood SCT (auto-PBSCT) for Ph+ALL patients aged between 55 and 70 years who had achieved complete molecular remission. Melphalan, cyclophosphamide, etoposide, and dexamethasone were used for conditioning. A total of 12 courses of maintenance therapy, including dasatinib, were performed. The required number of CD34+ cells was harvested in all five patients. No patient died within 100 days after auto-PBSCT, and no unexpected serious adverse events were observed. Although 1-year event-free survival was 100%, hematological relapse was observed in three patients at a median of 801 days (range, 389-1088 days) after auto-PBSCT. Molecular progressive disease was observed in the other two patients, although they maintained their first hematological remission at the last visit. Auto-PBSCT can be safely performed for Ph+ALL with TKIs. A limitation of auto-PBSCT was suggested, despite the increase in the intensity of a single treatment. The development of long-term therapeutic strategies by including new molecular targeted drugs is warranted to maintain long-term molecular remission.

Effects of different types of allogeneic hematopoietic stem cell transplantation donors on Philadelphia chromosome-positive acute lymphoblastic leukemia during the tyrosine kinase inhibitor era: A systematic review and meta-analysis

BACKGROUND

Matched donor (MD) allogeneic hematopoietic stem cell transplantation (allo-HSCT) is currently the preferred choice of treatment for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) patients who have achieved complete remission. This systematic review and meta-analysis was conducted to investigate the effects of allo-HSCTs from different donor types for Ph+ ALL patients who received tyrosine kinase inhibitors (TKIs).

METHODS

Studies in EMBASE and MEDLINE between inception and December 2020 were identified using search terms related to "Ph+ ALL" and "HSCT." Eligible studies were studies with Ph+ ALL patients who received a TKI and allo-HSCT. The primary outcomes of interest-the overall survival (OS) or relapse-free survival (RFS)-needed to be reported. The Mantel-Haenszel method was used to combine the effect estimates and associated 95% confidence intervals (CIs) of each donor type.

RESULTS

Fourteen cohort studies were identified for the meta-analysis. Haploidentical (HID)-HSCT for Ph+ ALL patients resulted in a superior RFS to MD-HSCT, with a pooled odds ratio (OR) of 1.57 (95% CI, 1.05-2.32; I2 = 0%). However, HID-HSCT and MD-HSCT had comparable OS. Furthermore, HID-HSCT group had a significantly lower relapse rate than MD-HSCT group. On the other hand, the risks of graft-versus-host disease (GvHD) were higher for HID-HSCT and pooled OR of chronic GvHD rate. The OS and RFS of matched sibling-HSCT, matched unrelated-HSCT, and cord blood-HSCT were comparable with those of HID-HSCT.

CONCLUSION

This systematic review and meta-analysis showed that HID-HSCT is as effective as MD-HSCT in Ph+ ALL patients.

Ph+ ALL in 2022: is there an optimal approach?

Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) carried a very poor prognosis prior to the advent of tyrosine kinase inhibitors (TKIs) that block the activity of the BCR-ABL1 oncoprotein. With improvements in TKI efficacy and allogeneic hematopoietic cell transplantation (HCT), survival has improved over the past 3 decades, and the role of chemotherapy and allogeneic HCT is now changing. Better risk stratification, the application of the third-generation TKI ponatinib, and the use of immunotherapy with the CD19-CD3 bifunctional T-cell engaging antibody blinatumomab in place of chemotherapy has made therapy for Ph+ ALL more tolerable and arguably more efficacious, especially for older patients who comprise most patients with Ph+ ALL.

Propensity score matching/reweighting analysis comparing autologous and allogeneic stem cell transplantation for B-lineage acute lymphoblastic leukemia

We compared the outcomes of autologous stem cell transplantation (auto-SCT) with those of allogeneic stem cell transplantation (allo-SCT) from a human leukocyte antigen-matched related donor in patients with Philadelphia chromosome-negative B-lineage acute lymphoblastic leukemia (ALL). Newly diagnosed patients who underwent allo-SCT (n = 486) or auto-SCT (n = 99) after achieving first complete remission (CR) were included. Propensity score matching (PS) and an inverse probability of the treatment weighting (IPTW) analysis were applied to compensate for imbalances in baseline characteristics. The 5 years rates of overall survival (OS) among those in the PS-matched cohorts were 57% [95% confidence interval (CI) 46-67%] for those who received allo-SCT and 44% (95% CI 33-54%) for those who received auto-SCT. Multivariable, propensity score-matched, and IPTW analyses all revealed no statistically significant differences in OS between the two groups [hazard ratios (HR) 0.81, 95% CI 0.53-1.27, p = 0.36; HR 0.84, 95% CI 0.40-1.78, p = 0.65; HR 0.71, 95% CI 0.25-2.02, p = 0.53, respectively]. Prospective trials that include autologous transplantation as a treatment option are needed to examine the potential of autologous transplantation.

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.

Pattern of autologous stem cell transplants at a tertiary care government hospital, with emphasis on transplant outcomes with pre-harvest CD34+ level

Purpose

Autologous stem cell transplantation (ASCT) is an established therapy for many hematological diseases. This study assessed the pattern of ASCTs at a tertiary care center and associated factors, including pre-harvest CD34+ stem cell levels, leading to improved engraftment outcomes.

Methodology

A retrospective study was conducted in India, between February 2009-August 2020. Patients who underwent ASCT for different hematological malignancies (n=65) were included, and the patients' age, sex, type and stage of disease, pre- and post-harvest CD34+ counts, and time to attain platelet/neutrophil engraftment or febrile neutropenia were analyzed. The post-harvest CD34+ dose was calculated. Pre-conditioning was performed using Granulocyte Colony Stimulating Factor (GCSF)±Plerixafor. Progression-free survival (PFS) was calculated using relapse/death as the endpoint.

Results

The median age of the cohort (n=65) was 49 years, with a male preponderance. Multiple myeloma was the most common malignancy (70.8% [46/65]), requiring ASCT. The median time to ASCT was 13 months. All patients had received GCSF, while Plerixafor was used in 17 patients with a pre-harvest CD34+ count of <10 cells/μL. The median pre-harvest CD34+ concentration and post-harvest CD34+ cell dose was 27.54 cells/μL (n=26) and 5.23×10⁶ cells/kg body weight (n=65), respectively. The median time to engraftment was 11 and 12 days, for neutrophils and platelets, respectively. One patient did not engraft and was excluded from the analysis. The time required to attain neutrophil engraftment was significantly lower (p=0.02) among freshly harvested stem cells (n=48) than that of cryopreserved products (n=17). Platelet engraftment associated with CD34+ pre- and post-harvest levels was not significant (p=0.06). The time to attain neutropenia and subsequent febrile neutropenia was significantly lower with an adequate post-harvest CD34+ dose (p=0.009). Febrile neutropenia was seen in 83.1% (54/65) patients. The median time for febrile neutropenia was 4 days post-ASCT. Pre- and post-harvest CD34+ concentrations were directly proportional to each other (p<0.001). The median PFS was 112 months (n=65). Survival was better in males (median PFS: 112 months) vs. females (median PFS: 59 months) (p=0.27). Eight patients relapsed, and eight patients had died.

Conclusion

Although unrelated to age or sex, the post-harvest CD34+ dose was inversely related to febrile neutropenia. As pre- and post-harvest CD34+ levels were directly proportional, pre-harvest CD34+ concentrations may be reliably used to assess engraftment outcomes. Rapid neutrophil engraftment was noted in fresh stem cells with PFS of 112 months, and was better among males, the exact reason being unknown. Thus, a larger number of patients should be followed up to obtain an accurate picture.

Dasatinib and dexamethasone followed by hematopoietic cell transplantation for adults with Ph-positive ALL

Dasatinib and dexamethasone induction then allogeneic hematopoietic cell transplantation was feasible and effective for untreated Ph⁺ ALL.

Treatment failure was associated with BCR-ABL1 T315I mutation, the p210 BCR-ABL1 isoform, or isolated CNS relapse.

Post-remission strategies after dasatinib-corticosteroid induction in adult Philadelphia chromosome (Ph)–positive acute lymphoblastic leukemia (ALL) are not well studied. We evaluated dasatinib and dexamethasone induction then protocol-defined post-remission therapies, including hematopoietic cell transplantation (HCT). Adults (N = 65) with Ph-positive ALL received dasatinib-dexamethasone induction, methotrexate-based central nervous system (CNS) prophylaxis, reduced-intensity conditioning (RIC) allogeneic HCT, autologous HCT, or chemotherapy alone, and dasatinib-based maintenance. Key end points were disease-free survival (DFS) and overall survival (OS). The median age was 60 years (range, 22-87 years). The complete remission rate was 98.5%. With a median follow-up of 59 months, 5-year DFS and OS were 37% (median, 30 months) and 48% (median, 56 months), respectively. For patients receiving RIC allogeneic HCT, autologous HCT, or chemotherapy, 5-year DFS were 49%, 29%, and 34%, and 5-year OS were 62%, 57%, and 46%, respectively. Complete molecular response rate after CNS prophylaxis was 40%. Relative to the p190 isoform, p210 had shorter DFS (median 10 vs 34 months, P = .002) and OS (median 16 months vs not reached, P = .05). Relapse occurred in 25% of allogeneic HCT, 57% of autologous HCT, and 36% of chemotherapy patients. T315I mutation was detected in 6 of 8 marrow relapses. Dasatinib CNS concentrations were low. Dasatinib-dexamethasone followed by RIC allogeneic HCT, autologous HCT, or chemotherapy was feasible and efficacious, especially with RIC allogeneic HCT. Future studies should address the major causes of failure: T315I mutation, the p210 BCR-ABL1 isoform, and CNS relapse. This study was registered at www.clinicaltrials.gov as #NCT01256398.

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.

INCB84344-201: Ponatinib and steroids in frontline therapy of unfit patients with Ph+ acute lymphoblastic leukemia

In patients with newly diagnosed Ph⁺ ALL, ponatinib and prednisone therapy resulted in long molecular remissions and few resistance mutations.

The observed high rates of discontinuation and dose modification suggest that a lower dose may be more appropriate in older/unfit patients.

Tyrosine kinase inhibitors have improved survival for patients with Philadelphia chromosome–positive (Ph⁺) acute lymphoblastic leukemia (ALL). However, prognosis for old or unfit patients remains poor. In the INCB84344-201 (formerly GIMEMA LAL 1811) prospective, multicenter, phase 2 trial, we tested the efficacy and safety of ponatinib plus prednisone in newly diagnosed patients with Ph⁺ ALL ≥60 years, or unfit for intensive chemotherapy and stem cell transplantation. Forty-four patients received oral ponatinib 45 mg/d for 48 weeks (core phase), with prednisone tapered to 60 mg/m²/d from days-14-29. Prophylactic intrathecal chemotherapy was administered monthly. Median age was 66.5 years (range, 26-85). The primary endpoint (complete hematologic response [CHR] at 24 weeks) was reached in 38/44 patients (86.4%); complete molecular response (CMR) in 18/44 patients (40.9%) at 24 weeks. 61.4% of patients completed the core phase. As of 24 April 2020, median event-free survival was 14.31 months (95% CI 9.30-22.31). Median overall survival and duration of CHR were not reached; median duration of CMR was 11.6 months. Most common treatment-emergent adverse events (TEAEs) were rash (36.4%), asthenia (22.7%), alanine transaminase increase (15.9%), erythema (15.9%), and γ-glutamyltransferase increase (15.9%). Cardiac and vascular TEAEs occurred in 29.5% (grade ≥3, 18.2%) and 27.3% (grade ≥3, 15.9%), respectively. Dose reductions, interruptions, and discontinuations due to TEAEs occurred in 43.2%, 43.2%, and 27.3% of patients, respectively; 5 patients had fatal TEAEs. Ponatinib and prednisone showed efficacy in unfit patients with Ph⁺ ALL; however, a lower ponatinib dose may be more appropriate in this population. This trial was registered at www.clinicaltrials.gov as #NCT01641107.

Prognostic factors for progression in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia in complete molecular response within 3 months of therapy with tyrosine kinase inhibitors

BACKGROUND

The achievement of a 3-month complete molecular response (CMR) is a major prognostic factor for survival in patients with Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). However, 25% of patients relapse during therapy with tyrosine kinase inhibitors (TKIs).

METHODS

The authors reviewed 204 patients with Ph-positive ALL who were treated between January 2001 and December 2018 using the combination of hyper-CVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone) plus a TKI (imatinib, 44 patients [22%]; dasatinib, 88 patients [43%]; or ponatinib, 72 patients [35%]). Progression-free survival (PFS) was defined as the time from the start date of therapy to the date of relapse, death, or last follow-up. Overall survival (OS) was defined as the time from the start date of therapy to the date of death or last follow-up.

RESULTS

Overall, a 3-month CMR was observed in 57% of patients, including 32% of those who received imatinib, 52% of those who received dasatinib, and 74% of those who received ponatinib. The median follow-up was 74 months (imatinib, 180 months; dasatinib, 106 months; ponatinib, 43 months). Among 84 patients in 3-month CMR, 17 (20%) proceeded to undergo allogeneic stem cell transplantation (ASCT). The 5-year PFS and OS rates were 68% and 72%, respectively. By multivariate analysis, ponatinib therapy was the only significant favorable independent factor predicting for progression (P = .028; hazard ratio, 0.388; 95% CI, 0.166-0.904) and death (P = .042; hazard ratio, 0.379; 95% CI, 0.149-0.966). ASCT was not a prognostic factor for PFS and OS by univariate analysis.

CONCLUSIONS

In patients with Ph-positive ALL, ponatinib is superior to other types of TKIs in inducing and maintaining a CMR, thus preventing disease progression. ASCT does not improve outcome once a 3-month CMR is achieved.

Emerging tyrosine kinase inhibitors for the treatment of adult acute lymphoblastic leukemia

Introduction: The broadening of targeted and immunotherapeutic strategies markedly impacted on the management of acute lymphoblastic leukemia (ALL). The advent of tyrosine kinase inhibitors (TKIs) changed the history of Philadelphia-chromosome positive (Ph+) ALL. Nowadays, almost all Ph+ ALL patients treated with TKIs achieve a complete hematologic response, and most become minimal residual disease negative. In Ph- ALL, genomic profiling studies have identified a subtype associated with a high relapse risk and a transcriptional profile similar to that of Ph+ ALL, the so-called Ph-like ALL. Given the high prevalence of kinase-activating lesions in this subset, there is compelling evidence from experimental models and clinical observations favoring TKI administration.Areas covered: We discuss the main findings exploring the efficacy of TKIs in ALL.Expert opinion: The use of more potent TKIs will further enhance the inhibitory activity on leukemia cells and increase the possibility of eradicating the disease at a molecular level. In the future, 'combined' approaches of different inhibitors may be considered to prevent/avoid resistance and/or mutations. A rapid identification of Ph-like ALL patients is needed to propose early TKI-based intervention. Several questions remain open, including the initial TKI choice in Ph+ ALL and whether Ph-like ALL patients might benefit from immunotherapy.

Is stem cell transplantation still needed for adult Philadelphia chromosome-positive acute lymphoblastic leukemia receiving tyrosine kinase inhibitors therapy?: A systematic review and meta-analysis

Background

Hematopoietic stem cell transplantation (HSCT) is the current mainstay treatment for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph⁺ ALL). However, tyrosine kinase inhibitors (TKI) also play a significant role in the treatment of these patients. We conducted this systematic review and meta-analysis to compare the efficacy of allogeneic (allo-) HSCT, autologous (auto-) HSCT, and chemotherapy (CMT) alone–all in combination with TKIs in adult Ph⁺ ALL patients.

Materials and methods

This systematic review identified studies from the EMBASE and MEDLINE databases from inception to April 2021 using search terms related to “ALL” and “HSCT.” Eligible studies could be randomized controlled trials or cohort studies that included adult Ph⁺ ALL patients who received a TKI and either allo-HSCT, auto-HSCT, or CMT alone, and that reported the number of patients in each group for each of our primary outcomes of interest: overall survival (OS) or disease-free survival (DFS). Point estimates and associated 95% confidence intervals (CI) from each study were combined using the Hantel-Maenszel method.

Results

After two rounds of review, 26 cohort studies were determined to be eligible for the meta-analysis. Adult Ph⁺ ALL patients who received HSCT had better survival outcomes than those who did not receive any HSCT (pooled odds ratio [OR] for OS of 1.61, 95%CI: 1.08–2.40; I² = 59%, and for DFS of 3.23, 95%CI: 2.00–5.23; I² = 62% for allo-HSCT; and, pooled OR for OS of 7.04, 95%CI: 1.97–25.15; I² = 0%, and for DFS of 5.78, 95%CI: 1.04–32.19; I² = 42% for auto-HSCT). Allo-HSCT recipients had comparable OS and DFS, but lower relapse rate compared to auto-HSCT recipients. Funnel plot generally demonstrated no presence of publication bias.

Conclusions

This systematic review and meta-analysis demonstrated superior results of HSCT in Ph⁺ ALL patients compared to CMT alone. Moreover, auto-HSCT could be implemented with comparable survival outcomes to allo-HSCT in patients with no available donor or when haploidentical HSCT is not feasible.

The impact of tyrosine kinase inhibitors on allogeneic hematopoietic stem cell transplantation for adult patients with Philadelphia chromosome-positive acute lymphoblastic leukemia

In the tyrosine kinase inhibitor (TKI) era, allogeneic hematopoietic stem cell transplantation (allo-HSCT) is still the most potential approach for cure of adult patients with Philadelphia chromosome-positive acute lymphocytic leukemia (Ph⁺ ALL). TKI plus chemotherapy has strikingly increased response rates and depth of response, and facilitated allo-HSCT, which decreases relapse and improves survival eventually. Meanwhile, for those with older age or comorbidities at diagnosis, TKI in combination with reduced-intensity chemotherapy or chemotherapy-free strategy reduces treatment-related mortality, deferred intensive chemotherapy increases molecular responses and reduced-intensity conditioning (RIC) allo-HSCT improves survival finally. Of note, according to minimal residual disease (MRD) and BCR/ABL1 kinase domain mutation screening, prophylactic or preemptive maintenance therapy with a sensitive TKI decreases relapse further. Regarding transplantation-related mortality and impaired quality of life related to complications of allo-HSCT, autologous-HSCT (auto-HSCT) among those with early and persistent molecular remission and the most potent TKI ponatinib plus intensive chemotherapy has exhibited non-inferior survival to allo-HSCT. Even so, risk-adapted strategy isn't available now. Lastly, outcomes of relapse after allo-HSCT are dismal due to TKIs exposure, and new therapeutic interventions combined with TKIs shed light on this thorny problem.

Hematopoietic cell transplantation for acute lymphoblastic leukemia: review of current indications and outcomes

The treatment landscape for patients with acute lymphoblastic leukemia (ALL) is changing. Continued investigation into the biology of ALL, and broader use and more precise methods of measuring residual disease allow for improved risk stratification of patients and identification of the subset of patients at greatest risk of disease relapse and who may benefit from hematopoietic cell transplantation (HCT) in first complete remission. Further, recent advances in HCT preparative regimens, donor selection, graft manipulation, and graft-versus-host disease prophylaxis and treatment have resulted in fewer transplant-related morbidities and mortality and better survival outcomes. Finally, the development of effective immunotherapeutic salvage agents, such as the chimeric antigen receptor T-cell therapy, tisagenlecleucel, have significantly changed the treatment landscape of this disease, allowing patients with advanced disease to be considered for HCT with curative intent. In this review, we will provide an update on the indications and outcome of pediatric and adult ALL.

Outcomes and prognostic factors in adolescents and young adults with ALL treated with a modified BFM-90 protocol

The use of pediatrics-inspired protocols in adolescent and young adult (AYA) acute lymphoblastic leukemia (ALL) results in superior survival compared with the adult protocols. Pediatrics-inspired protocols carry an increased risk of toxicity and treatment-related mortality in low resource settings, which can offset the potential benefits. We studied the outcomes and prognostic factors in the treatment of AYA ALL with a pediatrics-inspired regimen. We retrieved data regarding demographics, investigations, treatment details, and toxicities from the electronic medical records of patients diagnosed with ALL in the 15- to 25-year-old age group who were initiated on a modified Berlin-Frankfurt-Münster 90 (BFM-90) protocol between January 2013 and December 2016 at the Tata Memorial Centre. A total of 349 patients in the 15- to 25-year-old age group were treated with a modified BFM-90 protocol. The use of this pediatrics-inspired protocol resulted in a 3-year event-free survival (EFS) and overall survival (OS) of 59.4% and 61.8%, respectively. Only 15 patients underwent an allogeneic stem cell transplant. Minimal residual disease (MRD) persistence postinduction emerged as the only factor predictive of poor outcomes. A modified BFM-90 protocol is an effective and safe regimen for AYA ALL with an OS and EFS comparable to the published literature.

Comparison of autologous and allogeneic stem cell transplantation for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia

Objectives: To analyze the outcomes of patients who received autologous stem cell transplantation (auto-SCT), matched sibling donor stem cell transplantation (MSD-SCT) and haploidentical stem cell transplantation (haplo-SCT) and provide the basis for the choice of transplantation method in Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). Methods: We retrospectively investigated the outcomes of 119 adult patients with Ph+ ALL in our center. The overall survival (OS) rate, leukemia-free survival (LFS) rate, cumulative incidence of relapse (CIR) rate, non-relapse mortality (NRM) rate and the impact of achievement of complete molecular response (CMR) within 3 months and sustaining CMR up to transplantation (s3CMR) on transplantation method were explored. Results: The estimated OS, LFS, CIR and NRM rates at 3 years were not significantly different among three groups (p = 0.960, 0.917, 0.375 and 0.096, respectively). For the 65 patients who achieved s3CMR, there was no significant difference in OS (84.5% vs 72.5% vs 100%, p = 0.374), LFS (75.2% vs 64.5% vs 83.3%, p = 0.668), CIR (17.2% vs 8.1% vs 16.7%, p = 0.583) and NRM (3.1% vs 23.4% vs 0%, p = 0.055) among auto-SCT group, MSD-SCT group and haplo-SCT group. However, in patients who did not achieve s3CMR, auto-SCT recipients tended to have higher CIR (60% vs 33.2% vs 24.0%, p = 0.013) than the allo-HSCT group. Conclusions: Auto-SCT with maintenance therapy after HSCT appears to be an attractive treatment option for patients with Ph+ ALL especially for those whose s3CMR was kept up to transplantation. For non-s3CMR patients, allogeneic transplantation may be more effective from lower relapse.

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

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

Treatment and outcome of Philadelphia chromosome-positive acute lymphoblastic leukemia in adults after relapse

INTRODUCTION

Despite the significant progress that has been made over the last years in the front-line treatment of Philadelphia (Ph) chromosome-positive acute lymphoblastic leukemia (ALL), relapses are frequent and their treatment remains a challenge, especially among patients with resistant BCR-ABL1 mutations.

AREAS COVERED

This manuscript reviews available data for the treatment of adult patients with relapsed/refractory Ph-positive ALL, with a focus on the role of tyrosine kinase inhibitors (TKIs), monoclonal antibodies, and immunotherapy.

EXPERT OPINION

Although a majority of patients with first relapsed Ph-positive ALL respond to subsequent salvage chemotherapy plus TKI combination, their outcomes remain poor. The main predictor of survival is the achievement of major molecular response anytime during the morphological response. More treatment strategies to improve survival are under investigation. Monoclonal antibodies and bispecific antibody constructs hold considerable promise in improving the outcomes of patients with relapsed ALL including Ph-positive ALL.

Comparative study on allogeneic with autologous hematopoietic stem cell transplantation in adult patients with Philadelphia chromosome-positive acute lymphoblastic leukemia in the era of TKIs: a systematic review and meta-analysis

In the era of tyrosine kinase inhibitors (TKIs), allogeneic hematopoietic stem cell transplantation (allo-HSCT) is recommended as a standard approach for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) achieving complete remission (CR). However, the role of autologous hematopoietic stem cell transplantation (auto-HSCT) in adult patients achieving complete molecular remission (CMR) is an alternative, less toxic treatment options, especially for the patients who lack suitable donors and are unfit for allo-HSCT. Thus, we conducted a systematic review and meta-analysis to compare the efficacy of allo-HSCT and auto-HSCT for the treatment of adult patients with Ph+ ALL. We searched the PubMed, Embase, Scopus, and Cochrane Library for studies published before June 2019 without language restriction. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for overall survival (OS) and relapse-free survival (RFS) and odds ratios (ORs) and 95% CIs for relapse rate (RR) and treatment-related mortality (TRM). Four prospective studies and one retrospective study were included with a total of 810 patients. We found auto-HSCT was superior to allo-HSCT in OS (HR = 1.42, 95% CI: 1.06-1.91, P = 0.02), and there was no difference between allo-HSCT and auto-HSCT for RFS (HR = 1.10, 95% CI: 0.86-1.40, P = 0.44) and RR (OR = 0.53, 95% CI: 0.22-1.26, P = 0.15). The risk of TRM for patients undergoing allo-HSCT was significantly higher than that of the patients who received auto-HSCT (OR = 5.06, 95% CI: 1.03-24.75, P = 0.05). Our meta-analysis shows that auto-HSCT may be an attractive and alternative treatment option for adult Ph+ ALL patients achieving CMR, with similar or better outcomes than allo-HSCT in the era of TKIs.

[Comparison of autologous versus matched sibling donor stem cell transplantation for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia]

目的

比较自体造血干细胞移植（auto-HSCT）和同胞全相合造血干细胞移植（MSD-HSCT）治疗费城染色体阳性急性淋巴细胞白血病（Ph⁺ ALL）的疗效，为患者移植方式的选择提供依据。

方法

回顾性总结2008年1月至2017年12月于中国医学科学院血液病医院行auto-HSCT（31例）及MSD-HSCT（47例）的78例Ph⁺ ALL患者的临床特征，比较不同移植方式患者的总生存（OS）率、无白血病生存（LFS）率、累积复发率（CIR）及非复发死亡率（NRM），并观察是否3个月内实现完全分子学缓解并持续至移植（s3CMR）条件下不同移植方式对预后的影响。

结果

auto-HSCT组、MSD-HSCT组粒细胞植入的中位时间分别为12（10～29）d、14（11～24）d（P＝0.006），血小板植入的中位时间分别为17.5（10～62）d、17（10～33）d（P＝0.794）。MSD-HSCT组中，Ⅱ～Ⅳ度和Ⅲ～Ⅳ度急性移植物抗宿主病（GVHD）的发生率分别为27.7%（13/47）和8.5%（4/47），局限型和广泛型慢性GVHD的发生率为17.0%（8/47）和12.8%（6/47）。auto-HSCT组、MSD-HSCT组3年CIR、NRM、LFS率差异均无统计学意义（P值均>0.05）。在达到s3CMR的44例患者中，auto-HSCT组和MSD-HSCT组的3年OS率［（84.0±8.6）%对（78.0±8.7）%，P＝0.612］、LFS率［（70.3±10.3）%对（68.2±10.1）%，P＝0.970］、CIR［（24.9±10.0）%对（14.4±8.0）%，P＝0.286］和NRM［（4.7±4.7）%对（17.4±8.1）%，P＝0.209］差异均无统计学意义；未达到s3CMR的34例患者中，auto-HSCT组与MSD-HSCT组相比，3年CIR明显升高［（80.0±14.7）%对（39.6±10.9）%，P＝0.057］。

结论

对于化疗后达s3CMR的Ph⁺ ALL患者，auto-HSCT是一种有效的巩固治疗选择，与MSD-HSCT疗效相当；对于未达到s3CMR的患者，MSD-HSCT复发率更低。

A systematic literature review and meta-analysis of minimal residual disease as a prognostic indicator in adult B-cell acute lymphoblastic leukemia

Minimal (or 'measurable') residual disease in acute lymphoblastic leukemia appears to be a prognostic indicator, with potential value in informing individualized treatment decisions. Complete understanding of the strength of the association between minimal residual disease and long-term outcomes is, however, lacking. A systematic literature review and meta-analysis were performed to elucidate the clinical significance of minimal residual disease with respect to relapse-free survival and overall survival in precursor B-cell acute lymphoblastic leukemia. A total of 23 articles and abstracts, most published between 2012 and 2016, were identified for inclusion in the primary meta-analysis. Typically, patients were in their first complete remission at the time of minimal residual disease assessment; in two studies, all patients were in their second, or later, complete remission. The primary analysis revealed improved relapse-free survival across all studies for patients who achieved minimal residual disease negativity (random effects hazard ratio, 2.34; 95% confidence interval, 1.91-2.86). Improved overall survival for patients who achieved minimal residual disease negativity was also observed (hazard ratio, 2.19; 95% confidence interval, 1.63-2.94). There was no observed difference in the impact of minimal residual disease status in subgroups based on disease stage, minimal residual disease sensitivity threshold level, Philadelphia chromosome status, histological phenotype, risk group, minimal residual disease testing location, minimal residual disease timing after induction, or minimal residual disease detection method. Despite heterogeneity in study design and patient populations between the contributing studies, these data provide a compelling argument for minimal residual disease as a clinical tool for assessing prognosis and guiding treatment decisions in precursor B-cell acute lymphoblastic leukemia.

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.

[The prognostic significance of minimal residual disease detection after first induction treatment in adult acute lymphoblastic leukemia patients treated with autologous stem cell transplantation]

Objective: To investigate the prognostic significance of detection of minimal residual disease after first induction treatment (MRD(1)) in adult acute lymphoblastic leukemia (ALL) patients treated with autologous stem cell transplantation (auto-HSCT). Methods: The clinical data of 87 ALL patients who underwent auto-HSCT during February 2006 to April 2017 with MRD(1) detection data by flow cytometry were analyzed retrospectively. The relationship between MRD(1) and relapse and survival of ALL patients after auto-HSCT was studied. Results: Of 87 patients, 26 (29.9%) were MRD(1) positive. The proportion of high-risk immunophenotype (pro-B, pro-T, pre-T, mature T) was significantly higher in MRD(1)-positive patients than that in MRD(1) negative patients (34.6% vs 14.5%, P=0.038). There was no significant difference between positive and negative MRD(1) patients at age, sex, lineage (T/B), immunophenotype (standard risk/high risk), high white blood cell count (B-ALL>30×10(9)/L or T-ALL>100×10(9)/L), high-risk chromosome/gene ratio, the time from first complete remission to transplantation and pre-treatment regimen. The 5-year overall survival (OS) and leukemia-free survival (LFS) in MRD(1) negative and positive patients were 72.7% vs 47.3% (P=0.004) and 75.7% vs 29.6% (P<0.001), respectively. Multivariate analysis showed that positive MRD(1) was an independent risk factor for OS (HR=3.007, 95% CI 1.256-7.200, P=0.013) , and positive MRD(1) and high-risk immunophenotype were risk factors for LFS (HR=3.986, 95% CI 1.813-8.764, P=0.001; HR=2.981, 95% CI 1.373-6.473, P=0.006) . Conclusions: Auto-HSCT could not reverse the poor prognosis of MRD(1) positive patients. Auto-HSCT treatment is optional for patients with MRD(1) negative and maintaining MRD(1) negative status during intensive therapy.

The role of stem cell transplantation in the management of Philadelphia chromosome-positive acute lymphoblastic leukemia

The concurrent administration of tyrosine kinase inhibitors (TKIs) with standard chemotherapy together with allogeneic hematopoietic stem cell transplantation (alloHSCT) has improved the outcome of patients with Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). Although to date, no study has shown alloHSCT to be inferior to chemotherapy plus TKIs in any subgroup of adult Ph+ ALL, there is some evidence suggesting no additional benefit of alloHSCT in patients with deep molecular responses to intensive chemotherapy with a second-generation, and especially, third-generation TKI. As none of these positive and negative studies are controlled, randomized trials are needed to fully define the role of alloHSCT in Ph+ ALL, especially in those with deep molecular response. However, if studies combining TKIs with new approaches such as immunotherapy lead to durable responses, alloHSCT in the first complete remission could be avoided in the near future in the majority of patients with Ph+ ALL.

How I treat Philadelphia chromosome-positive acute lymphoblastic leukemia

The introduction of agents targeted at specific molecular events is changing the treatment paradigms in a number of malignancies. Historically, we have relied entirely on DNA-interactive, cytotoxic drugs for treating patients with leukemia. Increased understanding of the leukemic cell biology and pathogenesis, and the ways they evade the immune surveillance mechanisms, will likely lead to the development of more effective agents, and regimens less reliant on chemotherapy, able to achieve deep levels of disease eradication. In Philadelphia chromosome-positive acute lymphoblastic leukemia, the introduction of increasingly potent tyrosine kinas inhibitors (TKIs) has revolutionized therapy. These drugs have been established as the cornerstone of any therapeutic strategy in this disease, and a number of trials have better defined the best ways to incorporate them into the established paradigms. Despite using TKIs, we have continued to remain reliant on cytotoxic chemotherapy regimens and allogeneic hematopoietic cell transplant to achieve the best long-term outcomes. However, with the introduction of more potent TKIs and other novel agents, as well as better methods for monitoring minimal/measurable residual disease, we are entering an era where we hope to diminish our reliance on transplantation and cytotoxic chemotherapy in this disease.

Recent advances in the biology and treatment of B-cell acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is a hematologic malignancy arising from precursors of the lymphoid lineage. Conventional cytotoxic chemotherapies have resulted in high cure rates of up to 90% in pediatric ALL, but the outcomes for adult patients remain suboptimal with 5-year survival rates of only 30%-40%. Over the last decade, major advances have been made in our understanding and management of ALL. Identification of new prognostic genomic markers and incorporation of minimal residual diseases' assessment into therapeutic protocols have improved risk stratification and treatment strategies. The use of pediatric-inspired regimens for adolescent and young adults, and the advent of tyrosine kinase inhibitors and novel targeted therapies, including monoclonal antibodies and chimeric antigen receptor T cells, have redefined the therapeutic paradigm of ALL, and significantly improved the outcomes. In this article, we will provide an overview of the current knowledge regarding the biology and treatment of ALL, and highlight recent diagnostic and therapeutic advances made in this area over the past 5 years.

Final analysis of the JALSG Ph+ALL202 study: tyrosine kinase inhibitor-combined chemotherapy for Ph+ALL

The Japan Adult Leukemia Study Group (JALSG) Ph+ALL202 study reported a high complete remission (CR) rate for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) patients treated with imatinib-combined chemotherapy. However, the long-term treatment efficacy remains uncertain. Here, we report a final analysis of the JALSG Ph+ALL202 study. The outcomes were compared with those of the JALSG ALL93 and ALL97 studies, which were conducted in the pre-imatinib era. Ninety-nine newly diagnosed Ph+ALL patients were enrolled in Ph+ALL202 (median age, 45 years; median follow-up, 4.5 years). CR was achieved in 96/99 (97%) patients. Fifty-nine of these 96 patients (61%) underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) in their first CR (CR1). The 5-year overall and disease-free survival (DFS) rates were 50 and 43%, respectively, which were significantly higher compared to those in the pre-imatinib era (15 and 19%, respectively). Multivariate analysis revealed that imatinib administration, allo-HSCT in CR1, and a white blood cell count < 30 × 10⁹/L were favorable independent prognostic factors for long-term DFS. Improved odds of receiving allo-HSCT and a lower relapse rate leaded to good long-term outcomes. The 3-year DFS tended to be higher in PCR-negative than that in PCR-positive patients (29 vs. 14%) in the non-HSCT patients, and this tendency was also seen in the allo-HSCT patients (59 vs. 50%). The higher rate of CR upon imatinib use may have contributed to these improvements.

Comparable results of autologous and allogeneic haematopoietic stem cell transplantation for adults with Philadelphia-positive acute lymphoblastic leukaemia in first complete molecular remission: An analysis by the Acute Leukemia Working Party of the EBMT

BACKGROUND

Allogeneic haematopoietic stem cell transplantation (alloHSCT) is considered a standard treatment for patients with Philadelphia chromosome-positive acute lymphoblastic leukaemia (Ph+ ALL) achieving complete remission after induction containing tyrosine kinase inhibitors (TKIs).

METHODS

We retrospectively compared results of myeloablative alloHSCT from either matched sibling donor (MSD) or unrelated donor (URD) with autologous (auto) HSCT for adults with Ph+ ALL in molecular remission, treated between 2007 and 2014.

RESULTS

In univariate analysis, the incidence of relapse at 2 years was 47% after autoHSCT, 28% after MSD-HSCT and 19% after URD-HSCT (P = 0.0002). Respective rates of non-relapse mortality were 2%, 18%, and 22% (P = 0.001). The probabilities of leukaemia-free survival were 52%, 55% and 60% (P = 0.69), while overall survival rates were 70%, 70% and 69% (P = 0.58), respectively. In multivariate analysis, there was a trend towards increased risk of overall mortality after MSD-HSCT (hazard ratio [HR], 1.5, P = 0.12) and URD-HSCT (HR, 1.6, P = 0.08) when referred to autoHSCT. The use of total body irradiation (TBI)-based regimens was associated with reduced risk of relapse (HR, 0.65, P = 0.02) and overall mortality (HR, 0.67, P = 0.01).

CONCLUSION

In the era of TKIs, outcomes of myeloablative autoHSCT and alloHSCT for patients with Ph+ ALL in first molecular remission are comparable. Therefore, autoHSCT appears to be an attractive treatment option potentially allowing for circumvention of alloHSCT sequelae. Irrespective of the type of donor, TBI-based regimens should be considered the preferable type of conditioning for Ph+ ALL.

Management of older adults with acute lymphoblastic leukemia: challenges & current approaches

The management of acute lymphoblastic leukemia (ALL) in older patients is challenging. Older patients often have multiple comorbidities and poor performance status, and disease factors associated with poor prognosis are more common in this age group. Patient and disease-related factors should be taken into account to determine whether intensive therapy is appropriate. The use of comorbidity indices and comprehensive geriatric assessment tools can be valuable in this setting. Fit patients should be considered for aggressive therapies including allogeneic hematopoietic stem cell transplantation, whereas low intensity options may be more suitable for the frail. The Philadelphia (Ph) chromosome is present in up to half of the cases of ALL in older patients. The incorporation of TK inhibitors into the treatment plans of older patients with Ph-positive ALL has improved the outcomes significantly. For less fit patients with Ph-positive ALL, the use of TK inhibitors with reduced-intensity chemotherapy or steroids alone results in high rates of remission, but, without further consolidation, relapses are inevitable. Many novel targeted and immunotherapeutic agents are being developed, offering more effective and tolerable treatment options.

Hematopoietic stem cell transplant in adults with acute lymphoblastic leukemia: the present state

INTRODUCTION

Allogeneic hematopoietic stem cell transplant (allo-HSCT) has an important role in management of acute lymphoblastic leukemia (ALL). Proper patient selection is central to ensure optimal outcomes. Areas covered: This review covers various aspects of HSCT in ALL patients, including indications, donor selection, conditioning regimens, and post-transplant management. Expert commentary: Allo-HSCT is important in post-remission management of ALL but proper risk-stratification is a major challenge. Incorporation of minimal residual disease (MRD) and molecular testing will improve patient allocation. Patients receiving pediatric-inspired induction who achieve molecular remission might not need allo-HSCT in first remission. Allo-HSCT should be considered in patients who don't achieve MDR negativity, didn't receive intensive induction, or have high risk cytogenetic and molecular features. Despite improved responses with tyrosine kinase inhibitors (TKIs) in Philadelphia positive (Ph+) ALL, allo-HSCT remains standard. Matched sibling donors are the optimal graft source, but other sources are valid alternatives. There is no single optimal conditioning regimen and retrospective studies found myeloablative and reduced intensity regimens to be comparable. Following allo-HSCT, there is no role for maintenance therapy in Philadelphia-negative ALL. In Ph+ ALL, maintenance TKIs improve outcomes. The integration of targeted and immunotherapies in the peri-transplant period holds potential for improved outcomes.

Current paradigms in the management of Philadelphia chromosome positive acute lymphoblastic leukemia in adults

Philadelphia chromosome-positive (Ph-positive) acute lymphoblastic leukemia (ALL) is a biologically, clinically, and genetically distinct subtype of precursor-B ALL. The Ph chromosome, results from a reciprocal translocation of the ABL1 kinase gene on chromosome 9 to the breakpoint cluster region (BCR) gene on chromosome 22. Depending on the translocation breakpoint, typically a p210 BCR-ABL1 or a p190 BCR-ABL onc protein are generated; both are constitutively active tyrosine kinases that play a central role to alter signaling pathways of cell proliferation, survival, and self-renewal, leading to leukemogenesis. In Ph-positive ALL, the p190-BCR-ABL (minor [m]-bcr) subtype is more frequent than the p210-BCR-ABL (major [M]-bcr) subtype, commonly found in chronic myeloid leukemia. The Philadelphia chromosome is the most frequent recurrent cytogenetic abnormality in elderly patients with ALL. Its incidence increases with age, reaching ∼50% in patients with ALL aged 60 years and over. Patients traditionally had a very poor outcome with chemotherapy, particularly if they do not undergo allogeneic hematopoietic cell transplantation (allo-HCT) in first complete remission (CR1). With the availability of multiple tyrosine kinase inhibitors (TKI), the therapeutic armamentarium is expanding quickly. However, there is no consensus on how to best treat Ph-positive ALL. With modern therapy, improved outcomes have led to the emergence of a number of controversies, including the need for intensive chemotherapy, the ideal TKI, and whether all eligible patients should receive an allo-HSCT, and if so, what type. Here, we discuss these controversies in light of the available literature.

Current management of Philadelphia chromosome positive ALL and the role of stem cell transplantation

Treatment of Philadelphia chromosome positive acute lymphoblastic leukemia exemplifies how the addition of potent targeted agents, directed at the molecular aberrations responsible for leukemic transformation, can overcome resistance mechanisms to traditional regimens and lead to improved outcomes. The introduction of BCR-ABL1 targeted tyrosine kinase inhibitors (TKIs) has significantly improved the outcomes not only by allowing more patients to undergo allogeneic hematopoietic cell transplantation (alloHCT) but also by decreasing our reliance on this potentially toxic strategy, particularly in the less fit population. Long-term data using chemotherapy and TKI combinations demonstrate that a proportion of patients treated can achieve durable relapse-free survival without undergoing alloHCT. Furthermore, the availability of sensitive minimal residual disease monitoring assays may allow early detection of the patients who are more likely to relapse and who are likely candidates for early alloHCT. The emergence of more potent TKIs with significant activity against resistant mutations has allowed deintensification of chemotherapy regimens. Available data indicate that complete reliance on TKIs, alone or with minimal additional therapy, and elimination of more intensive chemotherapy or alloHCT is unlikely to achieve long term cure in most patients. However, introduction of other highly effective agents that can be combined with TKIs may allow further minimization of chemotherapy and alloHCT in the future, as we have witnessed in acute promyelocytic leukemia.

Combination of IKZF1 deletion and early molecular response show significant roles on prognostic stratification in Philadelphia chromosome-positive acute lymphoblastic leukemia patients

We retrospectively analyzed the samples collected from 66 patients with Ph⁺ALL enrolled on ChiCTR-TNRC-09000309 clinical trial. CR rate was 95.5%, and estimated 2-year OS and DFS were 51.7 ± 11.7% and 26.9 ± 11.6%, 3-year OS and DFS were 31.6 ± 12.0% and 23.4 ± 11.6%. By combining IKZF1 deletion and early molecular responses, we redefined the patients as low, intermediate, and high risk 3 groups separately. Patients with double negative in IKZF1 and early molecular response experienced significant superior survival, while patients with double positive would have the worst outcome, and patients who were one or the other with IKZF1 deletion or MRD status had intermediate outcome. Significant differences were found among 3 groups in regard to both OS (p < .001) and DFS (p < .001). Our findings suggest that Ph⁺ALL is a heterogeneous group of diseases with significantly different prognosis. Combination of IKZF1 deletion and MRD status enable better risk stratification of patients for assignment to optimal therapeutic strategies.

Efficacy and safety of autologous peripheral blood stem cell transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia: A study protocol for a multicenter exploratory prospective study (Auto-Ph17 study)

INTRODUCTION

The prognosis of Philadelphia chromosome positive acute lymphoblastic leukemia (Ph + ALL) has been dramatically improved since the introduction of tyrosine kinase inhibitors (TKIs). Although allogeneic hematopoietic cell transplantation (allo-HCT) is a major treatment option, the role of autologous peripheral blood stem cell transplantation (auto-PBSCT) has been reconsidered, especially in patients who achieved early molecular remission.

METHODS AND ANALYSIS

This is a multicenter exploratory study for Ph + ALL patients aged between 55 and 70 years who achieved complete molecular remission within 3 cycles of chemotherapy. The target sample size is 5, and the registration period is 2 years. The primary endpoint is Day100- mortality after transplantation, and the secondary endpoints are survival, relapse rate, nonrelapse mortality, and adverse events.This study is divided into 3 phases: peripheral blood stem cell harvest, transplantation, and maintenance. Chemomobilization is performed using a combination of cyclophosphamide (CPM), doxorubicin, vincristine (VCR), and prednisolone (PSL). As a preparative regimen, the LEED regimen is used, which consists of melphalan, CPM, etoposide, and dexamethasone. Twelve cycles of maintenance therapy using a combination of VCR, PSL, and dasatinib are performed.In association with relapse, the minimal residual disease (MRD) of BCR-ABL chimeric gene and T-cell subsets are analyzed both before and after auto-PBSCT.

ETHICS AND DISSEMINATION

The protocol was approved by the institutional review board of Nagoya University Hospital and all the participating hospitals. Written informed consent was obtained from all patients before registration, in accordance with the Declaration of Helsinki. Results of the study will be disseminated via publications in peer-reviewed journals.

TRIAL REGISTRATION

Trial registration number UMIN000026445.

Which tyrosine kinase inhibitor should we use to treat Philadelphia chromosome-positive acute lymphoblastic leukemia?

The incorporation of tyrosine kinase inhibitors (TKIs) into chemotherapy regimens has significantly improved the long-term survival of patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). Successive generations of TKIs with increased potency against BCR-ABL and broader spectrum of activity against ABL kinase domain mutations have led to incremental improvements in the outcomes of patients with this disease. In particular, ponatinib, a potent pan-BCR-ABL TKI capable of overcoming the T315I mutation, holds significant promise in the treatment of Ph+ ALL, although the potential cardiovascular toxicity of this agent remains a concern. With the development of more potent TKIs that are capable of inducing deep and sustained remissions, future studies re-evaluating the need for intensive chemotherapy as well as the role for stem cell transplantation in first remission for patients with Ph+ ALL are warranted.

The evolving role of chemotherapy and hematopoietic cell transplants in Ph-positive acute lymphoblastic leukemia in adults

The introduction of the tyrosine kinase inhibitors (TKI) into the treatment of patients with Ph or BCR-ABL1-positive acute lymphoblastic leukemia has revolutionized the treatment of this poor prognosis acute leukemia. The combination of TKI with chemotherapy has improved response rates and allowed more patients to proceed to allogeneic hematopoietic cell transplant (alloHCT). Older patients have excellent responses to TKI and corticosteroids or in combination with minimal chemotherapy. This raises the question as to whether patients require full-intensity chemotherapy with TKI to achieve molecular remissions. The pediatricians have proposed that cure is achievable without alloHCT in children. These results have suggested that many patients may not require traditional chemotherapy in addition to TKI to achieve remission, and that patients who achieve a negative minimal residual disease state may not require alloHCT. The data in support of these questions is presented here and a suggested future clinical trial design based on these data is proposed.