BCR-ABL translocation as a favorable prognostic factor in elderly patients with acute lymphoblastic leukemia in the era of potent tyrosine kinase inhibitors

Cryptic to conventional cytogenetics: Philadelphia-like ALL presenting with hypereosinophilia

BCR::ABL1-like B-lymphoblastic leukaemia (B-ALL) neoplasms lack the BCR::ABL1 translocation but have a gene expression profile like BCR::ABL1 positive B-ALL. This includes alterations in cytokine receptors and signalling genes, such as CRLF2, ABL1, ABL2, JAK2, PDGFRB and EPOR Cases with CRLF2 rearrangements account for approximately 50% of cases of Philadelphia-like acute lymphoblastic leukaemia (Ph-like ALL), and the frequency of specific genomic lesions varies with ethnicity such that IGH::CRLF2 translocations are more common in Hispanics and Native Americans.We report two cases of BCR::ABL1-like ALL, with significant eosinophilia. A Hispanic man in his early 20s and a Hispanic woman in her 50s presented with leukocytosis and eosinophilia. Bone marrow flow cytometry revealed lymphoblasts expressing CD19, CD10, partial CD20, CD22, CD79a, CD38, CD34, TdT and HLA-DR. Examination of the bone marrow biopsy and aspirate exhibited a hypercellular bone marrow with increased blasts and elevated eosinophils. Fluorescence in situ hybridisation (FISH) demonstrated a cryptic chromosomal rearrangement between the X chromosome and chromosome 14 at breakpoints involving IGH at 14q32 and CRLF2 at Xp22.33, t(X;14)(p22.33; q32).These findings confirmed the diagnosis of BCR::ABL1-like B-ALL with IGH::CRLF2 rearrangement. One patient (man) attained complete remission with induction therapy using the paediatric CALGB 10403 protocol, while the other patient (woman) had a poor outcome after receiving a hyper-fractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone regimen. These two cases demonstrate an unusual presentation of BCR::ABL1-like B-ALL and emphasise the importance of appropriate cytogenetic studies for correct diagnosis. When treated with conventional chemotherapy, these cases carry a poor prognosis and might require allogeneic transplantation.

Hyper-CVAD versus dose-adjusted EPOCH as initial treatment for adults with acute lymphoblastic leukemia

OBJECTIVES

We recently performed a single-arm phase II trial of DA-EPOCH in adults with acute lymphoblastic leukemia (ALL). We sought to compare these results to those with standard Hyper-CVAD.

METHODS

We created a retrospective matched cohort of patients who received Hyper-CVAD (n = 69) at our center and otherwise met eligibility criteria for the DA-EPOCH trial (n = 53).

RESULTS

Our outcomes support the use of Hyper-CVAD over DA-EPOCH in Ph- disease for both overall survival (OS; HR 0.18, p = .004) and event-free survival (EFS; HR 0.51, p = .06). In contrast, outcomes were similar in Ph+ disease (OS HR 0.97, p = .96; EFS HR 0.65, p = .21). Rates of morphologic remission and measurable residual-disease negativity were similar between the regimens. Hyper-CVAD was associated with significantly more febrile neutropenia (OR 1.9, p = .03) and a greater incidence of Grade 4 or 5 adverse events (20% vs. 6%). Average transfusions per cycle of both red blood cells (p < .001) and platelets (p < .001) were five-fold higher with Hyper-CVAD.

CONCLUSIONS

Our findings support continued use of Hyper-CVAD for Ph- ALL but suggest that DA-EPOCH may be a reasonable alternative for Ph+ ALL. These data also highlight a potential role for DA-EPOCH in resource-limited settings or when more intense therapy is not feasible.

Reconstructing Clonal Evolution-A Systematic Evaluation of Current Bioinformatics Approaches

The accurate reconstruction of clonal evolution, including the identification of newly developing, highly aggressive subclones, is essential for the application of precision medicine in cancer treatment. Reconstruction, aiming for correct variant clustering and clonal evolution tree reconstruction, is commonly performed by tedious manual work. While there is a plethora of tools to automatically generate reconstruction, their reliability, especially reasons for unreliability, are not systematically assessed. We developed clevRsim-an approach to simulate clonal evolution data, including single-nucleotide variants as well as (overlapping) copy number variants. From this, we generated 88 data sets and performed a systematic evaluation of the tools for the reconstruction of clonal evolution. The results indicate a major negative influence of a high number of clones on both clustering and tree reconstruction. Low coverage as well as an extreme number of time points usually leads to poor clustering results. An underlying branched independent evolution hampers correct tree reconstruction. A further major decline in performance could be observed for large deletions and duplications overlapping single-nucleotide variants. In summary, to explore the full potential of reconstructing clonal evolution, improved algorithms that can properly handle the identified limitations are greatly needed.

Characteristics and Outcome of Elderly Patients (>55 years) with Acute Lymphoblastic Leukemia

Simple Summary

Disease-specific mortality of acute lymphoblastic leukemia (ALL) increases with age. So far, only a few analyses have investigated disease characteristics of elderly patients (>55 years) with newly diagnosed ALL. The aim of our retrospective study was to evaluate the treatment results of 93 elderly patients who received intensive chemotherapy between May 2003 and October 2020. We identify poor performance status and older age at the time of diagnosis as risk factors for inferior outcomes, while ALL immunophenotype, BCR::ABL1 status, the complexity of karyotype, and intensity of treatment did not significantly affect overall survival (OS). With 17.3% of patients dying while in complete remission (CR), an event-free survival (EFS) and OS of 32.9% and 47.3% at 3 years, our data suggest that intensive treatment of elderly ALL patients is feasible but associated with significant toxicity. These results underline the need for novel, less toxic treatment approaches for this vulnerable cohort of patients.

Abstract

Prognosis of elderly ALL patients remains dismal. Here, we retrospectively analyzed the course of 93 patients > 55 years with B-precursor (n = 88) or T-ALL (n = 5), who received age-adapted, pediatric-inspired chemotherapy regimens at our center between May 2003 and October 2020. The median age at diagnosis was 65.7 years, and surviving patients had a median follow-up of 3.7 years. CR after induction therapy was documented in 76.5%, while the rate of treatment-related death within 100 days was 6.4%. The OS of the entire cohort at 1 and 3 year(s) was 75.2% (95% CI: 66.4–84.0%) and 47.3% (95% CI: 36.8–57.7%), respectively, while the EFS at 1 and 3 years(s) was 59.0% (95% CI: 48.9–69.0%) and 32.9% (95% CI: 23.0–42.8%), respectively. At 3 years, the cumulative incidence (CI) of relapse was 48.3% (95% CI: 38.9–59.9%), and the CI rate of death in CR was 17.3% (95% CI: 10.9–27.5%). Older age and an ECOG > 2 represented risk factors for inferior OS, while BCR::ABL1 status, immunophenotype, and intensity of chemotherapy did not significantly affect OS. We conclude that intensive treatment is feasible in selected elderly ALL patients, but high rates of relapse and death in CR underline the need for novel therapeutic strategies.

Philadelphia-positive B-lymphoblastic leukemia in a middle-income country - A real-world multicenter cohort

Outside of clinical trials, few studies have addressed the outcomes of Ph+ acute lymphoblastic leukemia (ALL) in adults, especially from developing world. In this study, we conducted a multicenter analysis on the outcomes of patients aged > 15 years with Ph+ ALL, aiming to get to know an overview of the Brazilian experience as well as to explore baseline factors associated with relapse and mortality in our setting. Over these 10 years, patients were treated with diverse protocols, all of them always combined with a frontline tyrosine-kinase inhibitor. A total of 123 Ph+ ALL patients was included. Imatinib was the first line TKI in 97 %. The complete response rate was 79 %. The early death rate was 15 %, being associated with increasing age at diagnosis (p = 0.06). The use of intensive versus attenuated induction regimen was not associated with higher induction mortality (p = 0.99). Overall, 29 % of patients aged ≤ 60 years underwent allogeneic transplantation, 87 % in first CR. 4-year overall survival (OS) and relapse-free survival were 25 % and 24 %, respectively. The incidence of relapse (death as a competitor) was 29 %, while the non-relapse mortality was 42 %. Only age was independently associated with OS, and lactate dehydrogenase level and central nervous disease at diagnosis were related to relapse in our cohort. This is the first historical cohort multicenter study on Ph+ ALL from Brazil. Reporting these outcomes is essential to encourage public policies to expand access to new drugs and transplantation in middle-income countries.

New approaches to the treatment of older adults with acute lymphoblastic leukemia

Outcomes for older adults (defined here as ≥55-65 years old) with acute lymphoblastic leukemia (ALL) are poor, with long-term survival less than 20%. Pediatric chemotherapy regimens produce long-term cure rates of 80% to 90% in children and 60% to 70% in adolescents and young adults with Ph-negative ALL, however, tolerability of intensive chemotherapy becomes problematic with advanced age due to comorbidities and reduced tolerability of chemotherapy leading to high rates of treatment-related mortality. For older adults with Ph-positive ALL, BCR-ABL1-directed tyrosine kinase inhibitors in combination with corticosteroids or chemotherapy produce deep remissions with low treatment-related toxicity but optimal postremission therapy is not known. New therapeutic approaches for older adults with ALL involve integration of the novel targeted agents including monoclonal antibody-based therapy with blinatumomab and inotuzumab ozogamicin in the frontline. Ongoing studies will ideally define optimal combinations and sequencing of novel agents with or without chemotherapy, tyrosine kinase inhibitors, and/or corticosteroids to maximize efficacy while avoiding treatment-related death. Anti-CD19 chimeric antigen receptor modified T cells are a promising modality, with high rates of remission and minimal residual disease negativity achieved in early phase trials for adults with relapsed/refractory B-cell ALL but the tolerability of chimeric antigen receptor modified T cell therapies in older adults is yet to be well defined. Advances in minimal residual disease detection have helped to effectively stratify adults in complete response in terms of relapse risk and predicted relative benefit for allogeneic hematopoietic cell transplant. For older adults with ALL in complete response at high risk for relapse for whom myeloablative conditioning is predicted to result in excessive transplant-related mortality, reduced-intensity conditioning allogeneic hematopoietic cell transplant is a less toxic approach for providing a graft-versus-leukemia effect and long-term disease control.

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.

Targeted next-generation sequencing of circulating cell-free DNA vs bone marrow in patients with acute myeloid leukemia

Circulating cell-free DNA (ccfDNA) allows for noninvasive peripheral blood sampling of cancer-associated mutations and has established clinical utility in several solid tumors. We performed targeted next-generation sequencing of ccfDNA and bone marrow at the time of diagnosis and after achieving remission in 22 patients with acute myeloid leukemia (AML). Among 28 genes sequenced by both platforms, a total of 39 unique somatic mutations were detected. Five mutations (13%) were detected only in ccfDNA, and 15 (38%) were detected only in bone marrow. Among the 19 mutations detected in both sources, the concordance of variant allelic frequency (VAF) assessment by both methods was high (R2 = 0.849). Mutations detected in only 1 source generally had lower VAF than those detected in both sources, suggesting that either method may miss small subclonal populations. In 3 patients, sequencing of ccfDNA detected new or persistent leukemia-associated mutations during remission that appeared to herald overt relapse. Overall, this study demonstrates that sequencing of ccfDNA in patients with AML can identify clinically relevant mutations not detected in the bone marrow and may play a role in the assessment of measurable residual disease. However, mutations were missed by both ccfDNA and bone marrow analyses, particularly when the VAF was <10%, suggesting that ccfDNA and bone marrow may be complementary in the assessment and monitoring of patients with AML.

Elderly acute lymphoblastic leukemia: a Mayo Clinic study of 124 patients

Poor outcomes in elderly acute lymphoblastic leukemia (ALL) are well recognized, but the contributors are ill-defined. We characterized 124 patients ≥60 years old at our institution. The majority (n = 102, 82%) were treated with intensive chemotherapy. Of these, 8/102 (8%) died within the first 100 days; 92/102 (90%) achieved complete remission (CR/CRi). Only 31/124 (25%) patients underwent allogeneic hematopoietic stem cell transplantation. The median overall survival (OS) for the entire cohort was 19.8 months. In a multivariate analysis, ECOG performance status ≥2, high white blood cell count, and high lactate dehydrogenase (at time of diagnosis) negatively influenced OS (p<.01). In a subgroup analysis of the intensive treatment group, BCR-ABL1+ patients had markedly better OS (hazard ratio 0.3, 95% CI 0.1-0.7; p<.01). In summary, despite few early deaths and a high CR/CRi rate, elderly ALL continues to have a poor prognosis, underscoring the need for more effective therapies.

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.

Novel Therapies for Older Adults With Acute Lymphoblastic Leukemia

PURPOSE OF REVIEW

Older adults with acute lymphoblastic leukemia (ALL) have worse survival compared to their younger counterparts. Here, we review the reasons for the poorer outcomes of older patients with ALL and also summarize the current and future therapeutic approaches to ALL in the elderly population.

RECENT FINDINGS

The poor outcomes of older adults with ALL are driven largely by lack of tolerance to standard-dose chemotherapy, which leads to unacceptably high rates of myelosuppression-related deaths. Recent studies have shown promising results with the use of low-intensity or chemotherapy-free regimens in older patients with ALL, which are able to retain efficacy without excess toxicity. Novel antibody constructs such as inotuzumab ozogamicin and blinatumomab as well as potent later-generation tyrosine kinase inhibitors such as ponatinib hold significant promise in the management of ALL in the older adult. Innovative combination strategies may further improve the outcomes of these patients.