Treatment of older patients with acute lymphoblastic leukemia

SOHO State of the Art Updates and Next Questions | Next Questions: Acute Lymphoblastic Leukemia

The integration of immune and targeted therapies into the treatment of acute lymphoblastic leukemia (ALL) has significantly improved outcomes, reduced the intensity and duration of chemotherapy, and the reliance on allogeneic stem cell transplantation (SCT). In younger patients with Philadelphia chromosome (Ph)-negative ALL, treatment with Hyper-CVAD and blinatumomab +/- inotuzumab has improved the 3-year overall survival (OS) to above 85%. In older patients, using less intensive chemotherapy (mini-Hyper-CVD) in combination with inotuzumab and blinatumomab has improved the 5-year OS rate to 50%. In Ph+ ALL, the chemotherapy-free combinations of blinatumomab and ponatinib (or dasatinib) have become a new standard of care resulting in 3-year OS of 85% to 90%. Because the methotrexate-cytarabine courses were omitted in the nonchemotherapy regimens, central nervous system (CNS) relapses were noted, particularly in patients with a WBC count > 70 × 109/L, requiring to consider increasing the number of prophylactic intrathecals (from 12 to 15) and perhaps developing a CNS risk-directed high-dose systemic chemotherapy. In relapsed/refractory ALL, a dose-dense regimen integrating blinatumomab and inotuzumab with low-intensity chemotherapy followed by consolidation with chimeric antigen receptor T-cell therapy is being investigated. The detection of measurable residual disease (MRD) following ALL therapy is predictive of disease relapse. Using next-generation sequencing allows the detection of MRD at 1 × 10-6 which was shown to be superior to multiparameter flow cytometry and polymerase chain reaction in predicting relapse, and could be used to decide on the duration of therapy or need to change therapy. Herein, we review the recent updates and areas of unmet need in ALL.

Recommendations for the treatment and management of adult B-Cell acute lymphoblastic leukemia in Asia-Pacific: Outcomes from a pilot initiative

The outcomes of adult B-cell acute lymphoblastic leukemia (ALL) remain poor. Recent advancements in the field of leukemia research show potential for improved patient care. However, the adoption of research findings into clinical practice is fraught with practice- and country-specific challenges. The continued addition of new findings warrants critical evaluation for the feasibility of incorporation into clinical practice. A uniform set of evidence-based guidelines can favorably assist physicians in making optimal clinical decisions. Such a resource may also serve as a reference point for strategic planning of initiatives aimed at addressing critical barriers in the optimal management of B-cell ALL. This initiative was undertaken to seek a collaborative perspective and understand the existing challenges. Concordance-based recommendations were outlined through a systematic discussion on various aspects of treatment and management of adult B-cell ALL. The outcomes and experiences gained from this exercise will serve as a foundation for future efforts encompassing the more granular aspects of the management of B-cell ALL across the Asia-Pacific region.

Inotuzumab Ozogamicin as Induction Therapy for Patients Older Than 55 Years With Philadelphia Chromosome-Negative B-Precursor ALL

PURPOSE

Despite recent advances in adapting the intensity of treatment for older patients with ALL, current protocols are associated with high rates of early deaths, treatment-related toxicity, and dismal prognosis. We evaluated inotuzumab ozogamicin and dexamethasone (Dex) as induction therapy in older patients with ALL within the German Multicenter Study Group for Adult ALL (GMALL).

PATIENTS AND METHODS

The open-label, multicenter, phase II, INITIAL-1 trial enrolled 45 patients older than 55 years with newly diagnosed, CD22-positive, BCR::ABL-negative B-precursor ALL (B-ALL). Patients received up to three cycles of inotuzumab ozogamicin/Dex and up to six cycles of age-adapted GMALL consolidation and maintenance therapy.

RESULTS

Forty-three evaluable patients with common/pre-B (n = 38) and pro-B ALL (n = 5), with a median age of 64 years (range, 56-80), received at least two cycles of inotuzumab ozogamicin induction therapy. All patients achieved complete remission (CR/CR with incomplete hematologic recovery). Twenty-three (53%) and 30 (71%) patients had no evidence of molecularly assessed measurable residual disease (minimum 10e-4 threshold) after the second and third inductions, respectively. After a median follow-up of 2.7 years, event-free survival at one (primary end point) and 3 years was 88% (95% CI, 79 to 98) and 55% (95% CI, 40 to 71), while overall survival (OS) was 91% (95% CI, 82 to 99) and 73% (95% CI, 59 to 87), respectively. None of the patients died during 6 months after the start of induction. Most common adverse events having common toxicity criteria grade ≥3 during induction were leukocytopenia, neutropenia, thrombocytopenia, anemia, and elevated liver enzymes. One patient developed nonfatal veno-occlusive disease after induction II.

CONCLUSION

Inotuzumab ozogamicin-based induction followed by age-adapted chemotherapy was well tolerated and resulted in high rates of remission and OS. These data provide a rationale for integrating inotuzumab ozogamicin into first-line regimens for older patients with B-ALL.

Treatment of adult ALL patients with third-generation CD19-directed CAR T cells: results of a pivotal trial

BACKGROUND

Third-generation chimeric antigen receptor (CAR)-engineered T cells (CARTs) might improve clinical outcome of patients with B cell malignancies. This is the first report on a third-generation CART dose-escalating, phase-1/2 investigator-initiated trial treating adult patients with refractory and/or relapsed (r/r) acute lymphoblastic leukemia (ALL).

METHODS

Thirteen patients were treated with escalating doses of CD19-directed CARTs between 1 × 10⁶ and 50 × 10⁶ CARTs/m². Leukapheresis, manufacturing and administration of CARTs were performed in-house.

RESULTS

For all patients, CART manufacturing was feasible. None of the patients developed any grade of Immune effector cell-associated neurotoxicity syndrome (ICANS) or a higher-grade (≥ grade III) catokine release syndrome (CRS). CART expansion and long-term CART persistence were evident in the peripheral blood (PB) of evaluable patients. At end of study on day 90 after CARTs, ten patients were evaluable for response: Eight patients (80%) achieved a complete remission (CR), including five patients (50%) with minimal residual disease (MRD)-negative CR. Response and outcome were associated with the administered CART dose. At 1-year follow-up, median overall survival was not reached and progression-free survival (PFS) was 38%. Median PFS was reached on day 120. Lack of CD39-expression on memory-like T cells was more frequent in CART products of responders when compared to CART products of non-responders. After CART administration, higher CD8 + and γδ-T cell frequencies, a physiological pattern of immune cells and lower monocyte counts in the PB were associated with response.

CONCLUSION

In conclusion, third-generation CARTs were associated with promising clinical efficacy and remarkably low procedure-specific toxicity, thereby opening new therapeutic perspectives for patients with r/r ALL. Trial registration This trial was registered at www.

CLINICALTRIALS

gov as NCT03676504.

Mini-hyper-CVD plus inotuzumab ozogamicin, with or without blinatumomab, in the subgroup of older patients with newly diagnosed Philadelphia chromosome-negative B-cell acute lymphocytic leukaemia: long-term results of an open-label phase 2 trial

BACKGROUND

The outcome of older patients with B-cell acute lymphocytic leukaemia is inferior to that in younger patients due to the adverse disease biology and their inability to tolerate intensive therapy. We aimed to study the long-term outcomes of inotuzumab ozogamicin with or without blinatumomab in combination with low-intensity chemotherapy in these patients.

METHODS

For this open-label phase 2 trial, patients aged 60 years or older with newly diagnosed, Philadelphia-chromosome negative, B-cell acute lymphocytic leukaemia, and an ECOG performance status of 3 or lower were eligible. This study was conducted at the University of Texas MD Anderson Cancer Center. The induction chemotherapy consisted of mini-hyper-CVD and has been published before; inotuzumab ozogamicin was administered intravenously on day 3 of the first four cycles at a dose of 1·3-1·8 mg/m2 in cycle 1, followed by 1·0-1·3 mg/m2 in subsequent cycles (cycles 2-4). Maintenance therapy with dose-reduced POMP (6-mercaptopurine, vincristine, methotrexate, and prednisone) was given for 3 years. From patient 50 onwards, the study protocol was amended to fractionate inotuzumab ozogamicin to a maximum cumulative dose of 2·7 mg/m2 (0·9 mg/m2 during cycle 1 fractionated into 0·6 mg/m2 on day 2 and 0·3 mg/m2 on day 8 of cycle 1, and 0·6 mg/m2 in cycles 2-4 fractionated into 0·3 mg/m2 on day 2 and 0·3 mg/m2 on day 8) followed by blinatumomab for four cycles (cycles 5-8). POMP maintenance was shortened to 12 cycles with one cycle of blinatumomab administered by continuous infusion after every three cycles of POMP. The primary endpoint was progression-free survival and was analysed on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov (NCT01371630) and the present data is from the newly diagnosed, older subgroup of patients treated on the phase 2 portion of this trial; the trial is still enrolling patients.

RESULTS

Between Nov 11, 2011, and March 31, 2022, 80 patients were enrolled and treated (32 female and 48 male patients; median age 68 years [IQR 63-72]), 31 of whom were treated after the protocol amendment. With a median follow-up of 92·8 months (IQR 8·8-67·4), the 2-year progression-free survival was 58·2% (95% CI 46·7-68·2) and 5-year progression-free survival was 44·0% (31·2-54·3). At a median follow-up of 104·4 months (IQR 6·6-89·2) for the patients treated before the protocol amendment and 29·7 months (8·8-41·0) for those treated after the protocol amendment, median progression-free survival did not differ significantly between the two groups (34·7 months [95% CI 15·0-68·3] vs 56·4 months [11·3-69·7]; p=0·77). The most common grade 3-4 events were thrombocytopenia in 62 (78%) patients and febrile neutropenia in 26 (32%) patients. Six (8%) patients developed hepatic sinusoidal obstruction syndrome. There were eight (10%) deaths due to infectious complications, nine (11%) from complications related to secondary myeloid malignancy, and four (5%) from sinusoidal obstruction syndrome.

INTERPRETATION

Inotuzumab ozogamicin with or without blinatumomab added to low-intensity chemotherapy showed promising activity in terms of progression-free survival in older patients with B-cell acute lymphocytic leukaemia. Further attenuation of the chemotherapy regimen might improve tolerability while maintaining efficacy in older patients.

FUNDING

Pfizer and Amgen.

Molecular Characterization of the Response to Conventional Chemotherapeutics in Pro-B-ALL Cell Lines in Terms of Tumor Relapse

Little is known about optimally applying chemotherapeutic agents in a specific temporal sequence to rapidly reduce the tumor load and to improve therapeutic efficacy. The clinical optimization of drug efficacy while reducing side effects is still restricted due to an incomplete understanding of the mode of action and related tumor relapse mechanisms on the molecular level. The molecular characterization of transcriptomic drug signatures can help to identify the affected pathways, downstream regulated genes and regulatory interactions related to tumor relapse in response to drug application. We tried to outline the dynamic regulatory reprogramming leading to tumor relapse in relapsed MLL-rearranged pro-B-cell acute lymphoblastic leukemia (B-ALL) cells in response to two first-line treatments: dexamethasone (Dexa) and cytarabine (AraC). We performed an integrative molecular analysis of whole transcriptome profiles of each treatment, specifically considering public knowledge of miRNA regulation via a network-based approach to unravel key driver genes and miRNAs that may control the relapse mechanisms accompanying each treatment. Our results gave hints to the crucial regulatory roles of genes leading to Dexa-resistance and related miRNAs linked to chemosensitivity. These genes and miRNAs should be further investigated in preclinical models to obtain more hints about relapse processes.

SOHO State of the Art Updates and Next Questions: Mini-Hyper-CVD Combinations for Older Adults: Results of Recent Trials and a Glimpse into the Future

Acute lymphoblastic leukemia (ALL) is an aggressive blood cancer that affects both children and adults. Although the majority of children diagnosed with ALL are now cured and outcomes are improving for younger adults, older adults diagnosed with ALL usually succumb to their disease. Traditional chemotherapy regimens are poorly tolerated and ineffective in most older adults. Recently, novel chemotherapy agents such as inotuzumab ozogamicin and venetoclax have been successfully combined with dose reduced chemotherapy (mini-hyper-CVD) with promising results. Further study is needed to define the optimal combination and sequencing of novel agents and chemotherapy for different patient populations. This review discusses the challenge of treating older adults with traditional chemotherapy, experience to date with novel agents in combination with mini-hyper-CVD, as well as future directions and unanswered questions.

Nrf2 Overexpression Decreases Vincristine Chemotherapy Sensitivity Through the PI3K-AKT Pathway in Adult B-Cell Acute Lymphoblastic Leukemia

Uncontrolled proliferation is an important cancer cell biomarker, which plays a critical role in carcinogenesis, progression and development of resistance to chemotherapy. An improved understanding of novel genes modulating cancer cell proliferation and mechanism will help develop new therapeutic strategies. The nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor, decreases apoptosis when its expression is upregulated. However, the relationship between Nrf2 and Vincristine (VCR) chemotherapy resistance in B-cell acute lymphoblastic leukemia (B-ALL) is not yet established. Our results showed that Nrf2 levels could sufficiently modulate the sensitivity of B-ALL cells to VCRby regulating an apoptotic protein, i.e., the Bcl-2 agonist of cell death (BAD). Chemotherapeutic agents used for the treatment of B-ALL induced Nrf2 overactivation and PI3K-AKT pathway activation in the cells, independent of the resistance to chemotherapy; thus, a potential resistance loop during treatment for B-ALL with a drug combination is established. Therefore, B-ALL patients with a high expression of Nrf2 might mean induction chemotherapy with VCR effective little.

Isatuximab monotherapy in patients with refractory T-acute lymphoblastic leukemia or T-lymphoblastic lymphoma: Phase 2 study

The poor prognosis of acute T‐cell lymphoblastic leukemia (T‐ALL) and T‐cell lymphoblastic lymphoma (T‐LBL) in older adults and patients with relapsed/refractory illness is an unmet clinical need, as there is no defined standard of care and there are few treatment options. Abnormally elevated CD38 expression in T‐ALL and T‐LBL is associated with tumor expansion and disease development, making CD38 a potential target for anti‐T‐ALL and T‐LBL treatment. Isatuximab is a monoclonal antibody that binds to a specific epitope on CD38. The purpose of the study was to assess the efficacy and safety of isatuximab monotherapy in a phase 2, multicenter, one‐arm, open‐label study in patients with relapsed or refractory T‐ALL or T‐LBL (Clinical Trials.gov identifier NCT02999633). The primary endpoint was to assess the efficacy of isatuximab by overall response rate (ORR). An interim analysis based on the efficacy and safety of isatuximab in the first 19 patients enrolled was scheduled, however only 14 patients were enrolled in the study. No patient achieved complete response (CR) or CR with incomplete peripheral recovery. Most patients (11 [78.6%]) developed progressive disease and had progressive disease as their best response. A total of 10 (71.4%) patients had treatment emergent adverse events considered treatment‐related, with infusion reactions as the most frequent drug‐related TEAE, occurring in 8 (57.1%) patients. Despite the low efficacy of isatuximab in the current study, it is likely that the use of immunotherapy medication in T‐ALL will be expanded through logically targeted approaches, together with advances in the design of T‐cell therapy and clinical experience and will provide restorative options beyond chemotherapy and targeted treatments.

Ixazomib in addition to chemotherapy for the treatment of acute lymphoblastic leukemia in older adults

We sought to assess the safety of adding ixazomib, an oral proteasome inhibitor, to a multi-agent treatment regimen for older adults with acute lymphoblastic leukemia (ALL). Patients 51 to 75 years of age with newly diagnosed ALL were screened. Induction consisted of prednisone (P), vincristine (V), and doxorubicin (D). For BCR-ABL1+ patients, dasatinib was added. On Days 1, 8, 15 of induction, ixazomib was given orally. After induction patients received 1 cycle of consolidation in which ixazomib was given on Days 1, 8, 15. After consolidation, patients in remission (CR) were offered stem cell transplantation. Among the 19 patients treated, 15 (79%) [90% CI, 58-92%] achieved CR or CRi. At 2 years, the overall survival was 47% [95%CI, 29-72%]. In this study the dose of 2.3 mg of ixazomib in combination was the MTD for older patients with ALL and is the recommended dose for future phase 2 studies.

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.

Acute lymphoblastic leukemia in older adults: curtain call for conventional chemotherapy?

Unlike younger adults with acute lymphoblastic leukemia (ALL), older adults are rarely cured due to a combination of intrinsic disease resistance and treatment-related toxicities. Novel therapeutics such as inotuzumab ozogamicin, blinatumomab, venetoclax, and ABL kinase inhibitors have high activity in ALL and are well tolerated by older adults. Frontline treatment regimens for older adults using novel therapeutics with reduction or omission of conventional chemotherapy are being developed with early results demonstrating high remission rates and lower toxicity, but long-term efficacy and toxicity data are lacking. Collaboration between academic and pharmaceutical stakeholders is needed to develop clinical trials to define the optimal treatment regimens for older adults with ALL.

T-Lymphoblastic Leukemia/Lymphoma and Thymoma: A Case Report and Review of the Literature of a Rare Association

The co-occurrence of thymoma and T-lymphoblastic lymphoma/leukemia is an extremely rare but previously reported association that poses a diagnostic and therapeutic challenge. We describe a 67-year-old patient with long-standing untreated B1 thymoma that presented with constitutional symptoms and a painless soft tissue mass on the right chest wall. Pathological analysis of the biopsy from the mass demonstrated T-lymphoblastic leukemia/lymphoma. The patient went through a complicated course, was refractory to several lines of therapy, and eventually underwent allogeneic hematopoietic stem cell transplantation in complete remission from a matched related donor. The association between thymoma and malignant neoplasms has been described in the literature, most notably with colorectal adenocarcinoma and thyroid cancer. Thymoma-associated leukemia is, however, extremely unusual, with limited reports in the literature. Distinguishing between thymoma and leukemia can be challenging and often requires meticulous diagnostic efforts. For patients with a past history of thymoma, awareness of this particular association should be bared in mind to allow earlier diagnosis and therapy.

KTE-X19 for relapsed or refractory adult B-cell acute lymphoblastic leukaemia: phase 2 results of the single-arm, open-label, multicentre ZUMA-3 study

BACKGROUND

Despite treatment with novel therapies and allogeneic stem-cell transplant (allo-SCT) consolidation, outcomes in adult patients with relapsed or refractory B-precursor acute lymphoblastic leukaemia remain poor, underlining the need for more effective therapies.

METHODS

We report the pivotal phase 2 results of ZUMA-3, an international, multicentre, single-arm, open-label study evaluating the efficacy and safety of the autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy KTE-X19 in adult patients with relapsed or refractory B-precursor acute lymphoblastic leukaemia. Patients were enrolled at 25 sites in the USA, Canada, and Europe. Eligible patients were aged 18 years or older, with Eastern Cooperative Oncology Group performance status of 0-1, and morphological disease in the bone marrow (>5% blasts). After leukapheresis and conditioning chemotherapy, patients received a single KTE-X19 infusion (1 × 106 CAR T cells per kg bodyweight). The primary endpoint was the rate of overall complete remission or complete remission with incomplete haematological recovery by central assessment. Duration of remission and relapse-free survival, overall survival, minimal residual disease (MRD) negativity rate, and allo-SCT rate were assessed as secondary endpoints. Efficacy and safety analyses were done in the treated population (all patients who received a dose of KTE-X19). This study is registered with ClinicalTrials.gov, NCT02614066.

FINDINGS

Between Oct 1, 2018, and Oct 9, 2019, 71 patients were enrolled and underwent leukapheresis. KTE-X19 was successfully manufactured for 65 (92%) patients and administered to 55 (77%). The median age of treated patients was 40 years (IQR 28-52). At the median follow-up of 16·4 months (13·8-19·6), 39 patients (71%; 95% CI 57-82, p<0·0001) had complete remission or complete remission with incomplete haematological recovery, with 31 (56%) patients reaching complete remission. Median duration of remission was 12·8 months (95% CI 8·7-not estimable), median relapse-free survival was 11·6 months (2·7-15·5), and median overall survival was 18·2 months (15·9-not estimable). Among responders, the median overall survival was not reached, and 38 (97%) patients had MRD negativity. Ten (18%) patients received allo-SCT consolidation after KTE-X19 infusion. The most common adverse events of grade 3 or higher were anaemia (27 [49%] patients) and pyrexia (20 [36%] patients). 14 (25%) patients had infections of grade 3 or higher. Two grade 5 KTE-X19-related events occurred (brain herniation and septic shock). Cytokine release syndrome of grade 3 or higher occurred in 13 (24%) patients and neurological events of grade 3 or higher occurred in 14 (25%) patients.

INTERPRETATION

KTE-X19 showed a high rate of complete remission or complete remission with incomplete haematological recovery in adult patients with relapsed or refractory B-precursor acute lymphoblastic leukaemia, with the median overall survival not reached in responding patients, and a manageable safety profile. These findings indicate that KTE-X19 has the potential to confer long-term clinical benefit to these patients.

FUNDING

Kite, a Gilead Company.

AXL inhibition in macrophages stimulates host-versus-leukemia immunity and eradicates naive and treatment resistant leukemia

Acute leukemias are systemic malignancies associated with a dire outcome. Due to low immunogenicity, leukemias display a remarkable ability to evade immune control and are often resistant to checkpoint blockade. Here, we discover that leukemia cells actively establish a suppressive environment to prevent immune attacks by co-opting a signaling axis that skews macrophages towards a tumor promoting tissue repair phenotype, namely the GAS6/AXL axis. Using aggressive leukemia models, we demonstrate that ablation of the AXL receptor specifically in macrophages, or its ligand GAS6 in the environment, stimulates anti-leukemic immunity and elicits effective and lasting NK- and T-cell dependent immune response against naive and treatment resistant leukemia. Remarkably, AXL deficiency in macrophages also enables PD1 checkpoint blockade in PD1-refractory leukemias. Lastly, we provide proof-of-concept that a clinical grade AXL inhibitor can be used in combination with standard of care therapy to cure established leukemia, regardless on AXL expression in malignant cells.

Comparison of CALGB 10403 (Alliance) and COG AALL0232 toxicity results in young adults with acute lymphoblastic leukemia

Adolescents and young adults (AYAs) with acute lymphoblastic leukemia have improved outcomes when treated with pediatric-inspired regimens. CALGB 10403 was the largest prospective study to evaluate the feasibility of using a pediatric regimen in AYAs with acute lymphoblastic leukemia up to 40 years of age. This article presents the toxicity events observed in the CALGB 10403 study and compares these toxicities vs those observed among AYAs treated on the same arm of the companion Children's Oncology Group (COG) AALL0232 study. Toxicities in CALGB 10403 were similar to those observed in COG AALL0232. Some grade 3 to 4 adverse events were more often reported in CALGB 10403 compared with COG AALL0232 (hyperglycemia, hyperbilirubinemia, transaminase elevation, and febrile neutropenia). Adverse events correlated with body mass index ≥30 kg/m2 and some with increasing age. The mortality rate in CALGB 10403 was low (4%) and similar to that in the COG AALL0232 trial. A caveat to this analysis is that only 39% of CALGB 10403 patients completed all planned protocol treatment. In COG AALL0232, although 74% of patients aged <18 years completed treatment, only 57% of patients aged ≥18 years completed treatment. This scenario suggests that issues associated with age and treating physician may be a factor. Due to its improved survival rates compared with historical controls, the CALGB 10403 regimen is now a standard of care. The hope is that the rate of protocol completion will increase as more familiarity is gained with this regimen. These trials were registered at www.clinicaltrials.gov as #NCT00558519 (CALGB 10403) and #NCT00075725 (COG AALL0232).

Integrin α6 mediates the drug resistance of acute lymphoblastic B-cell leukemia

Resistance to multimodal chemotherapy continues to limit the prognosis of acute lymphoblastic leukemia (ALL). This occurs in part through a process called adhesion-mediated drug resistance, which depends on ALL cell adhesion to the stroma through adhesion molecules, including integrins. Integrin α6 has been implicated in minimal residual disease in ALL and in the migration of ALL cells to the central nervous system. However, it has not been evaluated in the context of chemotherapeutic resistance. Here, we show that the anti-human α6-blocking Ab P5G10 induces apoptosis in primary ALL cells in vitro and sensitizes primary ALL cells to chemotherapy or tyrosine kinase inhibition in vitro and in vivo. We further analyzed the underlying mechanism of α6-associated apoptosis using a conditional knockout model of α6 in murine BCR-ABL1+ B-cell ALL cells and showed that α6-deficient ALL cells underwent apoptosis. In vivo deletion of α6 in combination with tyrosine kinase inhibitor (TKI) treatment was more effective in eradicating ALL than treatment with a TKI (nilotinib) alone. Proteomic analysis revealed that α6 deletion in murine ALL was associated with changes in Src signaling, including the upregulation of phosphorylated Lyn (pTyr507) and Fyn (pTyr530). Thus, our data support α6 as a novel therapeutic target for ALL.

Recent Advances in Managing Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is characterized by chromosomal translocations and somatic mutations that lead to leukemogenesis. The incorporation of pediatric-type regimens has improved survival in young adults, and the incorporation of tyrosine kinase inhibitors for patients with Philadelphia chromosome-positive disease has led to further improvements in outcomes. However, older patients often have poor-risk biology and reduced tolerance to chemotherapy, leading to lower remission rates and overall survival. Regardless of age, patients with relapsed or refractory ALL have extremely poor outcomes. The advent of next-generation sequencing has facilitated the revolution in understanding the genetics of ALL. New genetic risk stratification together with the ability to measure minimal residual disease, leukemic blasts left behind after cytotoxic chemotherapy, has led to better tools to guide postremission approaches-that is, consolidation chemotherapy or allogeneic stem cell transplantation. In this article, we discuss the evolving and complex genetic landscape of ALL and the emerging therapeutic options for patients with relapsed/refractory ALL and older patients with ALL.

Concepts in immuno-oncology: tackling B cell malignancies with CD19-directed bispecific T cell engager therapies

The B cell surface antigen CD19 is a target for treating B cell malignancies, such as B cell precursor acute lymphoblastic leukemia and B cell non-Hodgkin lymphoma. The BiTE® immuno-oncology platform includes blinatumomab, which is approved for relapsed/refractory B cell precursor acute lymphoblastic leukemia and B cell precursor acute lymphoblastic leukemia with minimal residual disease. Blinatumomab is also being evaluated in combination with other agents (tyrosine kinase inhibitors, checkpoint inhibitors, and chemotherapy) in various treatment settings, including frontline protocols. An extended half-life BiTE molecule is also under investigation. Patients receiving blinatumomab may experience cytokine release syndrome and neurotoxicity; however, these events may be less frequent and severe than in patients receiving other CD19-targeted immunotherapies, such as chimeric antigen receptor T cell therapy. We review BiTE technology for treating malignancies that express CD19, analyzing the benefits and limitations of this bispecific T cell engager platform from clinical experience with blinatumomab.

Approach to the Adult Acute Lymphoblastic Leukemia Patient

During recent decades, understanding of the molecular mechanisms of acute lymphoblastic leukemia (ALL) has improved considerably, resulting in better risk stratification of patients and increased survival rates. Age, white blood cell count (WBC), and specific genetic abnormalities are the most important factors that define risk groups for ALL. State-of-the-art diagnosis of ALL requires cytological and cytogenetical analyses, as well as flow cytometry and high-throughput sequencing assays. An important aspect in the diagnostic characterization of patients with ALL is the identification of the Philadelphia (Ph) chromosome, which warrants the addition of tyrosine kinase inhibitors (TKI) to the chemotherapy backbone. Data that support the benefit of hematopoietic stem cell transplantation (HSCT) in high risk patient subsets or in late relapse patients are still questioned and have yet to be determined conclusive. This article presents the newly published data in ALL workup and treatment, putting it into perspective for the attending physician in hematology and oncology.

Guidelines Insights: Acute Lymphoblastic Leukemia, Version 1.2019

Survival outcomes for older adults with acute lymphoblastic leukemia (ALL) are poor and optimal management is challenging due to higher-risk leukemia genetics, comorbidities, and lower tolerance to intensive therapy. A critical understanding of these factors guides the selection of frontline therapies and subsequent treatment strategies. In addition, there have been recent developments in minimal/measurable residual disease (MRD) testing and blinatumomab use in the context of MRD-positive disease after therapy. These NCCN Guidelines Insights discuss recent updates to the NCCN Guidelines for ALL regarding upfront therapy in older adults and MRD monitoring/testing in response to ALL treatment.

Molecular profiling of adult acute myeloid and lymphoid leukemia in a major referral center in Lebanon: a 10-year experience report and review of the literature

Recurrent genetic abnormalities confer distinct morphologic features and play a role in determining the clinical behavior, prognosis and adequate treatment of acute leukemia. In the MENA region, only one study targets the frequency of genetic modifications in AML, reporting a higher occurrence of acute promyelocytic leukemia in Lebanon. Determining the frequency of translocations and gene mutations in acute myeloid and lymphoid leukemia cases in an adult patients' population in Lebanon and comparing the resultant genetic profile with the published international molecular profile of adult acute leukemia. Laboratory results of adult patients diagnosed with AML or ALL presenting to AUBMC for genetic profiling between years 2006 until June 2016 were reviewed. Genetic profiling of AML cases in our CAP accredited molecular diagnostics laboratory consists of a validated lab developed RT-PCR for the detection of RUNX1/RUNX1T1, CBFB/MYH11, KMT2A/MLLT3, PML-RARA, and BCR-ABL and mutations in the FLT3 receptor, NPM1, c-kit and CEPBA genes. The ALL panel tests for the presence of BCR-ABL1, ETV6/RUNX1; KMT2A/AFF1, and TCF3-PBX1. We reviewed 580 AML and 175 ALL cases. In the AML cohort, the M:F ratio was 1.3:1 with a mean age of 50 years. t(15;17) was present in 7.6%, t(8;21) in 4.2%, inv(16) in 3.7%, t(9;22) in 2.2% and t(9;11) in 1.7% of cases. FLT3 mutation (ITD or TKD) was present in 25.2% of all cases and 30.1% of Cytogenetics-normal (CN) patients. Mutations of the NPM1 gene was present in 31.4% of AML cases and in 43.8% of CN patients. Double positive (NPM1+/FLT3+) cases accounted for 20% of NK patients. CEBPA and c-kit mutations were detected in 7.3% and 2.4% respectively. In the ALL cohort, the mean age was 37 years. B- and T-lymphoblastic leukemia constituted 84.6% and 15.4% of ALL cases and the M:F ratio was 1.2:1 and 2.86:1 respectively. B-ALL patients were positive for t(9;22) in 14.2%, t(4;11) in 5.4%, t(1;19) in 2.7% and t(12;21) in 1.4%. T-ALL patients were negative for translocations found in our ALL panel. A lower mean age was found in our adult leukemic Lebanese population as compared to the Western cases. Other interesting findings were the lower percentage of inv(16), lower incidence of TCF3-PBX1, and the mild increase in Philadelphia positivity in our AML cohort. In our ALL cohort, t(9;22) positivity was less than expected for adult lymphoblastic leukemia. Full molecular profiling by next generation sequencing is required for further classification of cases into prognostic categories. This study will be a baseline reference for future research and epidemiological data useful for transplant centers and oncologists both in Lebanon and the region.

Chemotherapy-free and reduced intensity approaches in elderly patients with B-lineage acute lymphoblastic leukemia

Management of older patients - defined by convention above the age of 60 years, but varying widely within study groups - with acute lymphoblastic leukemia (ALL) is still a challenge. The complete remission (CR) rate in these patients is lower than in other age groups and the percentage of deaths in induction or in CR remains high, ranging from 7 to 40%. Overall survival rates do not exceed 30%, depending on the age group included in the different trials group and on the follow-up duration. These unsatisfactory results are sustained by the fact that pre-existing comorbidities often hamper treatment delivery and if treatment intensification improves the CR rates it also increases toxicity and the percentage of deaths. Overall, the median life expectancy is rising world-wide, being in the western world around/over 80 years (and increasing); in addition, the proportion of elderly individuals is growing progressively. This means that the management of these frail patients represents a true clinical unmet need. While in Ph+ ALL the introduction of tyrosine kinase inhibitors (TKI) has markedly impacted on the outcome of patients of all ages, in Ph- ALL prognosis in the elderly still remains largely unsatisfactory. Novel strategies - mostly based on the use of monoclonal antibodies or of targeted strategies if druggable mutations can be identified - are largely needed. In the present review, we will discuss the past and current scenario, and provide an overview on the developing approaches for both Ph- and Ph+ elderly ALL, represented in particular by immunotherapy.

Current challenges and opportunities in treating adult patients with Philadelphia-negative acute lymphoblastic leukaemia

Significant advances have been made in recent years in the field of Philadelphia-negative acute lymphoblastic leukaemia (ALL). New insights into the biology and genetics of ALL as well as novel clinical observations and new drugs are changing the way we diagnose, risk-stratify and treat adult patients with ALL. New genetic subtypes and alterations refine risk stratification and uncover new actionable therapeutic targets. The incorporation of more intensive, paediatric and paediatric-inspired approaches for young adults seem to have a positive impact on survival in this population. Minimal residual disease at different time points can assist in tailoring risk-adapted interventions for patients based on individual response. Finally, novel targeted approaches with monoclonal antibodies, immunotherapies and small molecules are moving through clinical development and entering the clinic. The aim of this review is to consolidate the abundance of emerging data and to review and revisit the concepts of risk-stratification, choice of induction and post-remission strategies as well as to discuss and update the approach to specific populations with ALL, such as young adult, elderly/unfit and relapsed/refractory patients with ALL.

Concise Review: Emerging Principles from the Clinical Application of Chimeric Antigen Receptor T Cell Therapies for B Cell Malignancies

Gene-engineered T cell therapies are soon to be United States Food and Drug Administration (FDA) approved for at least two types of B cell malignancies in pediatric and adult patients, in the form of CD19 targeted chimeric antigen receptor T (CAR T) cell therapy. This represents a triumph of a true bench to bedside clinical translation of a therapy that was conceived of in the early 1990s. Clinical results have demonstrated efficacious responses in patients with the CD19 positive diseases B cell acute lymphoblastic leukemia and diffuse large B cell lymphoma. However, significant challenges have emerged, including worrisome immune-related toxicities, therapy resistance, and understanding how to administer CD19 CAR T cells in clinical practice. Although much remains to be learned, pioneering clinical trials have led to foundational insights about the clinical translation of this novel therapy. Here, we review the "lessons learned" from the pre-clinical and human experience with CAR T cell therapy. Stem Cells 2018;36:36-44.

How should we treat a patient with relapsed Ph-negative B-ALL and what novel approaches are being investigated?

Despite significant improvements in outcome of newly diagnosed B-precursor ALL, the results in relapsed or refractory adult ALL are overall poor. Large retrospective studies revealed significant differences in terms of outcome, with particularly poor response rates in early or refractory relapses, whereas late relapses usually respond very well to repeated standard induction. Particularly new immunotherapy compounds like the CD19 bispecific antibody Blinatumomab and the conjugated CD22 antibody Inotuzumab yielded promising response rates compared to standard therapies in randomised trials. Long-term survival is however still poor. The optimal use of these compounds remains to be defined. Chimeric antigen receptor T-cells are another promising treatment approach and multicenter clinical trials in adult ALL are awaited. For selected patients molecular directed therapies may have a role in relapsed ALL; standard diagnostic algorithms need to be defined. One of the major challenges is to define the role of stem cell transplantation after relapse. Whereas this procedure appears to be the only chance for cure, the mortality and relapse rate are still high and optimisation is urgently needed. Future strategies include optimised use of new compounds as part of combination regimens and the earlier treatment of upcoming relapse in the situation of persistent or recurrent minimal residual disease.