Guidelines Insights: Acute Lymphoblastic Leukemia, Version 1.2019

Honokiol induces apoptosis and autophagy in dexamethasone-resistant T-acute lymphoblastic leukemia CEM-C1 cells

Objective: To study whether and, if so, how honokiol overcome dexamethasone resistance in DEX-resistant CEM-C1 cells. Methods: We investigated the effect of honokiol (0-20 µM) on cell proliferation, cell cycle, cell apoptosis and autophagy in DEX-resistant CEM-C1 cells and DEX-sensitive CEM-C7 cells. We also determined the role of c-Myc protein and mRNA in the occurrence of T-ALL associated dexamethasone resistance western blot and reverse transcription-qPCR (RT-qPCR) analysis. Results: Cell Counting Kit (CCK)-8 assay shows that DEX-resistant CEM-C1 cell lines were highly resistant to dexamethasone with IC50 of 364.1 ± 29.5 µM for 48 h treatment. However, upon treatment with dexamethasone in combination with 1.5 µM of honokiol for 48 h, the IC50 of CEM-C1 cells significantly decreased to 126.2 ± 12.3 µM, and the reversal fold was 2.88. Conversely, the IC50 of CEM-C7 cells was not changed combination of dexamethasone and honokiol as compared to that of CEM-C7 cells treated with dexamethasone alone. It has been shown that honokiol induced T-ALL cell growth inhibition by apoptosis and autophagy via downregulating cell cycle-regulated proteins (Cyclin E, CDK4, and Cyclin D1) and anti-apoptotic proteins BCL-2 and upregulating pro-apoptotic proteins Bax and led to PARP cleavage. Honokiol may overcome dexamethasone resistance in DEX-resistant CEM-C1 cell lines via the suppression of c-Myc mRNA expression. Conclusion: The combination of honokiol and DEX were better than DEX alone in DEX-resistant CEM-C1 cell lines. Honokiol may regulate T-ALL-related dexamethasone resistance by affecting c-Myc.

Flotetuzumab as a salvage immunotherapy in advanced CD123-positive hematological malignancies, a phase 1 pilot study

CD123 "expression" is common in hematological malignancies, including acute lymphoblastic leukemia (ALL). Flotetuzumab is a novel, investigational CD3/CD123 DART®. We conducted a phase 1 study evaluating safety and efficacy of flotetuzumab in relapsed/refractory ALL (Cohort A) and other advanced CD123-positive hematological malignancies (excluding myeloid malignancies) (cohort B). Thirteen patients (9 in Cohort A and 4 in Cohort B) were treated at dose level 1 (500 ng/kg/day) before early closure due to discontinuation of drug development by sponsor. Two dose limiting toxicities (Grade 4 thrombocytopenia and neutropenia) occurred in one patient in Cohort B. Cytokine release syndrome occurred in most patients (85%), all being grade ≤2. Responses only occurred in Cohort B, with a partial response in one patient with Hodgkin's lymphoma and morphological complete remission in the bone marrow in one patient with blastic plasmacytoid dendritic cell neoplasm. In conclusion, flotetuzumab had a manageable safety profile in advanced CD123-positive hematological malignancies.

CD19 chimeric antigen receptor-T cells as bridging therapy to allogeneic hematopoietic cell transplantation improves outcome in patients with refractory/relapsed B-cell acute lymphoblastic leukemia

Chimeric antigen receptor (CAR)-T cell therapy has been confirmed improving remission rates in refractory patients or relapsed B-cell acute lymphoblastic leukemia (R/R B-ALL). However, the added benefits of undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) following CAR-T therapy remain a subject of debate. In this research we investigated the efficiency and long-term outcomes of CD19 CAR-T bridging with allo-HSCT in R/R B-ALL patients. A total of 42 patients were brought into the cohort studies. Our findings revealed that patients who appected CAR-T followed by HSCT had a 1-year overall survival (OS) rate of 70 % and a 1-year leukemia-free survival (LFS) rate of 95 %. Moreover, patients who underwent this combined treatment had higher OS and LFS rates compared to those who received CAR-T therapy alone. In conclusion, the results of this clinical trial provide compelling evidence for the safety and efficacy of using CAR-T therapy as a bridging strategy to allo-HSCT in patients with R/R B-ALL.

High expression of SLC27A2 predicts unfavorable prognosis and promotes inhibitory immune infiltration in acute lymphoblastic leukemia

Solute carrier family 27 member 2 (SLC27A2) is involved in fatty acid metabolism in tumors and represents a prospective target for cancer therapy. However, the role and mechanism of action of SLC27A2 in acute lymphoblastic leukemia (ALL) remain unclear. In this study, we aimed to explore the intrinsic associations between SLC27A2 and ALL and evaluate the prognostic significance, biological functions, and correlation with immune infiltration. We used the transcriptome and clinical data from the TARGET dataset. Differentially expressed genes (DEGs) in the SLC27A2 low- and high-expression groups were analyzed for prognostic implications and functional enrichment. Furthermore, we analyzed the relationship between SLC27A2 gene expression and immune cell infiltration using the ESTIMATE method, which was evaluated using the TIGER platform. Finally, we knocked down SLC27A2 in the Jurkat ALL cell line and conducted cell proliferation, western blotting, flow cytometry, and CCK-8 assays to elucidate the biological function of SLC27A2 in ALL. Patients with ALL who have higher expression levels of SLC27A2 have poorer overall survival and event-free survival. According to gene set enrichment analysis, the DEGs were primarily enriched with immune system processes and the PI3K-Akt signaling pathway. There was an inverse relationship between SLC27A2 expression and immune cell invasion, suggesting involvement of the former in tumor immune evasion. In vitro experiments showed that knockdown of SLC27A2 inhibited cell proliferation and protein expression and altered the Akt pathway, with a reduced proportion of B cells. In conclusion, SLC27A2 plays a vital role in the development of ALL.

Management of adult acute lymphoblastic leukemia in the Gulf Cooperation Council (GCC) countries: A consensus report from the GCC Adult ALL Working Group

Leukemia burden is growing in the Gulf Council Cooperation (GCC) countries. Nonetheless, there is no unified protocol for managing adult acute lymphoblastic leukemia (ALL) patients in the GCC-countries. Therefore, the GCC Adult-ALL Treaters working group developed this consensus to address the adult-ALL treatment protocols in the GCC-countries and related toxicities' management. Besides, the consensus aimed to highlight the current unmet needs and treatment gaps and provide recommendations to optimize adult-ALL care and patient-centered communication. A three-step modified Delphi method to develop evidence-based recommendations through two-voting rounds and in-between virtual meetings are used in the manuscript development. A 12 experts' panel from five GCC-countries and two international experts were invited to participate in this consensus. This consensus consisted of 35-statements that highlighted the experts' recommendations to optimize ALL adults' care in the first line setting and manage pediatric or pediatric-inspired regimens-related toxicities. Besides, guidance was provided for future research direction and improve patient-centered communication. In conclusion, the adult-ALL management landscape is evolving, and the current evidence highlights better response and survival outcomes with pediatric or pediatric-inspired regiments. Therefore, protocols are needed to optimize the adult-ALL management in the GCC and tailored clinical-trials findings according to the GCC patients' characteristics and local-healthcare infrastructure.

Health Care Resource Utilization and Total Costs of Care for Adult Patients With Relapsed or Refractory Acute Lymphoblastic Leukemia in the United States: A Retrospective Claims Analysis

PURPOSE

Although immunotherapies such as blinatumomab and inotuzumab have led to improved outcomes, financial burden and health resource utilization (HRU) have increased for adult patients with relapsed or refractory B-cell acute lymphoblastic leukemia (R/R B-ALL). This study assessed real-world HRU and costs of care among adult patients with R/R B-ALL by line of therapy (LoT) in the United States.

METHODS

We selected patients from the MarketScanⓇ Database (January 1, 2016 through December 31, 2020) as follows: ≥1 claims of ALL-indicated first-line (1L) therapies, ≥1 diagnosis of ALL before the index date (1L initiation date), 6-month continuous enrollment before the index date, second-line (2L) therapy initiation, ≥18 years old at 2L, no clinical trial enrollment, no diagnosis of other forms of non-Hodgkin's lymphoma, and no claim for daratumumab or nelarabine during the study period. Outcome measures included claim-based time to next treatment (TTNT), all-cause and adverse event (AE)-related HRU, and all-cause and AE-related costs.

FINDINGS

The R/R B-ALL cohort (N = 203) was 60% male, median age of 41 years, and median Charlson Comorbidity Index score of 3.0. Mean (SD) follow-up was 17.8 (11.8) months. Of those who received 2L, 55.7% (113/203) required 3L, and 15% (30/203) initiated 4L+. Patients relapsed quickly, with a median TTNT of 170 days, 169 days, and 205 days for 2L, 3L, and 4L+, respectively. Hospitalization rates were high across each LoT (2L, 88%; 3L, 73%; 4L+, 73%), and the mean (SD) inpatient length of stay increased by LoT as follows: 8.6 (6.8) days for 2L, 10.6 (13.3) for 3L, and 11.6 (13.6) for 4L+. Mean (SD) overall costs were substantial within each LoT at $513,279 ($599,209), $340,419 ($333,555), and $390,327 ($332,068) for 2L, 3L, and 4L+, respectively. The mean (SD) overall/per-patient-per-month AE-related costs were $358,676 ($497,998) for 2L, $202,621 ($272,788) for 3L, and $210,539 ($267,814) for 4L+. Among those receiving blinatumomab or inotuzumab within each LoT, the mean (SD) total costs were $566,373 ($621,179), $498,070 ($376,260), and $512,908 ($159,525) for 2L, 3L, and 4L+, respectively.

IMPLICATIONS

These findings suggest that adult patients with R/R B-ALL relapse frequently with standard of care and incur a substantial HRU and cost burden with each LoT. Those treated with blinatumomab or inotuzumab incurred higher total costs within each LoT compared with the overall R/R B-ALL cohort. Alternative therapies with longer duration of remission are urgently needed, and HRU should be considered for future studies examining the optimal sequencing of therapy.

Targeting nucleolin improves sensitivity to chemotherapy in acute lymphoblastic leukemia

PURPOSE

Most patients with acute lymphoblastic leukemia (ALL) are treated with chemotherapy as primary care. Although the treatment response is usually positive, resistance and relapse often occur via unknown mechanisms. The purpose of this study was to identify factors associated with chemotherapy resistance in ALL. Here, we present clinical and experimental evidence that overexpression of nucleolin (NCL), a multifunctional nucleolar protein, is linked to drug resistance in ALL.

METHODS

NCL mRNA and protein levels were compared between cell lines and patient samples using qRT-PCR and immunoblotting. NCL mRNA levels were compared between patients of different disease stages from our clinic patients' specimens and publicly available ALL patient datasets. Cells and patient-derived xenograft mouse experiments were performed to assess the effect of NCL inhibition on ALL chemotherapy effectiveness.

RESULTS

Analysis of patient specimens, and publicly available RNA-sequencing datasets revealed a strong correlation between the abundance of NCL and disease relapse or poor survival in B-ALL. Altering NCL expression results in changes in drug sensitivity in ALL cell lines. High levels of NCL upregulated components of the ATP-binding cassette transporters via activation of the ERK pathway, resulting in a decrease in drug accumulation inside the cells. Targeting NCL with AS1411, an NCL-binding oligonucleotide aptamer, significantly increased the sensitivity of ALL cell lines and cells/patient-derived ALL xenograft mice to chemotherapeutic drugs and prolonged mouse survival.

CONCLUSION

Our results highlight NCL as a prognostic marker in B-ALL and a potential therapeutic target to combat chemotherapy resistance in ALL.

Flow cytometric signature of CD371-positive B-cell acute lymphoblastic leukemia

OBJECTIVES

Multiparametric flow cytometry (MFC) aids in the diagnosis and management of B-cell acute lymphoblastic leukemia (B-ALL) by establishing a baseline immunophenotype for leukemic cells and measuring minimal residual disease (MRD) throughout the course of treatment. Aberrant expression patterns of myeloid markers in B-ALL are also examined during long-term surveillance. Here, we investigated the utility of the newly described myeloid marker cluster of differentiation (CD)371 in MRD surveillance via MFC in patients with CD371-positive B-ALL.

METHODS

Eight-color MFC with standard panels (including CD371) was used to evaluate 238 patients with newly diagnosed B-ALL. Expression levels of key markers were retrospectively assessed at diagnosis, as well as days 15 and 33 of therapy.

RESULTS

CD371 was expressed in 8.4% of patients with B-ALL. CD371 positivity was associated with older age at diagnosis, higher expression levels of CD34 and CD38, and lower expression levels of CD10 and CD20. Residual leukemic cells demonstrated decreased CD10 expression and increased CD45 expression after therapy, whereas CD371 expression remained stable.

CONCLUSIONS

Patients with CD371-positive B-ALL exhibit a specific signature that merits further analysis, particularly because it has been associated with DUX4 rearrangement.

IgD/FcδR is involved in T-cell acute lymphoblastic leukemia and regulated by IgD-Fc-Ig fusion protein

T-cell acute lymphoblastic leukemia (T-ALL) has a poor prognosis as a result of severe immunosuppression and rapid tumor progression with resistance to conventional chemotherapy. Excessive IgD may play a role in T cell activation via IgD Fc receptor (FcδR). Here we aimed to investigate the effects of IgD in T-ALL and demonstrated the potential benefit by targeting IgD/FcδR in T-ALL patients with IgD-Fc-Ig fusion protein. In T-ALL patients' blood samples and cell lines, the level of IgD, the percentage of FcδR expressing cells and the binding affinity were determined by flow cytometry. T cell viability, proliferation and apoptosis were analyzed. A mouse xenograft model was used to evaluate the in vivo effect of IgD-Fc-Ig, an IgD-FcδR blocker. The levels of serum IgD and FcδR were abnormally increased in part of T-ALL patients and IgD could induce over-proliferation and inhibit apoptosis of T-ALL cells in vitro. FcδR was constitutively expressed on T-ALL cells. IgD-Fc-Ig showed similar binding affinity to FcδR and selectively blocked the stimulation effect of IgD on T-ALL cells in vitro. In vivo study exhibited that IgD-Fc-Ig may also have therapeutic benefit. IgD-Fc-Ig administration inhibited human T-ALL growth and extended survival in xenograft T-ALL mice. In conclusion, this work supports the idea of targeting IgD/FcδR in T-ALL patients with excessive IgD. IgD-Fc-Ig fusion protein might be a potential biological drug with high selectivity for T-ALL treatment.

Silencing of IRF8 Mediated by m6A Modification Promotes the Progression of T-Cell Acute Lymphoblastic Leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy with a poor prognosis, urging for novel therapeutic targets and treatment strategies. N6-methyladenosine (m6A) is a crucial methylation modification that affects the pathogenesis of leukemia by regulating the mRNA of key genes. Interferon regulatory factor 8 (IRF8) is a crucial transcription factor for hematological lineage commitment, but its role in T-ALL is unclear. Here, IRF8 is shown to suppress T-ALL. The expression of IRF8 is abnormally silenced in patients with T-ALL. Knockout of Irf8 significantly hastens the progression of Notch1-induced T-ALL in vivo. Overexpression of IRF8 suppresses the proliferation and invasion of T-ALL cells by inhibiting the phosphatidylinositol 3-kinase/AKT signaling pathway. The fat mass- and obesity-associated protein (FTO), an m6A demethylase, is responsible for directly binding to m6A sites in 3' untranslated region of IRF8 messenger RNA (mRNA) and inducing mRNA degradation via m6A modification. Targeting the FTO-IRF8 axis is used as a proof of concept therapy; inhibition of FTO's demethylase activity drastically alleviates the proliferation of leukemic cells and prolongs the survival of T-ALL mice by restoring IRF8 expression. This study elucidates the pathogenesis of T-ALL from the perspective of epitranscriptomics and provides new insight into the genetic mechanisms and targeted therapy of T-ALL.

Diagnostic Value and Prognosis Significance of Cerebrospinal Fluid Examination by Flow Cytometry in Pediatric Acute Lymphoblastic Leukemia

Purpose: To explore the diagnostic value and the prognostic significance of cerebrospinal fluid (CSF) examination by flow cytometry (FC) in children with central nervous system leukemia (CNSL). Method: This is a retrospective observational study. We select 986 pediatric patients with newly diagnosed acute lymphoblastic leukemia from January 2012 to December 2018 as the research objects and analyze the sensitivity and specificity of different methods for diagnosing CNSL. The recurrence rate and survival rate of CNSL in different groups were compared. Results: Among the 986 cases, 31 cases (positive rate of 3.14%) were positive by FC, and the cytospin-based cytomorphology (CC) test was positive in 6 cases (positive rate of 0.61%). CC combined with FC might improve the diagnostic sensitivity (from 30% to 65%, 𝑥2 value was 5.143, P  =  .016). The 2-year event-free survival (EFS) of 31 FC  +  children was 59.5%  ±  9.2%, and that of 955 FC - children was 74.1%  ±  1.8% (P  =  .004). The 2-year overall survival (OS) of the 2 groups were 63.6%  ±  9.7% and 80.2%  ±  1.5%, respectively (P  =  .004). In order to exclude the influence of CNSL, we divided the patients into 3 groups: CNSL group and non-CNSL group with CSF FC + , FC - group. There was no significant difference in EFS between FC - group and non-CNSL group with FC  +  (2-year EFS were 74.1%  ±  1.8% and 68.7%  ±  9.8%, respectively, P  =  .142), and there was a significant difference in OS (2-year OS were 80.2%  ±  1.5% and 67.5%  ±  10.3%, respectively, P  =  .029). Conclusion: The test of FC combined with CC may improve the diagnostic sensitivity of CNSL. The EFS and OS of children with FC  +  are worse than those of children with FC -. However, for those patients with non-CNSL, but only FC  +  at the initial diagnosis, the EFS is not significantly affected by strengthening systemic chemotherapy and increasing the number of intrathecal injections.

CLIC-01: Manufacture and distribution of non-cryopreserved CAR-T cells for patients with CD19 positive hematologic malignancies

Access to commercial CD19 CAR-T cells remains limited even in wealthy countries like Canada due to clinical, logistical, and financial barriers related to centrally manufactured products. We created a non-commercial academic platform for end-to-end manufacturing of CAR-T cells within Canada's publicly funded healthcare system. We report initial results from a single-arm, open-label study to determine the safety and efficacy of in-house manufactured CD19 CAR-T cells (entitled CLIC-1901) in participants with relapsed/refractory CD19 positive hematologic malignancies. Using a GMP compliant semi-automated, closed process on the Miltenyi Prodigy, T cells were transduced with lentiviral vector bearing a 4-1BB anti-CD19 CAR transgene and expanded. Participants underwent lymphodepletion with fludarabine and cyclophosphamide, followed by infusion of non-cryopreserved CAR-T cells. Thirty participants with non-Hodgkin's lymphoma (n=25) or acute lymphoblastic leukemia (n=5) were infused with CLIC-1901: 21 males (70%), median age 66 (range 18-75). Time from enrollment to CLIC-1901 infusion was a median of 20 days (range 15-48). The median CLIC-1901 dose infused was 2.3 × 10⁶ CAR-T cells/kg (range 0.13-3.6 × 10⁶/kg). Toxicity included ≥ grade 3 cytokine release syndrome (n=2) and neurotoxicity (n=1). Median follow-up was 6.5 months. Overall response rate at day 28 was 76.7%. Median progression-free and overall survival was 6 months (95%CI 3-not estimable) and 11 months (95% 6.6-not estimable), respectively. This is the first trial of in-house manufactured CAR-T cells in Canada and demonstrates that administering fresh CLIC-1901 product is fast, safe, and efficacious. Our experience may provide helpful guidance for other jurisdictions seeking to create feasible and sustainable CAR-T cell programs in research-oriented yet resource-constrained settings.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT03765177, identifier NCT03765177.

Efficacy and safety of blinatumomab in Chinese adults with Ph-negative relapsed/refractory B-cell precursor acute lymphoblastic leukemia: A multicenter open-label single-arm China registrational study

OBJECTIVES

The prognosis for adults with relapsed/refractory (R/R) B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is poor. Blinatumomab is a CD3/CD19-directed BiTE® (bispecific T-cell engager) molecule approved globally for the treatment of BCP-ALL in adults and children. This multicenter open-label single-arm China registrational study evaluated the safety, efficacy, and pharmacokinetics of blinatumomab in Chinese adults with Philadelphia chromosome-negative (Ph-) R/R BCP-ALL (NCT03476239).

METHODS

Patients aged ≥ 18 years were treated with up to 5 cycles of blinatumomab. The primary objective was to evaluate the hematological response rate (complete remission/complete remission with partial hematological recovery [CR/CRh]) within 2 cycles of blinatumomab.

RESULTS

At the interim analysis (April 12, 2019), 90 patients (median age 31.5 years [range: 18-74]; 53.3% female; 77.8% with bone marrow blasts ≥ 50% at study entry) were enrolled at 23 study centers in China and had received blinatumomab. As of data cutoff, 43 patients (47.8%) continued the study. The CR/CRh rate within 2 cycles of blinatumomab was 45.6% (41/90 [CR, 37; CRh, 4]; 95% CI: 35.0-56.4). Median overall survival was 9.2 months (95% CI: 6.5-11.7); median relapse-free survival was 4.3 months (95% CI: 3.2-9.4). Mean serum concentration at steady-state and systemic clearance of blinatumomab in Chinese patients were within the range reported in adults from global clinical trials. No new safety risks were identified in Chinese patients.

CONCLUSIONS

The efficacy and safety of blinatumomab in these heavily pre-treated Chinese patients with Ph- R/R BCP-ALL is comparable to that for patients within global clinical trials.

Amino acid metabolism: challenges and opportunities for the therapeutic treatment of leukemia and lymphoma

Leukemia and lymphoma-the most common hematological malignant diseases-are often accompanied by complications such as drug resistance, refractory diseases and relapse. Amino acids (AAs) are important energy sources for malignant cells. Tumor-mediated AA metabolism is associated with the immunosuppressive properties of the tumor microenvironment, thereby assisting malignant cells to evade immune surveillance. Targeting abnormal AA metabolism in the tumor microenvironment may be an effective therapeutic approach to address the therapeutic challenges of leukemia and lymphoma. Here, we review the effects of glutamine, arginine and tryptophan metabolism on tumorigenesis and immunomodulation, and define the differences between tumor cells and immune effector cells. We also comment on treatments targeting these AA metabolism pathways in lymphoma and leukemia and discuss how these treatments have profound adverse effects on tumor cells, but leave the immune cells unaffected or mildly affected.

Infusion of haploidentical HSCs combined with allogenic MSCs for the treatment of ALL patients

Although haploidentical stem cell transplantation (haplo-HSCT) offers almost all acute lymphoblastic leukaemia (ALL) patients an opportunity for immediate transplantation, it exhibits a higher incidence of graft failure and graft versus host disease (GVHD). Mesenchymal stem cells (MSCs) are characterised by their haematopoiesis-promoting and immunomodulatory capacity. Thus, we designed a combination of haplo-HSCT and MSCs for ALL patients. ALL patients (n = 110) were given haploidentical HSCs combined with allogenic MSCs, and ALL patients without MSC infusion (n = 56) were included as controls. The 100-day cumulative incidences of grade ≥2 acute GVHD (aGVHD) and grade ≥3 aGVHD were 40.00% and 9.09% compared to 42.32% (P = 0.79) and 22.79% (P = 0.03) in patients without MSC infusion, respectively. The 3-year cumulative incidences of chronic GVHD (cGVHD) and extensive cGVHD were 22.27% and 10.27% compared to 32.14% (P = 0.19) and 22.21% (P = 0.04) in patients without MSC infusion, respectively. No significant differences in the 3-year relapse incidence, nonrelapse mortality, leukaemia-free survival or overall survival in groups with and without MSC cotransplantation were observed. Multivariate analysis showed that MSC infusion contributed to a lower risk of developing extensive cGVHD. Our data suggested that haplo-HSCT combined with MSCs may provide an effective and safe treatment for ALL patients.

Clinical and Genetic Characteristics of IKZF1 Mutation in Chinese Children With B-Cell Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is a malignancy associated with altered lymphoid precursor hyperplasia and accompanied with different genetic mutations. Few studies have been reported on the association between gene mutations and clinical features of IKZF1 mutation in children with B-cell ALL (B-ALL). We investigated clinical and genetic characteristics in 200 newly diagnosed pediatric B-ALL through multiplex ligation-dependent probe amplification (MLPA) and targeted next-generation sequencing (NGS) method. We found that IKZF1 mutations, including large segment deletions, small insertions or deletions (InDels) and single nucleotide variations (SNVs), were detected in 22 patients with a positive mutation rate of 11.0%. IKZF1 mutation was significantly associated with higher WBC count (19.38 × 10⁹/L vs. 5.80 × 10⁹/L, p = 0.002). Compared with IKZF1 wild-type cases, a higher frequency of IL7R gene mutation was discovered in IKZF1 mutant cases (9.1% vs. 0.0%, p = 0.012). Patients with IKZF1 mutation were less sensitive to glucocorticoid induction than patients without IKZF1 mutation (63.6% vs. 9.0%, p < 0.001). On the 15th day of induction, minimal residual disease (MRD) > 10⁻³ level were higher in IKZF1 mutant patients than wild-type patients (45.5% vs. 22.3%, p = 0.018). In conclusion, our study reveals the association between genetic mutations and clinical features in Chinese children with B-ALL, which might contribute to molecular classification, risk stratification and prognosis evaluation, and provide new ideas for targeted therapy in ALL.

DT7 peptide-modified lecithin nanoparticles co-loaded with γ-secretase inhibitor and dexamethasone efficiently inhibit T-cell acute lymphoblastic leukemia and reduce gastrointestinal toxicity

T-cell acute lymphoblastic leukemia (T-ALL) is a serious hematologic malignancy and glucocorticoid resistance is the main recurrent cause for a high relapsed and death rate. Here, we proposed an effective therapeutic regimen of combining gamma-secretase inhibitors (GSIs) with dexamethasone (DEX) to overcome glucocorticoid resistance. Moreover, the bone marrow targeting DT7 peptide-modified lecithin nanoparticles co-loaded with DEX and GSI (TLnp/D&G) were developed to enhance T-ALL cells recognition and endocytosis. In vitro cytotoxicity studies showed that TLnp/D&G significantly inhibited cell survival and promoted apoptosis of T-ALL cells. Mechanically, we found that GSIs promoted DEX-induced cell apoptosis by two main synergetic mechanisms: 1) GSIs significantly upregulated glucocorticoid receptor (GR) expression in T-ALL and restored the glucocorticoid-induced pro-apoptotic response. 2) Both DEX and GSI synergistically inhibited BCL2 and suppressed the survival of T-ALL cells. Furthermore, in vivo studies demonstrated that TLnp/D&G showed high bone marrow accumulation and better antileukemic efficacy both in leukemia bearing models and in systemic Notch1-induced T-ALL models, with excellent biosafety and reduced gastrointestinal toxicity. Overall, our study provides new strategies for the treatment of T-ALL and promising bone marrow targeting systems with high transformation potential.

A Novel Risk Defining System for Pediatric T-Cell Acute Lymphoblastic Leukemia From CCCG-ALL-2015 Group

Objective

T-cell acute lymphoblastic leukemia (T-ALL) is a rare hematological malignancy with a poor prognosis. The present study aims to identify the precise risk grouping of children with T-ALL.

Methods

We analyzed the outcomes for 105 consecutive patients treated using the Chinese Children’s Cancer Group ALL-2015 (CCCG-ALL-2015) protocol registered with the Chinese Clinical Trial Registry (ChiCTR-IPR-14005706) between 2015 and 2020 in our center. Nine out of 21 clinical and biological indicators were selected for the new scoring system based on the analysis in this study.

Results

The 5-year overall survival (OS), event-free survival (EFS), and disease-free survival (DFS) rates for the 105 patients were 83.1 ± 4.8%, 72.4 ± 5.6%, and 78.4 ± 3.6%, respectively. Based on the new scoring system, 90 evaluable children were regrouped into low-risk (n=22), intermediate-risk (n=50), and high-risk (n=18) groups. The 5-year survival (OS, EFS, and RFS) rates for all patients in the low-risk group were 100%, significantly higher than the rates for those in the intermediate-risk group (91.2 ± 5.2%, 74.4 ± 8.6%, and 82.5 ± 6.2%, respectively) and high-risk group (59.0 ± 13.2%, 51.9 ± 12.4%, and 51.9 ± 12.4%, respectively) (all P values &lt; 0.01).

Conclusion

The CCCG-ALL-2015 program significantly improved the treatment outcomes for childhood T-ALL as compared with the CCCG-ALL-2008 protocol. Our new refined risk grouping system showed better stratification among pediatric T-ALL patients and better potential in evaluating therapeutic efficacy.

Induction-related mortality in adolescents and young adults with acute lymphoblastic leukemia in a resource-limited setting: do treatment-related complications create more impact than disease biology?

Background

Acute lymphoblastic leukemia (ALL) is a malignant clonal bone marrow disorder with a high mortality rate during the initial therapy. This retrospective study aimed to describe and analyze the risk factors and causes of induction-related mortality (IRM) in an adolescent and adult ALL population treated in a low- and middle-income country.

Methods

From 2009 to 2016, a total of 167 patients were included, of which 50.9% were male with a median age of 28 years. B-immunophenotype represented 97.6%, and high-risk cytogenetics were present in 23.3%. During induction therapy, 91% had at least 1 complication, most of which were infectious, with an IRM of 12%.

Results

Factors associated with increased mortality rate were central nervous system (CNS) status [CNS-3: hazard ratio (HR) 3.029; 95% confidence interval (CI), 0.79-11.49; P=0.103 and CNS-2: HR, 9.98; 95% CI, 2.65-37.65; P=0.001] and dialysis requirement (HR, 9.15; 95% CI, 2.44-34.34; P=0.001).

Conclusion

Our study confirms that ALL patients treated in resource-constrained settings have high rates of IRM, mainly attributed to advanced disease and high tumor burden at diagnosis.

Prognostic Significance of Cytokine Release Syndrome in B Cell Hematological Malignancies Patients After Chimeric Antigen Receptor T Cell Therapy

Cytokine release syndrome (CRS) is the most common on-target toxicity of chimeric antigen receptor (CAR) T cell therapy. However, the prognostic significance of CRS has not been well elucidated. The aim of our study was to evaluate the association between CRS and efficacy after anti-CD19 CAR-T therapy in a retrospective cohort of 22 patients with relapsed/refractory B cell hematological malignancies. The complete remission (CR) rates after CAR-T therapy were 68%, and median value for progression-free survival (PFS) was 6.8 months. Eight of 22 (36.4%) patients showed ≥ grade 2 CRS. Statistical analysis found that patients with ≥ grade 2 CRS had higher CR rates and longer PFS than those with < grade 2 CRS. Moreover, bridging hematopoietic stem cell transplantation was another independent predictor for PFS. These data suggested that appropriate CRS may be beneficial to the efficacy of CAR-T therapy. The Clinical Trial Registration number is NCT03110640, NCT03302403.

Weakly Supervised Ternary Stream Data Augmentation Fine-Grained Classification Network for Identifying Acute Lymphoblastic Leukemia

Due to the high incidence of acute lymphoblastic leukemia (ALL) worldwide as well as its rapid and fatal progression, timely microscopy screening of peripheral blood smears is essential for the rapid diagnosis of ALL. However, screening manually is time-consuming and tedious and may lead to missed or misdiagnosis due to subjective bias; on the other hand, artificially intelligent diagnostic algorithms are constrained by the limited sample size of the data and are prone to overfitting, resulting in limited applications. Conventional data augmentation is commonly adopted to expand the amount of training data, avoid overfitting, and improve the performance of deep models. However, in practical applications, random data augmentation, such as random image cropping or erasing, is difficult to realistically occur in specific tasks and may instead introduce tremendous background noises that modify actual distribution of data, thereby degrading model performance. In this paper, to assist in the early and accurate diagnosis of acute lymphoblastic leukemia, we present a ternary stream-driven weakly supervised data augmentation classification network (WT-DFN) to identify lymphoblasts in a fine-grained scale using microscopic images of peripheral blood smears. Concretely, for each training image, we first generate attention maps to represent the distinguishable part of the target by weakly supervised learning. Then, guided by these attention maps, we produce the other two streams via attention cropping and attention erasing to obtain the fine-grained distinctive features. The proposed WT-DFN improves the classification accuracy of the model from two aspects: (1) in the images can be seen details since cropping attention regions provide the accurate location of the object, which ensures our model looks at the object closer and discovers certain detailed features; (2) images can be seen more since erasing attention mechanism forces the model to extract more discriminative parts' features. Validation suggests that the proposed method is capable of addressing the high intraclass variances located in lymphocyte classes, as well as the low interclass variances between lymphoblasts and other normal or reactive lymphocytes. The proposed method yields the best performance on the public dataset and the real clinical dataset among competitive methods.

ITGA7 relates to disease risk, pathological feature, treatment response and survival in Ph- acute lymphoblastic leukemia

Background: This study aimed to investigate clinical involvement of ITGA7 in Philadelphia-chromosome-negative acute lymphoblastic leukemia (Ph^- ALL). Methods: We sampled bone marrow (BM) from 91 Ph^- ALL patients and 20 healthy donors (HDs), detecting ITGA7 expression in BM. Results: ITGA7 was highly expressed in Ph^- ALL patients at differentiating values between Ph^- ALL patients and HDs. Elevated ITGA7 expression was associated with CNS leukemia (CNSL) occurrence and increased percentage of BM blasts in Ph^- ALL patients. Elevated ITGA7 expression was linked with lower complete remission rate (CR), worse event-free survival, and worse overall survival in Ph^- ALL patients. Conclusion: ITGA7 highly expressed, correlated with CNSL occurrence and higher BM blasts, furthermore predicts lower CR rate and worse prognosis.

Optimizing autologous hematopoietic stem cell transplantation for acute leukemia

Autologous hematopoietic stem cell transplantation (ASCT) remains an important postremission treatment for acute leukemia (AL). It is known that some prognostic factors, such as age, cytogenetic and molecular risk stratification, and minimal residual disease (MRD) status, are closely related to clinical outcomes following ASCT. Moreover, there are multiple measurements, including pretransplant treatment, stem cell mobilization and collection, conditioning regimens, and maintenance treatment after transplantation, that can affect prognosis after ASCT. Our clinical practice of ASCT should be better standardized to further improve patient outcomes. This review outlines optimization and quality control measures for ASCT developed at the Institute of Hematology and Blood Diseases Hospital of the Chinese Academy of Medical Sciences, the first established and largest autologous stem cell transplant center in China. These measures will enhance the development of best practices and strategies for AL ASCT therapies, thereby improving patient outcomes.

Application of Next-Generation Sequencing-Based Mutational Profiling in Acute Lymphoblastic Leukemia

PURPOSE OF REVIEW

Recent efforts to characterize hematologic cancers with genetic and molecular detail have largely relied on mutational profiling via next-generation sequencing (NGS). The application of NGS-guided disease prognostication and clinical decision making requires a basic understanding of sequencing advantages, pitfalls, and areas where clinical care might be enhanced by the knowledge generated. This article identifies avenues within the landscape of adult acute lymphoblastic leukemia (ALL) where mutational data hold the opportunity to enhance understanding of disease biology and patient care.

RECENT FINDINGS

NGS-based assessment of measurable residual disease (MRD) after ALL treatment allows for a sensitive and specific molecular survey that is at least comparable, if not superior, to existing techniques. Mutational assessment by NGS has unraveled complex signaling networks that drive pathogenesis of T-cell ALL. Sequencing of patients with familial clustering of ALL has also identified novel germline mutations whose inheritance predisposes to disease development in successive generations. While NGS-based assessment of hematopoietic malignancies often provides actionable information to clinicians, patients with acute lymphoblastic leukemia are left underserved due to a lack of disease classification and prognostication schema that integrate molecular data. Ongoing research is positioned to enrich the molecular toolbox available to clinicians caring for adult ALL patients and deliver new insights to guide therapeutic selection, monitor clinical response, and detect relapse.

Development and validation of a comorbidity index for predicting survival outcomes after allogeneic stem cell transplantation in adult patients with acute leukemia: a Korean nationwide cohort study

Background

Allogeneic hematopoietic stem cell transplantation (alloSCT) is a potentially curative treatment option for acute leukemia. We aimed to identify the comorbidity factors affecting survival outcomes after alloSCT and develop a new comorbidity index tool for predicting overall survival (OS).

Methods

A Korean nationwide cohort of 3,809 adults with acute leukemia treated with alloSCT between January 2002 and December 2018 was analyzed as the development cohort. A retrospective cohort comprising 313 consecutive adults with acute leukemia who underwent alloSCT between January 2019 and April 2020 was analyzed as the validation cohort.

Results

In the development cohort, advanced age, male sex, and comorbidities such as previous non-hematologic malignancy, hypertension, and coronary or cerebral vascular disease were significantly related to poor OS. Subsequently, a new comorbidity scoring system was developed, and risk groups were created, which included the low-risk (score ≤0.17), intermediate-risk (0.17< score ≤0.4), high-risk (0.4< score ≤0.55), and very high-risk (score >0.55) groups. The 1-year OS rates were discriminatively estimated at 73.5%, 66.2%, 61.9%, and 50.9% in the low-risk, intermediate-risk, high-risk, and very high-risk groups in the development cohort, respectively (P<0.001). The developed scoring system yielded discriminatively different 1-year OS rates and 1-year incidence of non-relapse mortality according to the risk group (P=0.085 and P=0.018, respectively). Furthermore, the developed model showed an acceptable performance for predicting 1-year non-relapse mortality with an area under the curve of 0.715.

Conclusion

The newly developed predictive scoring system could be a simple and reliable tool helping clinicians to assess risk of alloSCT in adults with acute leukemia.

Deubiquitinases in hematological malignancies

Deubiquitinases (DUBs) are enzymes that control the stability, interactions or localization of most cellular proteins by removing their ubiquitin modification. In recent years, some DUBs, such as USP7, USP9X and USP10, have been identified as promising therapeutic targets in hematological malignancies. Importantly, some potent inhibitors targeting the oncogenic DUBs have been developed, showing promising inhibitory efficacy in preclinical models, and some have even undergone clinical trials. Different DUBs perform distinct function in diverse hematological malignancies, such as oncogenic, tumor suppressor or context-dependent effects. Therefore, exploring the biological roles of DUBs and their downstream effectors will provide new insights and therapeutic targets for the occurrence and development of hematological malignancies. We summarize the DUBs involved in different categories of hematological malignancies including leukemia, multiple myeloma and lymphoma. We also present the recent development of DUB inhibitors and their applications in hematological malignancies. Together, we demonstrate DUBs as potential therapeutic drug targets in hematological malignancies.

Correlation analysis of long non-coding RNA TUG1 with disease risk, clinical characteristics, treatment response, and survival profiles of adult Ph- Acute lymphoblastic leukemia

Background

Long non‐coding RNA taurine‐upregulated gene 1 (lncRNA TUG1) is reported to be involved in the progression and development of several malignancies; however, its role in Philadelphia chromosome‐negative acute lymphoblastic leukemia (Ph⁻ALL) is unknown. The present study aimed to explore the correlation of lncRNA TUG1 with disease risk, disease condition, and prognosis of adult Ph⁻ALL.

Methods

Total 101 adult Ph⁻ ALL patients and 40 bone marrow (BM) donors were included, followed by detection of BM monocyte cell lncRNA TUG1 expression by reverse transcription‐quantitative polymerase chain reaction. According to the quantiles of lncRNA TUG1 expression in Ph⁻ ALL patients, these patients were divided into four tiers: tier 1 (ranked in 0%~25%), tier 2 (ranked in 25%~50%), tier 3 (ranked in 50%~75%), and tier 4 (ranked in 75%~100%).

Results

LncRNA TUG1 was upregulated in Ph⁻ ALL patients compared with healthy donors. Further analysis indicated that in Ph⁻ ALL patients, higher lncRNA TUG1 tier was correlated with the presence of central nervous system leukemia, increased white blood cell level, and bone marrow blasts. Furthermore, higher lncRNA TUG1 tier was negatively associated with complete remission (CR) within 4 weeks, total CR, and allogeneic hematopoietic stem cell transplant achievement. In addition, higher lncRNA TUG1 tier was associated with decreased disease‐free survival and overall survival, which was further verified to be an independent factor by Cox's regression analysis.

Conclusion

lncRNA TUG1 presents potential to be a novel biomarker for disease risk assessment and survival surveillance in Ph⁻ ALL management.

Quality of life in adults with acute lymphoblastic leukemia in France: results from a French cross-sectional study

In recent years, treatment of acute lymphoblastic leukemia (ALL) has improved substantially, leading to longer survival. This has necessitated a greater focus on health-related quality of life (HRQoL), but data are lacking. In a part-prospective, part-retrospective study, we enrolled 219 adults with ALL in France to assess the impact of key disease and treatment characteristics on HRQoL. Overall HRQoL and most specific QoL domain scores were consistently better among patients receiving front-line therapy, those currently in complete remission, and those who had previously received hematopoietic stem-cell transplantation. Furthermore, HRQoL was consistently impaired in patients with minimal residual disease present (MRD+). In multivariate analyses, multiple lines of therapy, MRD+, leukopenia, comorbidities, and anemia were significantly associated with impaired HRQoL. This study provides real-world data on HRQoL in adults with ALL in France and shows the positive impact of MRD-negative status on HRQoL.

Diagnostic Validation of a Clinical Laboratory-Oriented Targeted RNA Sequencing System for Detecting Gene Fusions in Hematologic Malignancies

Targeted RNA sequencing (RNA-seq) is a highly accurate method for sequencing transcripts of interest with a high resolution and throughput. However, RNA-seq has not been widely performed in clinical molecular laboratories because of the complexity of data processing and interpretation. We developed and validated a customized RNA-seq panel and data processing protocol for fusion detection using 4 analytical validation samples and 51 clinical samples, covering seven types of hematologic malignancies. Analytical validation showed that the results for target gene coverage and between- and within-run precision and linearity tests were reliable. Using clinical samples, RNA-seq based on filtering and prioritization strategies detected all 25 known fusions previously found by multiplex reverse transcriptase-PCR and fluorescence in situ hybridization. It also detected nine novel fusions. Known fusions detected by RNA-seq included two IGH rearrangements supported by expression analysis. Novel fusions included six that targeted just one partner gene. In addition, 18 disease- and drug resistance-associated transcript variants in ABL1, GATA2, IKZF1, JAK2, RUNX1, and WT1 were designated simultaneously. Expression analysis showed distinct clustering according to subtype and lineage. In conclusion, this study showed that our customized RNA-seq system had a reliable and stable performance for fusion detection, with enhanced diagnostic yield for hematologic malignancies in a clinical diagnostic setting.

The role of E255K/V-inclusive mutations in a Philadelphia-positive acute lymphoblastic leukemia with mutation evolution during sequential TKIs therapies: A case report

RATIONALE

Until recently, the survival rate in patients with Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL) was approximately 30%. Tyrosine kinase inhibitors (TKIs), which are a new class of drugs that target BCR-ABL fusion protein, have shown to be effective in treating Ph+ ALL in adults. However, the resistance mechanisms that promote the disease recurrence have altered the initial success of these revolutionary agents.

PATIENT CONCERNS

A 71-year-old Chinese female patient who suffered from severe shoulder and back pain for 1 week.

DIAGNOSIS

The patient was diagnosed with Ph+ ALL (B-cell) because of the following items. Complete blood count showed extremely abnormal white blood cell count (26.26×109/l), hemoglobin concentration (65 g/l) and platelet count (14×109/l). And because that Bone marrow aspirate showed 72.5% lymphoblasts and 59.30% lymphoblasts were confirmed by flow cytometry (FCM). At mean time, Real-time fluorescent quantitative PCR analysis confirmed that the P190 BCR/ABL fusion gene expression was 5.9%. Karyotype analysis indicated the following: 45, XX, -7, t (922) (q34; q11) [cp3].

INTERVENTIONS

The patient was treated with chemotherapy and different TKIs including imatinib, dasatinib, ponatinib, and bosutinib.

OUTCOMES

The patient achieved complete remissions with different TKIs after diagnose but relapsed afterward and died of infection.

LESSONS

Multidrug-resistant mutations within the BCR-ABL1 kinase domain are an emerging clinical problem for patients receiving sequential TKIs therapy. Acquisition of E255K/V-inclusive mutations is usually associated with ponatinib resistance, thus it is necessary to screen out new real pan-inhibitor compounds for all BCR/ABL mutations and figure out the potential efficacy of asciminib-based drug combinations in the future.

The time-dependent effects of early-onset Epstein-Barr viremia on adult acute leukemia patients following allo-HSCT with ATG-containing MAC regimen

Epstein-Barr virus (EBV) viremia is a common complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The purpose of this study was to evaluate the impacts of early-onset EBV viremia in acute leukemia (AL) patients who underwent allo-HSCT with anti-thymocyte globulin (ATG)-containing myeloablative conditioning (MAC) regimen. Two hundred and ninety-six patients were included between January 2013 and December 2015. In 126 patients (42.6%) who developed early-onset EBV viremia, with a median time of 48 (range 18~99) days after allo-HSCT. The cumulative incidence of EBV viremia at 30 and 90 days after allo-HSCT were 4.1 and 39.9%, respectively. Prognostic analysis showed that the adjusted overall survival in early-EBV^pos group was significantly lower than early-EBV^neg group within the first 26.7 months after allo-HSCT [hazard ratio (HR), 1.63, P = 0.012], but significantly higher than those afterward (after 26.7 months: HR 0.11, P = 0.035); for the adjusted event-free survival, early-EBV^pos group was significantly inferior in early-EBV^pos group within the first 10.8 months after transplantation (HR: 1.55, P = 0.042), and this adverse effect was not detected any more after 10.8 months (HR: 0.58, P = 0.107). Compared with early-EBV^neg group after adjusting by aGVHD and CMV viremia, HR for death from transplant-related mortality was 2.78-fold higher in patients with early-EBV viremia in piecewise constant Cox analysis (P = 0.006), and this adverse effect was not detected any more after the cut-point time (HR: 0.67, P = 0.361). No differences in terms of relapse and relapse mortality were observed between early-EBV^pos and early-EBV^neg group (P > 0.05). In conclusion, the impacts on transplant outcomes of early-EBV viremia were time-dependent, which may help to optimize management strategies for early-EBV viremia after allo-HSCT, especially in AL patients with ATG-containing MAC regimen.

Clinical Utility of Droplet Digital PCR to Monitor BCR-ABL1 Transcripts of Patients With Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia Post-chimeric Antigen Receptor19/22 T-Cell Cocktail Therapy

Philadelphia chromosome–positive acute lymphoblastic leukemia (Ph⁺ ALL) accounts for 20–30% of adult patients with ALL, characterized by translocation of t_{(9, 22)}. Tyrosine kinase inhibitors (TKIs) have significantly improved the outcome even though there are still some problems including relapse due to drug-resistant mutations and suboptimal molecular remission depth. Previously, we reported the safety and efficacy of sequential infusion of CD19/22 chimeric antigen receptor T-cell (CAR-T) immunotherapy in the treatment of relapsed/refractory (R/R) B-cell neoplasms including cases with Ph⁺ ALL. Given possible deeper reaction, more patients were expected to reach optimal minimal residual disease (MRD) response. An alternative method, duplex droplet digital PCR (ddPCR) with high sensitivity was established, which could provide absolute quantification of MRD without the need for calibration curves. Here, we retrospectively collected 95 bone marrow samples from 10 patients with R/R Ph⁺, who received 19/22 CAR-T-cell cocktail therapy. Notably, sequential molecular remission for more than 3 months (SMR3), a significant indicator based on ddPCR after CAR-T infusion was established, which was defined as a sequential molecular remission for not <3 months with negative MRD. In this cohort, no recurrence was observed in six patients achieving SMR3, where four of whom accepted allogeneic hematopoietic stem cell transplantation (allo-HSCT) after CAR-T cell regimen. Unfortunately, the other four patients who did not reach SMR3 relapsed, and did not receive extra specific treatment except CAR-T regimen. To sum up, ddPCR may be an alternative, especially when nucleic acid was insufficient in clinical practice. No achievement of SMR3 may be an early warning of potential relapse after CAR-T and indicating the initiation of other therapies including allo-HSCT.

Overcoming Glucocorticoid Resistance in Acute Lymphoblastic Leukemia: Repurposed Drugs Can Improve the Protocol

Glucocorticoids (GCs) are a central component of multi-drug treatment protocols against T and B acute lymphoblastic leukemia (ALL), which are used intensively during the remission induction to rapidly eliminate the leukemic blasts. The primary response to GCs predicts the overall response to treatment and clinical outcome. In this review, we have critically analyzed the available data on the effects of GCs on sensitive and resistant leukemic cells, in order to reveal the mechanisms of GC resistance and how these mechanisms may determine a poor outcome in ALL. Apart of the GC resistance, associated with a decreased expression of receptors to GCs, there are several additional mechanisms, triggered by alterations of different signaling pathways, which cause the metabolic reprogramming, with an enhanced level of glycolysis and oxidative phosphorylation, apoptosis resistance, and multidrug resistance. Due to all this, the GC-resistant ALL show a poor sensitivity to conventional chemotherapeutic protocols. We propose pharmacological strategies that can trigger alternative intracellular pathways to revert or overcome GC resistance. Specifically, we focused our search on drugs, which are already approved for treatment of other diseases and demonstrated anti-ALL effects in experimental pre-clinical models. Among them are some “truly” re-purposed drugs, which have different targets in ALL as compared to other diseases: cannabidiol, which targets mitochondria and causes the mitochondrial permeability transition-driven necrosis, tamoxifen, which induces autophagy and cell death, and reverts GC resistance through the mechanisms independent of nuclear estrogen receptors (“off-target effects”), antibiotic tigecycline, which inhibits mitochondrial respiration, causing energy crisis and cell death, and some anthelmintic drugs. Additionally, we have listed compounds that show a classical mechanism of action in ALL but are not used still in treatment protocols: the BH3 mimetic venetoclax, which inhibits the anti-apoptotic protein Bcl-2, the hypomethylating agent 5-azacytidine, which restores the expression of the pro-apoptotic BIM, and compounds targeting the PI3K-Akt-mTOR axis. Accordingly, these drugs may be considered for the inclusion into chemotherapeutic protocols for GC-resistant ALL treatments.

Anti-CD19 CAR-T cell therapy bridge to HSCT decreases the relapse rate and improves the long-term survival of R/R B-ALL patients: a systematic review and meta-analysis

Chimeric antigen receptor (CAR) T cell therapy improves the remission rate of refractory/relapsed B-acute lymphoblastic leukemia (R/R B-ALL) patients, but the relapse rate remains high. Recent studies suggest patients who underwent post-chimeric antigen receptor T cell therapy hematopoietic stem cell transplantation (post- HSCT) would achieve durable remission and better survival, but this remains controversial. To this end, we conducted a meta-analysis to assess the role of post-HSCT in R/R B-ALL. The Cochrane Library, Embase, and PubMed were used to identify relevant studies; the latest search update was on July 05, 2020. We used the Cochran Q test and I-squared statistics to test for heterogeneity among the studies analyzed. The fixed model and random model were used to combine results when appropriate. We performed all statistical analyses with Stata 12, and P < 0.05 was considered statistically significant. We included 18 studies with 758 patients in the meta-analysis. Our results indicated that post-HSCT was associated with lower relapse rate (RR: 0.40, 95% CI: 0.32-0.50, P = 0.000), better overall survival (HR: 0.37, 95% CI: 0.19-0.71, P = 0.003), better leukemia-free survival (HR: 0.20, 95% CI: 0.10-0.40, P = 0.000). However, post-HSCT did not influence OS in Caucasians, and CAR-T cells with CD28 co-stimulation factor bridged to HSCT did not influence OS. Post-HSCT decreased the relapse rate and improved the long-term survival of R/R B-ALL patients. R/R B-ALL patients would benefit from post-HSCT after CAR-T cell therapy.

Factors associated with outcomes after a second CD19-targeted CAR T-cell infusion for refractory B-cell malignancies

CD19-targeted chimeric antigen receptor-engineered (CD19 CAR) T-cell therapy has shown significant efficacy for relapsed or refractory (R/R) B-cell malignancies. Yet, CD19 CAR T cells fail to induce durable responses in most patients. Second infusions of CD19 CAR T cells (CART2) have been considered as a possible approach to improve outcomes. We analyzed data from 44 patients with R/R B-cell malignancies (acute lymphoblastic leukemia [ALL], n = 14; chronic lymphocytic leukemia [CLL], n = 9; non-Hodgkin lymphoma [NHL], n = 21) who received CART2 on a phase 1/2 trial (NCT01865617) at our institution. Despite a CART2 dose increase in 82% of patients, we observed a low incidence of severe toxicity after CART2 (grade ≥3 cytokine release syndrome, 9%; grade ≥3 neurotoxicity, 11%). After CART2, complete response (CR) was achieved in 22% of CLL, 19% of NHL, and 21% of ALL patients. The median durations of response after CART2 in CLL, NHL, and ALL patients were 33, 6, and 4 months, respectively. Addition of fludarabine to cyclophosphamide-based lymphodepletion before the first CAR T-cell infusion (CART1) and an increase in the CART2 dose compared with CART1 were independently associated with higher overall response rates and longer progression-free survival after CART2. We observed durable CAR T-cell persistence after CART2 in patients who received cyclophosphamide and fludarabine (Cy-Flu) lymphodepletion before CART1 and a higher CART2 compared with CART1 cell dose. The identification of 2 modifiable pretreatment factors independently associated with better outcomes after CART2 suggests strategies to improve in vivo CAR T-cell kinetics and responses after repeat CAR T-cell infusions, and has implications for the design of trials of novel CAR T-cell products after failure of prior CAR T-cell immunotherapies.

Next-generation sequencing improves BCR-ABL1 mutation detection in Philadelphia chromosome-positive acute lymphoblastic leukaemia

BCR-ABL1 kinase domain mutation testing in tyrosine kinase inhibitor (TKI)-resistant Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukaemia (ALL) patients is routinely performed by Sanger sequencing (SS). Recently, next-generation sequencing (NGS)-based approaches have been developed that afford greater sensitivity and straightforward discrimination between compound and polyclonal mutations. We performed a study to compare the results of SS and NGS in a consecutive cohort of 171 Ph+ ALL patients. At diagnosis, 0/44 and 3/44 patients were positive for mutations by SS and NGS respectively. Out of 47 patients with haematologic resistance, 45 had mutations according to both methods, but in 25 patients NGS revealed additional mutations undetectable by SS. Out of 80 patients in complete haematologic response but with BCR-ABL1 ≥0·1%, 28 (35%) and 52 (65%) were positive by SS and NGS respectively. Moreover, in 12 patients positive by SS, NGS detected additional mutations. NGS resolved clonal complexity in 34 patients with multiple mutations at the same or different codons and identified 35 compound mutations. Our study demonstrates that, in Ph+ ALL on TKI therapy, NGS enables more accurate assessment of mutation status both in patients who fail therapy and in patients with minimal residual disease above 0·1%.

The management of hematologic malignancies during the COVID-19 pandemic

Introduction: Patients with hematological malignancies have experienced a more severe clinical course of COVID-19 and higher mortality than those with solid tumors and those without cancer. The ongoing pandemic poses many challenges in assuring the correct and timely diagnosis of hemato-oncology patients as well as the optimal treatment.Areas covered: The present paper reviews current data on the incidence and clinical course of COVID-19 in patients with hematological malignancies. A literature review of the MEDLINE database for articles was conducted via PubMed. Publications from December 2019 through September 2020 were scrutinized. The search terms used were SARS-Cov-2 OR COVID-19 in conjunction with hematological malignancies OR leukemia OR lymphoma OR multiple myeloma OR cancer. Recommendations and expert opinions either published or presented on ASH, ASCO, ESMO, NCCN websites were also reviewed.Expert opinion: The COVID-19 pandemic has brought a pressing need to improve the management of patients with hematological malignancies, including establishing prompt diagnoses and providing effective treatment while also minimalizing the risk of SARS-Cov2 infection. The recommendations developed by many organizations based on expert opinions are helpful in making proper decisions. All cancer patients should be advised to get vaccinated against influenza and pneumococcus.

Value of pre-transplant consolidation chemotherapy in adults with acute lymphoblastic leukemia undergoing allogeneic hematopoietic stem cell transplantation without minimal residual disease in first complete remission

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is recommended for adults acute lymphoblastic leukemia (ALL) with minimal residual disease (MRD) negative during their first complete remission (CR1). However, the role of pre-transplant consolidation chemotherapy remains unclear. We evaluated 78 CR1/MRD-negative patients, the consolidation and non-consolidation groups had similar 5-year OS (74.8% [95% CI: 62.2-87.3%] vs. 74.2% [95% CI: 53.2-95.1%], p = .894), RFS (72.2% [95% CI: 59.6-84.7%] vs. 73.1% [95% CI: 54.2-91.9%], p = .942), CIR (9.4% [95% CI: 9.1-9.7%] vs. 18.9% [95% CI: 17.3-20.4%], p = .376), and NRM (18.4% [95% CI: 17.7-19.0%] vs. 8.0% [95% CI: 7.3-8.6%], p = .375). Multivariable analysis confirmed that high cytogenetic risk independently predicted poor OS and RFS, although pre-transplant consolidation chemotherapy did not predict the prognosis. Based on these findings, we recommend performing transplantation immediately for adult ALL patients after they have achieved CR1/MRD-negative status when there are readily available donors.

The Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of acute leukemia

Acute leukemia is a constellation of rapidly progressing diseases that affect a wide range of patients regardless of age or gender. Traditional treatment options for patients with acute leukemia include chemotherapy and hematopoietic cell transplantation. The advent of cancer immunotherapy has had a significant impact on acute leukemia treatment. Novel immunotherapeutic agents including antibody-drug conjugates, bispecific T cell engagers, and chimeric antigen receptor T cell therapies have efficacy and have recently been approved by the US Food and Drug Administration (FDA) for the treatment of patients with acute leukemia. The Society for Immunotherapy of Cancer (SITC) convened a panel of experts to develop a clinical practice guideline composed of consensus recommendations on immunotherapy for the treatment of acute lymphoblastic leukemia and acute myeloid leukemia.

The value of 18F-FDG PET/CT in the prediction of clinical outcomes of patients with acute leukemia treated with allogeneic hematopoietic stem cell transplantation

The present study aimed to determine whether ¹⁸F-FDG PET/CT performed before and/or after allogeneic hematopoietic stem cell transplantation (allo-HSCT) can predict clinical outcomes in acute leukemia (AL). A total of 79 examinations comprising 72 patients with AL who underwent ¹⁸F-FDG PET/CT before and/or after allo-HSCT were retrospectively enrolled between January 2011 and January 2019. Outcomes were assessed using overall survival (OS) and disease-free survival (DFS). A total of 63 examinations were PET-positive, while 16 examinations were PET-negative. Increased BM and splenic ¹⁸F-FDG uptake were observed in 24 (19/79) and 14% (11/79) of examinations, respectively. ¹⁸F-FDG-avid lymph nodes were observed in 38% (30/79) of examinations. E_NE_ME_S involvement was detected in 44% (35/79) of examinations. The presence of E_NE_ME_S involvement [OS hazard ratio (HR), 6.399; 95% confidence interval (CI), 1.843–22.224; P=0.003; post-HSCT OS: HR, 7.203; 95% CI, 1.510–34.369; P=0.013; DFS HR, 3.671; 95% CI, 1.145–11.768; P=0.029], post-transplantation minimal residual disease (DFS HR, 4.381; 95% CI, 1.594–12.040; P=0.004; pre-HSCT OS HR, 11.455; 95% CI, 1.336–98.179; P=0.026) and disease status (OS HR, 0.330; 95% CI, 0.128–0.848; P=0.021; post-HSCT OS HR, 0.195; 95% CI, 0.050–0.762; P=0.019; DFS: HR, 0.278; 95% CI, 0.091–0.851; P=0.025) could serve as an adverse prognostic factor in patients with AL treated with allo-HSCT. ¹⁸F-FDG PET/CT before and/or after allo-HSCT was a predictor for OS and DFS in patients with AL. E_NE_ME_S involvement detected using ¹⁸F-FDG PET/CT may help identify patients with AL who are likely to have unfavorable clinical outcomes.

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

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

Prognostic significance of a normal karyotype in adult patients with BCR-ABL1-positive acute lymphoblastic leukemia in the tyrosine kinase inhibitor era

OBJECTIVE

The occurrence of cryptic Philadelphia (Ph) chromosome translocation is rare in BCR-ABL1-positive acute lymphoblastic leukemia (BCR-ABL1+ ALL) and is of unknown significance in the tyrosine kinase inhibitor (TKI) era.

METHODS

We retrospectively studied a series of adult patients receiving TKI-based therapy to evaluate the prognostic impact of the normal karyotype (NK) (n=22) in BCR-ABL1+ ALL by comparison with the isolated Ph+ karyotype (n=54).

RESULTS

There were no statistically significant differences in clinical characteristics and complete remission rate between the two groups. Compared with the isolated Ph+ group, the NK/BCR-ABL1+ group had a higher relapse rate (55.0% versus 29.4%, p=0.044). Overall survival (OS) and disease-free survival (DFS) were significantly shorter in the NK/BCR-ABL1+ group than in the isolated Ph+ group [median OS: 24.5 versus 48.6 (months), p=0.013; median DFS: 11.0 (months) versus undefined, p=0.008]. The five-year OS and DFS for patients with NK/BCR-ABL1+ were 19.2% and 14.5%, respectively; those for patients with isolated Ph+ were 49.5% and 55.7%, respectively. Thirty-four (44.7%) patients underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) in this study. Among the patients who received allo-HSCT, the median OS and DFS in the NK/BCR-ABL+ group (n=9) were 35.5 and 27.5 months, respectively, while those in the isolated Ph+ group (n=25) were undefined. There was a trend of significant statistical difference in the OS between the two subgroups (p=0.066), but no significant difference in the DFS. Multivariate analysis revealed that NK was independently associated with worse OS and DFS in BCR-ABL1+ ALL patients [Hazard ratio (HR) 2.256 (95% confidence interval (CI), 1.005-5.066), p=0.049; HR 2.711 (95% CI, 1.319-5.573), p=0.007].

CONCLUSION

Our results suggest that the sub-classification of an NK could be applied in the prognostic assessments of BCR-ABL1+ ALL. In addition, allo-HSCT should be actively performed to improve prognosis in these patients.