Treatment Of Lymphoid Malignancies Research Articles

Nanotechnology Advances in the Detection and Treatment of Lymphoid Malignancies.

Lymphoid malignancies are complex diseases with distinct biological behaviors, clinical presentations, and treatment responses. Ongoing research and advancements in biotechnology enhance the understanding and management of these malignancies, moving towards more personalized approaches for diagnosis and treatment. Nanotechnology has emerged as a promising tool to improve some limitations of conventional diagnostics as well as treatment strategies for lymphoid malignancies. Nanoparticles (NPs) offer unique advantages such as enhanced multimodal detection, drug delivery, and targeted therapy capabilities, with the potential to improve precision medicine and patient outcomes. Here, we comprehensively examine the current landscape of nanoconstructs applied in the management of lymphoid disease. Through a comprehensive analysis of preclinical studies, we highlight the translational potential of NPs in revolutionizing the field of hematological malignancies, with a specific focus on lymphoid neoplasms.

Treatment of lymphoid malignancies in patients with primary immunodeficiencies associated with DNA repair defects

Nijmegen breakage syndrome (NBS) and ataxia-telangiectasia (AT; Louis–Bar syndrome) are primary immunodeficiencies (PID) associated with chromosome instability and DNA repair defects that predispose individuals to an increased risk of various malignancies. In our study, we retrospectively analyzed clinical characteristics and outcomes of 28 cancer cases in 14 patients with AT and 10 patients with NBS who had been treated at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology between January 2007 and December 2022. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology. The most common type of malignancy was mature B-cell non-Hodgkin lymphoma (B-NHL) (42%), with diffuse large B-cell lymphoma (DLBCL) accounting for 91% of all B-NHL cases. Other cases included T-cell acute lymphoblastic leukemia (ALL) (n = 3), B-cell ALL (n = 2), Hodgkin lymphoma (n = 3), NK/T-cell lymphoma (n = 1), T-cell lymphoblastic lymphoma (n = 1), peripheral T- cell lymphoma (n = 2), medulloblastoma (n = 1) epithelioid rhabdomyosarcoma (n = 1), T-cell prolymphocytic leukemia (n = 2). A total of 4 patients were diagnosed with second malignancies (2 children with AT and 2 children with NBS. The diagnosis of PID was suspected or confirmed before the initiation of cancer therapy in 62% of AT patients and in 100% of NBS patients. Treatment was given in accordance with standard protocols with chemotherapy dose modifications. A total of 93% of patients with AT and 80% of patients with NBS required dose reduction. The level of response was quite high: 81% of patients with AT and 58% of patients with NBS achieved complete remission. According to our data, the use of reduced-dose chemotherapy regimens helps to achieve an acceptable toxicity profile without reducing the overall effectiveness of treatment.

Chimeric antigen receptor T-cell as a significant player in the innovative treatment of hematological cancers

Introduction and purpose: Chimeric antigen receptor‐T (CAR‐T) cells have achieved inspiring outcomes in the treatment for lymphoid malignancies, especially diffuse large B-cell lymphoma (DLBCL) and acute lymphoblastic leukemia (ALL), providing alternative therapeutic options for patients who failed to respond to conventional treatments. CAR-T are based on the patient's T lymphocytes, which through genetic modification, gain new abilities to detect and fight cancer cells. Although the percentage of complete remissions after standard treatment of B-cell malignancies is quite high, methods that could have an even better result regarding patient survival by reducing the side effects of treatment are still being sought to improve the quality of patients' lives. CAR-T is a culmination of many years of research in the dynamically developing area of immunotherapy as a revolutionary therapy of hematological cancers treatments. State of knowledge: In order to explore the topic, analysis included research available in the PubMed database. The research focused on the possibility of using CAR-T cell therapy in selected hematological cancers. Conclusion: CAR-T is one of the most advanced and personalized methods of immunotherapy. Despite the side effects of this method, there is still scope for improvement. Our overview summarizes all the issues that have been overcome in designing this therapy, as well as highlighting all the challenges that still need to be addressed.

Defining the Role of the Gut Microbiome in the Pathogenesis and Treatment of Lymphoid Malignancies.

The gut microbiome is increasingly being recognized as an important immunologic environment, with direct links to the host immune system. The scale of the gut microbiome's genomic repertoire extends the capacity of its host's genome by providing additional metabolic output, and the close communication between gut microbiota and mucosal immune cells provides a continued opportunity for immune education. The relationship between the gut microbiome and the host immune system has important implications for oncologic disease, including lymphoma, a malignancy derived from within the immune system itself. In this review, we explore past and recent discoveries describing the role that bacterial populations play in lymphomagenesis, diagnosis, and therapy. We highlight key relationships within the gut microbiome-immune-oncology axis that present exciting opportunities for directed interventions intended to shape the microbiome for therapeutic effect. We conclude with a limited summary of active clinical trials targeting the microbiome in hematologic malignancies, along with future directions on gut microbiome investigations within lymphoid malignancies.

Aliivibrio fischeri L-Asparaginase production by engineered Bacillus subtilis: a potential new biopharmaceutical.

L-Asparaginase (L-ASNase) is an enzyme applied in the treatment of lymphoid malignancies. However, an innovative L-ASNase with high yield and lower side effects than the commercially available preparations are still a market requirement. Here, a new-engineered Bacillus subtilis strain was evaluated for Aliivibrio fischeri L-ASNase II production, being the bioprocess development and the enzyme characterization studied. The pBS0E plasmid replicative in Bacillus sp and containing PxylA promoter inducible by xylose and its repressive molecule sequence (XylR) was used for the genetic modification. Initially, cultivations were carried out in orbital shaker, and then the process was scaled up to stirred tank bioreactor(STB). After the bioprocess, the cells were recovered and submitted to ultrasound sonication for cells disruption and intracellular enzyme recovery. The enzymatic extract was characterized to assess its biochemical, kinetic and thermal properties using L-Asparagine and L-Glutamine as substrates. The results indicated the potential enzyme production in STBachieving L-ASNase activity up to 1.539 U mL-1. The enzymatic extract showed an optimum pH of 7.5, high L-Asparagine affinity (Km = 1.2275mmol L-1) and low L-Glutaminase activity (0.568-0.738 U mL-1). In addition, thermal inactivation was analyzed by two different Kinect models to elucidate inactivation mechanisms, low kinetic thermal inactivation constants for 25ºC and 37ºC (0.128 and 0.148h-1, respectively) indicate an elevated stability. The findings herein show that the produced recombinant L-ASNase has potential to be applied for pharmaceutical purposes.

Abstract 5576: In vitro efficacy and safety studies to support engineered T cell therapies

Abstract Engineered T cell therapies such as Chimeric Antigen Receptor T cells (CAR-T) and T Cell Receptor (TCR) T cells have emerged as a promising cancer therapy. To date, four anti-CD19 CAR-T and one anti-BCMA CAR-T products have been approved by the FDA for the treatment of lymphoid malignancies. Many more T cell therapy products are currently being explored, directed towards both liquid and solid tumors as well as for other clinical indications. High-quality and robust in vitro and in vivo assay are essential for the discovery and characterization of lead T cell therapy products. Furthermore, despite demonstrating therapeutically successful, the further development of T cell immunotherapies has been hindered by safety concerns. Selected target antigens might be expressed in healthy tissues or engineered T cells may non-specifically bind to antigens in healthy tissues, potentially resulting in severe side effects. In addition, the random integration of the CAR- or TCR-encoded DNA cassettes in the host cell genome has the potential risk of causing insertional mutagenesis and may contribute to oncogenic transformation of the T cells. The aim of this study was to develop several in vitro assays for the assessment of efficacy and safety of T cell therapies using CAR-T cells targeting the Human Epidermal growth factor Receptor 2 (HER2) as a model system. Cytotoxicity co-culture assays were developed using increasing effector:target cells ratios and an impedance-based readout to quantify the viability of HER2-positive and -negative cancer cell lines in real-time, to confirm the activity and selectivity of the HER2-CAR-T cells. Furthermore, co-culture assays were also developed for a variety of primary or iPSC-derived healthy human cells (representing various tissues) to assess potential unwanted effects of the HER2-CAR-T cells against healthy cells. In addition, an oncogenicity assay was developed to quantify the survival and proliferation of the HER2-CAR-T cells in the absence and presence of cytokines by flow cytometry, to determine whether the genomic editing of the T cells affected their cytokine-dependency. In conclusion, Charles River Laboratories developed several in vitro assays for the preclinical assessment of T cell therapy efficacy, potency, specificity and safety to aid early-stage lead discovery, optimization and development, and to support Investigational New Drug applications. These assays are only a fraction of the End-to-End solution Charles River Laboratories offers for advancing Cell Therapies into the clinic. Citation Format: Sophie Vermond, Benita Quist, Sabrina de Munnik, Monique Hazenoot, Madalina Avramescu, Rene McLaughlin, Gemma Moiset, Marijn Vlaming. In vitro efficacy and safety studies to support engineered T cell therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5576.

Increased Risk of Toxicity with Novel PI3K Delta Inhibitor Combinations Compared with Standard Use in Non-Hodgkin Lymphoma Patients

Introduction: PI3Kδ inhibition has demonstrated significant efficacy in the treatment of lymphoid malignancies, leading to the approval of idelalisib as a single agent for follicular lymphoma and SLL and in combination with rituximab in CLL. However, therapy is not curative and agents in this class are associated with treatment limiting toxicities (e.g. pneumonitis, colitis, transaminitis). Clinical trials are investigating novel combinations in efforts to increase response depth while limiting treatment durations to avoid toxicities. Given the unique side effects associated with PI3Kδ inhibition, data is needed to guide use in routine clinical practice and to direct future development of this therapeutic class.Methods: We report on the cumulative experience of therapy with PI3Kδ inhibitors (idelalisib, duvelisib or INCB040093) administered with or without rituximab or obinutuzumab as well as investigational combinations (+JAK1inhibitor, +SYK inhibitor, or + bendamustine rituximab). Demographic and clinical data were collected on all non-Hodgkin lymphoma patients treated with a PI3Kδ inhibitor at a single institution. Data on all treatment related adverse events (AEs) were graded according to the CTCAE V4.03 criteria. Cause specific cox-proportional hazards models were used to model the risk of grade 3 or 4 AEs associated with treatment regimen, treatment history, and age, in the presence of the competing risk of death.Results: Seventy-nine patients were treated with a PI3Kδ inhibitor (median age 68 years, 87% relapsed/refractory , 78% on clinical trial) for a median of 3.5 months (range 0.2 to 30). Thirty-four patients were treated with a single agent PI3Kδ inibitor +/- an anti-CD20 antibody (standard group) and 45 patients were treated with a novel PI3Kδ combination (novel group). There were no significant differences in demographics or previous treatment between these two groups.All patients experienced AEs and 68.4% of patients had at least one grade 3/4 (severe) AE, many of which were immune-mediated and infectious events. Two patients died from treatment related toxicity (cause-specific mortality 7%). The incidence rate of severe AEs was significantly higher in the novel combinations group (5.2 vs. 2.1 per person-year; p<0.05). Fifty-four percent of patients discontinued because of an AE. Figure one illustrates a higher cumulative probability of discontinuing from an AE in the novel group, which had a significantly higher risk of discontinuation from AE compared to the standard group (HR 2.8, 95%CI 1.41, 5.76; p<0.01). There was no increase in colitis/diarrhea or hepatic transaminitis in novel combinations compared to standard use. However, we did see a significantly increased risk of pneumonitis in the novel group (HR 4.07, 95% CI 1.23, 13.42; p<0.02) compared to standard use, largely due to use of the idelalisib + SYK inhibitor doublet. The novel group was also at a higher, though non-significant, risk of severe infectious AEs (HR1.81, 95%CI 0.62, 5.93; p>0.05) mostly due to sinopulmonary infections. Previously untreated patients had over two times the risk of a severe AE compared to previously treated patients (HR 2.62, 95%CI 1.19,5.18; p<0.01). There was no evidence of a difference in risk of severe AEs between younger and older patients (HR 1.07, 95%CI 0.62, 1.86, p>0.05).Conclusions: Several ongoing studies are investigating novel PI3Kδ-based combinations given initial results demonstrated with idelalisib. Our data suggests that the known immune-mediated and infectious toxicities are more common with novel targeted combinations studied to date. Combinations of B-cell signaling inhibitors appear particularly toxic and should be avoided. Phase I investigations should use a traditional conservative dose escalation schema with prolonged monitoring for delayed side effects. Antimicrobial prophylaxis may be needed in future combinatorial investigations. Further, clinical use and future development should focus on relapsed patients given the increased risk of immune-mediated events in untreated patients. [Display omitted] DisclosuresCasulo:Gilead: Honoraria, Other: travel support; Infinity: Consultancy; Celgene: Research Funding. Reagan:Seattle Genetics: Research Funding. Friedberg:Bayer HealthCare Pharmaceuticals.: Other: Data and Safety Monitoring Board: Bayer HealthCare Pharmaceuticals.. Barr:Seattle Genetics: Consultancy; Gilead: Consultancy; Infinity: Consultancy; Celgene: Consultancy; Novartis: Consultancy; AbbVie: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding.

Impact of Steroid-Induced Diabetes on Prognosis of Patients with Aggressive Lymphoid Malignancies: A Prospective Study

Background: Hyperglycemia is frequent during steroid therapy and thus it is not uncommon during treatment of lymphoid malignancies. Steroid-induced diabetes (SID) can be complicated by an increased risk of infections, lower chemotherapy efficacy, and even increased mortality. Aim: To determine the prevalence of SID in patients with aggressive lymphoid malignancies during induction therapy and to analyze its impact on treatment outcomes. Methods: The study included 52 patients with lymphoid malignancies; 28 with acute lymphoblastic leukemia (ALL) and 24 with aggressive non-Hodgkin’s lymphomas (NHL). We studied the relation between the development of SID during induction therapy and the rates of complete remission (CR), complication and relapse and survival. Results: Steroid-induced diabetes occurred during induction therapy in 18/28 (64%) and 8/24 (33%) of patients with ALL and NHL, respectively. Older age, and elevated bilirubin level were significantly associated with the development of SID during induction therapy in ALL patients (p = 0.02 and 0.005, respectively), while only older age showed a significant association in NHL patients (p = 0.002). Compared with patients who did not develop SID, those with SID had significantly higher prevalence of febrile neutropenia in the ALL group (p = 0.001) and pneumonia in the NHL group (p = 0.009). Both ALL and NHL patients with SID were significantly less likely to achieve CR and had a significantly worse overall survival. Conclusion: The results of this study suggest that SID is frequent during induction therapy in patients with lymphoid malignancies and associated with more complications and worse treatment outcomes.

Drug interactions with Bruton's tyrosine kinase inhibitors: clinical implications and management.

Bruton's tyrosine kinase (BTK) plays an essential role in B-cell development, differentiation and B-cell receptor (BCR) signaling. The use of Bruton's tyrosine kinase inhibitors (BTKi) in the treatment of lymphoid malignancies has dramatically increased, owing to both impressive efficacy and ease of administration. However, BTKi have a range of drug-drug and drug-food interactions, which may alter drug efficacy and/or increase toxicity. Healthcare professionals should be aware of the probability of drug interactions with BTKi and make recommendations accordingly. In this article, we discuss the relevant drug-drug and drug-food interactions associated with ibrutinib, acalabrutinib, and zanubrutinib, and provide clinical practice recommendations for managing these interactions based on the available literature.

Expanding Access to Chimeric Antigen Receptor T-Cell Therapies: Challenges and Opportunities.

Chimeric antigen receptor (CAR) T-cell therapy is a major advancement in the treatment of lymphoid malignancies, especially diffuse large B-cell lymphoma and acute lymphoblastic leukemia (ALL). Since the U.S. Food and Drug Administration (FDA) approval of two CAR T-cell therapies, axicabtagene ciloleucel and tisagenlecleucel, experience has highlighted various barriers to their broader access and use, including challenges related to manufacturing a patient-specific product, high costs and inadequate reimbursement, incomplete or nonsustained disease responses, and potential for causing life-threatening toxicities. Research on disparities, application, and practice of hematopoietic cell transplantation (HCT) can inform opportunities to address similar barriers to use of CAR T-cell therapies that are currently available as well as other cellular therapies that are expected to become available in the near future. To ensure optimal patient outcomes, these therapies should preferably be administered at centers that have experience and established quality processes and practices. We review opportunities for centers, manufacturers, payers, and policy makers to address barriers to care. We also provide a summary of available and alternative payments models for commercial CAR T-cell and other cellular therapies.

In silico assessment of plant L-asparaginase and estimating its allergenicity in comparison to bacteria asparaginase

L-asparaginase is widely distributed among microorganisms, animals and plants. L-asparaginase has been utilized as a drug in the treatment of lymphoid malignancies and plays a crucial role in asparagine metabolism in plant stress response mechanisms. Multiple sequence alignment of Neighbor–Joining phylogenetic tree was executed utilizing Mega 4.0. Two plants asparaginase were identified whose three dimensional structures compared well with two bacterial samples of L-asparaginase used in humans as a therapeutic drug. Prediction of antigen cites, B-cell epitope identification and prediction of epitopes by use of Cytotoxic T-lymphocyte was performed using various in silico server resources. The survey showed that between the 40 plants, 2 identified items of human, 12 bacteria and 6 algae of asparaginase genes, generally two main branches created that samples of green algae is in the neighborhood of to the bacterial samples. Interestingly the data showed that the two bacterial samples of L-asparaginase used in medicine, when compared to plant asparaginase genes, have less similarity to asparaginase genes of human, while the two human asparaginase genes are located perfectly between the plant groups with their sequence revealing high similarity with plant species. Although there was some allergen epitope found in plant asparaginase, these are different from the allergen epitopes of microbial asparaginase that are used as a drug in humans with no common sequence being found between them. This manuscript provides evidence suggesting the potential utilization of Phaseolus vulgaris asparaginase, which has less epitopes, better predicting tool scores and high similarity, in drug design as an enzymetherapy in leukemia and other cancers.

Gene Polymorphisms and Vincristine-Induced Neuropathy in Patients Who Received R-CHOP Chemotherapy

Gene Polymorphisms and Vincristine-Induced Neuropathy in Patients Who Received R-CHOP Chemotherapy

Glucocorticoids Regulate the Splicing Factor MBNL1, a Potential Control Point for B-Cell Specification

Glucocorticoids, such as dexamethasone and prednisone, are mainstays in the treatment of lymphoid malignancies and autoimmune diseases. To understand the mechanism of how glucocorticoids induce cell death, we integrated a comprehensive, genome-wide shRNA screen with differential gene expression analysis in B-cell acute lymphoblastic leukemia (B-ALL). In addition to activating pro-apoptosis genes and repressing anti-apoptosis genes, we found that repression of B-cell development genes contributes to dexamethasone-induced cell death in B-ALL. Similarly, elevated glucocorticoid levels brought on by stress in stroke victims causes lymphocytopenia by inducing of apoptosis in immature B-cells, but not hemopoietic stem cells or mature B-cells. Additionally, chronic stress has been associated with immune suppression and increased risk for autoimmune disease. Together these findings suggest that glucocorticoids play a normal role in B-cell development, and that elevated glucocorticoid levels in response to stress can alter that development. A control point in this mechanism may be MBNL1. MBNL1 is a sequence-specific RNA binding factor that alters mRNA splicing, stability, and localization. In this work, we show that glucocorticoid suppression of MBNL1 contributes to induction of cell death in B-ALL. Deletion of MBNL1 by CRISPR/Cas9 in the B-ALL cell line NALM-6 induces accumulation and depletion of mRNA levels for hundreds of genes. A large number of B-cell specification genes, including CD19, CD79A, SPI1, and LEF1, are repressed upon MBNL1 deletion, whereas the most highly activated gene is CD34, which is a marker for the less mature lymphoid progenitor cells. Depletion of MBNL1 also changed the splicing of B-cell development genes, including quantitative depletion of LEF1 exon 6. These data suggest that depletion of MBNL1 induces de-differentiation of B-cell precursors. Consistent with this model, an analysis of gene expression in differentiating B-cells revealed a rapid elevation of MBNL1 expression during B-cell specification (after the lymphoid precursor stage), and a concomitant repression of CELF2, an RNA-binding splicing factor that has been shown to oppose MBNL1. We therefore propose that glucocorticoids play a physiological role in B-cell development by restraining B-cell specification through repression of key genes, including MBNL1. Figure Disclosures Tasian: Aleta Biotherapeutics: Membership on an entity's Board of Directors or advisory committees; Gilead Sciences: Research Funding; Incyte Corportation: Research Funding.

The Possible Role of Gut Microbiota and Microbial Translocation Profiling During Chemo-Free Treatment of Lymphoid Malignancies.

The crosstalk between gut microbiota (GM) and the immune system is intense and complex. When dysbiosis occurs, the resulting pro-inflammatory environment can lead to bacterial translocation, systemic immune activation, tissue damage, and cancerogenesis. GM composition seems to impact both the therapeutic activity and the side effects of anticancer treatment; in particular, robust evidence has shown that the GM modulates the response to immunotherapy in patients affected by metastatic melanoma. Despite accumulating knowledge supporting the role of GM composition in lymphomagenesis, unexplored areas still remain. No studies have been designed to investigate GM alteration in patients diagnosed with lymphoproliferative disorders and treated with chemo-free therapies, and the potential association between GM, therapy outcome, and immune-related adverse events has never been analyzed. Additional studies should be considered to create opportunities for a more tailored approach in this set of patients. In this review, we describe the possible role of the GM during chemo-free treatment of lymphoid malignancies.

Lymphocyte-Specific Chromatin Accessibility Pre-determines Glucocorticoid Resistance in Acute Lymphoblastic Leukemia

Glucocorticoids play a critical role in the treatment of lymphoid malignancies. While glucocorticoid efficacy can be largely attributed to lymphocyte-specific apoptosis, its molecular basis remains elusive. Here, we studied genome-wide lymphocyte-specific open chromatin domains (LSOs), and integrated LSOs with glucocorticoid-induced RNA transcription and chromatin modulation using an invivo patient-derived xenograft model of acute lymphoblastic leukemia (ALL). This led to the identification of LSOs critical for glucocorticoid-induced apoptosis. Glucocorticoid receptor cooperated with CTCF at these LSOs to mediate DNA looping, which was inhibited by increased DNA methylation in glucocorticoid-resistant ALL and non-lymphoid cell types. Our study demonstrates that lymphocyte-specific epigenetic modifications pre-determine glucocorticoid resistance in ALL and may account for the lack of glucocorticoid sensitivity in other cell types.

Risk of Infectious Complications in Patients with Chronic Lymphocytic Leukemia in the Era of BCR Inhibitors: A Retrospective Single Institution Experience

Introduction. The development of novel therapeutic agents in the treatment of lymphoid malignancies seemed to decrease the rate of complications, including infections, in spite of standard immuno-chemotherapy regimens. Patients receiving Ibrutinib experienced serious infections and other recent studies found that these patients are at risk for serious or opportunistic infections.Aim. The aim of our study was to evaluate incidence and type of infections in CLL patients treated with BCR inhibitors: Ibrutinib and Idelalisib plus Rituximab.Results. Our retrospective study included 46 CLL patients treated at our Institution since 2015: 37 patients were treated with Ibrutinib and 9 patients were treated with Idelalisib plus Rituximab. The median number of prior treatment regimens was 2 (range 0-5); only 1 patient started Ibrutinib as first-line therapy because of TP53 mutation.We recorded 32 episodes of infections, of which 23 occurred in 11 patients (out of 37, 30%) treated with Ibrutinib and 9 episodes in 5 patients (out of 9, 55%) treated with Idelalisib plus Rituximab. Daily Ibrutinib dose was 420 mg, Idelalisib was used at the dose of 150 mg twice a day. The median duration of treatment was 12 and 13 months in Ibrutinib and Idelalisib, respectively. We confirmed the higher prevalence of infections occurred during the first year of Ibrutinib treatment (84% in Varughese et al vs. 83% in our case series) and we found a high prevalence (78%) of infective episodes with Idelalisib plus Rituximab.The rate of infections was 0.6 episodes/patient for Ibrutinib and 1.0 episodes/patient for Idelalisib; each patient with infection showed a median of 2.1 and 1.8 episodes for Ibrutinib and Idelalisib, respectively.In the group of Ibrutinib the most common infections involved the upper respiratory tract (14 events, 61%), followed by urinary tract (6 events, 26%); in the Idelalisib group we found 6 infections (66%) of upper respiratory tract. Differences were found also in the pathogens implicated in the infections (Table I).All the infections, except one bacterial sepsis, were grade I or II; the patients were treated with antibacterial, antiviral or antifungal drugs in 56% of the cases.Only 3 patients treated with Ibrutinib required hospitalization and antibacterial or antifungal treatment as inpatients but no deaths were registered.In 30% of the Ibrutinib cases and in 53% of the Idelalisib cases the treatment was temporarily stopped.None of the patients received antifungal prophylaxis and nobody had invasive fungal infections. All patients received prophylaxis for Pneumocystis jirovecii and flu shot but no antiviral prophylaxis. Moreover, we detected 10 blood viral (EBV, CMV, HBV, BK) reactivations, without active disease, of which 60% with Idelalisib and 40% with Ibrutinib.Discussion. In conclusion when we treat as second or following line CLL patients with Ibrutinib we should take in account that about 30% of patients will develop one or more episodes of infective complications; in more than 60% the type of infection is bacterial. When we use Idelalisib plus Rituximab the rate of infections will be higher, around 55%, only 1/3 will be bacterial, but viral complications will be common. DisclosuresPagano:Gilead: Speakers Bureau; Merck: Speakers Bureau; Pfizer: Speakers Bureau; Basilea: Speakers Bureau; Janssen: Speakers Bureau.

Akt2 mediates glucocorticoid resistance in lymphoid malignancies through FoxO3a/Bim axis and serves as a direct target for resistance reversal

Glucocorticoids (GCs) are widely used drugs in the treatment of lymphoid malignancies; resistance of GCs in lymphocytes confers poor prognosis and the mechanisms are poorly understood. Here, we found T-acute lymphoblastic leukemia (T-ALL) cells acquire resistance to dexamethasone (DEX)-mediated killing through abnormal activation of Akt, resulting in inhibition of the FoxO3a/Bim pathway. The resistant state was reported to be associated with increased glycolysis, NOTCH1 activating mutations and activated PI3K/ serum GS regulated kinases (SGK) pathway. Use of aforementioned pathway inhibitors blocked FoxO3a-phosphorylation and partially improved DEX-mediated killing of GC-resistant T-ALL cells, further revealing the essential role of the FoxO3a/Bim pathway in the development of GC resistance. Inhibition of Akt is most effective at restoring sensitivity to DEX of GC-resistant lymphocytes in vitro and in vivo, but shows significant hepatotoxicity in vivo. A significantly elevated expression of Akt2 not Akt1 in intrinsically, secondarily GC-resistant lymphocytes and relapsed/refractory ALL patients implicates a more specific target for GC resistance. Mechanistically, Akt2 has a stronger binding capacity with FoxO3a compared to Akt1, and acts as a direct and major negative regulator of FoxO3a activity driving GC resistance. Pharmacologic inhibition of Akt2 more effectively restores sensitivity to GCs than inhibition of Akt1 in vitro, shows higher synergistic effect acting with DEX, and reverses GC resistance in GC-resistant T- or B- lymphoid tumors in vivo with reduced liver toxicity. In summary, these results suggest that Akt2 might serve as a more direct and specific kinase mediating GC resistance through FoxO3a/Bim signaling pathway, and Akt2 inhibition may be explored as a promising target for treating GC-resistant hematopoietic malignancies.

Management of toxicities associated with pegaspargase in treatment of patients with lymphoid malignancy: experience from 443 cases in a single center

目的总结培门冬酶治疗淋巴系统肿瘤的不良反应以及处理经验。方法通过回顾性分析北京同仁医院血液科2011年8月至2015年12月使用培门冬酶患者的临床资料，总结培门冬酶相关的不良反应以及处理经验。结果129例患者使用培门冬酶，累计共使用443例次，不良反应发生情况：2例（1.6%）患者出现过敏反应；19例（14.7%）患者发生胰腺炎（其中包括6例急性症状性胰腺炎、13例单纯胰酶升高的化学性胰腺炎），15例（11.6%）患者出现高甘油三酯血症，85例（65.9%）患者出现高血糖，7例（5.4%）患者出现低血糖；25例（19.4%）患者出现2级以上的转氨酶增高，21例（15.5%）患者发生高胆红素血症，62例（48.1%）患者发生低白蛋白血症；61例（47.3%）患者出现APTT延长，22例（17.1%）患者出现PT延长，15例（11.6%）患者出现TT延长，75例（58.1%）患者出现低纤维蛋白原血症，有11例患者（8.5%）出现血栓事件，有3例（2.3%）患者出现活动性出血。以上不良反应，分别经过抗过敏、抑制胰液分泌、降脂、降糖、保肝、补充血浆、止血等对症治疗后症状均好转。部分严重不良反应影响培门冬酶的按计划应用甚至导致停用。结论培门冬酶的不良反应非常广泛，有些非常严重，需要治疗时密切监测。

Abstract 3173: Lymphocyte-specific chromatin accessibility predetermines glucocorticoid resistance in acute lymphoblastic leukemia

Abstract Glucocorticoids are well known for their immunosuppressive activity, and play a critical role in the treatment of lymphoid malignancies. However, the development of resistance remains a significant barrier to cure and the mechanisms are poorly defined. Moreover, glucocorticoids are rarely efficacious in treating myeloid and other non-lymphoid malignancies, and the mechanisms of lymphocyte-specific efficacy are unclear. To address these issues, we first carried out a global analysis of DNase I hypersensitive sites in 18 lymphoid and 64 non-lymphoid cell types to map lymphocyte-specific open chromatin domains (LSOs). We then integrated these domains with genome-wide glucocorticoid-induced gene transcription and epigenetic modulation in an in vivo patient-derived xenograft (PDX) model of acute lymphoblastic leukemia (ALL). Performing chromatin immunoprecipitation and assays for transposase-accessible chromatin (ATAC), we determined a strong correlation between glucocorticoid receptor (GR) binding and chromatin accessibility, acetylated histone marks and binding of a DNA structural protein (CTCF), and identified 1,536 GR bound LSOs. We next analyzed RNA-seq data in glucocorticoid sensitive and resistant ALL PDXs for expression changes in genes located within 100 kb of the LSOs after glucocorticoid treatment in vivo, and identified four groups comprising 389 genes that were significantly differentially expressed. Of the 198 up-regulated genes, 143 showed increased H3K27Ac enrichments at 177 LSOs. Forty-two LSOs showed the increase only in glucocorticoid sensitive but not resistant ALLs. Applying this to an extended panel of ALL PDXs, basal DNA methylation at the 42 LSOs was significantly higher in resistant ALLs despite no difference within the gene bodies, whereas the basal chromatin accessibility indicated by ATAC abundance was diminished. Pathway analysis indicated that the LSO regulated genes were involved in repressing B- and T- cell receptor signaling pathways and activating the apoptotic pathway. One such LSO was at the pro-apoptotic BIM gene locus, where CTCF binding was found only in lymphocytes but not in other cell types. The GR cooperated with CTCF to mediate interactions between the promoter and the BIM LSO to direct DNA looping, thus triggering BIM transcription. Importantly, this LSO was heavily methylated in resistant ALLs as well as non-lymphoid cells. Azacitidine, a DNA demethylating drug that is routinely used in the clinic, could partially reverse these changes and restore glucocorticoid sensitivity. Taken together, this study demonstrated for the first time that lymphocyte-specific epigenetic modifications pre-determine glucocorticoid resistance in ALL and may account for the lack of glucocorticoid sensitivity in other cell type. Reversal of these epigenetic changes may lead to improvements in the use of glucocorticoids in the clinic. Citation Format: Duohui Jing, Yizhou Huang, Xiaoyun Liu, Keith Sia, Rebecca C. Poulos, Miriam Span, Chao Zhang, Jianqing Mi, Jason WH Wong, Dominik Beck, John E. Pimanda, Richard B. Lock. Lymphocyte-specific chromatin accessibility predetermines glucocorticoid resistance in acute lymphoblastic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3173.

Effect of combining glucocorticoids with Compound A on glucocorticoid receptor responsiveness in lymphoid malignancies.

Glucocorticoids (GCs) are a cornerstone in the treatment of lymphoid malignancies such as multiple myeloma (MM) and acute lymphoblastic leukemia (ALL). Yet, prolonged GC use is hampered by deleterious GC-related side effects and the emergence of GC resistance. To tackle and overcome these GC-related problems, the applicability of selective glucocorticoid receptor agonists and modulators was studied, in search of fewer side-effects and at least equal therapeutic efficacy as classic GCs. Compound A (CpdA) is a prototypical example of such a selective glucocorticoid receptor modulator and does not support GR-mediated transactivation. Here, we examined whether the combination of CpdA with the classic GC dexamethasone (Dex) may improve GC responsiveness of MM and ALL cell lines. We find that the combination of Dex and CpdA does not substantially enhance GC-mediated cell killing. In line, several apoptosis hallmarks, such as caspase 3/7 activity, PARP cleavage and the levels of cleaved-caspase 3 remain unchanged upon combining Dex with CpdA. Moreover, we monitor no additional inhibition of cell proliferation and the homologous downregulation of GR is not counteracted by the combination of Dex and CpdA. In addition, CpdA is unable to modulate Dex-liganded GR transactivation and transrepression, yet, Dex-mediated transrepression is also aberrant in these lymphoid cell lines. Together, transrepression-favoring compounds, alone or combined with GCs, do not seem a valid strategy in the treatment of lymphoid malignancies.