Ibrutinib significantly inhibited Bruton's tyrosine kinase (BTK) phosphorylation,in-vitro proliferation and enhanced overall survival in a preclinical Burkitt lymphoma (BL) model

Novel 5-Substituted Oxindole Derivatives as Bruton's Tyrosine Kinase Inhibitors: Design, Synthesis, Docking, Molecular Dynamics Simulation, and Biological Evaluation

Bruton's tyrosine kinase (BTK) is a non-RTK cytoplasmic kinase predominantly expressed by hemopoietic lineages, particularly B-cells. A new oxindole-based focused library was designed to identify potent compounds targeting the BTK protein as anticancer agents. This study used rational approaches like structure-based pharmacophore modeling, docking, and ADME properties to select compounds. Molecular dynamics simulations carried out at 20 ns supported the stability of compound 9g within the binding pocket. All the compounds were synthesized and subjected to biological screening on two BTK-expressing cancer cell lines, RAMOS and K562; six non-BTK cancer cell lines, A549, HCT116 (parental and p53-/-), U2OS, JURKAT, and CCRF-CEM; and two non-malignant fibroblast lines, BJ and MRC-5. This study resulted in the identification of four new compounds, 9b, 9f, 9g, and 9h, possessing free binding energies of -10.8, -11.1, -11.3, and -10.8 kcal/mol, respectively, and displaying selective cytotoxicity against BTK-high RAMOS cells. Further analysis demonstrated the antiproliferative activity of 9h in RAMOS cells through selective inhibition of pBTK (Tyr223) without affecting Lyn and Syk, upstream proteins in the BCR signaling pathway. In conclusion, we identified a promising oxindole derivative (9h) that shows specificity in modulating BTK signaling pathways.

Synthesis and Biological Evaluation of Oxindole Sulfonamide Derivatives as Bruton's Tyrosine Kinase Inhibitors

Bruton's tyrosine kinase (BTK) is a promising molecular target for several human B-cell-related autoimmune disorders, inflammation, and haematological malignancies. The pathogenic alterations in various cancer tissues depend on mutant BTK for cell proliferation and survival, and BTK is also overexpressed in a range of hematopoietic cells. Due to this, BTK is emerging as a potential drug target to treat various human diseases, and several reversible and irreversible inhibitors have been developed and are being developed. As a result, BTK inhibition, clinically validated as an anticancer treatment, is finding great interest in B-cell malignancies and solid tumours. This study focuses on the design and synthesis of new oxindole sulfonamide derivatives as promising inhibitors of BTK with negligible off-target effects. The most cytotoxic compounds with greater basicity were PID-4 (2.29±0.52 μM), PID-6 (9.37±2.47 μM), and PID-19 (2.64±0.88 μM). These compounds caused a selective inhibition of Burkitt's lymphoma RAMOS cells without significant cytotoxicity in non-BTK cancerous and non-cancerous cell lines. Further, PID-4 showed promising activity in inhibiting BTK and downstream signalling cascades. As a potent inhibitor of Burkitt's lymphoma cells, PID-4 is a promising lead for developing novel chemotherapeutics.

Assessment of Impact of Human Leukocyte Antigen-Type and Cytokine-Type Responses on Outcomes after Targeted Therapy Currently Used to Treat Chronic Lymphocytic Leukemia

Tumor growth and metastasis are reliant on intricate interactions between the host immune system and various counter-regulatory immune escape mechanisms employed by the tumor. Tumors can resist immune surveillance by modifying the expression of human leukocyte antigen (HLA) molecules, which results in the impaired presentation of tumor-associated antigens, subsequently evading detection and destruction by the immune system. The management of chronic lymphocytic leukemia (CLL) is based on symptom severity and includes various types of targeted therapies, including rituximab, obinutuzumab, ibrutinib, acalabrutinib, zanubrutinib, idelalisib, and venetoclax. These therapies rely on the recognition of specific peptides presented by HLAs on the surface of tumor cells by T cells, leading to an immune response. HLA class I molecules are found in most human cell types and interact with T-cell receptors (TCRs) to activate T cells, which play a vital role in inducing adaptive immune responses. However, tumor cells may evade T-cell attack by downregulating HLA expression, limiting the efficacy of HLA-dependent immunotherapy. The prognosis of CLL largely depends on the presence or absence of genetic abnormalities, such as del(17p), TP53 point mutations, and IGHV somatic hypermutation status. These oral targeted therapies alone or in combination with anti-CD20 antibodies have replaced chemoimmunotherapy as the primary treatment for CLL. In this review, we summarize the current clinical evidence on the impact of HLA- and cytokine-type responses on outcomes after targeted therapies currently used to treat CLL.

Human Effectors of Acute and Chronic GVHD Overexpress CD83 and Predict Mortality

PURPOSE

Acute and chronic GVHD remain major causes of transplant-related morbidity and mortality (TRM) after allogeneic hematopoietic cell transplantation (alloHCT). We have shown CD83 chimeric antigen receptor (CAR) T cells prevent GVHD and kill myeloid leukemia cell lines. In this pilot study, we investigate CD83 expression on GVHD effector cells, correlate these discoveries with clinical outcomes, and evaluate critical therapeutic implications for transplant recipients.

EXPERIMENTAL DESIGN

CD83 expression was evaluated among circulating CD4+ T cells, B-cell subsets, T follicular helper (Tfh) cells, and monocytes from patients with/without acute or chronic GVHD (n = 48 for each group), respectively. CD83 expression was correlated with survival, TRM, and relapse after alloHCT. Differential effects of GVHD therapies on CD83 expression was determined.

RESULTS

CD83 overexpression on CD4+ T cells correlates with reduced survival and increased TRM. Increased CD83+ B cells and Tfh cells, but not monocytes, are associated with poor posttransplant survival. CD83 CAR T eliminate autoreactive CD83+ B cells isolated from patients with chronic GVHD, without B-cell aplasia as observed with CD19 CAR T. We demonstrate robust CD83 antigen density on human acute myeloid leukemia (AML), and confirm potent antileukemic activity of CD83 CAR T in vivo, without observed myeloablation.

CONCLUSIONS

CD83 is a promising diagnostic marker of GVHD and warrants further investigation as a therapeutic target of both GVHD and AML relapse after alloHCT.

Identification and Biological Evaluation of a Water-Soluble Fullerene Nanomaterial as BTK Kinase Inhibitor

Introduction

Thanks to recent advances in synthetic methodology, water-soluble fullerene nanomaterials that interfere with biomolecules, especially DNA/RNA and selected proteins, have been found with tremendous potential for applications in nanomedicine. Herein, we describe the synthesis and evaluation of a water-soluble glycine-derived [60]fullerene hexakisadduct (HDGF) with T _h symmetry, which is a first-in-class BTK protein inhibitor.

Methods

We synthesized and characterized glycine derived [60]fullerene using NMR, ESI-MS, and ATR-FT-IR. DLS and zeta potential were measured and high-resolution transmission electron microscopy (HRTEM) observations were performed. The chemical composition of the water-soluble fullerene nanomaterial was examined by X-ray photoelectron spectrometry. To observe aggregate formation, the cryo-TEM analysis was carried out. The docking studies and molecular dynamic simulations were performed to determine interactions between HDGF and BTK. The in vitro cytotoxicity was evaluated on RAJI and K562 blood cancer cell lines. Subsequently, we examined the induction of cell death by autophagy and apoptosis by determining the expression levels of crucial genes and caspases. We investigated the direct association of HDGF on inhibition of the BTK signalling pathway by examining changes in the calcium levels in RAJI cells after treatment. The inhibitory potential of HDGF against non-receptor tyrosine kinases was evaluated. Finally, we assessed the effects of HDGF and ibrutinib on the expression of the BTK protein and downstream signal transduction in RAJI cells following anti-IgM stimulation.

Results

Computational studies revealed that the inhibitory activity of the obtained [60]fullerene derivative is multifaceted: it hampers the BTK active site, interacting directly with the catalytic residues, rendering it inaccessible to phosphorylation, and binds to residues that form the ATP binding pocket. The anticancer activity of produced carbon nanomaterial revealed that it inhibited the BTK protein and its downstream pathways, including PLC and Akt proteins, at the cellular level. The mechanistic studies suggested the formation of autophagosomes (increased gene expression of LC3 and p62) and two caspases (caspase-3 and -9) were responsible for the activation and progression of apoptosis.

Conclusion

These data illustrate the potential of fullerene-based BTK protein inhibitors as nanotherapeutics for blood cancer and provide helpful information to support the future development of fullerene nanomaterials as a novel class of enzyme inhibitors.

Ibrutinib plus RICE or RVICI for relapsed/refractory mature B-cell non-Hodgkin lymphoma in children and young adults: SPARKLE trial

Part 1 results of the open-label, randomized, global phase 3 SPARKLE trial supported continued assessment of ibrutinib with either modified rituximab, ifosfamide, carboplatin, and etoposide (RICE) or rituximab, vincristine, ifosfamide, carboplatin, idarubicin, and dexamethasone (RVICI) in pediatric patients with relapsed/refractory (R/R) mature B-cell non-Hodgkin lymphoma (B-NHL). We report final results of Part 2 evaluating the efficacy of ibrutinib plus RICE or RVICI vs RICE/RVICI alone. Patients aged 1 to 30 years (initial diagnosis <18 years) were randomized 2:1 to receive ibrutinib with or without RICE/RVICI. Primary endpoint was event-free survival (EFS) based on independent committee-confirmed events. Fifty-one patients were enrolled. Median age was 15 years; Burkitt lymphoma, Burkitt leukemia, and Burkitt-like lymphoma (total: 45%) and diffuse large B-cell lymphoma/primary mediastinal B-cell lymphoma (51%) were the most common subtypes. At the preplanned interim analysis, median EFS was 6.1 vs 7.0 months with ibrutinib plus RICE/RVICI vs RICE/RVICI, respectively (hazard ratio, 0.9; 90% confidence interval, 0.5-1.6; P = .387); further enrollment was ceased. With ibrutinib plus RICE/RVICI vs RICE/RVICI, median overall survival was 14.1 vs 11.1 months, overall response rate was 69% vs 81%, and 46% vs 44% proceeded to stem cell transplantation. In both treatment arms, 100% of patients experienced grade ≥3 treatment-emergent adverse events. No EFS benefit was seen with ibrutinib. Salvage was generally poor in patients who received prior rituximab, regardless of treatment arm. No new safety signals were observed. Ibrutinib exposure in pediatric patients fell within the target range of exposure in adults. Trial is registered on www.clinicaltrials.gov (NCT02703272).

The New Treatment Methods for Non-Hodgkin Lymphoma in Pediatric Patients

One of the most common cancer malignancies is non-Hodgkin lymphoma, whose incidence is nearly 3% of all 36 cancers combined. It is the fourth highest cancer occurrence in children and accounts for 7% of cancers in patients under 20 years of age. Today, the survivability of individuals diagnosed with non-Hodgkin lymphoma varies by about 70%. Chemotherapy, radiation, stem cell transplantation, and immunotherapy have been the main methods of treatment, which have improved outcomes for many oncological patients. However, there is still the need for creation of novel medications for those who are treatment resistant. Additionally, more effective drugs are necessary. This review gathers the latest findings on non-Hodgkin lymphoma treatment options for pediatric patients. Attention will be focused on the most prominent therapies such as monoclonal antibodies, antibody–drug conjugates, chimeric antigen receptor T cell therapy and others.

Targeted inhibitors and antibody immunotherapies: Novel therapies for paediatric leukaemia and lymphoma

Despite improved outcomes achieved in the last decades for children with newly diagnosed leukaemia and lymphoma, treatment of patients with refractory/relapsed disease remains a challenge. The cure rate is still unsatisfactory and often achieved at the cost of significant morbidity. Exploring treatment with novel agents should offer less toxic therapeutic options, without compromising efficacy. Bispecific and antibody-drug conjugates targeting CD19 and CD22 (blinatumomab and inotuzumab ozogamicin) play an important role in the treatment of relapsed and refractory B-cell precursor acute lymphoblastic leukaemia (BCP-ALL); antibodies targeting CD123 and CD38 are also under investigation for acute myeloid leukaemia (AML) and T-ALL, respectively. Targeted therapy with small molecules is of primary importance for specific genetic subtypes, such as BCR-ABL-positive ALL, FLT3-ITD AML and anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma. KMT2A-directed targeted therapy with menin inhibitors holds promise to be of relevance in KMT2A-rearranged leukaemias, known to have dismal prognosis. Target inhibition in cellular pathways such as BCL-2, RAS, MEK, Bruton's tyrosine kinase, JAK-STAT or CDK4/CDK6 inhibition may be suitable for different diseases with common mutated pathways. Nevertheless, development and approval of new agents for paediatric cancers lags behind adult therapeutic options. New regulations were implemented to accelerate drug development for children. Considering the number of oncology medicinal products available for adults and the rarity of paediatric cancers, prioritisation based on scientific evidence and medical need, as well as international collaboration, is critical. Herein, we review the current status of drug development for children with leukaemia and lymphoma, excluding cellular therapy despite its well-known significance.

Down-regulation of cylindromatosis protein phosphorylation by BTK inhibitor promotes apoptosis of non-GCB-diffuse large B-cell lymphoma

BACKGROUND

Non-germinal center B-cell-like diffuse large B-cell lymphoma (non-GCB-DLBCL) has worse clinical outcome than GCB-DLBCL, and some relapsed/refractory non-GCB-DLBCL (R/R non-GCB-DLBCL) are even resistant to CD20 monoclonal antibody (rituximab). Bruton's tyrosine kinase inhibitors (BTKis) are new drugs for B-cell lymphoma. BTKis can promote apoptosis of DLBCL by inactivating nuclear transcription factor κB (NFκB) signaling pathway. Cylindromatosis (CYLD) is a tumor suppressor and ubiquitinase. CYLD can inactivate NFκB signaling pathway through ubiquitination and regulate the apoptosis of hematological tumors. The ubiquitination of CYLD can be regulated by phosphorylation, suggesting that the regulation of CYLD phosphorylation can be a potential mechanism to promote the apoptosis of hematological tumors. Therefore, we hypothesized that BTKis could promote the apoptosis of non-GCB-DLBCL by regulating the phosphorylation of CYLD, especially in rituximab resistant cases, and we proved this hypothesis through both in vivo and in vitro experiments.

METHODS

The baseline expression levels of CYLD phosphorylation in non-GCB-DLBCL patients and cell lines were detected by Western Blotting. The non-GCB-DLBCL cell lines were treated with BTKis, and apoptosis induced by BTKis treatment was detected by Western blotting, cell viability assay and Annexin V assay. To verify whether the effect of BTKis on apoptosis in non-GCN-DLBCL cells is CYLD dependent, the expression of CYLD was knocked down by lentiviral shRNAs. To verify the effect of BTKis on the phosphorylation of CYLD and the apoptosis in vivo and in rituximab resistant non-GCB-DLBCL, the xeograft model and rituximab resistant non-GCB-DLBCL cells were generated by tumor cell inoculation and escalation of drug concentrations, respectively.

RESULTS

BTKis induced apoptosis by down-regulating CYLD phosphorylationin in non GCB-DLBCL, xenograft mouse model, and rituximab-resistant cells, and this effect could be enhanced by rituximab. Knocking-down CYLD reversed apoptosis which was induced by BTKis. BTKis induced CYLD-dependent apoptosis in non-GCB-DLBCL including in rituximab-resistant cells.

CONCLUSIONS

The present results indicated that CYLD phosphorylation is a potential clinical therapeutic target for non-GCB-DLBCL, especially for rituximab-resistant relapsed/refractory cases.

Covalent Cysteine Targeting of Bruton's Tyrosine Kinase (BTK) Family by Withaferin-A Reduces Survival of Glucocorticoid-Resistant Multiple Myeloma MM1 Cells

Multiple myeloma (MM) is a hematological malignancy characterized by plasma cells' uncontrolled growth. The major barrier in treating MM is the occurrence of primary and acquired therapy resistance to anticancer drugs. Often, this therapy resistance is associated with constitutive hyperactivation of tyrosine kinase signaling. Novel covalent kinase inhibitors, such as the clinically approved BTK inhibitor ibrutinib (IBR) and the preclinical phytochemical withaferin A (WA), have, therefore, gained pharmaceutical interest. Remarkably, WA is more effective than IBR in killing BTK-overexpressing glucocorticoid (GC)-resistant MM1R cells. To further characterize the kinase inhibitor profiles of WA and IBR in GC-resistant MM cells, we applied phosphopeptidome- and transcriptome-specific tyrosine kinome profiling. In contrast to IBR, WA was found to reverse BTK overexpression in GC-resistant MM1R cells. Furthermore, WA-induced cell death involves covalent cysteine targeting of Hinge-6 domain type tyrosine kinases of the kinase cysteinome classification, including inhibition of the hyperactivated BTK. Covalent interaction between WA and BTK could further be confirmed by biotin-based affinity purification and confocal microscopy. Similarly, molecular modeling suggests WA preferably targets conserved cysteines in the Hinge-6 region of the kinase cysteinome classification, favoring inhibition of multiple B-cell receptors (BCR) family kinases. Altogether, we show that WA's promiscuous inhibition of multiple BTK family tyrosine kinases represents a highly effective strategy to overcome GC-therapy resistance in MM.

Ibrutinib Resistance Mechanisms and Treatment Strategies for B-Cell lymphomas

Chronic activation of B-cell receptor (BCR) signaling via Bruton tyrosine kinase (BTK) is largely considered to be one of the primary mechanisms driving disease progression in B-Cell lymphomas. Although the BTK-targeting agent ibrutinib has shown promising clinical responses, the presence of primary or acquired resistance is common and often leads to dismal clinical outcomes. Resistance to ibrutinib therapy can be mediated through genetic mutations, up-regulation of alternative survival pathways, or other unknown factors that are not targeted by ibrutinib therapy. Understanding the key determinants, including tumor heterogeneity and rewiring of the molecular networks during disease progression and therapy, will assist exploration of alternative therapeutic strategies. Towards the goal of overcoming ibrutinib resistance, multiple alternative therapeutic agents, including second- and third-generation BTK inhibitors and immunomodulatory drugs, have been discovered and tested in both pre-clinical and clinical settings. Although these agents have shown high response rates alone or in combination with ibrutinib in ibrutinib-treated relapsed/refractory(R/R) lymphoma patients, overall clinical outcomes have not been satisfactory due to drug-associated toxicities and incomplete remission. In this review, we discuss the mechanisms of ibrutinib resistance development in B-cell lymphoma including complexities associated with genomic alterations, non-genetic acquired resistance, cancer stem cells, and the tumor microenvironment. Furthermore, we focus our discussion on more comprehensive views of recent developments in therapeutic strategies to overcome ibrutinib resistance, including novel BTK inhibitors, clinical therapeutic agents, proteolysis-targeting chimeras and immunotherapy regimens.

Childhood, adolescent and young adult non-Hodgkin lymphoma: current perspectives

The 6th International Symposium on Childhood, Adolescent and Young Adult (CAYA) Non-Hodgkin Lymphoma (NHL) was held in Rotterdam, Netherlands, 26-29 September, 2018. This summary manuscript is a perspective on the presentations from the plenary scientific sessions, including wellness and survivorship, B-cell NHL, AYA lymphoma, translational NHL biology, lymphoma immunology, bone marrow transplantation and cell therapy, T/Natural Killer cell lymphoma, anaplastic large cell lymphoma, lymphoblastic lymphoma, novel lymphoma therapeutics and Hodgkin lymphoma. The symposium was attended by over 260 registrants from 42 different countries and included young, middle and senior investigators. Finally, the Angelo Rosolen, MD, Memorial Lecture was delivered by Alfred Reiter, MD.