Addition of BTK inhibitor orelabrutinib to rituximab improved anti-tumor effects in B cell lymphoma

PI3K inhibitor idelalisib enhances the anti-tumor effects of CDK4/6 inhibitor palbociclib via PLK1 in B-cell lymphoma

Relapsed or refractory diffuse large B cell lymphoma (DLBCL) and mantle cell lymphoma (MCL) patients still faced with poor survival, representing an unmet clinical need. In-depth research into the disease's pathogenesis and the development of targeted treatment strategies are urgently needed. Here, we conducted a comprehensive bioinformatic analysis of gene mutation and expression using data from our center and public databases. Cell cycle-related genes especially for CDKN2A/B-CDK4/6/CCND1 machinery altered frequently in DLBCL and MCL. Clinically, high CDK4 and CDK6 expression were correlated with poor prognosis of DLBCL and MCL patients. Furthermore, we also validated the pharmacological efficacy of CDK4/6 inhibitor palbociclib and its synergy effect with PI3K inhibitor idelalisib utilizing in vitro cell lines and in vivo cell-derived xenograft (CDX) and patient-derived xenograft (PDX) mouse models. Our results provided sufficient pre-clinical evidence to support the potential combination of palbociclib and idelalisib for DLBCL and MCL patients.

BTK inhibitors: past, present, and future

Bruton's tyrosine kinase (BTK) inhibitors have revolutionized the treatment landscape for B cell lymphomas such as chronic lymphocytic leukemia (CLL). The first-in-class BTK inhibitor ibrutinib has recently been succeeded by covalent BTK inhibitors that are safer but still face challenges of resistance mutations. The noncovalent BTK inhibitor pirtobrutinib was recently approved for relapsed and refractory CLL, and whether noncovalent BTK inhibitors will supplant covalent BTK inhibitors as upfront treatment options either alone or in combination will be determined. Meanwhile, newer BTK inhibitors and BTK degraders are vying for their place in the potential future landscape of B cell cancers as well as autoimmune diseases. This review will cover the latest progress in BTK inhibitor development and where the field is moving in light of these recent discoveries.

Zanubrutinib is effective in non-germinal-center B-cell-like diffuse large B-cell lymphoma with mutated CD79B, high TCL1A expression, or over- expressed MYC/BCL-2

To evaluate the effects of gene mutations on Bruton tyrosine kinase inhibitor, zanubrutinib's effectiveness in patients with diffuse large B-cell lymphoma (DLBCL), we examined pooled data from four single-arm studies (BGB-3111-AU-003 [NCT02343120], BGB-3111-207 [NCT03145064], BGB-3111_GA101_Study_001 [NCT02569476], BGB-3111-213 [NCT03520920]; n = 121). Objective response rate (ORR) was higher, though not statistically significant, in patients with activated B-cell-like (ABC)- and unclassified DLBCL (42.9% [21/49]) versus those with germinal-center B-cell-like DLBCL (14.3% [1/7]; p = 0.15). Patients with CD79B mutations had better ORR (60%) versus patients with wild-type alleles (25.9%, p < 0.01). Higher TCL1A expression correlated with better zanubrutinib response (p = 0.03), longer progression-free survival (p = 0.01), and longer overall survival (p = 0.12). TCL1A expression was higher in ABC-DLBCL (p < 0.001) and MYD88/CD79B-mutated subtypes (p < 0.0001). Eighteen patients with high MYC/BCL-2 expression responded better to zanubrutinib (ORR = 61 vs. 29%, p = 0.02). Our results support assessing CD79B mutations, co-expressor DLBCL, and TCL1A expression status to identify patients with DLBCL who will benefit from zanubrutinib.

Chidamide and orelabrutinib synergistically induce cell cycle arrest and apoptosis in diffuse large B-cell lymphoma by regulating the PI3K/AKT/mTOR pathway

OBJECTIVE

The initial therapeutic approach for diffuse large B-cell lymphoma (DLBCL) entails a rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) regimen. However, 40% of patients exhibit suboptimal responses, with some experiencing relapse and refractory conditions. This study aimed to explore novel therapeutic strategies and elucidate their underlying mechanisms in DLBCL.

METHODS

Bioinformatics techniques were employed to scrutinize correlations between the HDAC1, HDAC2, HDAC3, HDAC10, BTK, MYC, TP53, and BCL2 genes in DLBCL. In vitro experiments were conducted using DB and SU-DHL-4 cells treated with chidamide, orelabrutinib, and a combination of both. Cell viability was assessed by cell counting kit-8. Cell apoptosis and the cell cycle were determined using flow cytometry. Reactive oxygen species (ROS) production and mitochondrial function were assessed through ROS and JC-1 staining. RNA sequencing and western blot analyses were conducted to elucidate the molecular mechanisms underlying the combined action of chidamide and orelabrutinib in DLBCL cells.

RESULTS

This investigation revealed markedly enhanced antiproliferative effects when chidamide was combined with orelabrutinib. Compusyn software analysis indicated a synergistic effect of chidamide and orelabrutinib in inhibiting DLBCL cell proliferation, with a combination index (CI) < 1. This synergy further manifested as augmented cell cycle arrest, apoptosis induction, the downregulation of cell cycle-associated and antiapoptotic proteins, and the upregulation of proapoptotic proteins. Furthermore, the western blot and RNA-Seq findings suggested that combining chidamide and orelabrutinib modulated the PI3K/AKT/mTOR signaling pathway, thereby promoting DLBCL cell cycle arrest and apoptosis.

CONCLUSION

The findings of this study provide a compelling justification for the clinical utilization of chidamide and orelabrutinib to treat relapsed/refractory DLBCL.

A single-centre, real-world study of BTK inhibitors for the initial treatment of MYD88mut /CD79Bmut diffuse large B-cell lymphoma

BACKGROUND

MCD (MYD88L265P /CD79Bmut ) diffuse large B-cell lymphoma has a poor prognosis. There is no published clinical research conclusion regarding zanubrutinib or orelabrutinib for the initial treatment of MCD DLBCL.

AIMS

This study aimed to analyse the efficacy and safety of Bruton's tyrosine kinase inhibitor (BTKi) (zanubrutinib or orelabrutinib) therapy for newly diagnosed DLBCL patients with MYD88mut and/or CD79Bmut .

MATERIALS AND METHODS

Twenty-three newly diagnosed DLBCL patients with MYD88mut and/or CD79Bmut from June 2020 to June 2022 received BTKi combined with rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) or rituximab + lenalidomide (R2 ). A control group of 17 patients with MYD88mut and/or CD79Bmut DLBCL who received the standard R-CHOP therapy was also assessed. We retrospectively analysed clinical characteristics, safety, overall response rate (ORR), complete response (CR) rate and progression-free survival (PFS) of the two groups.

RESULTS

The main clinical features were a high International Prognostic Index (IPI) score (≥3, 22/40, 55%) and a high rate of extranodal involvement (27/40,67.5%). Among the 23 DLBCL patients, 18 received BTKi + R-CHOP, and five elderly DLBCL patients were treated with BTKi + R2 . Compared with those in the control group (ORR 70.6%, CRR 52.9%, 1-year PFS rate 41.2%), improved ORR, CRR and PFS results were observed in the BTKi + R-CHOP group (100%, 94.4% and 88.9%, p = 0.019, 0.007, and 0.0001). In subgroup analyses based on genetic subtypes, cell origin, dual expression or IPI score, patients in the BTKi + R-CHOP group had better PFS than patients in the control group. In the BTKi + R-CHOP group, no significant difference was found in ORR, CRR and PFS based on subtype analysis, while BTKi-type subgroups exhibited statistically significant differences in 1-year PFS (p = 0.028). There were no significant differences in grade 3-4 haematological toxicity (p = 1) and grade 3-4 non-haematological toxicity (p = 0.49) between the BTKi + R-CHOP and R-CHOP treatment groups. In the BTKi + R2 group, the ORR was 100%, the CRR was 80%, and the 1-year PFS rate was 80%. The incidences of grade 3-4 haematologic toxicity and non-haematological toxicity were both 40%. No bleeding or cardiovascular events of grade 3 or higher occurred in any patients.

DISCUSSION

The efficacy of BTKi combined with R-CHOP was similar to previous reports, which was significantly better than R-CHOP alone. It is necessary to fully consider that 14 patients in the BTKi + R-CHOP group received a BTKi as maintenance therapy when evaluating efficacy. Meanwhile, the addition of a BTKi may improve the prognosis of non-GCB, DEL or high-IPI-score DLBCL patients with MYD88mut and/or CD79Bmut . In our study, five elderly DLBCL patients with MYD88mut and/or CD79Bmut were achieved better ORR, CRR, PFS than the historical data of R-miniCHOP treatment and Ibrutinib + R2 treatment. However, the efficacy and benefit of BTKis for this type of DLBCL need to be further analysed using a larger sample size.

CONCLUSION

This study suggests that newly diagnosed DLBCL patients with MYD88mut and/or CD79Bmut may benefit from BTKis according to real-world clinical data.

Efficacy and safety of Orelabrutinib-based regimens in diffuse large B-cell lymphoma: a single-center retrospective analysis

Currently, combining chemotherapy with Bruton tyrosine kinase inhibitors (BTKi) has demonstrated significant effectiveness in treating patients with diffuse large B-cell lymphoma. Orelabrutinib is a second-generation BTK inhibitor, and presently, there have been few reports of Orelabrutinib being used to treat DLBCL. We conducted a retrospective investigation to explore the safety and efficacy of Orelabrutinib in combination with chemotherapy or immunotherapy. The study comprised 19 patients with a median age of 61 years. The overall response rate (ORR) was 89.5% with a complete response (CR) rate of 73.7% and a partial response rate (PR) of 15.8%. The estimated 2-year overall survival (OS) and progression-free survival (PFS) rates were 78.6% (95%CI, 59.8%-100%) and 72.2% (95% CI, 52.4%-99.6%), respectively, with a median follow-up time of 11 months (range 2-24). The most prevalent grade 3 or 4 adverse events (AEs), neutropenia (52.6%), anemia (36.8%), thrombocytopenia (26.3%), febrile neutropenia (26.3%), and lung infection (10.5%), were the most common. Our results reveal that Orelabrutinib is an effective therapy for DLBCL patients. Furthermore, our first investigation of the Orelabrutinib application lays a foundation for larger retrospective studies.

Determination of Orelabrutinib in Human Plasma Using LC-MS/MS

BACKGROUND

Orelabrutinib is a second-generation Bruton tyrosine kinase inhibitor that improves the management of B-cell malignancies. The objective of this study was to develop and validate an LC-MS/MS method for quantifying orelabrutinib in human plasma.

METHODS

Plasma samples were processed using acetonitrile to precipitate proteins. Ibrutinib-d5 was used as the internal standard. The mobile phase comprised 10 mM ammonium formate containing 0.1% formic acid and acetonitrile (62:38, vol/vol). The multiple reaction monitoring transitions at m / z = 428.1 → 411.2 and 446.2 → 309.2 were selected for orelabrutinib and ibrutinib-d5, respectively, after ionization in the positive mode.

RESULTS

Total runtime was 4.5 minutes. The validated curve ranges were 1.00-500 ng/mL. This method exhibited acceptable selectivity, dilution integrity, matrix effects, and recovery. Interrun and intrarun accuracy ranged from -3.4% to 6.5%, and interrun and intrarun precision was between 2.8% and 12.8%. Stability was studied under different conditions. The incurred sample reanalysis demonstrated good reproducibility.

CONCLUSIONS

The LC-MS/MS method provided a simple, specific, and rapid quantification of orelabrutinib in the plasma of patients with mantle cell lymphoma or chronic lymphocytic leukemia/small lymphocytic lymphoma. The results indicated that orelabrutinib exhibits large variability between individuals and should be prudently used in combination with CYP3A4 inhibitors.

High-dose methotrexate, thiotepa, orelabrutinib combined with or without rituximab in primary or secondary central nervous system diffuse large B-cell lymphoma: a single-center retrospective analysis

Purpose: Central nervous system lymphoma (CNSL) is an aggressive non-Hodgkin's lymphoma (NHL) confined to the central nervous system (CNS). Orelabrutinib is an oral second-generation Bruton tyrosine kinase (BTK) inhibitor and a novel therapeutic strategy for CNSL. The purpose of this study was to evaluate the effectiveness and safety of high-dose methotrexate (HD-MTX), thiotepa, and orelabrutinib combined with or without rituximab (MTO±R)regimen in the treatment of patients with CNSL. Methods: A total of 14 patients with CNS diffuse large B-cell lymphoma (DLBCL) were included in this retrospective study. All patients received the regimen MTO±R. Overall response rate (ORR), complete response rate(CR), partial response (PR), stable disease (SD), progressive disease (PD), progression-free survival (PFS), overall survival (OS), and the safety of MTO±R were assessed by the investigator. Results: Fourteen patients were evaluable for safety, and 13 patients were evaluable for efficacy. The overall CR rate was 69.2%, and the ORR was 92.3% for total patients. For PCNSL, the CR rate and ORR were 55.6% and 88.9%, respectively. For relapsed/refractory CNSL, the CR rate and ORR were 66.7% and 91.7%, respectively. The median follow-up time was 12.8 months. The median PFS was 11.3 months, and the median OS was not achieved. The 12-month PFS and OS rates were 60% and 70%, respectively. Adverse events occurred in 17 cycles, and Grade 3 AEs occurred in 5 patients (35.7%). Conclusion: MTO±R was an efficacious and well-tolerated regimen in patients with CNSL. A novel BTK inhibitor in combination with chemotherapy offers a new potential therapeutic strategy for patients with CNSL.

Development and Applications of Chimera Platforms for Tyrosine Phosphorylation

Chimeric small molecules that induce post-translational modification (PTM) on a target protein by bringing it into proximity to a PTM-inducing enzyme are furnishing novel modalities to perturb protein function. Despite recent advances, such molecules are unavailable for a critical PTM, tyrosine phosphorylation. Furthermore, the contemporary design paradigm of chimeric molecules, formed by joining a noninhibitory binder of the PTM-inducing enzyme with the binder of the target protein, prohibits the recruitment of most PTM-inducing enzymes as their noninhibitory binders are unavailable. Here, we report two platforms to generate phosphorylation-inducing chimeric small molecules (PHICS) for tyrosine phosphorylation. We generate PHICS from both noninhibitory binders (scantily available, platform 1) and kinase inhibitors (abundantly available, platform 2) using cysteine-based group transfer chemistry. PHICS triggered phosphorylation on tyrosine residues in diverse sequence contexts and target proteins (e.g., membrane-associated, cytosolic) and displayed multiple bioactivities, including the initiation of a growth receptor signaling cascade and the death of drug-resistant cancer cells. These studies provide an approach to induce biologically relevant PTM and lay the foundation for pharmacologic PTM editing (i.e., induction or removal) of target proteins using abundantly available inhibitors of PTM-inducing or -erasing enzymes.

The preclinical discovery and development of orelabrutinib as a novel treatment option for B-cell lymphoid malignancies

INTRODUCTION

Bruton's tyrosine kinase (BTK) inhibitors have recently been approved for clinical use against several B-cell indolent lymphoid malignancies, both as single agents or in combination. One second-generation BTK inhibitor that is being developed for the treatment of B-cell hematological malignancies, as well as for autoimmune disorders, is orelabrutinib.

AREAS COVERED

This paper reviews recent developments in the use of orelabrutinib against B-cell indolent lymphoid malignancies such as chronic lymphocytic leukemia, mantle cell lymphoma, diffuse large B-cell lymphoma, Waldenstrom macroglobulinemia and central nervous system lymphoma. Google Scholar and PubMed were initially searched for articles, and the corpus of articles was broadened by reviewing the references of the identified papers. All were in English. The corpus comprised papers from 2016 to April 2023. In addition, a manual search was performed of conference proceedings from the last five years of The American Society of Hematology, American Society of Clinical Oncology and the European Hematology Association.

EXPERT OPINION

Orelabrutinib is an active drug in indolent and aggressive B-cell lymphoid malignancies. It demonstrates high selectivity, good efficacy and an excellent safety profile. Nevertheless, further clinical trials are required to optimize its use. In addition, several other highly selective BTK inhibitors are being examined in early-phase studies.

Bruton tyrosine kinase inhibitors in the management of Waldenström macroglobulinemia

Bruton tyrosine kinase (BTK) inhibitors have taken a central role in the management of patients with Waldenström macroglobulinemia and are the only agents approved by the Food and Drug Administration (FDA) to treat these patients. Although associated with high rates of durable responses, unmet needs with BTK inhibitor therapy include indefinite duration therapy, high cost, scarcity of complete responses, and lower rates and shorter duration of response in patients with CXCR4 mutations. Herein, we review the data supporting the use of covalent BTK inhibitors, selected management issues, clinical trials with covalent BTK inhibitor combination regimens, and up-and-coming non-covalent BTK inhibitors.

Inhibition of USP1 reverses the chemotherapy resistance through destabilization of MAX in the relapsed/refractory B-cell lymphoma

The patients with relapsed and refractory diffuse large B-cell lymphoma (DLBCL) have poor prognosis, and a novel and effective therapeutic strategy for these patients is urgently needed. Although ubiquitin-specific protease 1 (USP1) plays a key role in cancer, the carcinogenic effect of USP1 in B-cell lymphoma remains elusive. Here we found that USP1 is highly expressed in DLBCL patients, and high expression of USP1 predicts poor prognosis. Knocking down USP1 or a specific inhibitor of USP1, pimozide, induced cell growth inhibition, cell cycle arrest and autophagy in DLBCL cells. Targeting USP1 by shRNA or pimozide significantly reduced tumor burden of a mouse model established with engraftment of rituximab/chemotherapy resistant DLBCL cells. Pimozide significantly retarded the growth of lymphoma in a DLBCL patient-derived xenograft (PDX) model. USP1 directly interacted with MAX, a MYC binding protein, and maintained the stability of MAX through deubiquitination, which promoted the transcription of MYC target genes. Moreover, pimozide showed a synergetic effect with etoposide, a chemotherapy drug, in cell and mouse models of rituximab/chemotherapy resistant DLBCL. Our study highlights the critical role of USP1 in the rituximab/chemotherapy resistance of DLBCL through deubiquitylating MAX, and provides a novel therapeutic strategy for rituximab/chemotherapy resistant DLBCL.

Orelabrutinib and venetoclax synergistically induce cell death in double-hit lymphoma by interfering with the crosstalk between the PI3K/AKT and p38/MAPK signaling

PURPOSE

Double-hit lymphoma (DHL) is a rare and aggressive mature B-cell malignancy with concurrent MYC and BCL2 rearrangements. When DHL becomes relapsed or refractory, it becomes resistant to the majority of therapeutic approaches and has subpar clinical results. Therefore, innovative therapeutics for this particular patient population are urgently needed.

METHODS

Orelabrutinib, a new oral BTK inhibitor, combined with the Bcl-2 inhibitor venetoclax, was used to confirm the antitumor effect of DHL. Cell counting kit-8 and Annexin V-FITC/PI assays were used to examine the interaction of this combined regimen on DHL cell lines and primary lymphoma cells. RNA sequencing, EdU incorporation assay, mitochondrial membrane potential assay, and western blotting were employed to explore the molecule mechanism for the cytotoxicity of orelabrutinib with or without venetoclax against DHL cell lines.

RESULTS

In this study, orelabrutinib combined with venetoclax synergistically induced DHL cell death, as evidenced by the inhibition of cell proliferation, the induct of cell cycle arrest, and the promotion of cell apoptosis via the mitochondrial pathway. Orelabrutinib treatment alters genome-wide gene expression in DHL cells. The combined regimen decreases the expression of BTK and Mcl-1, potentially interfering with the activity and crosstalk of PI3K/AKT signaling and p38/MAPK signaling. In addition, the combination of orelabrutinib and venetoclax shows cytotoxic activity in primary B-lymphoma cells.

CONCLUSION

In summary, these findings reveal a novel therapy targeting BCR signaling and the Bcl-2 family for DHL patients with a poor prognosis.

Current Perspectives: Evidence to Date on BTK Inhibitors in the Management of Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system leading to demyelination and neurodegeneration. Basic and translational studies have shown that B cells and myeloid cells are critical players for the development and course of the disease. Bruton’s tyrosine kinase (BTK) is essential for B cell receptor-mediated B cell activation and for normal B cell development and maturation. In addition to its role in B cells, BTK is also involved in several functions of myeloid cells. Although significant number of disease-modifying treatments (DMTs) have been approved for clinical use in MS patients, novel targeted therapies should be studied in refractory patients and patients with progressive forms of the disease. On the basis of its role in B cells and myeloid cells, BTK inhibitors can provide attractive therapeutic benefits for MS. In this article, we review the main effects of BTK inhibitors on different cell types involved in the pathogenesis of MS and summarise recent advances in the development of BTK inhibitors as novel therapeutic approaches in different MS clinical trials. Available data regarding the efficacy and safety of these drugs are described.

Evaluation of orelabrutinib monotherapy in patients with relapsed or refractory Waldenström's macroglobulinemia in a single-arm, multicenter, open-label, phase 2 study

BACKGROUND

Orelabrutinib is a novel, small molecule, selective irreversible Bruton tyrosine kinase inhibitor. The purpose of this study was to evaluate the efficacy and safety of orelabrutinib in patients with relapsed or refractory Waldenström's macroglobulinemia (R/R WM).

METHODS

This is a prospective, multicenter study of orelabrutinib in patients with WM who had at least one prior line of treatment. Orelabrutinib was administered orally at a daily dose of 150 mg until disease progression or unacceptable toxicity. The primary endpoint was major response rate (MRR) assessed by the Independent Review Committee (IRC) according to IWWM-6. This study is registered with ClinicalTrials.gov, NCT04440059. This trial was also registered on Center for Drug Evaluation (www.chinadrugtrials.org.cn) in March 2019, with a number of CTR2019036.

FINDINGS

Between August 2019 and December 2020, 66 R/R WM patients were assessed for eligibility. Forty-seven eligible patients were evaluated for efficacy at a median follow-up of 16.4 months (interquartile range: 12.5, 19.5). As assessed by IRC, the MRR was 80.9%, and the overall response rate was 89.4%. The median time to at least a minor response was 1.9 months. The PFS rates was 89.4% at 12 months. For patients with MYD88^L265P /CXCR4^NEG, MYD88^L265P /CXCR4 ^S338X, and MYD88^NEG /CXCR4^NEG mutations, the MRRs were 84.6%, 100%, and 25.0%. Most adverse events were Grades 1 or 2 (91.0%). The common grade 3 or higher adverse events occurring were neutropenia (10.6%), thrombocytopenia (6.4%), and pneumonia (4.3%). Serious adverse events (SAE) occurred in 10 patients (21.3%). One treatment-related death was reported (hepatitis B reactivation).

INTERPRETATION

Orelabrutinib has shown good efficacy and manageable safety profiles in patients with R/R WM.

FUNDING

InnoCare Pharma.

Bruton tyrosine kinase inhibitors in B-cell lymphoma: beyond the antitumour effect

Targeting B-cell receptor signalling using Bruton tyrosine kinase (BTK) inhibitors (BTKis) has become a highly successful treatment modality for B-cell malignancies, especially for chronic lymphocytic leukaemia. However, long-term administration of BTKis can be complicated by adverse on- and/or off-target effects in particular cell types. BTK is widely expressed in cells of haematopoietic origin, which are pivotal components of the tumour microenvironment. BTKis, thus, show broad immunomodulatory effects on various non-B immune cell subsets by inhibiting specific immune receptors, including T-cell receptor and Toll-like receptors. Furthermore, due to the off-target inhibition of other kinases, such as IL-2-inducible T-cell kinase, epidermal growth factor receptor, and the TEC and SRC family kinases, BTKis have additional distinct effects on T cells, natural killer cells, platelets, cardiomyocytes, and other cell types. Such mechanisms of action might contribute to the exceptionally high clinical efficacy as well as the unique profiles of adverse effects, including infections, bleeding, and atrial fibrillation, observed during BTKi administration. However, the immune defects and related infections caused by BTKis have not received sufficient attention in clinical studies till date. The broad involvement of BTK in immunological pathways provides a rationale to combine BTKis with specific immunotherapies, such as immune checkpoint inhibitor or chimeric antigen receptor-T-cell therapy, for the treatment of relapsed or refractory diseases. This review discusses and summarises the above-mentioned issues as a reference for clinicians and researchers.

SOHO State of the Art Updates and Next Questions: Targeted therapies and emerging novel treatment approaches for Waldenström Macroglobulinemia

Waldenström Macroglobulinemia (WM) is a rare hematologic malignancy characterized by the presence of lymphoplasmacytic lymphoma cells involving the bone marrow and production of a monoclonal IgM paraprotein. Recurrent somatic mutations in MYD88^L265P and CXCR4 have been reported in 90% to 95% and 30% to 40% of patients with WM, respectively. Standard treatment regimens combine the anti-CD20 antibody rituximab with alkylating agents (eg, bendamustine, cyclophosphamide), nucleoside analogs (eg, fludarabine, cladribine), or proteasome inhibitors (eg, bortezomib, carfilzomib, and ixazomib). Covalent BTK inhibitors (eg, ibrutinib, acalabrutinib, zanubrutinib) have shown to be safe and highly effective in patients with WM. Novel and promising agents in this disease include next-generation covalent BTK inhibitors (eg, tirabrutinib, orelabrutinib), non-covalent BTK inhibitors (eg, pirtobrutinib, ARQ531), BCL-2 antagonists (eg, venetoclax), and CXCR4-targeted agents (eg, mavorixafor, ulocuplumab), among others. Future studies will focus on developing fixed-duration combinations regimens with these novel agents aimed at increasing durable responses while minimizing toxicity and cost.

Expression and Clinical Significance of Th1/Th2/Th17 Cytokines and Lymphocyte Subsets in PCNSL

Purpose

Primary central nervous system lymphoma (PCNSL) responds favorably to radiation, chemotherapy and targeted drug therapy. However survival is usually worse, the treatment-related drug resistance and recurrence are still clinical problems to be solved urgently. Studies have shown that cytokines are expressed in varying degrees in patients with lymphoma, which is significantly related to the progression, poor prognosis and drug resistance of lymphoma. We explore the expression and clinical significance of Th1/Th2/Th17 cytokines and lymphocyte subsets in patients with PCNSL to provide a more sufficient theoretical basis for its diagnosis and treatment.

Patients and Methods

We measured and analysed the levels of Th1/Th2/Th17 cytokines and the distribution of lymphocyte subsets (including Treg cells, CD3+, CD4+, CD8+, CD19+, and CD4+/CD8+) in 39 patients with PCNSL and 96 patients with diffuse large B-cell lymphoma (DLBCL) without central nervous system involvement. The cytokines of 13 healthy people and the lymphocyte subsets of 27 healthy people were measured as the control group.

Results

We found a significant difference in the level of Th1/Th2/Th17 cytokines and lymphocyte subsets between PCNSL and healthy controls, especially IL-2, after treatment, which was significantly higher than before treatment (p<0.01). However, the level of CD19+ and CD4+/CD8+ decreased while CD8+ and CD3+ increased after treatment (regardless of whether the treatment was effective), and the difference was statistically significant. In addition, our analysis of different prognostic factors found that HD-MTX-based chemotherapy appears to have a longer progression-free survival and overall survival than osimertinib-based chemotherapy.

Conclusion

There are significant differences in Th1/Th2/Th17 cytokines and lymphocyte subsets among PCNSL, DLBCL, and healthy controls, and their detection is helpful for the diagnosis, treatment, and prognosis of PCNSL. HD-MTX-based chemotherapy may still be the first choice for PCNSL.

Orelabrutinib Combined With Lenalidomide and Immunochemotherapy for Relapsed/Refractory Primary Central Nervous System Lymphoma: A Retrospective Analysis of Case Series

Background

Relapsed/refractory (r/r) primary central nervous system lymphoma (PCNSL) is an intractable situation without sound treatment. Bruton’s tyrosine kinase (BTK) represents an attractive drug target in PCNSL. Orelabrutinib is a new-generation BTK inhibitor with high cerebrospinal fluid (CSF) concentration. This study aimed to evaluate the efficacy and safety of orelabrutinib-containing combination therapy in patients with r/r PCNSL.

Methods

We retrospectively analyzed r/r PCNSL patients who received combination therapy with rituximab, high-dose methotrexate, temozolomide, orelabrutinib and lenalidomide, and further explored the relationship between the efficacy and genetic characteristics.

Results

A total of fifteen patients were included in this retrospective study. The overall response rate (ORR) was 86.7%, the complete remission (CR) rate was 73.3% and the disease control rate (DCR) was 93.3%. Among 13 responders, 9 patients are still receiving oral orelabrutinib and lenalidomide. The most common adverse event (AEs) was transaminase increase (66.7%). No grade 4 AE or drug-related death was reported. Genomic sequencing showed that patients who responded to orelabrutinib had abnormal NF-κB activation, while those who had no response were mainly enriched with transcriptional misregulation. Patients who had mutations in TLR, BCR, or NF-κB pathway achieved complete or partial response to the orelabrutinib-containing therapy. Moreover, the blood and cerebrospinal fluid circulating tumor DNA (ctDNA) were closely associated with tumor recurrence and treatment response and sustained tumor responses correlated with the clearance of ctDNA.

Conclusion

Orelabrutinib-containing regimen was effective and well-tolerated in patients with r/r PCNSL. Genome sequencing of tumor samples could help to screen patients who may respond to the orelabrutinib-containing regimen, and liquid biopsy may contribute to tracing tumor burden and monitoring treatment response.

Discovery of Pteridine-7(8H)-one Derivatives as Potent and Selective Inhibitors of Bruton's Tyrosine Kinase (BTK)

Bruton's tyrosine kinase (BTK) is an attractive therapeutic target in the treatment of cancer, inflammation, and autoimmune diseases. Covalent and noncovalent BTK inhibitors have been developed, among which covalent BTK inhibitors have shown great clinical efficacy. However, some of them could produce adverse effects, such as diarrhea, rash, and platelet dysfunction, which are associated with the off-target inhibition of ITK and EGFR. In this study, we disclosed a series of pteridine-7(8H)-one derivatives as potent and selective covalent BTK inhibitors, which were optimized from 3z, an EGFR inhibitor previously reported by our group. Among them, compound 24a exhibited great BTK inhibition activity (IC50 = 4.0 nM) and high selectivity in both enzymatic (ITK >250-fold, EGFR >2500-fold) and cellular levels (ITK >227-fold, EGFR 27-fold). In U-937 xenograft models, 24a significantly inhibited tumor growth (TGI = 57.85%) at a 50 mg/kg dosage. Accordingly, 24a is a new BTK inhibitor worthy of further development.

Orelabrutinib-bruton tyrosine kinase inhibitor-based regimens in the treatment of central nervous system lymphoma: a retrospective study

BACKGROUND

Central nervous system lymphoma (CNSL) is an aggressive lymphoma. Orelabrutinib, an oral Bruton tyrosine kinase inhibitor, is a new treatment strategy for CNSL. This study aims to evaluate the efficacy and safety of orelabrutinib-based regimens in the treatment of patients with CNSL.

METHODS

Twenty-three patients with CNSL were included in this retrospective study. All patients received the orelabrutinib-based regimen. Efficacy was evaluated based on investigators' assessment of overall response rate (ORR), complete response/unconfirmed complete response (CR/CRu), partial response (PR), stable disease (SD), progressive disease (PD), duration of response (DOR), progression-free survival (PFS) and overall survival (OS). The safety of orelabrutinib-based regimens has also been evaluated.

RESULTS

A total of 17.39% of patients received orelabrutinib-based regimens for consolidation therapy, and 82.61% of patients for induction therapy (4 newly diagnosed CNSL, 15 relapsed/refractory CNSL). In the newly diagnosed CNSL group, the ORR was 100% (1 CR, 1 CRu, 2 PR). The 6-month DOR rate, 6-month PFS rate, and 6-month OS rate were 100%, 100%, and 100%, respectively. Of the 15 relapsed/refractory CNSL patients, five therapy regimens were applied (orelabrutinib, n = 3; orelabrutinib/immunotherapy, n = 3; orelabrutinib/chemotherapy, n = 2; orelabrutinib/immunochemotherapy, n = 6; orelabrutinib/radiotherapy, n = 1). The ORR was 60.00% (4 CR, 5 PR). The 6-month DOR rate, 6-month PFS rate, and 6-month OS rate were 92.30%, 67.70%, and 70.00%, respectively. Twenty-one patients reported adverse events (AEs), and 6 patients experienced grade ≥ 3 AEs.

CONCLUSION

Orelabrutinib-based regimens were efficacious and well-tolerated in patients with CNSL. These combined therapies offer a new potential therapeutic strategy for patients with CNSL.