Bruton's tyrosine kinase inhibitors in the treatment of primary central nervous system lymphoma: A mini-review

Efficacy and safety of orelabrutinib combined with rituximab and high dose methotrexate in primary or secondary central nervous system diffuse large B-cell lymphoma: a retrospective analysis

Central nervous system lymphoma (CNSL) are mainly diffuse large B-cell lymphomas (DLBCLs). Orelabrutinib is a second-generation Bruton's tyrosine kinase (BTK) inhibitor and has shown single-agent activity in CNSL. This study aims to evaluate the efficacy and safety of orelabrutinib combined with rituximab and high dose methotrexate (ORM) regimen in the treatment of patients with CNSL. We retrospectively analyzed data from CNSL patients treated with ORM regimen at Jiangsu Province Hospital, the First Affiliated Hospital of Nanjing Medical University from April 2021 to October 2023. Patients receiving rituximab plus high-dose methotrexate (RM regimen) from June 2017 to January 2024 were identified as the control group. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Adverse events (AEs) were assessed according to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. A total of 32 patients were identified: 14 patients in the ORM group and 18 in the RM group. CR rates were 84.6% in the ORM group and 44.4% in the RM group (P = 0.032). Median PFS was 18.6 months in the RM group and 26.3 months in the ORM group (P = 0.133). Median OS was 34.1 months in the RM group and has not yet been reached in the ORM group (P = 0.041). Patients in the ORM group showed a higher 2-year OS rate than those in the RM group (82.1% vs. 57.5%). No grade 5 AE was reported in both groups. The incidence of grade 3-4 AE was comparable between the two treatment groups. ORM regimen was effective and well-tolerated in patients with CNSL. This combination therapy provides a new potential therapeutic strategy for patients with CNSL.

Outcomes and relapse patterns in primary central nervous system lymphoma: Longitudinal analysis of 559 patients diagnosed from 1983 to 2020

BACKGROUND

Contemporary outcomes and relapse patterns in primary CNS lymphoma (PCNSL) are lacking. We analyzed factors associated with relapse in a large cohort with extensive follow-up.

METHODS

T1-post-contrast-enhancing disease was characterized in immunocompetent PCNSL (diffuse large B-cell) patients from 1983 to 2020. Patients were stratified by response to induction and consolidation (complete/unconfirmed [CR/CRu], partial, stable, progression [POD]). Refractory was POD during (or relapse ≤3 months of) induction. Initial relapse site was categorized as local (involving/adjacent to baseline), distant intraparenchymal, leptomeningeal, or other. Progression-free (PFS) and overall survival (OS) were assessed with proportional hazards. Cumulative incidence with competing risks was used to assess local relapse.

RESULTS

Median follow-up was 7.4 years (N = 559). Most (321, 57%) were recursive partitioning analysis class 2 (age ≥50, Karnosfky Performance Status [KPS] ≥70). Most had supratentorial (420, 81%), multifocal (274, 53%), bilateral (224, 43%), and deep structure involvement (314, 56%). Nearly all received methotrexate-based induction (532, 95%). There was no difference in PFS or OS from consolidation based on initial response to induction (CR/CRu vs PR) in patients who ultimately achieved a CR/CRu to consolidation. PFS at 1-, 5 years for 351 patients with CR/CRu to consolidation was 80% (95% confidence interval [95% CI]: 76%-84%) and 46% (95% CI: 41%-53%), respectively; 1-year cumulative incidence of local versus nonlocal relapse was 1.8% versus 15%, respectively. For 97 refractory patients, 1-year cumulative incidence of local versus nonlocal relapse was 57% versus 42%, respectively. Deep structure involvement (HR 1.89, 95% CI: 1.10%-3.27%) was associated with local relapse in refractory patients.

CONCLUSIONS

We report the first comprehensive relapse patterns in a large PCNSL cohort. While relapses post-CR to consolidation are typically distant and unpredictable, refractory patients had a relatively high incidence of local relapse. These findings can help optimize multimodality therapy for this highest-risk population.

Clinical characteristics and prognosis of patients with newly diagnosed primary central nervous system lymphoma: a multicentre retrospective analysis

Bruton's tyrosine kinase inhibitors (BTKi) exhibit superior efficacy in relapsed/refractory primary central nervous system lymphoma (PCNSL), but few studies have evaluated patients with newly diagnosed PCNSL, and even fewer studies have evaluated differences in efficacy between treatment with BTKi and traditional chemotherapy. This study retrospectively analyzed the clinical characteristics of 86 patients with PCNSL and identified predictors of poor prognosis for overall survival (OS). After excluding patients who only received palliative care, 82 patients were evaluated for efficacy and survival. According to the induction regimen, patients were divided into the traditional chemotherapy, BTKi combination therapy, and radiotherapy groups; the objective response rates (ORR) of the three groups were 71.4%, 96.2%, and 71.4% (P = 0.037), respectively. Both median progression-free survival and median duration of remission showed statistically significant differences (P = 0.019 and P = 0.030, respectively). The median OS of the BTKi-containing therapy group was also longer than that of the traditional chemotherapy group (not reached versus 47.8 (32.5-63.1) months, P = 0.038).Seventy-one patients who achieved an ORR were further analyzed, and achieved an ORR after four cycles of treatment and maintenance therapy had prolonged OS (P = 0.003 and P = 0.043, respectively). In conclusion, survival, and prognosis of patients with newly diagnosed PCNSL are influenced by the treatment regimen, with the BTKi-containing regimen showing great potential.

Efficacy and Safety of BTKis in Central Nervous System Lymphoma: A Systematic Review and Meta-Analysis

BACKGROUND

This systematic review and meta-analysis aimed to evaluate the efficacy and safety of Bruton tyrosine kinase inhibitors (BTKis) for central nervous system lymphoma (CNSL).

METHODS

A systematic review was carried out to identify relevant studies from the PubMed, Embase, Cochrane Library, Web of Science, WanFang, CNKI, and CBM databases. The studies included patients with CNSL who received BTKis and reported the overall response (OR), complete remission (CR), and partial response (PR). An overall effect analysis was performed using STATA 15.0. A random-effects model was utilized to calculate the pooled rates, and 95% confidence intervals (CI) were determined for all outcomes.

RESULTS

A total of 21 studies involving 368 patients were included in the meta-analysis. For newly diagnosed CNSL, due to the small simple size, we conducted a quantitative description, and the ORR could reach up to 100%. For relapsed/refractory patients, the pooled ORR was 72% (95% CI: 64-80%, I2 = 54.89%, p = 0.00), with a pooled CR and PR of 43% (95% CI: 33-54%, I2 = 65.40%, p = 0.00) and 23% (95% CI: 13-35%, I2 = 78.05%, p = 0.00), respectively. Most adverse events were hematology-related and generally manageable.

CONCLUSION

BTKis showed acceptable efficacy and safety in treating patients with CNSL. However, large and well-designed trials are still required to confirm BTKis as a treatment for CNSL.

A novel Bruton's tyrosine kinase inhibitor JDB175 shows potent efficacy to suppress central nervous system lymphoma

Patients with central nervous system (CNS) lymphoma face limited treatment options and poor treatment outcomes, emphasizing the urgent need for effective therapeutic strategies. One limiting factor contributing to the suboptimal efficacy is the inadequate penetration of most treatment drugs across the blood-brain barrier (BBB). Recent insights into the pathophysiology of CNS lymphoma have identified the Bruton's tyrosine kinase (BTK) signaling pathway as a potential target. Some clinical trials have shown impressive responses to BTK inhibitors in CNS lymphoma. However, currently approved BTK inhibitors have low BBB penetration rates, limiting their efficacy. In this study, we discovered that JDB175, a novel and highly selective BTK inhibitor, exhibits excellent BBB penetration capabilities and demonstrates favorable activity in a mouse model of CNS lymphoma while showing no significant signs of toxicity. JDB175 effectively inhibits the BTK signaling pathway in human lymphoma cells, suppressing their proliferation, inducing cell cycle arrest, and promoting apoptosis. The significance of this study lies in addressing the critical unmet medical need for effective treatments for CNS lymphoma. This finding indicates a promising avenue for improved treatments in CNS lymphoma, potentially opening doors for further clinical investigation and therapeutic advancements.

Chinese expert consensus on Bruton tyrosine kinase inhibitors in the treatment of B-cell malignancies

Targeted therapy with Bruton tyrosine kinase (BTK) inhibitors have revolutionized the treatment of patients with various B-cell malignancies. BTK inhibitors such as ibrutinib, zanubrutinib, orelabrutinib, and acalabrutinib have shown good clinical efficacy and better safety profiles than those of traditional chemotherapy and chemoimmunotherapy regimens. Multiple studies on new BTK inhibitors are ongoing, which may provide more therapeutic options for the treatment of B-cell malignancies. Considering the unmet need of evidence on BTK inhibitors in all clinical settings and to standardize the use of BTK inhibitors available in mainland China, Taiwan, Hong Kong, and Macau regions, this consensus has been formulated for the treatment of various B-cell malignancies based on the clinical practice and available evidences on the use of BTK inhibitors. The recommendations of this consensus will provide guidance to physicians and clinical researchers on the effective treatment of B-cell malignancies with BTK inhibitors.

MYD88L265P augments proximal B-cell receptor signaling in large B-cell lymphomas via an interaction with DOCK8

Diffuse large B-cell lymphoma (DLBCL) is a clinically and genetically heterogeneous disease with at least 5 recognized molecular subtypes. Cluster 5 (C5)/MCD tumors frequently exhibit concurrent alterations in the toll-like receptor (TLR) and B-cell receptor (BCR) pathway members, MYD88L265P and CD79B, and have a less favorable prognosis. In healthy B cells, the synergy between TLR and BCR signaling pathways integrates innate and adaptive immune responses and augments downstream NF-κB activation. In addition, physiologic TLR9 pathway engagement via MYD88, protein tyrosine kinase 2 (PYK2), and dedicator of cytokinesis 8 (DOCK8) increases proximal BCR signaling in healthy murine B cells. Although C5/MCD DLBCLs are selectively sensitive to Bruton tyrosine kinase (BTK) inhibition in in vitro studies and certain clinical trials, the role of mutated MYD88 in proximal BCR signaling remains undefined. Using engineered DLBCL cell line models, we found that concurrent MYD88L265P and CD79B alterations significantly increased the magnitude and duration of proximal BCR signaling, at the level of spleen tyrosine kinase and BTK, and augmented PYK2-dependent DOCK8 phosphorylation. MYD88L265P DLBCLs have significantly increased colocalization of DOCK8 with both MYD88 and the proximal BCR-associated Src kinase, LYN, in comparison with MYD88WT DLBCLs, implicating DOCK8 in MYD88L265P/proximal BCR cross talk. Additionally, DOCK8 depletion selectively decreased proximal BCR signaling, cellular proliferation, and viability of DLBCLs with endogenous MYD88L265P/CD79BY196F alterations and increased the efficacy of BTK blockade in these lymphomas. Therefore, MYD88L265P/DOCK8-enhanced proximal BCR signaling is a likely mechanism for the increased sensitivity of C5/MCD DLBCLs to BTK blockade.

Extranodal lymphoma: pathogenesis, diagnosis and treatment

Approximately 30% of lymphomas occur outside the lymph nodes, spleen, or bone marrow, and the incidence of extranodal lymphoma has been rising in the past decade. While traditional chemotherapy and radiation therapy can improve survival outcomes for certain patients, the prognosis for extranodal lymphoma patients remains unsatisfactory. Extranodal lymphomas in different anatomical sites often have distinct cellular origins, pathogenic mechanisms, and clinical manifestations, significantly influencing their diagnosis and treatment. Therefore, it is necessary to provide a comprehensive summary of the pathogenesis, diagnosis, and treatment progress of extranodal lymphoma overall and specifically for different anatomical sites. This review summarizes the current progress in the common key signaling pathways in the development of extranodal lymphomas and intervention therapy. Furthermore, it provides insights into the pathogenesis, diagnosis, and treatment strategies of common extranodal lymphomas, including gastric mucosa-associated lymphoid tissue (MALT) lymphoma, mycosis fungoides (MF), natural killer/T-cell lymphoma (nasal type, NKTCL-NT), and primary central nervous system lymphoma (PCNSL). Additionally, as PCNSL is one of the extranodal lymphomas with the worst prognosis, this review specifically summarizes prognostic indicators and discusses the challenges and opportunities related to its clinical applications. The aim of this review is to assist clinical physicians and researchers in understanding the current status of extranodal lymphomas, enabling them to make informed clinical decisions that contribute to improving patient prognosis.

Leptomeningeal Metastasis: A Review of the Pathophysiology, Diagnostic Methodology, and Therapeutic Landscape

The present review aimed to establish an understanding of the pathophysiology of leptomeningeal disease as it relates to late-stage development among different cancer types. For our purposes, the focused metastatic malignancies include breast cancer, lung cancer, melanoma, primary central nervous system tumors, and hematologic cancers (lymphoma, leukemia, and multiple myeloma). Of note, our discussion was limited to cancer-specific leptomeningeal metastases secondary to the aforementioned primary cancers. LMD mechanisms secondary to non-cancerous pathologies, such as infection or inflammation of the leptomeningeal layer, were excluded from our scope of review. Furthermore, we intended to characterize general leptomeningeal disease, including the specific anatomical infiltration process/area, CSF dissemination, manifesting clinical symptoms in patients afflicted with the disease, detection mechanisms, imaging modalities, and treatment therapies (both preclinical and clinical). Of these parameters, leptomeningeal disease across different primary cancers shares several features. Pathophysiology regarding the development of CNS involvement within the mentioned cancer subtypes is similar in nature and progression of disease. Consequently, detection of leptomeningeal disease, regardless of cancer type, employs several of the same techniques. Cerebrospinal fluid analysis in combination with varied imaging (CT, MRI, and PET-CT) has been noted in the current literature as the gold standard in the diagnosis of leptomeningeal metastasis. Treatment options for the disease are both varied and currently in development, given the rarity of these cases. Our review details the differences in leptomeningeal disease as they pertain through the lens of several different cancer subtypes in an effort to highlight the current state of targeted therapy, the potential shortcomings in treatment, and the direction of preclinical and clinical treatments in the future. As there is a lack of comprehensive reviews that seek to characterize leptomeningeal metastasis from various solid and hematologic cancers altogether, the authors intended to highlight not only the overlapping mechanisms but also the distinct patterning of disease detection and progression as a means to uniquely treat each metastasis type. The scarcity of LMD cases poses a barrier to more robust evaluations of this pathology. However, as treatments for primary cancers have improved over time, so has the incidence of LMD. The increase in diagnosed cases only represents a small fraction of LMD-afflicted patients. More often than not, LMD is determined upon autopsy. The motivation behind this review stems from the increased capacity to study LMD in spite of scarcity or poor patient prognosis. In vitro analysis of leptomeningeal cancer cells has allowed researchers to approach this disease at the level of cancer subtypes and markers. We ultimately hope to facilitate the clinical translation of LMD research through our discourse.

PROTACs: A novel strategy for cancer drug discovery and development

Proteolysis targeting chimera (PROTAC) technology has become a powerful strategy in drug discovery, especially for undruggable targets/proteins. A typical PROTAC degrader consists of three components: a small molecule that binds to a target protein, an E3 ligase ligand (consisting of an E3 ligase and its small molecule recruiter), and a chemical linker that hooks first two components together. In the past 20 years, we have witnessed advancement of multiple PROTAC degraders into the clinical trials for anticancer therapies. However, one of the major challenges of PROTAC technology is that only very limited number of E3 ligase recruiters are currently available as E3 ligand for targeted protein degradation (TPD), although human genome encodes more than 600 E3 ligases. Thus, there is an urgent need to identify additional effective E3 ligase recruiters for TPD applications. In this review, we summarized the existing RING-type E3 ubiquitin ligase and their small molecule recruiters that act as effective E3 ligands of PROTAC degraders and their application in anticancer drug discovery. We believe that this review could serve as a reference in future development of efficient E3 ligands of PROTAC technology for cancer drug discovery and development.