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.

Lymphoma, a group of widely prevalent hematological malignancies of lymphocyte origin, has become the focus of significant clinical research due to their high propensity for refractory/relapsed (R/R) disease, leading to poor prognostic outcomes. The complex molecular circuitry in lymphomas, especially in the aggressive phenotypes, has made it difficult to find a therapeutic option that can salvage R/R disease. Furthermore, the association of lymphomas with the Bone Marrow (BM) microenvironment has been found to portend worse outcomes in terms of heightened chances of relapse and acquired resistance to chemotherapy. This review assesses the current therapy options in three distinct types of lymphomas: diffuse large B-cell lymphoma, follicular lymphoma and mantle cell lymphoma. It also explores the role of the BM tumor microenvironment as a secure ‘niche’ for lymphoma cells to grow, proliferate and survive. It further evaluates potential mechanisms through which the tumor cells can establish molecular connections with the BM cells to provide pro-tumor benefits, and discusses putative therapeutic strategies for disrupting the BM-lymphoma cell communication.

Canopy FGF signaling regulator 2 (CNPY2) has emerged as a crucial player in cancer development by promoting cell proliferation, tissue repair, and angiogenesis. This review synthesizes the current understanding of CNPY2’s role in solid tumors, particularly renal cell carcinoma, prostate cancer, hepatocellular carcinoma, and non-small-cell lung cancer. CNPY2 modulates key pathways such as p53, MYLIP, NF-κB, and AKT/GSK3β, thereby driving tumor growth and progression. In renal cell carcinoma, CNPY2 paradoxically promotes tumor growth through p53 upregulation, while in hepatocellular carcinoma, CNPY2 drives cell cycle progression via p53 destabilization. In prostate cancer, it enhances tumor progression by stabilizing androgen receptors through MYLIP interaction, and in non-small-cell lung cancer, it contributes to chemoresistance and metastasis through NF-κB and AKT/GSK3β signaling. Additionally, CNPY2 influences the tumor microenvironment, impacting immune function and metastatic potential. As a potential biomarker, CNPY2 shows promise for cancer detection and prognosis, particularly when used in combination with other markers. Early therapeutic strategies, including siRNA and miRNA approaches, are under exploration, though challenges remain due to CNPY2’s expression in normal tissues and potential off-target effects. This review underscores the need for further research to fully elucidate CNPY2’s oncogenic mechanisms and develop targeted therapies. Improved understanding of CNPY2’s diverse roles may lead to novel diagnostic and therapeutic approaches in solid tumors.

Background/Objectives: Enfortumab vedotin plus pembrolizumab (EV+pembro) is the standard first-line treatment for metastatic urothelial carcinoma (mUC), yet no validated on-treatment biomarker identifies patients deriving a durable benefit. We evaluated whether circulating tumor DNA (ctDNA) clearance is associated with response and survival with this regimen alone. Methods: This single-center retrospective study included 25 patients with mUC receiving first-line EV+pembro. A tumor-informed assay (Signatera) measured ctDNA longitudinally. Responses were assessed by RECIST 1.1. Progression-free survival (PFS) and overall survival (OS) hazard ratios (HRs) were estimated by Cox regression and, to address immortal time bias, with clearance as a time-dependent covariate. Results: Fifteen of 25 patients (60%) achieved ctDNA clearance (ever undetectable). The objective response rate was 76% overall and 100% (15/15) with clearance versus 40% (4/10) without (p = 0.0012). Clearance was associated with longer PFS (HR 0.16, 95% CI 0.05–0.54; p = 0.003) and OS (HR 0.08, 95% CI 0.01–0.68; p = 0.021), with similar Firth penalized HRs (0.17 and 0.11). In the time-dependent analysis, the associations were attenuated (PFS HR 0.35, 95% CI 0.09–1.15, p = 0.085; OS HR 0.14, 95% CI 0.01–0.84, p = 0.029; profile likelihood CIs). A post-nadir ctDNA rise preceded progression or death by a median of 95 days in four patients (death in two). Conclusions: In this first-line EV+pembro cohort, all patients who cleared ctDNA responded, and clearance was associated with longer survival, although this association was attenuated in the time-dependent analysis. These hypothesis-generating findings support the prospective evaluation of ctDNA-guided monitoring.