Phase I First-in-Human Study of Venetoclax in Patients With Relapsed or Refractory Non-Hodgkin Lymphoma

Inextricable association of connective tissue disease with B‑cell lymphoma (Review)

Connective tissue disease (CTD) is a kind of autoimmune disease with multisystem damage that mainly involves the bone, muscle and the vascular system. Patients with CTD have an increased incidence of malignant tumors, particularly hematological malignancies, compared to the general population. This association of autoimmune diseases with lymphoproliferative diseases is bidirectional. There is a heightened risk of B-cell lymphoma development among patients with CTD, and patients with autoimmune disease display a higher prevalence of non-Hodgkin lymphoma compared to the general population. More than 80% of malignant tumours occur after or at the same time as CTD develops. Among secondary lymphomas, the most common aggressive type of lymphoma is diffuse large B-cell lymphoma, while the most common indolent type is marginal zone lymphoma. Novel targets in patients with B-cell lymphoma are BCL2, the NF-κB pathway, components of the BCR activator of RhoGEF and GTPase signalling pathway and the PI3K-mTOR pathway. In this review, information is provided on the common types of B-cell lymphoma in CTD, the pathogenic factors implicated in lymphoma development and recent advancements in therapies effective for both autoimmune conditions and malignant lymphoproliferative diseases.

Capillary Sampling Enables Venetoclax Concentration Measurement in Acute Myeloid Leukaemia Within Academic Multicentre Trial

Venetoclax has improved outcomes for acute myeloid leukaemia (AML) patients unfit for intensive chemotherapy. Managing cytopenias and infections remains challenging. Previous pharmacokinetic studies have shown considerable variability in venetoclax concentrations between individuals; however, data regarding whether higher levels increase toxicity or impact efficacy are limited. This study assessed the feasibility of using fingertip capillary blood plasma, collected via microsampling, to measure venetoclax trough concentrations and explored their association with toxicity and treatment outcomes. Concentrations were measured during the first two therapy cycles in 89 patients with newly diagnosed or relapsed or refractory AML receiving azacitidine and venetoclax. Validation with 37 parallel venipuncture and capillary samples showed excellent correlation (R2 of 0.835, p < 0.0001). No significant associations were found between venetoclax concentrations and patient characteristics such as gender, age and weight. While no statistically significant effects on therapy outcomes or adverse events were identified, trends suggested lower concentrations in refractory patients and higher in those with morphologic leukaemia free state or extended cycle length. Additionally, three separate CYP3A4 and CYP3A5 single-nucleotide polymorphisms were analysed in 81 patients for their potential impact on venetoclax concentrations. This study demonstrates that the capillary blood plasma method is viable for measuring venetoclax levels.

Venetoclax and decitabine vs intensive chemotherapy as induction for young patients with newly diagnosed AML

ABSTRACT

Venetoclax (VEN) combined with hypomethylating agents is approved for frontline therapy in older/unfit patients with acute myeloid leukemia (AML). However, prospective data on this low-intensity therapy in treatment-naive younger patients with AML are lacking. This study investigated the efficacy and safety of VEN plus decitabine (VEN-DEC) as induction in untreated young fit patients with AML in a randomized trial. Patients aged 18 to 59 years eligible for intensive chemotherapy were randomized 1:1 to receive VEN-DEC or IA-12 (idarubicin and cytarabine). All patients achieved composite complete remission (CRc) underwent high-dose cytarabine consolidation. The primary end point was CRc rate after induction. Of 255 screened, 188 were enrolled and randomly assigned, with 94 in each group. In the intention-to-treat population, CRc was 89% (84/94) in the VEN-DEC group vs 79% (74/94) in the IA-12 group (noninferiority P = .0021), with measurable residual disease negativity rates of 80% (67/84) vs 76% (56/74), respectively. VEN-DEC showed superior CRc in patients aged ≥40 years (91% vs 75%) and those with adverse risk (91% vs 42%) or epigenetic mutations (91% vs 67%), but lower CRc in RUNX1::RUNX1T1 fusion cases (44% vs 88%) than IA-12. Patients in the VEN-DEC group experienced fewer grade ≥3 infections (32% vs 67%) and shorter severe thrombocytopenia duration (median, 13 vs 19 days; P < .001). At a median follow-up of 12.1 months, overall and progression-free survival were similar between groups. In conclusion, VEN-DEC demonstrated noninferior response rates with superior safety over IA-12 in young patients with AML. The trial was registered at www.clinicaltrials.gov as #NCT05177731.

Effects of venetoclax, a BCL2 inhibitor, in systemic chronic active Epstein-Barr virus disease

Systemic chronic active Epstein-Barr virus disease (sCAEBV) is a chemotherapy-resistant, EBV-positive T- or NK-cell lymphoproliferative disorder characterized by persistent systemic inflammation driven by the activation of EBV-infected cells. In this study, we explored BCL2, an anti-apoptotic factor implicated in various hematopoietic malignancies, as a potential therapeutic target for sCAEBV, focusing on the effects of its inhibitor, venetoclax. We confirmed BCL2 expression in EBV-positive T- and NK-cell lines and peripheral blood mononuclear cells (PBMCs) from sCAEBV patients using western blotting. Immunofluorescence staining further revealed BCL2 expression in EBV-infected cells within patient-derived PBMCs. Venetoclax treatment reduced the viability of EBV-positive cell lines and patient-derived PBMCs in a dose-dependent manner and induced apoptosis in these cells. Moreover, venetoclax suppressed the mRNA expression of the inflammatory cytokine IFN-γ in patient-derived PBMCs. To evaluate the in vivo effects of venetoclax, we utilized sCAEBV xenograft model generated by transplanting patient-derived PBMCs into NOD/Shi-scid/IL-2Rγnull mice. No engraftment of EBV-infected cells was observed in mice treated with venetoclax, whereas one out of three mice in the untreated group exhibited engraftment of EBV-positive cells and tumor formation. Venetoclax treatment showed an insignificant trend to reducing IFN-γ levels in peripheral blood in established xenograft models. To our knowledge, this is the first report to suggest that venetoclax exerts not only anti-tumor effects but also potential anti-inflammatory effects in sCAEBV. BCL2 represents a promising therapeutic target to address the two pathological characteristics of sCAEBV: malignancy and inflammation.

Downregulation of rRNA synthesis by BCL-2 induces chemoresistance in diffuse large B cell lymphoma

Overexpression of the antiapoptotic oncogene BCL-2 predicts poor prognosis in diffuse large B cell lymphoma (DLBCL) treated with anthracycline-based chemoimmunotherapy. Anthracyclines exert antitumor effects by multiple mechanisms including inhibition of ribosome biogenesis (RiBi) through rRNA synthesis blockade. RiBi inhibitors induce p53 stabilization through the ribosomal proteins-MDM2-p53 pathway, with stabilized p53 levels depending on baseline rRNA synthesis rate. We found that the BH3-mimetic venetoclax could not fully reverse BCL-2-mediated resistance to RiBi inhibitors in DLBCL cells. BCL-2 overexpression was associated with decreased baseline rRNA synthesis rate, attenuating p53 stabilization by RiBi inhibitors. Drugs stabilizing p53 irrespective of RiBi inhibition reversed BCL-2-induced resistance in vitro and in vivo, restoring p53 activation and apoptosis. A small nucleolar size, indicative of low baseline rRNA synthesis, correlated with high BCL-2 levels and poor outcomes in DLBCL patients. These findings uncover alternative BCL-2-dependent chemoresistance mechanisms, providing a rationale for specific combination strategies in BCL-2 positive lymphomas.

Phase II study of venetoclax added to bendamustine and obinutuzumab in patients with high-risk follicular lymphoma as front-line therapy: PrE0403

Over-expression of BCL-2 defines follicular lymphoma (FL). Venetoclax (VEN), a selective BCL-2 inhibitor, has previously been evaluated with bendamustine-based chemoimmunotherapy. VEN was given continuously, resulting in promising efficacy but unacceptable toxicity. The Phase II PrE0403 study was designed to evaluate intermittent dosing of VEN (10 days per cycle) combined with obinutuzumab and bendamustine (VEN-OB) in untreated FL subjects with high-risk features defined as a FLIPI-1 score of ≥3 and/or high tumor burden by GELF criteria. A total of 56 subjects were planned to be accrued with a goal of having 51 subjects eligible to improve the historical 50% CR rate to 65% with an 85% power and 15% type I error rate. Immunohistochemistry (IHC) expression of 3 antiapoptotic proteins (BCL-xL, MCL-1, and BCL-2) was performed and correlated with clinical outcomes. All 56 subjects were eligible and treated. CR rate was 41/56 (73.2%) and ORR was 52/56 (92.5%) meeting the primary endpoint. 2-year estimated PFS was 87.5% (90% CI: 75.3,93.9%) and 2-year estimated OS was 94.6% (90% CI: 86.7, 97.9%). However, the incidence of treatment-related adverse events ≥ grade 3 was 83.9% and serious adverse events were seen in 57.1%. After induction, atypical infections, including Grade 5 events, occurred. Anti-apoptotic protein expression by IHC was not correlated with clinical outcomes. Thus, while meeting the primary efficacy end point, VEN-OB is considered overly toxic in high-risk FL.

A Model of Intratumor and Interpatient Heterogeneity Explains Clinical Trials of Curative Combination Therapy for Lymphoma

SIGNIFICANCE

A new model of intratumor and interpatient heterogeneity in response to drug combinations explains and predicts the results of clinical trials of curative-intent treatments for DLBCL. This model can be used to understand and inform optimal design of curative drug combinations and clinical trials. See related commentary by Goldstein et al., p. 153.

Venetoclax confers synthetic lethality to chidamide in preclinical models with transformed follicular lymphoma

Transformed follicular lymphoma (t-FL) is an aggressive and heterogeneous hematological malignancy with limited treatment success; the development of novel therapeutic approaches is urgently needed for patients with t-FL. Here, we conducted high-throughput screening (HTS) and in vitro experiments using t-FL cell lines and primary samples to assess the synergistic effects of the histone deacetylase inhibitor chidamide and the BCL-2 inhibitor venetoclax. In vivo efficacy was further tested in xenograft models. The combination of venetoclax and chidamide significantly inhibited cell proliferation, induced apoptosis, and arrested the cell cycle in the G0/G1 phase across multiple t-FL cell lines. Furthermore, the combined therapy effectively reduced tumor burden, extended overall survival in xenograft models, and synergistically targeted patient samples, while sparing normal PBMCs. Mechanistically, this combination disrupted mitochondrial membrane potential and modulated the Wnt signaling pathway, as evidenced by decreased protein expression levels of Wnt3a, Wnt5a/b, β-catenin, and phosphorylated GSK3β. Concurrently, the combined regimen enhanced their respective anticancer effects by inhibiting the key genes HDAC10 and BCL-xL. Taken together, venetoclax combined with chidamide presents a potent anticancer strategy in preclinical models of t-FL and merits further exploration in clinical trials to validate its effectiveness and safety for treating t-FL.

Follicular lymphoma: contemporary clinical management with a focus on recent therapeutic advances

Follicular lymphoma (FL) is the most common type of indolent lymphoma, and the prognosis is favorable for most patients. However, FL remains generally incurable, and relapse is common. Patients are at risk of developing treatment-resistant lymphoma, particularly when early disease progression occurs or transformation to aggressive lymphoma takes place. Furthermore, lymphoma is the leading cause of death among patients with FL, emphasizing the need for more effective treatment strategies. This review summarizes therapeutic approaches for FL, with a focus on therapies currently in development. Recent biological insights have driven the emergence of highly effective treatments, including novel immune and targeted therapies. Clinical trials are assessing the efficacy of these novel approaches, which are increasingly used in earlier line settings. In the future, FL therapy is expected to rely less on chemotherapeutic methods, extend remission, and potentially enable cures for a growing number of patients.

Atezolizumab, obinutuzumab and venetoclax for the treatment of patients with relapsed/refractory B non-Hodgkin lymphoma: Final analysis of a phase II trial from the LYSA group

Developing new therapeutic regimens for relapsed/refractory (R/R) B non-Hodgkin lymphoma (NHL) patients remains a significant unmet clinical need. Our objective was to evaluate atezolizumab (ATE), obinutuzumab (OBI) and venetoclax (VEN) combination in patients with R/R NHL who had received at least one prior anti-CD20-containing immunochemotherapy regimen. We report here the final analysis of the phase II LYSA-promoted multicentre trial (NCT03276468) of this combination in follicular lymphoma (FL, n = 58), diffuse large B-cell lymphoma (DLBCL, n = 58) and marginal zone lymphoma (MZL, n = 20). The primary end-point for FL and DLBCL was not met: ATE, OBI, and VEN resulted in an overall response rate (ORR) at the end of induction (EOI) of 53.6% for FL (cohort 1) and 23.6% for DLBCL (cohort 2) when a minimum of 70% and 48% was expected respectively. The median progression-free survival was 11.0 and 2.7 months in cohorts 1 and 2 respectively. In cohort 3 (MZL), the ORR at the EOI was evaluated at 66.7%. The most frequent adverse events (AEs) were cytopenias. We also observed 7.4% of autoimmune AE imputable to the combination. In this phase II study, ATE, OBI and VEN demonstrated moderate efficacy and a manageable toxicity profile when used as induction and maintenance therapy.

Targeting BCL2 in Waldenström macroglobulinemia: from biology to treatment management

Despite recent advances in the treatment of Waldenström macroglobulenimia (WM), including the development of Bruton tyrosine kinase inhibitors (BTKis), the disease remains incurable highlighting the urgent need for new treatments. The overexpression of BCL2 in WM cells promotes cell survival by resisting apoptosis and contributes to resistance to chemotherapy and targeted therapies. Concurrently, Bcl2 proteins that are encoded by oncogenes supporting cell survival are frequently upregulated in WM, even in the presence of DNA-damaging agents, and hence have emerged as an alternative therapeutic target. Venetoclax serves as a novel orally administered small agent that targets Bcl-2 protein by acting as a BCL2 homology domain 3 (BH3) mimetic and has shown promising results in WM patients, including those previously treated with BTKis. Furthermore, venetoclax, in combination with standard WM regimens, has shown enhanced activity, but further studies are required to elucidate the mechanism of its synergistic action and identify the patients who can benefit from the combined therapy. New BCL2 inhibitors are in advanced stages of clinical development and may offer additional options. The present review will focus on the current knowledge we have on BCL2 inhibitors in WM, the input of these compounds "from bench to bedside," and their utility in managing relapsed/refractory WM patients.

Outcomes of patients with relapsed/refractory lymphoplasmacytic lymphoma/waldenström macroglobulinemia treated with venetoclax: a multicenter retrospective analysis

Venetoclax showed promising activity in a small phase II trial in relapsed/refractory Waldenström macroglobulinemia (WM). To report the clinical activity of venetoclax and prognostic factors associated with outcomes in a larger cohort, we retrospectively identified 76 patients with relapsed/refractory lymphoplasmacytic lymphoma (LPL)/WM treated with venetoclax monotherapy at nine US medical centers. The median age at venetoclax treatment initiation was 66 years. MYD88, CXCR4, and TP53 mutations were detected in 65 (94%), 23 (40%), and 10 (22%) patients, respectively. The median number of prior lines of treatment was 3, including covalent BTK inhibitor in 82% and alkylating agent in 71% of patients. The overall and major response rates to venetoclax were 70% and 63%, respectively. The median and 2-year progression-free survival (PFS) were 28.5 months and 57%, respectively. The median and 2-year overall survival were not reached and 82%, respectively. Prior treatment with BTK inhibitor was the only factor associated with PFS in multivariate analysis (hazard ratio 2.97, p = 0.012). Venetoclax dose interruptions and/or reductions occurred in 27 patients (41%). Five patients (7%) developed laboratory tumor lysis syndrome (TLS), including 3 (4%) with clinical TLS. Venetoclax resulted in a high response rate and a prolonged PFS in patients with heavily pretreated LPL/WM.

Ibrutinib and Venetoclax in Relapsed and Refractory Follicular Lymphoma

BACKGROUND

Bruton tyrosine kinase (BTK) inhibitors are approved in several B-cell malignancies, including the recent authorization of zanubrutinib for relapsed or refractory follicular lymphoma (FL).

METHODS

Based on preclinical studies demonstrating synergy with ibrutinib and the B-cell lymphoma (BCL)-2 inhibitor, venetoclax, in FL cell lines, we conducted a multicenter phase Ib/II study evaluating this combination in relapsed or refractory FL.

RESULTS

The recommended phase 2 dose was ibrutinib 560 mg and venetoclax 600 mg. There was no evidence of clinical tumor lysis syndrome, despite the omission of a venetoclax ramp up. At a median duration of therapy of 6 months, the most common adverse events were low grade diarrhea (83%), infection (75%), and rash (58%). Amongst the 24 patients enrolled, the overall and complete response (CR) rates were 63% and 21%. At a median follow up of 6.9 months, the median progression-free survival was 8.2 months, and the median duration of CR (n = 5) was 38 months.

CONCLUSION

The combination of a BTK and BCL2 inhibitor is efficacious in relapsed/refractory FL and represents a unique dual-targeted approach warranting further investigation.

Treatment outcomes of BTK inhibitors and venetoclax with or without anti-CD20 monoclonal antibody in relapsed or refractory mantle cell lymphoma

To characterise the effectiveness of Bruton tyrosine kinase inhibitors with venetoclax in patients with refractory or relapsed mantle cell lymphoma, with or without the addition of an anti-CD20 antibody. Progression-free and overall survival were estimated for forty-nine patients treated with Bruton tyrosine kinase inhibitors and venetoclax (200 mg, daily) or in combination with an anti-CD20 monoclonal antibody between June 2018 and February 2022 in China. The median number of treatment lines before combination therapy was three (range, 2-7). The median patient age was 62 years, with a male-to-female ratio of 3.08:1. Patients exhibited high-risk features including Ki-67 ≥ 30% (89.8%), blastoid/pleomorphic histology (36.7%), high-risk mantle cell lymphoma International Prognostic Index group (42.9%), complex karyotype (27.7%), TP53 mutations (71.4%), TP53 mutations combined with other high-risk gene mutations including KMT2D, NSD2, CCND1, NOTCH1, CDKN2A, NOTCH2 and SMARCA4 (57.1%), and progression of disease within 24 months (65.3%), with similar efficacy and prognosis to low-risk cases. Basic clinical and cytogenetic characteristics, as well as efficacy and survival, were similar between the dual and triple combination therapy groups (all p > 0.05). The optimal overall response and complete remission rates were 67.4% and 53.1%, respectively. The 3-year progression-free and overall survival rates were 37.5% and 50.8%, respectively. Eastern Cooperative Oncology Group≥2was an independent predictor of progression-free survival. Eastern Cooperative Oncology Group performance status ≥ 2, TP53 mutations combined with other high-risk gene mutationswere independent factors for poor overall survival. The most common adverse reactions were haematological and pulmonary infections. The leading cause of death was disease progression (19/22). The combination of Bruton tyrosine kinase inhibitors and venetoclax, demonstrated good efficacy in patients with refractory or relapsed mantle cell lymphoma, particularly in the early treatment. There was no efficacy or survival advantages of adding CD20 antibodies. Patients in the ultrahigh-risk group required more aggressive treatments.

Advances in classification and treatment of primary cutaneous lymphomas

Primary cutaneous lymphomas (PCLs) are a heterogeneous group of extranodal non-Hodgkin lymphomas, characterized with skin involvement as the primary or predominant manifestation. While early-stage PCLs typically have a favorable prognosis, managing patients with aggressive progression or advaced stages remains a challenge. Recent advancements in molecular biology and sophisticated clinical laboratory tests have significantly improved the classification and management of PCLs, which provide more targeted and effective treatment strategies for patients. This review summarizes the latest classification schemes and therapeutic options for PCLs, with a focus on the latest developments and future directions in the field.

The BCL2 family: from apoptosis mechanisms to new advances in targeted therapy

The B cell lymphoma 2 (BCL2) protein family critically controls apoptosis by regulating the release of cytochrome c from mitochondria. In this cutting-edge review, we summarize the basic biology regulating the BCL2 family including canonical and non-canonical functions, and highlight milestones from basic research to clinical applications in cancer and other pathophysiological conditions. We review laboratory and clinical development of BH3-mimetics as well as more recent approaches including proteolysis targeting chimeras (PROTACs), antibody-drug conjugates (ADCs) and tools targeting the BH4 domain of BCL2. The first BCL2-selective BH3-mimetic, venetoclax, showed remarkable efficacy with manageable toxicities and has transformed the treatment of several hematologic malignancies. Following its success, several chemically similar BCL2 inhibitors such as sonrotoclax and lisaftoclax are currently under clinical evaluation, alone and in combination. Genetic analysis highlights the importance of BCL-XL and MCL1 across different cancer types and the possible utility of BH3-mimetics targeting these proteins. However, the development of BH3-mimetics targeting BCL-XL or MCL1 has been more challenging, with on-target toxicities including thrombocytopenia for BCL-XL and cardiac toxicities for MCL1 inhibitors precluding clinical development. Tumor-specific BCL-XL or MCL1 inhibition may be achieved by novel targeting approaches using PROTACs or selective drug delivery strategies and would be transformational in many subtypes of malignancy. Taken together, we envision that the targeting of BCL2 proteins, while already a success story of translational research, may in the foreseeable future have broader clinical applicability and improve the treatment of multiple diseases.

Prognostic outcomes of diffuse large B-cell lymphoma patients with myelocytomatosis oncogene (MYC) and B-cell lymphoma 2 (BCL2) co-expression

Double expressor lymphoma (DEL) refers to diffuse large B-cell lymphoma (DLBCL) cases characterized by the overexpression of both MYC and BCL2 proteins, as determined by immunohistochemistry (IHC), without requiring underlying genetic rearrangements. DEL is associated with more aggressive disease behavior and poorer prognosis. This study aimed to assess the impact of DEL on progression-free survival (PFS) and overall survival (OS) compared to non-DEL patients. We conducted a retrospective study at the Hospital, analyzing 177 patients diagnosed with DLBCL between March 2014 and March 2021. Patients were classified as DEL or non-DEL based on immunohistochemical analysis. Survival rates, clinical characteristics, and treatment responses were compared using Kaplan-Meier survival analysis, and multivariable Cox regression was performed to identify independent prognostic factors. Among 177 patients, 113 (63.8%) were DEL and 64 (36.2%) non-DEL. DEL patients had significantly worse outcomes, with a median follow-up of 39.4 months. The 3-year PFS (44.2% vs. 68.8%) and OS (54.9% vs. 81.3%) were significantly lower in DEL (PFS: p < 0.001; OS: p = 0.001). Median PFS in DEL was 19 months. Multivariable analysis confirmed DEL as an independent predictor of worse PFS (HR: 1.488, 95% CI: 1.091-2.03, p = 0.012) and OS (HR: 1.376, 95% CI: 1.011-1.873, p = 0.043). DEL status is strongly linked to poor survival in DLBCL, highlighting the need for targeted therapies beyond R-CHOP. Future research should explore personalized treatment strategies to improve outcomes in this high-risk group.

Updates on the Treatment of Richter's Syndrome, Including Novel Combination Approaches

Richter's syndrome (RS) or transformation of chronic lymphocytic leukemia (CLL) into a more aggressive lymphoma (e.g., diffuse large B cell lymphoma, DLBCL) is a distinct disease that portends an overall poor prognosis and remains a challenge for clinicians to identify and treat effectively. This review of the current literature focuses on the pathology, diagnosis, and management of Richter's syndrome. Clonally related RS has been found to have a worse prognosis than unrelated disease and the genomic profile of DLBCL-RS differs from that of de novo DLBCL. The standard of care therapy for RS has historically been chemoimmunotherapy; consolidative stem cell transplants have a role in improving durability of disease response. Given generally poor response rates to chemotherapy, there have been recent investigations into combination treatments with immune checkpoint inhibitors and small molecule targeted therapies, which have had mixed results. Additional studies are evaluating the use of bispecific antibodies, chimeric antigen receptor T cell therapy, and antibody drug conjugates. RS remains difficult to manage; however, advancements in the understanding of the underlying pathology of transformation and continued investigations into new therapies demonstrate promise for the future.

Research progress on gene mutations and drug resistance in leukemia

Leukemia is a type of blood cancer characterized by the uncontrolled growth of abnormal cells in the bone marrow, which replace normal blood cells and disrupt normal blood cell function. Timely and personalized interventions are crucial for disease management and improving survival rates. However, many patients experience relapse following conventional chemotherapy, and increasing treatment intensity often fails to improve outcomes due to mutated gene-induced drug resistance in leukemia cells. This article analyzes the association of gene mutations and drug resistance in leukemia. It explores genetic abnormalities in leukemia, highlighting recently identified mutations affecting signaling pathways, cell apoptosis, epigenetic regulation, histone modification, and splicing mechanisms. Additionally, the article discusses therapeutic strategies such as molecular targeting of gene mutations, alternative pathway targeting, and immunotherapy in leukemia. These approaches aim to combat specific drug-resistant mutations, providing potential avenues to mitigate leukemia relapse. Future research with these strategies holds promise for advancing leukemia treatment and addressing the challenges of drug-resistant mutations to improve patient outcomes.

Challenges of treating mantle cell lymphoma in older adults

Mantle cell lymphoma (MCL) is a rare, incurable B-cell non-Hodgkin lymphoma and over half of patients affected are older adults (≥65 years of age). New targeted treatments for MCL have emerged over the past two decades. Nonetheless, MCL-specific death rates for older adults remain elevated compared with younger adults, demonstrating the challenge of treating this population. The older adult population is at risk for overtreatment or undertreatment. Clinicians must be mindful of how to optimize the holistic care of older adults receiving treatment for MCL. Evaluating fitness through a geriatric assessment (GA) is an important step when choosing therapy. The treatment armamentarium includes both chemotherapy and non-chemotherapy options and toxicities must be considered in the context of the patient's GA and proactively managed. Herein, the treatment of MCL in older adults is reviewed and strategies for choosing treatment are offered to assist in treatment decision-making for this challenging population.

"The End of the Golden Weather": therapeutic strategies for mantle cell lymphoma relapsed or refractory to covalent BTK inhibitors

Mantle cell lymphoma (MCL) is a subtype of non-Hodgkin lymphoma, often characterized by a pattern of continued relapse after front-line chemoimmunotherapy. Although patients are usually able to regain durable disease control with covalent Bruton's tyrosine kinase inhibitors (cBTKi) at first relapse, it is now appreciated that such responses are often not sustained and the management of such patients represents a significant area of unmet need. There is an imperative to better understand resistance mechanisms and identify high-risk subsets of patients for whom cBTKi responses may be particularly short. Allogeneic stem cell transplant has an established role in appropriate candidates; however, contemporary consensus is to preferentially offer chimeric antigen receptor (CAR) T-cell therapy. In this Review, we consider the available data on both existing and emerging treatment options, including non-covalent BTK inhibitors, bispecific antibodies, antibody-drug conjugates and Bcl-2 inhibitors, and propose a treatment strategy, prioritizing clinical trials where available.

SOHO State of the Art Updates and Next Questions | Contemporary Standard of Care Therapy for Richter's Transformation and Future Directions

Richter's transformation (RT) is a life-threatening evolution of chronic lymphocytic leukemia (CLL) into a more aggressive lymphoma, typically diffuse large B-cell lymphoma (DLBCL), marking a challenging juncture in CLL management due to the associated poor prognosis and limited treatment options. This review delves into the current therapeutic landscape for RT. Despite the modest efficacy of traditional chemoimmunotherapy (CIT) regimens such as R-CHOP and its variations, this regimen remains the most commonly recommended standard of care. Multiple therapeutic strategies are under investigation, including targeted kinase inhibitors, checkpoint inhibitors, bispecific antibodies, and CAR T therapy. Given the complex nature of RT and the evolving therapeutic paradigms, ongoing research is imperative to refine treatment strategies and integrate novel therapeutic agents to enhance survival and quality of life for people with RT. Given the lack of a clear standard of approach in the management of RT, patients with RT should be prioritized to enroll on clinical trials where feasible.

Updates on the Biological Heterogeneity of Mantle Cell Lymphoma

Advancements in mantle cell lymphoma (MCL) have illuminated the disease's molecular diversity, leading to a wide variation in the outcomes observed in MCL. Current prognostic risk scores are continuously revised to incorporate new updates in the mechanistic or biologic understanding of MCL. Nevertheless, key high-risk features of MCL associated with rapid disease progression and poor survival, such as TP53 mutations, complex karyotypes, and blastoid or pleomorphic morphologies, remain absent from available prognostic tools. The greater accessibility of genomic technologies, such as next-generation sequencing (NGS), has enabled clinicians to identify specific genetic alterations that serve as prognostic signals and disease monitoring parameters, cultivating accurate risk profiling that is illustrative of MCL heterogeneity. Through an increased understanding of distinct MCL behaviors, novel therapies that mechanistically target disease biology, including Bruton's tyrosine kinase inhibitors, BCL-2 inhibitors, ROR1 inhibitors, and bispecific T-cell engagers, have broadened the treatment armamentarium for relapsed/refractory MCL cases. These interventions, in addition to chemoimmunotherapy and autologous stem cell transplantation mainstays, confer the individualization of treatment and improved survival outcomes. Further exploration of the considerable biological heterogeneity of MCL can enhance knowledge, management, and the treatment of this rare lymphoma subtype.

Frontline management of mantle cell lymphoma

ABSTRACT

Despite many recent therapeutic advances, mantle cell lymphoma (MCL) remains a largely incurable disease. Treatments for patients with relapsed/refractory (R/R) disease are limited in number and in response durability. Therefore, improving the efficacy of frontline (1L) treatment, and specifically maximizing the duration of first remission, remains of critical importance to obtain favorable long-term outcomes. As 1L treatments become more effective, improving tolerability is also becoming an increasingly realistic goal. Targeted agents, which are now mainstays of treatment in R/R MCL, are establishing new, paradigm-changing roles in frontline treatment. Here, we review data supporting current standard-of-care approaches and explore 6 main areas of possible focus for advancement of 1L management: optimizing the chemoimmunotherapy (CIT) backbone, adding targeted agents to CIT, redefining the role of autologous stem cell transplantation, improving maintenance therapy, using targeted agent combinations with omission of CIT, and using measurable residual disease-guided therapy. We highlight several ongoing phase 3 trials that may soon impact frontline MCL management, and outline some areas of necessary investigation as the field continues to strive toward a cure for this disease.

Unraveling MCL biology to understand resistance and identify vulnerabilities

ABSTRACT

Mantle cell lymphoma (MCL) is a rare (5%-7%), aggressive B-cell non-Hodgkin lymphoma with well-defined hallmarks (eg, cyclin D1, SOX11), and its expansion is highly dependent on the tumor microenvironment (TME). Parallel drastic progress in the understanding of lymphomagenesis and improved treatments led to a paradigm shift in this B-cell malignancy with now prolonged disease-free survival after intensive chemotherapy and anti-CD20-based maintenance. However, this toxic strategy is not applicable in frail or older patients, and a small but significant part of the cases present a refractory disease representing unmet medical needs. Importantly, the field has recently seen the rapid emergence of targeted and immune-based strategies with effective combinations relying on biological rationales to overcome malignant plasticity and intratumor heterogeneity. In this review, we expose how unraveling the biology of MCL allows to better understand the therapeutic resistances and to identify neo-vulnerabilities in tumors, which are essential to offer efficient novel strategies for high-risk patients. We first highlight the tumor intrinsic resistance mechanisms and associated Achilles heels within various pathways, such as NF-κB, mitochondrial apoptosis, DNA repair, and epigenetic regulators. We then place the tumor in its complex ecosystem to decipher the dialog with the multiple TME components and show how the resulting protumoral signals could be disrupted with innovative therapeutic strategies. Finally, we discuss how these progresses could be integrated into a personalized approach in MCL.

Systems biology-enabled targeting of NF-κΒ and BCL2 overcomes microenvironment-mediated BH3-mimetic resistance in DLBCL

In Diffuse Large B-cell Lymphoma (DLBCL), elevated anti-apoptotic BCL2-family proteins (e.g., MCL1, BCL2, BCLXL) and NF-κB subunits (RelA, RelB, cRel) confer poor prognosis. Heterogeneous expression, regulatory complexity, and redundancy offsetting the inhibition of individual proteins, complicate the assignment of targeted therapy. We combined flow cytometry "fingerprinting", immunofluorescence imaging, and computational modeling to identify therapeutic vulnerabilities in DLBCL. The combined workflow predicted selective responses to BCL2 inhibition (venetoclax) and non-canonical NF-κB inhibition (Amgen16). Within the U2932 cell line we identified distinct resistance mechanisms to BCL2 inhibition in cellular sub-populations recapitulating intratumoral heterogeneity. Co-cultures with CD40L-expressing stromal cells, mimicking the tumor microenvironment (TME), induced resistance to BCL2 and BCLXL targeting BH3-mimetics via cell-type specific upregulation of BCLXL or MCL1. Computational models, validated experimentally, showed that basal NF-κB activation determined whether CD40 activation drove BH3-mimetic resistance through upregulation of RelB and BCLXL, or cRel and MCL1. High basal NF-κB activity could be overcome by inhibiting BTK to resensitize cells to BH3-mimetics in CD40L co-culture. Importantly, non-canonical NF-κB inhibition overcame heterogeneous compensatory BCL2 upregulation, restoring sensitivity to both BCL2- and BCLXL-targeting BH3-mimetics. Combined molecular fingerprinting and computational modelling provides a strategy for the precision use of BH3-mimetics and NF-κB inhibitors in DLBCL.

Ibrutinib plus venetoclax in relapsed or refractory mantle cell lymphoma (SYMPATICO): a multicentre, randomised, double-blind, placebo-controlled, phase 3 study

BACKGROUND

The combination of ibrutinib and venetoclax leverages complementary mechanisms of action and has shown promising clinical activity in mantle cell lymphoma (MCL). This study evaluated the efficacy and safety of ibrutinib-venetoclax compared with ibrutinib-placebo in patients with relapsed or refractory MCL.

METHODS

SYMPATICO is a multicentre, randomised, double-blind, placebo-controlled, phase 3 study performed at 84 hospitals in Europe, North America, and Asia-Pacific. Eligible patients were adults (aged ≥18 years) with pathologically confirmed relapsed or refractory MCL after one to five previous lines of therapy and an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2. Patients were randomly assigned (1:1) to receive oral ibrutinib 560 mg once daily concurrently with oral venetoclax (5-week ramp-up to 400 mg once daily) or placebo for 2 years, then single-agent ibrutinib 560 mg once daily until disease progression or unacceptable toxicity. Randomisation and treatment assignment occurred via interactive response technology using a stratified permuted block scheme (block sizes of 2 and 4) with stratification by ECOG performance status, previous lines of therapy, and tumour lysis syndrome risk category. Patients and investigators were masked to treatment assignment. The primary endpoint was investigator-assessed progression-free survival in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03112174, and is closed to enrolment.

FINDINGS

Between April 26, 2018, and Aug 28, 2019, 267 patients were enrolled and randomly assigned; 134 to the ibrutinib-venetoclax group and 133 to the ibrutinib-placebo group. 211 (79%) of 267 patients were male and 56 (21%) were female. With a median follow-up of 51·2 months (IQR 48·2-55·3), median progression-free survival was 31·9 months (95% CI 22·8-47·0) in the ibrutinib-venetoclax group and 22·1 months (16·5-29·5) in the ibrutinib-placebo group (hazard ratio 0·65 [95% CI 0·47-0·88]; p=0·0052). The most common grade 3-4 adverse events were neutropenia (42 [31%] of 134 patients in the ibrutinib-venetoclax group vs 14 [11%] of 132 patients in the ibrutinib-placebo group), thrombocytopenia (17 [13%] vs ten [8%]), and pneumonia (16 [12%] vs 14 [11%]). Serious adverse events occurred in 81 (60%) of 134 patients in the ibrutinib-venetoclax group and in 79 (60%) of 132 patients in the ibrutinib-placebo group. Treatment-related deaths occurred in three (2%) of 134 patients in the ibrutinib-venetoclax group (n=1 COVID-19 infection, n=1 cardiac arrest, and n=1 respiratory failure) and in two (2%) of 132 patients in the ibrutinib-placebo group (n=1 cardiac failure and n=1 COVID-19-related pneumonia).

INTERPRETATION

The combination of ibrutinib-venetoclax significantly improved progression-free survival compared with ibrutinib-placebo in patients with relapsed or refractory MCL. The safety profile was consistent with known safety profiles of the individual drugs. These findings suggest a positive benefit-risk profile for ibrutinib-venetoclax treatment.

FUNDING

Pharmacyclics (an AbbVie Company) and Janssen Research and Development.

A First-in-Human Phase I Study of LOXO-338, an Oral Selective Bcl-2 Inhibitor, in Patients With Advanced Hematologic Malignancies

BACKGROUND

LOXO-338 is a novel, orally bioavailable small-molecule inhibitor of Bcl-2, designed to achieve selectivity for Bcl-2 over Bcl-xL, thus avoiding dose-limiting thrombocytopenia associated with Bcl-xL inhibition. This first-in-human, open-label, Phase 1 study investigated LOXO-338 in patients with chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL), or B-cell non-Hodgkin lymphoma (NHL) (NCT05024045).

PATIENTS AND METHODS

Patients with histologically confirmed advanced B-cell malignancies who had received ≥ 2 prior therapies were enrolled in Phase 1 dose escalation (interval 3 + 3 design). LOXO-338 was administered orally as 50 to 300 mg once-daily dose until discontinuation due to progressive disease or unacceptable toxicity. The primary objective was to determine the maximum tolerated dose (MTD)/recommended Phase 2 dose of LOXO-338. Secondary objectives included safety, tolerability, pharmacokinetics, and preliminary antitumor activity.

RESULTS

In total, 27 patients with CLL/SLL (n = 10) or NHL (n = 17) were treated. No dose-limiting toxicities occurred and the MTD was not reached. Treatment-emergent adverse events occurred in 23 patients (85%); anemia (22%) and fatigue (22%) were the most prevalent. Treatment-related adverse events (TRAEs) occurred in 15% and were mostly grade 1 (11%) or 2 (4%); grade ≥ 3 or serious TRAEs were not reported. Tumor lysis syndrome was not observed. The overall response rate was 19% (95% CI: 6.3, 38.1) and disease control rate was 67% (95% CI: 46, 83.5). LOXO-338 was orally bioavailable with dose-dependent increases in exposure.

CONCLUSION

LOXO-338 was well tolerated with a favorable safety profile in previously treated patients with advanced hematologic malignancies. Preliminary efficacy was observed in this heavily pretreated population supporting further investigation.

Chimeric Antigen Receptor-T Cells in the Modern Era of Chronic Lymphocytic Leukemia Treatment

Pathway inhibitors targeting Bruton tyrosine kinase (BTK) and B-cell lymphoma-2 (BCL-2) have dramatically changed the treatment landscape for both treatment-naïve and relapsed/refractory chronic lymphocytic leukemia (CLL). However, with increased utilization, a growing number of patients will experience progressive disease on both agents. This subgroup of "double refractory" patients has limited treatment options and poor prognosis. Chimeric antigen receptor (CAR)-T cells have transformed the treatment of relapsed/refractory B-cell malignancies. Although the earliest success of CAR-T cell therapy was in CLL, the clinical application of this modality has lagged until the recent approval of the first CAR-T cell product for CLL. In this review, we describe the current treatment options for upfront and subsequent therapies and the unmet need for novel agents highlighted by the burgeoning role and challenges of CAR-T cell therapy.

Follicular lymphoma research: an open dialogue for a collaborative roadmap

Follicular lymphoma (FL) is the second most common type of lymphoma (20% of all non-Hodgkin lymphomas), derived from germinal centre (GC) B cells, and is characterised by its significant clinical, prognostic and biological heterogeneity, leading to complexity in management. Despite significant biological investigation and indisputable clinical progress since the advent of the immunotherapy era more than 20 years ago, much remains to be done to understand and cure this lymphoma. Today, FL is metaphorically a giant puzzle on the table with patches of sky, landscape and foliage clearly appearing. However, many of the remaining pieces are held by various stakeholders (e.g. clinicians, pathologists, researchers, drug developers) without global agreement on what the gaps are, or any clear blueprint on how to solve the puzzle of understanding the heterogeneity of this disease and create curative and tailored therapies. With the advent of new investigation and drug technologies, together with recent advances in our capacity to manage big data, the time seems ripe for a change of scale. More than ever, this will require collaboration between and within all stakeholders to overcome the current bottlenecks in the field. As for every investigator, we acknowledge that this first draft is necessarily biased, incomplete and some FL expert readers might recognise some remaining gaps not addressed. We hope they will reply to make this effort a collaborative one to assemble all the pieces in the most ideal fashion. As such, this review intends to be a first step and an interactive platform to a collaborative roadmap towards better understanding and care of FL.

BCMA CAR-T induces complete and durable remission in plasmablastic lymphoma synchronous transformation of chronic lymphocytic leukemia: Case report and literature review

Richter transformation is still a serious risk in the era of innovative therapies, despite the fact that targeted therapy with Bruton's tyrosine kinase inhibitor has significantly improved the prognosis for chronic lymphocytic leukemia (CLL). We report a rare case of a 61-year-old male patient's CLL transforming into a synchronous clonal related plasmablastic lymphoma (PBL) after receiving ibrutinib. During COVID-19, the patient stopped taking ibrutinib, which caused the illness to worsen. Histology revealed that PBL was present in the right supraclavicular mass and that CLL had penetrated the bone marrow. Three cycles of CHP (cyclophosphamide, doxorubicin, and prednisone) were administered together with venetoclax and brentuximab vedotin. After receiving BCMA CAR-T cell treatment, the patient was in complete remission. For PBL transformation, a condition with a worse prognosis and few therapy choices, our results suggest the use of BCMA CAR-T and novel target agents.

Updates in the Management of Richter Transformation

Richter transformation (RT) is a rare albeit devastating complication of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL). RT is defined as an aggressive lymphoma, typically diffuse large B-cell lymphoma, in the setting of CLL. A clonal relationship to the preceding CLL clone is detected in the majority of RT cases and confers more aggressive clinicopathologic kinetics, resistance to standard chemoimmunotherapy regimens, and inferior survival. Taken together, these considerations precipitate a significant unmet need for novel therapeutic strategies that improve the outcomes of patients with RT. Through this review, we will explore current data on emerging regimens targeting BTK, BCL-2, CD79, CD20, PI3K, and PD-1-both as single agents and as combination therapies with or without concurrent chemoimmunotherapy. Furthermore, we will review the role of bispecific T-cell engagers, anti-CD19 chimeric antigen receptor T-cell therapies, and hematopoietic stem cell transplantation in RT. To guide therapeutic decision-making, we will outline an algorithmic approach to the management of RT, with particular emphasis on prioritization of clinical trial enrollment and utilization of an ever-evolving array of novel therapies.

Multi-Component, Time-Course screening to develop combination cancer therapies based on synergistic toxicity

Clinical trials in cancer are ideally built on a foundation of sound mechanistic rationale and well-validated drug activity in relevant disease models. The screening of approved and investigational drugs in cell-based phenotypic assays can provide evidence of drug activity, but alternative screening paradigms are needed to develop and optimize multidrug combination regimens. Here, we utilize in vitro screening outcomes across a panel of lymphoma cell lines to dissect the activity of four small-molecule drugs (Venetoclax, Ibrutinib, Prednisolone, and Lenalidomide) currently under investigation within ongoing clinical trials in lymphoma. Data from multiple concentration ranges and time points show that synergistic drug combinations promote apoptosis and cytotoxicity responses at concentrations and time points that are consistent with in vivo drug exposures. To fully map the interaction landscape of these agents in relevant cell models, we developed an in vitro assay format that facilitated time-course evaluations involving concurrent multidrug exposure which further highlighted rapid, synergistic apoptosis induction as a central engine for the activity of this multicomponent targeted therapy. In addition to several instances of exceptional drug+drug synergy, the genetically similar diffuse large B cell lymphoma models also displayed substantial heterogeneity in the degree of synergism between drug pairs. A parallel survey of chemotherapies exhibited limited combination benefit, supporting recent findings that multicomponent chemotherapy outcomes are driven by individual drug activity. Collectively, these data demonstrate how in vitro drug screening data can identify multidrug combinations that exploit drug synergy to overcome the functional diversity of human malignancies.

Advances in the understanding of molecular genetics and therapy of Richter transformation in chronic lymphocytic leukemia

Richter's transformation (RT) is defined as the evolution of chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) into an aggressive lymphoma, most commonly diffuse large B-cell lymphoma. This complication is rare and aggressive, with poor prognosis and dismal survival. Clonal relationship with the underlying CLL/SLL, observed in ∼80% of cases, represents one of the main factors affecting prognosis. Treatment has been historically based on chemoimmunotherapy, but frequent mutations in genes involved in cell survival and proliferation-such as TP53, NOTCH1, MYC, CDKN2A-confer resistance to standard treatments. During the last years, advances in the knowledge of the biological mechanisms underlying RT allowed to identify genetic and molecular lesions that can potentially be targeted by novel selective agents. Pathway and checkpoint inhibitors, bispecific antibodies and CAR T-cell therapy are currently under investigation and represent promising treatment options. This review summarizes current biological evidence and available data on novel therapeutic agents.

Advancing the understanding of venetoclax in t(11;14)-positive multiple myeloma: a comprehensive review of clinical evidence and future prospects

Venetoclax is a selective inhibitor of the anti-apoptotic protein B-cell lymphoma 2 (BCL2), as a targeted therapy for multiple myeloma (MM) patients. It was initially approved by the United States Food and Drug Administration for the treatment of chronic lymphocytic leukemia in April 2016 and later for acute myeloid leukemia in October 2020. However, venetoclax is used as an off-label in a subset group of relapsed and refractory multiple myeloma (RRMM) patients with the presence of translocation t(11;14). Preclinical and clinical studies have highlighted the potential of venetoclax in the management of MM patients, with a specific focus on t(11;14) as a predictive biomarker for initiating venetoclax-based treatment. Later, several studies in RRMM patients that used venetoclax in combination with dexamethasone or/and proteasome inhibitors have shown promising results, in which management guidelines have included venetoclax as one of the options to treat MM patients. Hence, this review focuses on the use of venetoclax in RRMM, clinical efficacy, safety, dosing strategies, and predictive biomarkers for initiating venetoclax. Additionally, we discuss ongoing studies that are investigating different combination of venetoclax regimens in MM patients.

Increased CCL2/CCR2 axis promotes tumor progression by increasing M2 macrophages in MYC/BCL2 double-expressor DLBCL

ABSTRACT

The pathogenesis of myelocytomatosis oncogene (MYC) and B-cell lymphoma 2 (BCL2) double-expressor diffuse large B-cell lymphoma (DE-DLBCL) remains unclear. To investigate how MYC and BCL2 contribute to tumor aggressiveness, we analyzed tumors from 14 patients each with DE-DLBCL and non-DE-DLBCL using whole transcriptome sequencing. Validation was performed using publicly available data sets, tumor tissues from 126 patients, DLBCL cell lines, and a syngeneic mouse lymphoma model. Our transcriptome analysis revealed significantly elevated messenger RNA levels of C-C motif chemokine ligand 2 (CCL2) and C-C chemokine receptor type 2 (CCR2) in DE-DLBCLs when compared with non-DE-DLBCLs (adjusted P value < .05). Transcriptomic analysis of public data sets and immunohistochemistry corroborated these findings, indicating increased levels of M2 macrophages but a reduction in T-cell infiltration in DE-DLBCLs when compared with non-DE-DLBCLs (all P < .05). CCR2 expression was observed mainly in tumor-infiltrating macrophages and not in DLBCL cells. Increased expression of CCL2 and CCR2 was significantly associated with a poor prognosis in patients with DLBCL. In the in vitro analyses, MYChigh/BCL2high DLBCL cells showed higher CCL2 expression and secretion than MYClow/BCL2low cells. MYC and BCL2 increased CCL2 expression and secretion by upregulation of nuclear factor κB p65 in DLBCL cells, and CCL2 promoted M2 polarization of macrophages. In a mouse lymphoma model, CCL2 contributed to the immunosuppressive microenvironment and tumor growth of MYChigh/BCL2high tumors. We demonstrated that the increased CCL2/CCR2 axis confers aggressiveness to DE-DLBCL by increasing M2 polarization and can be a potential therapeutic target.

Therapeutic advances in the targeting of ROR1 in hematological cancers

Receptor tyrosine kinases (RTKs) are key cell surface receptors involved in cell communication and signal transduction, with great importance in cell growth, differentiation, survival, and metabolism. Dysregulation of RTKs, such as EGFR, VEGFR, HER2 or ROR, could lead to various diseases, particularly cancers. ROR1 has emerged as a promising target in hematological malignancies. The development of ROR1 targeted therapies is continuously growing leading to remarkable novel therapeutical approaches using mAbs, antibody-drug conjugates, several small molecules or CAR T cells which have shown encouraging preclinical results. In the hematological field, mAbs, small molecules, BiTEs or CAR T cell therapies displayed promising outcomes with the clinical trials data encouraging the use of anti-ROR1 therapies. This paper aims to offer a comprehensive analysis of the current landscape of ROR1-targeted therapies in hematological malignancies marking the innovative approaches with promising preclinical and clinical. Offering a better understanding of structural and functional aspects of ROR1 could lead to new perspectives in targeting a wide spectrum of malignancies.

Combination Treatment of Resistant Acute Promyelocytic Leukemia Cells with Arsenic Trioxide and Anti-Apoptotic Gene Inhibitors

BACKGROUND

Arsenic trioxide (ATO) is an anticancer agent for treating acute promyelocytic leukemia (APL). However, 5-10% of patients fail to respond, developing relapsed/refractory disease. The aim of this study was to identify potential new therapeutic approaches for ATO-unresponsive APL by targeting the anti-apoptotic genes that contribute to drug resistance.

METHODS

RNA expression of dysregulated genes involved in the apoptotic pathway was analyzed by comparing ATO-resistant APL cell clones generated in our lab with the corresponding sensitive clones, at basal levels and after 48 h of treatment with ATO.

RESULTS

ATO-resistant APL cells showed upregulation of APAF1, BCL2, BIRC3, and NOL3 genes, while CD70 and IL10 genes were downregulated, compared to ATO-sensitive cells. Treatment with ATO strongly increased the expression of the anti-apoptotic genes BIRC3, NOL3, and BCL2A1 and significantly downregulated BCL2 in ATO-sensitive clones. Although all these genes can be relevant to ATO-resistance, we selected BCL2 and BIRC3 as druggable targets. A direct correlation between BCL2 expression and the sensitivity to the BCL2 inhibitor venetoclax was observed, indicating BCL2 as predictive biomarker of the response. Moreover, the combination of venetoclax with ATO exerted synergistic cytotoxic effects, thus reverting the resistance to ATO. APL treatment with SMAC mimetics such as LCL161 and xevinapant (inhibitors of BIRC3) was not as effective as the BCL2 inhibitor as a monotherapy but exerted synergistic effects in combination with ATO in cells with low BIRC expression.

CONCLUSIONS

This study demonstrates the therapeutic potential of venetoclax in combination with ATO in vitro and strongly encourages further investigation of relapsed/refractory APL with high BCL2 expression.

Wogonin induces mitochondrial apoptosis and synergizes with venetoclax in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is among the most aggressive hematological malignancies and patients are commonly treated with combinatorial immunochemotherapies such as R-CHOP. Till now, the prognoses are still variable and unsatisfactory, depending on the molecular subtype and the treatment response. Developing effective and tolerable new agents is always urgently needed, and compounds from a natural source have gained increasing attentions. Wogonin is an active flavonoid extracted from the traditional Chinese herbal medicine Scutellaria baicalensis Georgi and has shown extensive antitumor potentials. However, the therapeutic effect of wogonin on DLBCL remains unknown. Here, we found that treatment with wogonin dose- and time-dependently reduced the viability in a panel of established DLBCL cell lines. The cytotoxicity of wogonin was mediated through apoptosis induction, along with the loss of mitochondrial membrane potential and the downregulation of BCL-2, MCL-1, and BCL-xL. In terms of the mechanism, wogonin inhibited the PI3K and MAPK pathways, as evidenced by the clear decline in the phosphorylation of AKT, GSK3β, S6, ERK, and P38. Furthermore, the combination of wogonin and the BCL-2 inhibitor venetoclax elicited synergistically enhanced killing effect on DLBCL cells regardless of their molecular subtypes. Finally, administration of wogonin significantly impeded the progression of the DLBCL tumor in a xenograft animal model without obvious side effects. Taken together, the present study suggests a promising potential of wogonin in the treatment of DLBCL patients either as monotherapy or an adjuvant for venetoclax-based combinations.

Profiling protein-protein interactions to predict the efficacy of B-cell-lymphoma-2-homology-3 mimetics for acute myeloid leukaemia

B-cell-lymphoma-2 (BCL2) homology-3 (BH3) mimetics are inhibitors of protein-protein interactions (PPIs) that saturate anti-apoptotic proteins in the BCL2 family to induce apoptosis in cancer cells. Despite the success of the BH3-mimetic ABT-199 for the treatment of haematological malignancies, only a fraction of patients respond to the drug and most patients eventually develop resistance to it. Here we show that the efficacy of ABT-199 can be predicted by profiling the rewired status of the PPI network of the BCL2 family via single-molecule pull-down and co-immunoprecipitation to quantify more than 20 types of PPI from a total of only 1.2 × 106 cells per sample. By comparing the obtained multidimensional data with BH3-mimetic efficacies determined ex vivo, we constructed a model for predicting the efficacy of ABT-199 that designates two complexes of the BCL2 protein family as the primary mediators of drug effectiveness and resistance, and applied it to prospectively assist therapeutic decision-making for patients with acute myeloid leukaemia. The characterization of PPI complexes in clinical specimens opens up opportunities for individualized protein-complex-targeting therapies.

Synergistic effect of venetoclax and ibrutinib on ibrutinib-resistant ABC-type DLBCL cells

Despite the widespread use of R-CHOP therapy in diffuse large B-cell lymphoma (DLBCL), the therapeutic efficacy for this disease remains suboptimal, primarily due to the heterogeneity of refractory and/or relapsed diseases. To address this challenge, optimization of DLBCL treatment regimens has focused on the strategy of combining an additional drug "X" with R-CHOP to enhance efficacy. However, the failure of R-CHOP combined with the BTK inhibitor ibrutinib in treating ABC-type DLBCL patients has raised significant concerns regarding ibrutinib resistance. While some studies suggest that venetoclax may synergize with ibrutinib to kill ibrutinib-resistant cells, the underlying mechanisms remain unclear. Our study aimed to validate the enhanced tumor-suppressive effect of combining ibrutinib with venetoclax against ibrutinib-resistant cells and elucidate its potential mechanisms. Our experimental results demonstrated that ibrutinib-resistant cells exhibited significant cytotoxicity to the combination therapy of ibrutinib and venetoclax, inducing cell apoptosis through activation of the mitochondrial pathway and inhibition of aerobic respiration. Furthermore, we validated the inhibitory effect of this combination therapy on tumor growth in in vivo models. Therefore, our study proposes that the combination therapy of ibrutinib and venetoclax is a promising treatment strategy that can be applied in clinical practice for ABC-type DLBCL, offering a new solution to overcome the urgent challenge of ibrutinib resistance.

SETD1B mutations confer apoptosis resistance and BCL2 independence in B cell lymphoma

The translocation t(14;18) activates BCL2 and is considered the initiating genetic lesion in most follicular lymphomas (FL). Surprisingly, FL patients fail to respond to the BCL2 inhibitor, Venetoclax. We show that mutations and deletions affecting the histone lysine methyltransferase SETD1B (KMT2G) occur in 7% of FLs and 16% of diffuse large B cell lymphomas (DLBCL). Deficiency in SETD1B confers striking resistance to Venetoclax and an experimental MCL-1 inhibitor. SETD1B also acts as a tumor suppressor and cooperates with the loss of KMT2D in lymphoma development in vivo. Consistently, loss of SETD1B in human lymphomas typically coincides with loss of KMT2D. Mechanistically, SETD1B is required for the expression of several proapoptotic BCL2 family proteins. Conversely, inhibitors of the KDM5 histone H3K4 demethylases restore BIM and BIK expression and synergize with Venetoclax in SETD1B-deficient lymphomas. These results establish SETD1B as an epigenetic regulator of cell death and reveal a pharmacological strategy to augment Venetoclax sensitivity in lymphoma.

Dosing of Venetoclax in Pediatric Patients with Relapsed Acute Myeloid Leukemia: Analysis of Developmental Pharmacokinetics and Exposure-Response Relationships

PURPOSE

This work aimed to characterize the pharmacokinetics and exposure-response relationships of venetoclax in pediatric patients with relapsed or refractory (R/R) acute myeloid leukemia (AML) to identify venetoclax doses to be administered to pediatric patients in the phase 3 study.

METHODS

Data from 121 patients across three phase 1 studies enrolling pediatric patients with R/R malignancies were utilized to develop a population pharmacokinetic model to describe venetoclax pharmacokinetics in pediatric patients. Individual patient average venetoclax plasma concentration up to the event of interest, derived based on the population pharmacokinetics analysis, was used to evaluate the exposure-response relationships to efficacy (complete response) and safety (neutropenia and thrombocytopenia) endpoints for patients with AML who received venetoclax in combination with azacitidine, decitabine, or cytarabine (n = 36). The population pharmacokinetic model was then used to simulate exposures in pediatric age- and weight-based subgroups to identify the venetoclax doses for pediatric patients.

FINDINGS

The pharmacokinetic data were adequately described by the two-compartment population pharmacokinetic model with first-order absorption and elimination. The model accounted for cytochrome P450 3A developmental changes using a maturation function and incorporated allometric scaling to account for growth and body size effect. Weight was identified as a statistically significant covariate on clearance and volume of distribution and retained in the final model. Population pharmacokinetic estimates were comparable to previously reported estimates in adults. Exposure-response analyses suggested that the clinical efficacy of venetoclax in combination with high-dose cytarabine (HDAC) is maximized at 600 mg adult-equivalent, and higher doses are unlikely to enhance clinical efficacy. Venetoclax 600 mg adult-equivalent was selected for further development in combination with HDAC. Additionally, venetoclax 400 mg adult-equivalent was selected for bridging/maintenance therapy in combination with azacitidine. Flat exposure-response relationships were observed with Grade ≥3 neutropenia and thrombocytopenia. Doses were selected based on weight (allometric scaling) for children aged ≥2 years old and based on weight and CYP3A ontogeny for children aged <2 years. The selected age- and weight-based dosing scheme of venetoclax is projected to achieve venetoclax exposures in pediatric subgroups comparable to those observed in adults receiving venetoclax 400 mg or 600 mg.

IMPLICATIONS

This work characterized the pharmacokinetics and exposure-response relationships of venetoclax in pediatric patients and guided the selection of pediatric dosing regimens in support of the venetoclax phase 3 trial in pediatric AML (NCT05183035).

CLINICAL STUDIES

NCT03236857, NCT03181126, and NCT03194932.

Atezolizumab, venetoclax, and obinutuzumab combination in Richter transformation diffuse large B-cell lymphoma (MOLTO): a multicentre, single-arm, phase 2 trial

BACKGROUND

The diffuse large B-cell lymphoma (DLBCL) variant of Richter transformation (DLBCL-RT) is typically chemoresistant with poor prognosis. Aiming to explore a chemotherapy-free treatment combination that triggers anti-tumour immune responses, we conducted a phase 2 study of atezolizumab (a PD-L1 inhibitor) in combination with venetoclax and obinutuzumab in patients with DLBCL-RT.

METHODS

This was a prospective, open-label, multicentre, single-arm, investigator-initiated, phase 2 study in 15 hospitals in Italy and Switzerland. Eligible patients had a confirmed diagnosis of chronic lymphocytic leukaemia or small lymphocytic lymphoma as per the International Workshop on Chronic Lymphocytic Leukemia (IWCLL) 2008 criteria with biopsy-proven transformation to DLBCL; had not previously received treatment for DLBCL-RT, although they could have received chronic lymphocytic leukaemia therapies; were aged 18 years or older; and had an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2. No previous treatment with any of the drugs in the triplet combination was allowed. Patients received 35 cycles of 21 days of intravenous obinutuzumab (100 mg on day 1, 900 mg on day 2, 1000 mg on day 8 and day 15 of cycle 1; 1000 mg on day 1 of cycles 2-8) and intravenous atezolizumab (1200 mg on day 2 of cycle 1 and 1200 mg on day 1 of cycles 2-18), and continuous oral venetoclax (ramp-up from 20 mg/day on day 15 of cycle 1 according to chronic lymphocytic leukaemia schedule, then 400 mg/day from day 1 of cycle 3 to day 21 of cycle 35). The primary endpoint was overall response rate at day 21 of cycle 6 in the intention-to-treat population. We considered an overall response rate of 67% or more to be clinically active, rejecting the null hypothesis of a response of 40% or less. The study is registered with ClinicalTrials.gov, NCT04082897, and has been completed.

FINDINGS

Between Oct 9, 2019, and Oct 19, 2022, 28 patients were enrolled (12 [43%] male patients and 16 [57%] female patients). Median follow-up was 16·8 months (IQR 7·8-32·0). At cycle 6, 19 of 28 patients showed a response, yielding an overall response rate of 67·9% (95% CI 47·6-84·1). Treatment-emergent adverse events that were grade 3 or worse were reported in 17 (61%; 95% CI 40·6-78·5) of 28 patients, with neutropenia being the most frequent (11 [39%; 21·5-59·4] of 28 patients). Serious treatment-emergent adverse events were reported in eight (29%; 14·2-48·7) patients, which were most commonly infections (five [18%; 6·1-36·9] of 28 patients). There were two (7%) deaths attributable to adverse events during the study: one from sepsis and one from fungal pneumonia, which were not considered as directly treatment-related by the investigators. Six (21·4%) patients had immune-related adverse events, none of which led to discontinuation. No tumour lysis syndrome was observed.

INTERPRETATION

The atezolizumab, venetoclax, and obinutuzumab triplet combination was shown to be active and safe, suggesting that this chemotherapy-free regimen could become a new first-line treatment approach in patients with DLBCL-RT.

FUNDING

Roche.

Genomic analysis reveals molecular characterization of CD30+ and CD30- extranodal natural killer/T-cell lymphomas (ENKTLs)

Extranodal natural killer (NK)/T-cell lymphoma (ENKTL) is prevalent in the Asian population; however, little is known about its molecular characteristics. In this study, we examined the CD30 expression in ENKTLs and then performed whole exome sequencing on ten CD30+ ENKTL and CD30- ENKTL paired samples. CD30 was positive in 55.74% of the ENKTLs. Single nucleotide and insertion/deletion polymorphism analyses revealed that 53.41% of the somatic mutations in CD30+ ENKTLs were shared with CD30- ENKTLs, including mutations in SERPINA9, MEGF6, MUC6, and KDM5A. Frequently mutated genes were primarily associated with cell proliferation and migration, the tumor microenvironment, energy and metabolism, epigenetic modulators, vascular remodeling, and neurological function. PI3K-AKT, cAMP, cGMP-PKG, and AMPK pathways were enriched in both CD30+ and CD30- ENKTLs. Copy number variation analysis identified a unique set of genes in CD30+ ENKTLs, including T-cell receptor genes (TRBV6-1 and TRBV8), cell cycle-related genes (MYC and CCND3), immune-related genes (GPS2, IFNA14, TTC38, and CTSV), and a large number of ubiquitination-related genes (USP32, TRIM23, TRIM2, DUSP7, and UBE2QL1). BCL10 mutation was identified in 6/10 CD30+ ENKTLs and 7/10 CD30- ENKTLs. Immunohistochemical analysis revealed that the expression pattern of BCL10 in normal lymphoid tissues was similar to that of BCL2; however, its expression in ENKTL cells was significantly higher (67.92% vs. 16.98%), implying the potential application of BCL10 inhibitors for treating ENKTLs. These results provide new insights into the genetic characteristics of CD30+ and CD30- ENKTLs, and could facilitate the clinical development of novel therapies for ENKTL.

Advances in biology, diagnosis and treatment of DLBCL

Diffuse large B-cell lymphoma (DLBCL), with approximately 150,000 new cases worldwide each year, represent nearly 30% of all cases of non-Hodgkin lymphoma (NHL) and are phenotypically and genetically heterogeneous. A gene-expression profile (GEP) has identified at least three major subtypes of DLBCL, each of which has distinct clinical, biological, and genetic features: activated B-cell (ABC)-like DLBCL, germinal-center B-cell (GCB)-like DLBCL, and unclassified. Different origins are associated with different responses to chemotherapy and targeted agents. Despite DLBCL being a highly heterogeneous disease, more than 60% of patients with DLBCL can be cured after using rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) to inhibit the growth of cancer cells while targeting the CD20 receptor. In recent decades, the improvement of diagnostic levels has led to a refinement classification of DLBCL and the development of new therapeutic approaches. The objective of this review was to summarize the latest studies examining genetic lesions and therapies for DLBCL.

Evasion of apoptosis and treatment resistance in squamous cell carcinoma of the head and neck

Combinations of surgery, radiotherapy and chemotherapy can eradicate tumors in patients with locally advanced squamous cell carcinoma of the head and neck (LA SCCHN), but a significant proportion of tumors progress, recur, or do not respond to therapy due to treatment resistance. The prognosis for these patients is poor, thus new approaches are needed to improve outcomes. Key resistance mechanisms to chemoradiotherapy (CRT) in patients with LA SCCHN are alterations to the pathways that mediate apoptosis, a form of programmed cell death. Targeting dysregulation of apoptotic pathways represents a rational therapeutic strategy in many types of cancer, with a number of proteins, including the pro-survival B-cell lymphoma 2 family and inhibitors of apoptosis proteins (IAPs), having been identified as druggable targets. This review discusses the mechanisms by which apoptosis occurs under physiological conditions, and how this process is abnormally restrained in LA SCCHN tumor cells, with treatment strategies aimed at re-enabling apoptosis in LA SCCHN also considered. In particular, the development of, and future opportunities for, IAP inhibitors in LA SCCHN are discussed, in light of recent encouraging proof-of-concept clinical trial data.

Inhibition of bromodomain and extra-terminal proteins targets constitutively active NFκB and STAT signaling in lymphoma and influences the expression of the antiapoptotic proteins BCL2A1 and c-MYC

The antiapoptotic protein BCL2A1 is highly, but very heterogeneously expressed in Diffuse Large B-cell Lymphoma (DLBCL). Particularly in the context of resistance to current therapies, BCL2A1 appears to play an important role in protecting cancer cells from the induction of cell death. Reducing BCL2A1 levels may have therapeutic potential, however, no specific inhibitor is currently available. In this study, we hypothesized that the signaling network regulated by epigenetic readers may regulate the transcription of BCL2A1 and hence that inhibition of Bromodomain and Extra-Terminal (BET) proteins may reduce BCL2A1 expression thus leading to cell death in DLBCL cell lines. We found that the mechanisms of action of acetyl-lysine competitive BET inhibitors are different from those of proteolysis targeting chimeras (PROTACs) that induce the degradation of BET proteins. Both classes of BETi reduced the expression of BCL2A1 which coincided with a marked downregulation of c-MYC. Mechanistically, BET inhibition attenuated the constitutively active canonical nuclear factor kappa-light-chain-enhancer of activated B-cells (NFκB) signaling pathway and inhibited p65 activation. Furthermore, signal transducer of activated transcription (STAT) signaling was reduced by inhibiting BET proteins, targeting another pathway that is often constitutively active in DLBCL. Both pathways were also inhibited by the IκB kinase inhibitor TPCA-1, resulting in decreased BCL2A1 and c-MYC expression. Taken together, our study highlights a novel complex regulatory network that links BET proteins to both NFκB and STAT survival signaling pathways controlling both BCL2A1 and c-MYC expression in DLBCL.

Blinatumomab after R-CHOP bridging therapy for patients with Richter transformation: a phase 2 multicentre trial

Richter transformation (RT) is an aggressive lymphoma occurring in patients with chronic lymphocytic leukaemia. Here we investigated the anti-CD3/anti-CD19 T-cell-engager blinatumomab after R-CHOP (i.e. rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) in patients with untreated RT of diffuse large B-cell lymphoma histology (NCT03931642). In this multicentre phase 2 study, patients without complete response (CR) after two cycles of R-CHOP were eligible to receive an 8-week blinatumomab induction via continuous vein infusion with stepwise dosing until 112 μg/day. The primary endpoint was the CR rate after blinatumomab induction and secondary endpoint included safety, response duration, progression-free and overall survival. Thirty-nine patients started the first cycle of R-CHOP, 25 of whom received blinatumomab. After blinatumomab induction, five (20%) patients achieved CR, four (16%) achieved partial response, and six (24%) were stable. Considering the entire strategy, the overall response rate in the full-analysis-set was 46% (n = 18), with CR in 14 (36%) patients. The most common treatment-emergent adverse events of all grades in the blinatumomab-safety-set included fever (36%), anaemia (24%), and lymphopaenia (24%). Cytokine release syndrome (grade 1/2) was observed in 16% and neurotoxicity in 20% of patients. Blinatumomab demonstrated encouraging anti-tumour activity (the trial met its primary endpoint) and acceptable toxicity in patients with RT.

Novel Approaches to Managing Patients with Relapsed and Refractory Waldenström Macroglobulinemia

PURPOSE OF REVIEW

Waldenström macroglobulinemia is a rare non-Hodgkin lymphoma (NHL) characterized by lymphoplasmacytic bone marrow infiltration associated with an immunoglobulin M (IgM) monoclonal gammopathy. Over the past two decades, a number of important novel therapies have emerged for the treatment of relapsed and refractory (R/R) WM. The purpose of this review is to discuss these novel agents.

RECENT FINDINGS

Chemoimmunotherapy which formed the basis treatment for R/R WM is slowly being replaced by novel targeted agents. These therapies, including Bruton's tyrosine kinase inhibitors, proteasome inhibitors, and B-cell lymphoma 2 inhibitors, have widened the landscape of management. Emerging therapies currently under investigation, such as bispecific T-cell engagers, chimeric antigen T-cell receptor therapy, and novel small molecule inhibitors, have additionally shown the potential to improve response and survival. The treatment of R/R WM has greatly evolved, in large part due to a greater understanding of the biology of WM, and the evaluation of novel targeted agents in the basket trials of NHL, showing early activity in the small WM cohorts. Combination regimens with these established and emerging novel therapies have the potential to further improve disease control and induce higher rates of deep responses. Strategies aimed at altering the disease trajectory would require randomized controlled trials to provide relevant data on optimal integration and sequencing of more effective and tolerable regimens earlier in the disease course.