abt-199 and Lymphoma--Large-B-Cell--Diffuse

Richter syndrome (RS) of chronic lymphocytic leukemia (CLL) is typically chemoresistant, with a poor prognosis. We hypothesized that the oral Bcl-2 inhibitor venetoclax could sensitize RS to chemoimmunotherapy and improve outcomes. We conducted a single-arm, investigator-sponsored, phase 2 trial of venetoclax plus dose-adjusted rituximab, etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (VR-EPOCH) to determine the rate of complete response (CR). Patients received R-EPOCH for 1 cycle, then after count recovery, accelerated daily venetoclax ramp-up to 400 mg, then VR-EPOCH for up to 5 more 21-day cycles. Responders received venetoclax maintenance or cellular therapy off-study. Twenty-six patients were treated, and 13 of 26 (50%) achieved CR, with 11 achieving undetectable bone marrow minimal residual disease for CLL. Three additional patients achieved partial response (overall response rate, 62%). Median progression-free survival was 10.1 months, and median overall survival was 19.6 months. Hematologic toxicity included grade ≥3 neutropenia (65%) and thrombocytopenia (50%), with febrile neutropenia in 38%. No patients experienced tumor lysis syndrome with daily venetoclax ramp-up. VR-EPOCH is active in RS, with deeper, more durable responses than historical regimens. Toxicities from intensive chemoimmunotherapy and venetoclax were observed. Our data suggest that studies comparing venetoclax with chemoimmunotherapy to chemoimmunotherapy alone are warranted. This trial was registered at www.clinicaltrials.gov as #NCT03054896.

Topics: Aged; Antineoplastic Combined Chemotherapy Protocols; Bridged Bicyclo Compounds, Heterocyclic; Cyclophosphamide; Doxorubicin; Etoposide; Female; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphoma, Large B-Cell, Diffuse; Male; Middle Aged; Neutropenia; Prednisone; Progression-Free Survival; Sulfonamides; Vincristine

Outcomes remain poor in patients with diffuse large B cell lymphoma (DLBCL) who overexpress BCL-2 protein. We present population pharmacokinetics (PopPK) and exposure-response (ER) analyses for venetoclax (a selective BCL-2 inhibitor) administered with rituximab-cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in patients with relapsed/refractory (R/R) and previously untreated (1L) non-Hodgkin lymphoma (NHL) from the phase 1b/2 CAVALLI study, to confirm dose selection for future studies.. Analyses included 216 patients with R/R or 1L NHL treated for eight 21-day cycles with 400-800 mg venetoclax (cycle 1: days 4-10; cycles 2-8: days 1-10) in combination with R for eight cycles and CHOP for 6-8 cycles. A legacy PopPK model for venetoclax was used to describe the observed data and provide post hoc PK parameters. Venetoclax steady-state exposure (AUC. There was no significant association between venetoclax AUC. The PopPK and ER analyses, in addition to the positive benefit-risk observed in the clinical data, support the selection of 800 mg venetoclax given with R-CHOP for future studies in BCL-2-immunohistochemistry-positive patients with 1L DLBCL.. ClinicalTrials.gov Identifier NCT02055820.

Topics: Antineoplastic Combined Chemotherapy Protocols; Bridged Bicyclo Compounds, Heterocyclic; Cyclophosphamide; Doxorubicin; Humans; Lymphoma, Large B-Cell, Diffuse; Prednisone; Rituximab; Sulfonamides; Treatment Outcome; Vincristine

Standard chemotherapies for diffuse large B-cell lymphoma (DLBCL), based on the induction of exogenous DNA damage and oxidative stress, are often less effective in the presence of increased MYC and BCL-2 levels, especially in the case of double hit (DH) lymphomas harboring rearrangements of the MYC and BCL-2 oncogenes, which enrich for a patient's population characterized by refractoriness to anthracycline-based chemotherapy. Here we hypothesized that adaptive mechanisms to MYC-induced replicative and oxidative stress, consisting in DNA damage response (DDR) activation and BCL-2 overexpression, could represent the biologic basis of the poor prognosis and chemoresistance observed in MYC/BCL-2-positive lymphoma. We first integrated targeted gene expression profiling (T-GEP), fluorescence in situ hybridization (FISH) analysis, and characterization of replicative and oxidative stress biomarkers in two independent DLBCL cohorts. The presence of oxidative DNA damage biomarkers identified a poor prognosis double expresser (DE)-DLBCL subset, characterized by relatively higher BCL-2 gene expression levels and enrichment for DH lymphomas. Based on these findings, we tested therapeutic strategies based on combined DDR and BCL-2 inhibition, confirming efficacy and synergistic interactions in in vitro and in vivo DH-DLBCL models. These data provide the rationale for precision-therapy strategies based on combined DDR and BCL-2 inhibition in DH or DE-DLBCL.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Biomarkers, Tumor; Bridged Bicyclo Compounds, Heterocyclic; DNA Repair Enzymes; Drug Therapy, Combination; Female; Follow-Up Studies; Gene Expression Regulation, Leukemic; Humans; Lymphoma, Large B-Cell, Diffuse; Male; Middle Aged; Prognosis; Prospective Studies; Proto-Oncogene Proteins c-bcl-2; Retrospective Studies; Sulfonamides; Survival Rate; Thiophenes; Urea; Young Adult

Bromodomain and extraterminal (BET) proteins are transcriptional activators for multiple oncogenic processes in diffuse large B-cell lymphoma (DLBCL), including MYC, BCL2, E2F, and toll-like receptor signaling. We report results of a phase 1b dose-escalation study of the novel, subcutaneous BET inhibitor RO6870810 (RO) combined with the BCL-2 inhibitor venetoclax, and rituximab, in recurrent/refractory DLBCL. RO was delivered for 14 days of a 21-day cycle, whereas venetoclax was delivered continuously. A 3 + 3 escalation design was used to determine the safety of the RO+venetoclax doublet; rituximab was added in later cohorts. Thirty-nine patients were treated with a median of 2.8 cycles (range, 1-11). Dose-limiting toxicities included grade 3 febrile neutropenia, grade 4 diarrhea, and hypomagnesemia for the doublet; and grade 3 hyperbilirubinemia and grade 4 diarrhea when rituximab was added. The doublet maximum tolerated dose (MTD) was determined to be 0.65 mg/kg RO+600 mg venetoclax; for RO+venetoclax+rituximab, the MTDs were 0.45 mg/kg, 600 mg, and 375 mg/m2, respectively. The most frequent grade 3 and 4 adverse events were neutropenia (28%) and anemia and thrombocytopenia (23% each). Responses were seen in all cohorts and molecular subtypes. Sustained decreases in CD11b on monocytes indicated pharmacodynamic activity of RO. Overall response rate according to modified Lugano criteria was 38.5%; 48% of responses lasted for ≥180 days. Complete response was observed in 8 patients (20.5%). Optimization of the treatment schedule and a better understanding of predictors of response would be needed to support broader clinical use. This trial is registered on www.clinicaltrials.gov as NCT03255096.

Topics: Antineoplastic Combined Chemotherapy Protocols; Bridged Bicyclo Compounds, Heterocyclic; Humans; Lymphoma, Large B-Cell, Diffuse; Neoplasm Recurrence, Local; Rituximab; Sulfonamides

The phase 2 CAVALLI (NCT02055820) study assessed efficacy and safety of venetoclax, a selective B-cell lymphoma-2 (Bcl-2) inhibitor, with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in first-line (1L) diffuse large B-cell lymphoma (DLBCL), including patients demonstrating Bcl-2 protein overexpression by immunohistochemistry (Bcl-2 IHC+). Eligible patients were ≥18 years of age and had previously untreated DLBCL, Eastern Cooperative Oncology Group performance status ≤2, and International Prognostic Index 2 to 5. Venetoclax 800 mg (days 4-10, cycle 1; days 1-10, cycles 2-8) was administered with rituximab (8 cycles) and cyclophosphamide, doxorubicin, vincristine, and prednisone (6-8 cycles) in 21-day cycles. Primary end points were safety, tolerability, and research_plete response (CR) at end of treatment (EOT). Secondary end points were progression-free survival (PFS) and overall survival. Comparative analyses used covariate-adjusted R-CHOP controls from the GOYA/BO21005 study, an appropriate contemporary benchmark for safety and efficacy. Safety and efficacy analyses included 206 patients. CR rate at EOT was 69% in the overall population and was maintained across Bcl-2 IHC+ subgroups. With a median follow-up of 32.2 months, trends were observed for improved investigator-assessed PFS for venetoclax plus R-CHOP in the overall population (hazard ratio [HR], 0.61; 95% confidence interval [CI], 0.43-0.87) and Bcl-2 IHC+ subgroups (HR, 0.55; 95% CI, 0.34-0.89) vs R-CHOP. Despite a higher incidence of grade 3/4 hematologic adverse events (86%), related mortality was not increased (2%). Chemotherapy dose intensity was similar in CAVALLI vs GOYA. The addition of venetoclax to R-CHOP in 1L DLBCL demonstrates increased, but manageable, myelosuppression and the potential of improved efficacy, particularly in high-risk Bcl-2 IHC+ patient subgroups.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Bridged Bicyclo Compounds, Heterocyclic; Cyclophosphamide; Doxorubicin; Fatigue; Female; Gastrointestinal Diseases; Genes, bcl-2; Granulocyte Colony-Stimulating Factor; Hematologic Diseases; Humans; Infections; Kaplan-Meier Estimate; Lymphoma, Large B-Cell, Diffuse; Male; Middle Aged; Neoplasm Proteins; Prednisone; Proto-Oncogene Proteins c-bcl-2; Rituximab; Sulfonamides; Vincristine; Young Adult

Exposure-response analyses were performed for a venetoclax monotherapy study in 106 patients with varying subtypes of non-Hodgkin lymphoma (NHL) (NCT01328626). Logistic regression, time-to-event, and progression-free survival (PFS) analyses were used to evaluate the relationship between venetoclax exposure, NHL subtype and response, PFS, or occurrence of serious adverse events. Trends for small increases in the probability of response with increasing venetoclax exposures were identified, and became more evident when assessed by NHL subtype. Trends in exposure-PFS were shown for the mantle cell lymphoma (MCL) subtype, but not other subtypes. There was no increase in the probability of experiencing a serious adverse event with increasing exposure. Overall, the results indicate that venetoclax doses of 800-1200 mg as a single agent may be appropriate to maximize efficacy in MCL, follicular lymphoma, and diffuse large B-cell lymphoma subtypes with no expected negative impact on safety.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Bridged Bicyclo Compounds, Heterocyclic; Drug Administration Schedule; Female; Humans; Lymphoma, Follicular; Lymphoma, Large B-Cell, Diffuse; Lymphoma, Mantle-Cell; Male; Middle Aged; Progression-Free Survival; Sulfonamides; Treatment Outcome

Double-hit lymphoma (DHL) is a rare and aggressive mature B-cell malignancy with concurrent MYC and BCL2 rearrangements. When DHL becomes relapsed or refractory, it becomes resistant to the majority of therapeutic approaches and has subpar clinical results. Therefore, innovative therapeutics for this particular patient population are urgently needed.. Orelabrutinib, a new oral BTK inhibitor, combined with the Bcl-2 inhibitor venetoclax, was used to confirm the antitumor effect of DHL. Cell counting kit-8 and Annexin V-FITC/PI assays were used to examine the interaction of this combined regimen on DHL cell lines and primary lymphoma cells. RNA sequencing, EdU incorporation assay, mitochondrial membrane potential assay, and western blotting were employed to explore the molecule mechanism for the cytotoxicity of orelabrutinib with or without venetoclax against DHL cell lines.. In this study, orelabrutinib combined with venetoclax synergistically induced DHL cell death, as evidenced by the inhibition of cell proliferation, the induct of cell cycle arrest, and the promotion of cell apoptosis via the mitochondrial pathway. Orelabrutinib treatment alters genome-wide gene expression in DHL cells. The combined regimen decreases the expression of BTK and Mcl-1, potentially interfering with the activity and crosstalk of PI3K/AKT signaling and p38/MAPK signaling. In addition, the combination of orelabrutinib and venetoclax shows cytotoxic activity in primary B-lymphoma cells.. In summary, these findings reveal a novel therapy targeting BCR signaling and the Bcl-2 family for DHL patients with a poor prognosis.

Topics: Antineoplastic Agents; Apoptosis; Humans; Lymphoma, Large B-Cell, Diffuse; MAP Kinase Signaling System; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-myc

There are few effective therapeutic options available for R/R DLBCL patients who have undergone CAR-T therapy. We retrospectively assessed 10 R/R DLBCL patients with complete clinical records who received venetoclax-based combination therapy following CAR-T therapy failed in our center between July 2020 and December 2021. After receiving CAR-T therapy, they all relapsed within a few months. As salvage regimens, they were all given venetoclax-based combination therapy. The objective response rate (ORR) was 80 percent, and the complete response rate was 30 percent. At the time of the analysis, 7 patients were still living. Our research has demonstrated that venetoclax-based combination treatment for R/R DLBCL patients who failed CAR-T therapy has a high effectiveness and manageable toxicity.

Topics: Bridged Bicyclo Compounds, Heterocyclic; Humans; Lymphoma, Large B-Cell, Diffuse; Receptors, Chimeric Antigen; Retrospective Studies; Sulfonamides

Diffuse large B-cell lymphoma (DLBCL) is a prevalent and aggressive non-Hodgkin's lymphoma, and 40% of patients succumb to death. Despite numerous clinical trials aimed at developing treatment strategies beyond the conventional R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) regimen, there have been no positive results thus far. Although the selective BCL2 inhibitor venetoclax has shown remarkable efficacy in chronic lymphocytic leukemia, its therapeutic effect in DLBCL was limited. We hypothesized that the limited therapeutic effect of venetoclax in DLBCL may be attributed to the complex expression and interactions of BCL2 family members, including BCL2. Therefore, we aimed to comprehensively analyze the expression patterns of BCL2 family members in DLBCL. We analyzed 157 patients with de novo DLBCL diagnosed at Asan Medical Center and Ajou University Hospital. The mRNA expression levels of BCL2 family members were quantified using the NanoString technology. BCL2 family members showed distinct heterogeneous expression patterns both intra- and inter-patient. Using unsupervised hierarchical cluster analysis, we were able to classify patients with similar BCL2 family expression pattern and select groups with clear prognostic features, C1 and C6. In the group with the best prognosis, C1, the expression of pro-apoptotic and pro-apoptotic BH3-only group gene expressions were increased, while anti-apoptotic group expression was significantly increased in both C1 and C6. Based on this, we generated the BCL2 signature score using the expression of pro-apoptotic genes BOK and BCL2L15, and anti-apoptotic gene BCL2. The BCL2 signature score 0 had the best prognosis, score 1/2 had intermediate prognosis, and score 3 had the worst prognosis (EFS, p = 0.0054; OS, p = 0.0011). Multivariate analysis, including COO and IPI, showed that increase in the BCL2 signature score was significantly associated with poor prognosis for EFS, independent of COO and IPI. The BCL2 signature score we proposed in this study provides information on BCL2 family deregulation based on the equilibrium of pro-versus anti-apoptotic BCL2 family, which can aid in the development of new treatment strategies for DLBCL in the future.

Topics: Antibodies, Monoclonal, Murine-Derived; Antineoplastic Combined Chemotherapy Protocols; Cyclophosphamide; Doxorubicin; Humans; Lymphoma, Large B-Cell, Diffuse; Prednisone; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-myc; Rituximab; Vincristine

The BH3-mimetic drug Venetoclax, a specific inhibitor of anti-apoptotic BCL-2, has had clinical success for the treatment of chronic lymphocytic leukaemia and acute myeloid leukaemia. Attention has now shifted towards related pro-survival BCL-2 family members, hypothesising that new BH3-mimetic drugs targeting these proteins may emulate the success of Venetoclax. BH3-mimetics targeting pro-survival MCL-1 or BCL-XL have entered clinical trials, but managing on-target toxicities is challenging. While increasing evidence suggests BFL-1/A1 is a resistance factor for diverse chemotherapeutic agents and BH3-mimetic drugs in haematological malignancies, few studies have explored the role of BCL-W in the development, expansion, and therapeutic responses of cancer. Previously, we found that BCL-W was not required for the ongoing survival and growth of various established human Burkitt lymphoma and diffuse large B cell lymphoma cell lines. However, questions remained about whether BCL-W impacts lymphoma development. Here, we show that BCL-W appears dispensable for MYC-driven lymphomagenesis, and such tumours arising in the absence of BCL-W show no compensatory changes to BCL-2 family member expression, nor altered sensitivity to BH3-mimetic drugs. These results demonstrate that BCL-W does not play a major role in the development of MYC-driven lymphoma or the responses of these tumours to anti-cancer agents.

Topics: Antineoplastic Agents; Apoptosis; Burkitt Lymphoma; Cell Line, Tumor; Humans; Lymphoma, Large B-Cell, Diffuse; Myeloid Cell Leukemia Sequence 1 Protein; Proto-Oncogene Proteins c-bcl-2

The B cell leukemia/lymphoma 2 (BCL-2) inhibitor venetoclax is effective in chronic lymphocytic leukemia (CLL); however, resistance may develop over time. Other lymphoid malignancies such as diffuse large B cell lymphoma (DLBCL) are frequently intrinsically resistant to venetoclax. Although genomic resistance mechanisms such as BCL2 mutations have been described, this probably only explains a subset of resistant cases. Using 2 complementary functional precision medicine techniques - BH3 profiling and high-throughput kinase activity mapping - we found that hyperphosphorylation of BCL-2 family proteins, including antiapoptotic myeloid leukemia 1 (MCL-1) and BCL-2 and proapoptotic BCL-2 agonist of cell death (BAD) and BCL-2 associated X, apoptosis regulator (BAX), underlies functional mechanisms of both intrinsic and acquired resistance to venetoclax in CLL and DLBCL. Additionally, we provide evidence that antiapoptotic BCL-2 family protein phosphorylation altered the apoptotic protein interactome, thereby changing the profile of functional dependence on these prosurvival proteins. Targeting BCL-2 family protein phosphorylation with phosphatase-activating drugs rewired these dependencies, thus restoring sensitivity to venetoclax in a panel of venetoclax-resistant lymphoid cell lines, a resistant mouse model, and in paired patient samples before venetoclax treatment and at the time of progression.

Topics: Animals; Antineoplastic Agents; Apoptosis; Apoptosis Regulatory Proteins; bcl-X Protein; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Drug Resistance, Neoplasm; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphoma, Large B-Cell, Diffuse; Mice; Myeloid Cell Leukemia Sequence 1 Protein; Proto-Oncogene Proteins c-bcl-2

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease defined using a number of well-established molecular subsets. Application of non-negative matrix factorization (NMF) to whole exome sequence data has previously been used to identify six distinct molecular clusters in DLBCL with potential clinical relevance. In this study, we applied NMF-clustering to targeted sequencing data utilizing the FoundationOne Heme® panel from the Phase III GOYA (NCT01287741) and Phase Ib/II CAVALLI studies (NCT02055820) in de novo DLBCL. Biopsy samples, survival outcomes, RNA-Seq and targeted exome-sequencing data were available for 423 patients in GOYA (obinutuzumab [G]-cyclophosphamide, doxorubicin, vincristine, and prednisone [CHOP] vs rituximab [R]-CHOP) and 86 patients in CAVALLI (venetoclax+[G/R]-CHOP).. When the NMF algorithm was applied to samples from the GOYA study analyzed using a comprehensive genomic profiling platform, four of the six groups previously reported were observed: MYD88/CD79B, BCL2/EZH2, NOTCH2/TNFAIP3, and no mutations. Mutation profiles, cell-of-origin subset distributions and clinical associations of MYD88/CD79B and BCL2/EZH2 groups were similar to those described in previous NMF studies. In contrast, application of NMF to the CAVALLI study yielded only three; MYD88/CD79B-, BCL2/EZH2-like clusters, and a no mutations group, and there was a trend towards improved outcomes for BCL2/EZH2 over MYD88/CD79B.. This analysis supports the utility of NMF used in conjunction with targeted sequencing platforms for identifying patients with different prognostic subsets. The observed trend for improved overall survival in the BCL2/EZH2 group is consistent with the mechanism of action of venetoclax, suggesting that targeting sequencing and NMF has potential for identifying patients who are more likely to gain benefit from venetoclax therapy.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Bridged Bicyclo Compounds, Heterocyclic; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Enhancer of Zeste Homolog 2 Protein; Exome Sequencing; Female; Humans; Lymphoma, Large B-Cell, Diffuse; Male; Middle Aged; Mutation; Prognosis; Proto-Oncogene Proteins c-bcl-2; RNA-Seq; Sulfonamides; Treatment Outcome

CD47 expressed on cancer cells enables macrophage immune evasion. Blocking CD47 using anti-CD47 monoclonal antibodies (mAbs) is a promising strategy. The anti-CD47 mAb TJC4 has anti-tumor activity but lacks hematological toxicity. Venetoclax, a B-cell lymphoma 2 (BCL-2) inhibitor for B-cell malignancy, induces phosphatidylserine (PS) extracellular exposure, representing an "eat-me" signal for macrophages. The present study aimed to explore whether TJC4-Venetoclax combined therapy exerts synergistic anti-cancer properties in B-cell lymphoma. In vitro, flow cytometry and microscopy assessed whether TJC4 monotherapy or combination treatment could promote macrophage-mediated phagocytosis of tumor cells. Induced PS exposure on the cell membrane was measured using flow cytometry with Annexin V-FITC staining. In vivo, Venetoclax and TJC4's synergistic anti-tumor effects were evaluated. B cell lymphoma cell lines express high levels of CD47 and patients with diffuse large B cell lymphoma expressing CD47 have a worse clinical prognosis. TJC4 eliminates tumor cells via macrophage-mediated phagocytosis. In vitro and in vivo, the TJC4-Venetoclax combination increased phagocytosis significantly compared with either agent alone, showing synergistic phagocytosis, and displayed synergistic anti-cancer properties in B-cell lymphoma. Our results support the TJC4-Venetoclax combination as a promising therapy, and suppressing BCL-2 and CD47 simultaneously could represent a novel therapeutic paradigm for B-cell lymphoma.

Topics: Antibodies, Monoclonal; Antineoplastic Agents; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Humans; Immunologic Factors; Immunotherapy; Lymphoma, Large B-Cell, Diffuse; Phosphatidylserines; Proto-Oncogene Proteins c-bcl-2; Sulfonamides

The BCL2 inhibitor venetoclax has been approved to treat different hematological malignancies. Because there is no common genetic alteration causing resistance to venetoclax in chronic lymphocytic leukemia (CLL) and B-cell lymphoma, we asked if epigenetic events might be involved in venetoclax resistance. Therefore, we employed whole-exome sequencing, methylated DNA immunoprecipitation sequencing, and genome-wide clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 screening to investigate venetoclax resistance in aggressive lymphoma and high-risk CLL patients. We identified a regulatory CpG island within the PUMA promoter that is methylated upon venetoclax treatment, mediating PUMA downregulation on transcript and protein level. PUMA expression and sensitivity toward venetoclax can be restored by inhibition of methyltransferases. We can demonstrate that loss of PUMA results in metabolic reprogramming with higher oxidative phosphorylation and adenosine triphosphate production, resembling the metabolic phenotype that is seen upon venetoclax resistance. Although PUMA loss is specific for acquired venetoclax resistance but not for acquired MCL1 resistance and is not seen in CLL patients after chemotherapy-resistance, BAX is essential for sensitivity toward both venetoclax and MCL1 inhibition. As we found loss of BAX in Richter's syndrome patients after venetoclax failure, we defined BAX-mediated apoptosis to be critical for drug resistance but not for disease progression of CLL into aggressive diffuse large B-cell lymphoma in vivo. A compound screen revealed TRAIL-mediated apoptosis as a target to overcome BAX deficiency. Furthermore, antibody or CAR T cells eliminated venetoclax resistant lymphoma cells, paving a clinically applicable way to overcome venetoclax resistance.

Topics: Apoptosis Regulatory Proteins; bcl-2-Associated X Protein; Bridged Bicyclo Compounds, Heterocyclic; Drug Resistance, Neoplasm; Epigenesis, Genetic; Hematologic Neoplasms; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphoma, Large B-Cell, Diffuse; Myeloid Cell Leukemia Sequence 1 Protein; Proto-Oncogene Proteins c-bcl-2

Topics: Bridged Bicyclo Compounds, Heterocyclic; Humans; Lymphoma, Large B-Cell, Diffuse; Lymphoma, Non-Hodgkin; Piperidines; Pyrazoles; Pyrimidines; Splenic Rupture; Sulfonamides

Immunotherapy has evolved as a powerful tool for the treatment of B-cell malignancies, and patient outcomes have improved by combining therapeutic antibodies with conventional chemotherapy. Overexpression of antiapoptotic B-cell lymphoma 2 (Bcl-2) is associated with a poor prognosis, and increased levels have been described in patients with "double-hit" diffuse large B-cell lymphoma, a subgroup of Burkitt's lymphoma, and patients with pediatric acute lymphoblastic leukemia harboring a t(17;19) translocation. Here, we show that the addition of venetoclax (VEN), a specific Bcl-2 inhibitor, potently enhanced the efficacy of the therapeutic anti-CD20 antibody rituximab, anti-CD38 daratumumab, and anti-CD19-DE, a proprietary version of tafasitamab. This was because of an increase in antibody-dependent cellular phagocytosis by macrophages as shown in vitro and in vivo in cell lines and patient-derived xenograft models. Mechanistically, double-hit lymphoma cells subjected to VEN triggered phagocytosis in an apoptosis-independent manner. Our study identifies the combination of VEN and therapeutic antibodies as a promising novel strategy for the treatment of B-cell malignancies.

Topics: Bridged Bicyclo Compounds, Heterocyclic; Child; Cytophagocytosis; Humans; Lymphoma, Large B-Cell, Diffuse; Proto-Oncogene Proteins c-bcl-2; Sulfonamides

Topics: Animals; Apoptosis; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Forkhead Box Protein O1; Humans; Lymphoma, Large B-Cell, Diffuse; Mice; Phosphotransferases (Alcohol Group Acceptor); Proto-Oncogene Proteins c-bcl-2; Sulfonamides; Up-Regulation

To investigate the effect of Apatinib (an inhibitor targeting VEGFR-2) enhances chemosensitivity of ABT-199 on diffuse large B-cell lymphoma (DLBCL). Viability assay and flow cytometric assay for determining apoptosis, cell cycle, mitochondrial membrane potential, reactive oxygen species and immunoblotting were used to explore the combination effect in DLBCL cell lines, DLBCL patient samples, and DLBCL mouse models. RNA sequencing assay helped identify mechanisms of ABT-199 plus Apatinib. The results show that ABT-199 combined with Apatinib inhibited cell proliferation, reduced colony-forming capacity, and induced apoptosis and cell cycle arrest in DLBCL cells. Mechanistically, the combination therapy inhibited tumour cell growth and promoted tumour cell death by regulating EDN1 and MAPK-related pathways and activating the intrinsic apoptotic pathway. The effect of the combination therapy was also validated in primary DLBCL blasts and xenograft mouse models. Our findings indicate that Apatinib enhances the chemosensitivity of ABT-199 and might serve as a promising therapeutic strategy for DLBCL.

Topics: Animals; Apoptosis; Cell Line, Tumor; Cell Proliferation; Humans; Lymphoma, Large B-Cell, Diffuse; Mice; Reactive Oxygen Species; Vascular Endothelial Growth Factor Receptor-2; Xenograft Model Antitumor Assays

Richter syndrome (RS) represents the development of high-grade lymphoma in patients with chronic lymphocytic leukaemia (CLL) or small lymphocytic lymphoma (SLL) and presents a diagnostic and therapeutic challenge with an adverse prognosis. The genetic background and morphology of RS in CLL patients treated with chemoimmunotherapy is extensively characterised; however, our knowledge about RS in patients treated with targeted oral therapies should be extended. To understand the morphologic and molecular changes leading to RS in CLL patients treated with the Bruton's tyrosine kinase inhibitor, ibrutinib, and the BCL2 inhibitor, venetoclax, sequential samples from six CLL/SLL patients undergoing RS were collected in both the CLL and RS phases. A detailed immunophenotypic analysis of formalin-fixed, paraffin-embedded tissue specimens of RS phase was performed, followed by extensive molecular characterisation of CLL and RS samples, including the immunoglobulin heavy chain gene (IGH) rearrangement, TP53 mutations, drug-induced resistance mutations in BTK and BCL2 genes and various copy number changes and point mutations detectable with multiplex ligation-dependent probe amplification (MLPA). Rare, non-diffuse large B-cell lymphoma phenotypes of RS were observed in 3/6 cases, including plasmablastic lymphoma and a transitory entity between diffuse large B-cell lymphoma and classical Hodgkin lymphoma. The majority of cases were clonally related and harboured an unmutated variable region of the immunoglobulin heavy chain gene. Abnormalities affecting the TP53 gene occurred in all patients, and every patient carried at least one genetic abnormality conferring susceptibility to RS. In the background of RS, 2/5 patients treated with ibrutinib showed a BTK C481S resistance mutation. One patient developed a BCL2 G101V mutation leading to venetoclax resistance and RS. In conclusion, our findings contribute to better understanding of RS pathogenesis in the era of targeted oral therapies. Rare phenotypic variants of RS do occur under the treatment of ibrutinib or venetoclax, and genetic factors leading to RS are similar to those identified in patients treated with chemoimmunotherapy. To our best knowledge, we have reported the first BCL2 G101V mutation in an RS patient treated with venetoclax.

Topics: Adenine; Adult; Aged; Antineoplastic Agents; Bridged Bicyclo Compounds, Heterocyclic; Female; Genes, p53; Hodgkin Disease; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphoma; Lymphoma, Large B-Cell, Diffuse; Male; Middle Aged; Mutation; Piperidines; Prognosis; Proto-Oncogene Proteins c-bcl-2; Risk Factors; Sulfonamides

Cancer and normal cells use multiple antiapoptotic BCL2 proteins to prevent cell death. Therapeutic targeting of multiple BCL2 family proteins enhances tumor killing but is also associated with increased systemic toxicity. Here, we demonstrate that the dual targeting of MCL1 and BCL2 proteins using the small molecules S63845 and venetoclax induces durable remissions in mice that harbor human diffuse large B-cell lymphoma (DLBCL) tumors but is accompanied by hematologic toxicity and weight loss. To mitigate these toxicities, we encapsulated S63845 or venetoclax into nanoparticles that target P-selectin, which is enriched in tumor endothelial cells. In vivo and ex vivo imaging demonstrated preferential targeting of the nanoparticles to lymphoma tumors over vital organs. Mass spectrometry analyses after administration of nanoparticle drugs confirmed tumor enrichment of the drug while reducing plasma levels. Furthermore, nanoparticle encapsulation allowed 3.5- to 6.5-fold reduction in drug dose, induced sustained remissions, and minimized toxicity. Our results support the development of nanoparticles to deliver BH3 mimetic combinations in lymphoma and in general for toxic drugs in cancer therapy.

Topics: Animals; Antineoplastic Agents; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Drug Carriers; Drug Delivery Systems; Female; Humans; Lymphoma, Large B-Cell, Diffuse; Mice; Myeloid Cell Leukemia Sequence 1 Protein; Nanoparticles; Proto-Oncogene Proteins c-bcl-2; Pyrimidines; Sulfonamides; Therapeutic Index; Thiophenes

BH3 mimetics like venetoclax target prosurvival Bcl-2 family proteins and are important therapeutics in the treatment of hematological malignancies. We demonstrate that endogenous Bfl-1 expression can render preclinical lymphoma tumor models insensitive to Mcl-1 and Bcl-2 inhibitors. However, suppression of Bfl-1 alone was insufficient to fully induce apoptosis in Bfl-1-expressing lymphomas, highlighting the need for targeting additional prosurvival proteins in this context. Importantly, we demonstrated that cyclin-dependent kinase 9 (CDK9) inhibitors rapidly downregulate both Bfl-1 and Mcl-1, inducing apoptosis in BH3-mimetic-resistant lymphoma cell lines in vitro and driving in vivo tumor regressions in diffuse large B-cell lymphoma patient-derived xenograft models expressing Bfl-1. These data underscore the need to clinically develop CDK9 inhibitors, like AZD4573, for the treatment of lymphomas using Bfl-1 as a selection biomarker.

Topics: Animals; Antineoplastic Agents; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Cyclin-Dependent Kinase 9; Cycloheximide; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Humans; Leupeptins; Lymphoma, Large B-Cell, Diffuse; Macrocyclic Compounds; Mice; Mice, Inbred NOD; Mice, SCID; Minor Histocompatibility Antigens; Molecular Targeted Therapy; Myeloid Cell Leukemia Sequence 1 Protein; Neoplasm Proteins; Peptide Fragments; Piperazines; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Pyridines; Sulfonamides; Xenograft Model Antitumor Assays

The BCL2 inhibitor venetoclax is transforming the management of patients with chronic lymphocytic leukemia (CLL), given its high efficacy in relapsed/refractory CLL as observed in both early-phase and randomized clinical trials. The present study aimed to determine whether venetoclax is effective and well tolerated in patients with CLL or Richter's syndrome (RS) in a real-world setting and to highlight factors impacting survival. Data from a venetoclax French compassionate use program were collected for 67 patients (60 with CLL and 7 with RS). Most patients presented adverse genetic features, such as TP53 disruption (74%) or complex karyotype (58%). Tumor lysis syndrome was observed in 14 (22%) patients, and 16 (24%) patients were hospitalized for grade III/IV infection. In the CLL cohort, ORR was 75 %, 1-year PFS was 61% (95% CI = 47-72%) and 1-year OS 70% (95% CI = 56-80%). No impact of TP53 disruption was noted while complex karyotype was identified as a predictor of both inferior PFS (HR = 3.46; 95% CI = 1-12; log-rank p = 0.03) and OS (HR = 3.2; 95% CI = 0.9-11.4, log-rank p = 0.047). Among the seven patients with RS, two achieved an objective response to venetoclax; however, the median OS was only 1.1 month. The well-balanced safety/efficacy profile of venetoclax is confirmed in this real-world setting. Complex karyotype should be evaluated as a predictive factor of survival for patients treated by venetoclax.

Topics: Abnormal Karyotype; Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Bridged Bicyclo Compounds, Heterocyclic; Compassionate Use Trials; Drug Evaluation; Female; France; Genes, p53; Hematopoietic Stem Cell Transplantation; Humans; Infections; Kaplan-Meier Estimate; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphoma, Large B-Cell, Diffuse; Male; Middle Aged; Progression-Free Survival; Retrospective Studies; Sulfonamides; Treatment Outcome; Tumor Lysis Syndrome

Topics: Bridged Bicyclo Compounds, Heterocyclic; Humans; Lymphoma, Large B-Cell, Diffuse; Proto-Oncogene Proteins c-bcl-2; Sulfonamides

Richter Transformation (RT) develops in CLL as an aggressive, therapy-resistant, diffuse large B cell lymphoma (RT-DLBCL), commonly clonally-related (CLR) to the concomitant CLL. Lack of available pre-clinical human models has hampered the development of novel therapies for RT-DLBCL. Here, we report the profiles of genetic alterations, chromatin accessibility and active enhancers, gene-expressions and anti-lymphoma drug-sensitivity of three newly established, patient-derived, xenograft (PDX) models of RT-DLBCLs, including CLR and clonally-unrelated (CLUR) to concomitant CLL. The CLR and CLUR RT-DLBCL cells display active enhancers, higher single-cell RNA-Seq-determined mRNA, and protein expressions of IRF4, TCF4, and BCL2, as well as increased sensitivity to BET protein inhibitors. CRISPR knockout of IRF4 attenuated c-Myc levels and increased sensitivity to a BET protein inhibitor. Co-treatment with BET inhibitor or BET-PROTAC and ibrutinib or venetoclax exerted synergistic in vitro lethality in the RT-DLBCL cells. Finally, as compared to each agent alone, combination therapy with BET-PROTAC and venetoclax significantly reduced lymphoma burden and improved survival of immune-depleted mice engrafted with CLR-RT-DLBCL. These findings highlight a novel, potentially effective therapy for RT-DLBCL.

Topics: Adenine; Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Biomarkers, Tumor; Bridged Bicyclo Compounds, Heterocyclic; Cell Proliferation; Cell Transformation, Neoplastic; Gene Expression Regulation, Neoplastic; Humans; Lymphoma, Large B-Cell, Diffuse; Mice; Piperidines; Proteins; Proteolysis; Sulfonamides; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Treatment outcomes of relapsed/refractory diffuse large B cell lymphoma (R/R DLBCL) are far from satisfactory. Certain efficacy of ibrutinib has been observed in non-GCB subtype DLBCL patients. This study aimed to investigate the efficacy and safety of ibrutinib plus BCL2 inhibitor venetoclax in R/R DLBCL patients with non-GCB subtype and BCL2 overexpression. Combinational therapy (ibrutinib 560mg/day; venetoclax started 1 week later, oral dose increased from 100 to 400mg/day in 3 weeks) was conducted, and one cycle was 4 weeks. Both drugs were stopped when disease progress or serious adverse reactions appear. The primary end-point was overall response rate (ORR) at two cycles. From December 2018 to July 2020, a total of 13 patients were treated with the combined therapy. Among them, eleven (84.6%) patients previously received at least two treatment regimens, eight (61.5%) patients were C-myc and BCL2 double expression. The ORR at two cycles was 61.5%, with 3 (23.1%) patients achieved complete remission (CR) and 5 (38.4%) patients achieved partial remission (PR). The ORR at four cycles and six cycles was 53.8% and 46.2%, respectively. The median duration of response was 11 months (range, 1.5-13.6 months). The median progression-free survival and overall survival were 5.6 months (range, 0.4-15.6) and 11.3 months (range, 2.8-17.2), respectively. The most common adverse event was grade 1/2 neutropenia (53.8%), and nonhematologic toxicities included Grade1/2 diarrhea (46.2%) and elevated liver enzymes (30.8%). Combined therapy of ibrutinib and venetoclax showed promising efficacy and synergistic effects in R/R DLBCL patients with non-GCB subtype and BCL2 overexpression, and the toxicities were well-tolerated.

Topics: Adenine; Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Bridged Bicyclo Compounds, Heterocyclic; Female; Humans; Lymphoma, Large B-Cell, Diffuse; Male; Middle Aged; Neoplasm Recurrence, Local; Neutropenia; Piperidines; Proto-Oncogene Proteins c-bcl-2; Sulfonamides; Treatment Outcome

Topics: Antineoplastic Combined Chemotherapy Protocols; Bridged Bicyclo Compounds, Heterocyclic; Cyclophosphamide; Doxorubicin; Etoposide; Humans; Lymphoma, B-Cell; Lymphoma, Large B-Cell, Diffuse; Prednisone; Sulfonamides; Vincristine

Topics: Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Drug Synergism; Enzyme Activators; Humans; Lymphoma, Large B-Cell, Diffuse; Proteasome Endopeptidase Complex; Proteolysis; Proto-Oncogene Proteins c-myc; Sulfonamides

Anti-apoptotic Bcl-2-family members are frequently dysregulated in both blood and solid cancers, contributing to their survival despite ongoing oncogenic stress. Yet, such cancer cells often are highly dependent on Bcl-2 for their survival, a feature that is exploited by so-called BH3-mimetic drugs. Venetoclax (ABT-199) is a selective BH3-mimetic Bcl-2 antagonist that is currently used in the clinic for treatment of chronic lymphocytic leukemia patients. Unfortunately, venetoclax resistance has already emerged in patients, limiting the therapeutic success. Here, we examined strategies to overcome venetoclax resistance. Therefore, we used two diffuse large B-cell lymphoma (DLBCL) cell lines, Riva WT and venetoclax-resistant Riva (VR). The latter was obtained by prolonged culturing in the presence of venetoclax. We report that Riva VR cells did not become more sensitive to BIRD-2, a peptide targeting the Bcl-2 BH4 domain, and established cross-resistance towards BDA-366, a putative BH4-domain antagonist of Bcl-2. However, we found that Bcl-XL, another Bcl-2-family protein, is upregulated in Riva VR, while Mcl-1 expression levels are not different in comparison with Riva WT, hinting towards an increased dependence of Riva VR cells to Bcl-XL. Indeed, Riva VR cells could be resensitized to venetoclax by A-1155463, a selective BH3 mimetic Bcl-XL inhibitor. This is underpinned by siRNA experiments, demonstrating that lowering Bcl-XL-expression levels also augmented the sensitivity of Riva VR cells to venetoclax. Overall, this work demonstrates that Bcl-XL upregulation contributes to acquired resistance of DLBCL cancer cells towards venetoclax and that antagonizing Bcl-XL can resensitize such cells towards venetoclax.

Topics: Antineoplastic Agents; bcl-X Protein; Benzothiazoles; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Drug Resistance, Neoplasm; Humans; Isoquinolines; Lymphoma, Large B-Cell, Diffuse; Peptides; Sulfonamides

Current chemoimmunotherapy is unable to cure up to 40% of patients diagnosed with diffuse large B-cell lymphoma (DLBCL). Targeting the mechanisms by which DLBCL evades apoptosis is crucial to overcoming treatment failure in this heterogeneous disease as both current and novel treatments depend on the apoptosis of malignant cells. Despite the common overexpression of BCL-2, venetoclax is ineffective in DLBCL due to MCL-1 co-expression. This is driven by pro-growth PI3-kinase signaling, which is promoted in turn by PIM kinases. In this study, the novel dual-kinase inhibitor, IBL-202, was combined with venetoclax against a panel of DLBCL cell lines that have variable expression of pro-survival proteins. The results support the efficacy of simultaneously targeting inter-related molecules to overcome apoptotic escape in this biologically heterogeneous disease. As venetoclax, pan-PIM-kinase and pan-PI3-kinase inhibitors have, or are currently being studied in clinical trials, it may be rational to consider these drugs in combination for the treatment of DLBCL.

Topics: Apoptosis; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Humans; Lymphoma, Large B-Cell, Diffuse; Phosphatidylinositol 3-Kinases; Sulfonamides

Eleven years ago, a 64-year-old Caucasian man had LNH Follicular 3a, IV A stage, FLIPI 2 as a prognostic index of follicular lymphoma. He received 8 cycles of RCHOP followed by rituximab maintenance, with complete remission. Due to a systemic recurrence, a new treatment schedule (RCOMP, 6 cycles) was introduced with partial remission persisting during a long-term maintenance treatment with rituximab. Three years ago, LNH Follicular 3a progressed into GC type diffuse large B-cell lymphomas (DLBCL); 6 cycles of rituximab and bendamustine were followed by R-ICE and R OXALI DHAP treatments without beneficial effect. Due to the worse general condition (ECOG 3-4), the patient was treated with pixantrone (6 cycles) until July 10, 2019, with a partial response. On Jan 13, 2020, an extreme compassioned treatment with venetoclax alone was started; this drug was well tolerated and provided a satisfactory clinical and laboratory improvement. In June 2020, however, he developed bone marrow toxicity and septic fever. Nasal and pharyngeal secretions were SARS-CoV-2 RNA negative. Blood cultures for mycotic agents and Gram-positive, Gram-negative, and anaerobic bacteria were negative, but few days later, the patients died of sepsis due to unidentified agents. The use of venetoclax as a single drug to treat DLBCL BCL2 patients deserves further investigation.

Topics: Antineoplastic Combined Chemotherapy Protocols; Bridged Bicyclo Compounds, Heterocyclic; Humans; Lymphoma, Large B-Cell, Diffuse; Male; Middle Aged; Sulfonamides

Expression of the anti-apoptotic B-cell lymphoma 2 (BCL-2) protein in patients with diffuse large B-cell lymphoma (DLBCL) strongly correlates with resistance to standard therapy with cyclophosphamide, vincristine, doxorubicin, prednisolone, and rituximab (R-CHOP). Although studies focus mainly on the contribution of BCL-2, here we also investigate the contribution of other anti-apoptotic proteins to CHOP-therapy resistance in DLBCL. Functional dynamic BCL-2 homology (BH)3 profiling was applied to DLBCL cell lines upon CHOP treatment or single CHOP compounds. Cell-specific anti-apoptotic dependencies were validated with corresponding BH3-mimetics. We found high expression of anti-apoptotic BCL-2, MCL-1, and BCL-XL in DLBCL cell lines and patients. CHOP treatment resulted in both enhanced and altered anti-apoptotic dependency. Enhanced sensitivity to different BH3-mimetics after CHOP treatment was confirmed in specific cell lines, indicating heterogeneity of CHOP-induced resistance in DLBCL. Analysis of single CHOP compounds demonstrated that similar changes could also be induced by doxorubicin or vincristine, providing evidence for clinical combination therapies of doxorubicin or vincristine with BH3-mimetics in DLBCL. In conclusion, we show for the first time that CHOP treatment induces increased anti-apoptotic dependency on MCL-1 and BCL-XL, and not just BCL-2. These results provide new perspectives for the treatment of CHOP-resistant DLBCL and underline the potential of BH3 profiling in predicting therapy outcomes.

Topics: Aniline Compounds; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Bcl-2-Like Protein 11; bcl-X Protein; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Cell Survival; Cyclophosphamide; Doxorubicin; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Humans; Lymphoma, Large B-Cell, Diffuse; Myeloid Cell Leukemia Sequence 1 Protein; Prednisone; Prognosis; Proto-Oncogene Proteins c-bcl-2; Pyrimidines; Rituximab; Signal Transduction; Sulfonamides; Thiophenes; Treatment Outcome; Vincristine

Inhibition of the B-cell receptor (BCR) signaling pathway is a promising treatment strategy in multiple B-cell malignancies. However, the role of BCR blockade in diffuse large B-cell lymphoma (DLBCL) remains undefined. We recently characterized primary DLBCL subsets with distinct genetic bases for perturbed BCR/phosphoinositide 3-kinase (PI3K) signaling and dysregulated B-cell lymphoma 2 (BCL-2) expression. Herein, we explore the activity of PI3K inhibitors and BCL-2 blockade in a panel of functionally and genetically characterized DLBCL cell line models. A PI3K inhibitor with predominant α/δ activity, copanlisib, exhibited the highest cytotoxicity in all BCR-dependent DLBCLs. The proapoptotic effect of copanlisib was associated with DLBCL subtype-specific dysregulated expression of BCL-2 family members including harakiri (HRK) and its antiapoptotic partner BCL extra large (BCL-xL), BCL2 related protein A1, myeloid cell leukemia 1 (MCL-1), and BCL2 interacting mediator of cell death. Using functional BH3 profiling, we found that the cytotoxic activity of copanlisib was primarily mediated through BCL-xL and MCL-1-dependent mechanisms that might complement BCL-2 blockade. For these reasons, we evaluated single-agent activity of venetoclax in the DLBCLs and identified a subset with limited sensitivity to BCL-2 blockade despite having genetic bases of BCL-2 dysregulation. As these were largely BCR-dependent DLBCLs, we hypothesized that combined inhibition of PI3Kα/δ and BCL-2 would perturb BCR-dependent and BCL-2-mediated survival pathways. Indeed, we observed synergistic activity of copanlisib/venetoclax in BCR-dependent DLBCLs with genetic bases for BCL-2 dysregulation in vitro and confirmed these findings in a xenograft model. These results provide preclinical evidence for the rational combination of PI3Kα/δ and BCL-2 blockade in genetically defined DLBCLs.

Topics: Animals; Antineoplastic Agents; Apoptosis; Bridged Bicyclo Compounds, Heterocyclic; Cell Proliferation; Class I Phosphatidylinositol 3-Kinases; Drug Synergism; Female; Humans; Lymphoma, Large B-Cell, Diffuse; Mice; Mice, Inbred NOD; Mice, SCID; Proto-Oncogene Proteins c-bcl-2; Pyrimidines; Quinazolines; Sulfonamides; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

The so-called "double-hit" and "double-protein-expression" lymphoma with

Topics: Antineoplastic Agents; Apoptosis; Bridged Bicyclo Compounds, Heterocyclic; Cell Proliferation; Gene Rearrangement; Humans; Lymphoma, Large B-Cell, Diffuse; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-myc; Sulfonamides; Tumor Cells, Cultured

The BCL-2 inhibitor venetoclax has only limited activity in DLBCL despite frequent BCL-2 overexpression. Since constitutive activation of the B cell receptor (BCR) pathway has been reported in both ABC and GCB DLBCL, we investigated whether targeting SYK or BTK will increase sensitivity of DLBCL cells to venetoclax. We report that pharmacological inhibition of SYK or BTK synergistically enhances venetoclax sensitivity in BCL-2-positive DLBCL cell lines with an activated BCR pathway in vitro and in a xenograft model in vivo, despite the only modest direct cytotoxic effect. We further show that these sensitizing effects are associated with inhibition of the downstream PI3K/AKT pathway and changes in the expression of MCL-1, BIM, and HRK. In addition, we show that BCR-dependent GCB DLBCL cells are characterized by deficiency of the phosphatase SHP1, a key negative regulator of the BCR pathway. Re-expression of SHP1 in GCB DBLCL cells reduces SYK, BLNK, and GSK3 phosphorylation and induces corresponding changes in MCL1, BIM, and HRK expression. Together, these findings suggest that SHP1 deficiency is responsible for the constitutive activation of the BCR pathway in GCB DLBCL and identify SHP1 and BCL-2 as potential predictive markers for response to treatment with a venetoclax/BCR inhibitor combination.

Topics: Agammaglobulinaemia Tyrosine Kinase; Animals; Antineoplastic Agents; Apoptosis; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Cell Proliferation; Female; Humans; Lymphoma, Large B-Cell, Diffuse; Mice; Mice, Inbred NOD; Mice, SCID; Phosphatidylinositol 3-Kinases; Protein Tyrosine Phosphatase, Non-Receptor Type 6; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; Sulfonamides; Syk Kinase; Xenograft Model Antitumor Assays

Diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma are the most prevalent B-lymphocyte neoplasms in which abnormal activation of the Bruton tyrosine kinase (BTK)-mediated B-cell receptor signaling pathway contributes to pathogenesis. Ibrutinib is an oral covalent BTK inhibitor that has shown some efficacy in both indications. To improve ibrutinib efficacy through combination therapy, we first investigated differential gene expression in parental and ibrutinib-resistant cell lines to better understand the mechanisms of resistance. Ibrutinib-resistant TMD8 cells had higher

Topics: Adenine; Agammaglobulinaemia Tyrosine Kinase; Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Bridged Bicyclo Compounds, Heterocyclic; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Humans; Lymphoma, Follicular; Lymphoma, Large B-Cell, Diffuse; Mice; Piperidines; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Proto-Oncogene Proteins c-bcl-2; Pyrazoles; Pyrimidines; Signal Transduction; Sulfonamides; Xenograft Model Antitumor Assays

MicroRNAs (miRs) are involved in tumor progression by regulating tumor cells and tumor microenvironment. MiR21 is overexpressed in diffuse large B-cell lymphoma (DLBCL) and its biological impact on tumor microenvironment remains unclear.. MiR21 was assessed by quantitative RT-PCR in patients with newly diagnosed DLBCL. The mechanism of action of miR21 on lymphoma progression and tumor angiogenesis was examined in vitro in B-lymphoma cell lines and in vivo in a murine xenograft model.. Serum miR21 was significantly elevated in patients and associated with advanced disease stage, International Prognostic Index indicating intermediate-high and high-risk, and increased tumor angiogenesis. When co-cultured with immune cells and endothelial cells, miR21-overexpressing B-lymphoma cells were resistant to chemotherapeutic agents, but sensitive to Bcl-2 inhibitor ABT-199, irrespective of Bcl-2 expression on lymphoma cells. In both co-culture systems of Bcl-2. As a serum oncogenic biomarker of B-cell lymphoma, miR21 indicated B-lymphoma cell sensitivity to ABT-199 via ICOS/ICOSL-mediated interaction of Treg cells with endothelial cells.

Topics: Animals; Apoptosis; Bridged Bicyclo Compounds, Heterocyclic; Cell Proliferation; Cells, Cultured; Endothelium, Vascular; Female; Humans; Inducible T-Cell Co-Stimulator Ligand; Inducible T-Cell Co-Stimulator Protein; Lymphoma, Large B-Cell, Diffuse; Male; Mice; Mice, Inbred BALB C; Mice, Nude; MicroRNAs; Middle Aged; Prognosis; Sulfonamides; T-Lymphocytes, Regulatory; Xenograft Model Antitumor Assays

Aberrant regulation of BCL-2 family members enables evasion of apoptosis and tumor resistance to chemotherapy. BCL-2 and functionally redundant counterpart, MCL-1, are frequently over-expressed in high-risk diffuse large B-cell lymphoma (DLBCL). While clinical inhibition of BCL-2 has been achieved with the BH3 mimetic venetoclax, anti-tumor efficacy is limited by compensatory induction of MCL-1. Voruciclib, an orally bioavailable clinical stage CDK-selective inhibitor, potently blocks CDK9, the transcriptional regulator of MCL-1. Here, we demonstrate that voruciclib represses MCL-1 protein expression in preclinical models of DLBCL. When combined with venetoclax in vivo, voruciclib leads to model-dependent tumor cell apoptosis and tumor growth inhibition. Strongest responses were observed in two models representing high-risk activated B-cell (ABC) DLBCL, while no response was observed in a third ABC model, and intermediate responses were observed in two models of germinal center B-cell like (GCB) DLBCL. Given the range of responses, we show that CIVO, a multiplexed tumor micro-dosing technology, represents a viable functional precision medicine approach for differentiating responders from non-responders to BCL-2/MCL-1 targeted therapy. These findings suggest that the combination of voruciclib and venetoclax holds promise as a novel, exclusively oral combination therapy for a subset of high-risk DLBCL patients.

Topics: Animals; Antineoplastic Agents; Apoptosis; Benzopyrans; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Drug Synergism; Gene Expression Regulation; Humans; Imino Furanoses; Lymphoma, Large B-Cell, Diffuse; Mice; Myeloid Cell Leukemia Sequence 1 Protein; Proto-Oncogene Proteins c-bcl-2; Sulfonamides

To investigate the roles of BCL2, MCL1, and BCL-XL in the survival of diffuse large B-cell lymphoma (DLBCL).. Immunohistochemical analysis of 105 primary DLBCL samples, and Western blot analysis of 18 DLBCL cell lines for the expression of BCL2, MCL1, and BCL-XL. Pharmacologic targeting of BCL2, MCL1, and BCL-XL with ABT-199, homoharringtonine (HHT), and ABT-737. Analysis of DLBCL clones with manipulated expressions of BCL2, MCL1, and BCL-XL. Immunoprecipitation of MCL1 complexes in selected DLBCL cell lines. Experimental therapy aimed at inhibition of BCL2 and MCL1 using ABT-199 and HHT, single agent, or in combination, in vitro and in vivo on primary cell-based murine xenograft models of DLBCL.. By the pharmacologic targeting of BCL2, MCL1, and BCL-XL, we demonstrated that DLBCL can be divided into BCL2-dependent and MCL1-dependent subgroups with a less pronounced role left for BCL-XL. Derived DLBCL clones with manipulated expressions of BCL2, MCL1, and BCL-XL, as well as the immunoprecipitation experiments, which analyzed MCL1 protein complexes, confirmed these findings at the molecular level. We demonstrated that concurrent inhibition of BCL2 and MCL1 with ABT-199 and HHT induced significant synthetic lethality in most BCL2-expressing DLBCL cell lines. The marked cytotoxic synergy between ABT-199 and HHT was also confirmed in vivo using primary cell-based murine xenograft models of DLBCL.. As homoharringtonine is a clinically approved antileukemia drug, and ABT-199 is in advanced phases of diverse clinical trials, our data might have direct implications for novel concepts of early clinical trials in patients with aggressive DLBCL.

Topics: Animals; Apoptosis; bcl-X Protein; Biphenyl Compounds; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Cell Proliferation; Gene Expression Regulation, Neoplastic; Harringtonines; Homoharringtonine; Humans; Lymphoma, Large B-Cell, Diffuse; Mice; Myeloid Cell Leukemia Sequence 1 Protein; Nitrophenols; Piperazines; Proto-Oncogene Proteins c-bcl-2; Sulfonamides; Xenograft Model Antitumor Assays

Better treatments are needed for patients with diffuse large B-cell lymphoma (DLBCL) at high risk of failing standard therapy. Avoiding apoptosis is a hallmark of cancer, and in DLBCL the redundantly functioning antiapoptotic proteins BCL2 and MCL1 are frequently expressed. Here we explore drugs that cause loss of MCL1, particularly the potent new cyclin-dependent kinase inhibitor dinaciclib, which knocks down MCL1 by inhibiting CDK9. Dinaciclib induces apoptosis in DLBCL cells but is completely overcome by increased activity of BCL2. We find that clinical samples have frequent co-expression of MCL1 and BCL2, suggesting that therapeutic strategies targeting only one will lead to treatment failures owing to activity of the other. The BH3 mimetic ABT-199 potently and specifically targets BCL2. Single-agent ABT-199 had modest antitumor activity against most DLBCL lines and resulted in compensatory upregulation of MCL1 expression. ABT-199 synergized strongly, however, when combined with dinaciclib and with other drugs affecting MCL1, including standard DLBCL chemotherapy drugs. We show potent antitumor activities of these combinations in xenografts and in a genetically accurate murine model of MYC-BCL2 double-hit lymphoma. In sum, we reveal a rational treatment paradigm to strip DLBCL of its protection from apoptosis and improve outcomes for high-risk patients.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Bridged Bicyclo Compounds, Heterocyclic; Cell Proliferation; Cyclic N-Oxides; Drug Synergism; Female; Humans; Immunoenzyme Techniques; Indolizines; Lymphoma, Large B-Cell, Diffuse; Mice; Mice, Inbred NOD; Mice, SCID; Myeloid Cell Leukemia Sequence 1 Protein; Proto-Oncogene Proteins c-bcl-2; Pyridinium Compounds; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sulfonamides; Tissue Array Analysis; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Topics: Aged; Antineoplastic Agents; Bridged Bicyclo Compounds, Heterocyclic; Clinical Trials, Phase I as Topic; Humans; Lymphoma, Follicular; Lymphoma, Large B-Cell, Diffuse; Male; Proto-Oncogene Proteins c-bcl-2; Sulfonamides