Bortezomib Combination Therapy Research Articles

Exploratory study on the efficacy of bortezomib combining mitoxantrone or CD22-CAR T therapy targeting CD19-negative relapse after CD19-CAR T cell therapy with a simpler cell-line-based model.

Target-negative relapse after CD19 chimeric antigen receptor engineered (CAR) T cell therapy for patients with B lineage acute lymphoblastic leukemia (B-ALL) presents limited treatment options with dismal outcomes. Although CD22-CAR T cells mediate similarly potent antineoplastic effects in patients with CD19dim or even CD19-negative relapse following CD19-directed immunotherapy, a high rate of relapse associated with diminished CD22 cell surface expression has also been observed. Therefore, it is unclear whether any other therapeutic options are available. Mitoxantrone has shown significant antineoplastic activity in patients with relapsed or refractory leukemia over the past decades, and in some cases, the addition of bortezomib to conventional chemotherapeutic agents has demonstrated improved response rates. However, whether this mitoxantrone and bortezomib combination therapy is effective for those patients who have relapsed B-ALL after receiving CD19-CAR T cell therapy remains to be elucidated. In this study, we established a cellular model system using a CD19-positive B-ALL cell line Nalm-6 to investigate the treatment options for CD19-negative relapsed B-ALL after CD19-CAR T cell therapy. In addition to CD22-CAR T therapy, we observed that the combination of bortezomib and mitoxantrone exhibited effective anti-leukemia activity in the CD19-negative Nalm-6 cell line by downregulating p-AKT and p-mTOR. These results suggest that this combination therapy is a possible option for target-negative refractory leukemia cells after CAR-T cell treatment.

A combined regimen based on bortezomib and glucocorticoids for 6 patients with recurrent/refractory immune thrombotic thrombocytopenic purpura

Objective: To observe the efficacy and adverse reactions of a combination therapy regimen based on bortezomib and glucocorticoids in recurrent/refractory immune thrombocytopenic purpura (iTTP) . Methods: Six patients with recurrent/refractory TTP were included and treated with a glucocorticoid and two courses of bortezomib-based regimen. The clinical remission status of patients, changes in ADAMTS13 activity/ADAMTS13 inhibitor, and the occurrence of treatment-related adverse reactions were observed. Results: Of the 6 patients, 2 were males and 4 were females, with a median age of 21.5 (18-68) years. Refractory TTP was found in 1 case and recurrent TTP in 5 cases. Glucocorticoids were administered with reference to prednisone at 1 mg·kg(-1)·d(-1), and gradually reduced in dosage after achieving clinical remission. Bortezomib is subcutaneously administered at 1.3 mg/m(2) on days 1, 4, 8, and 11 with a 28-day treatment course consisting of 2 courses. Six patients achieved clinical remission after receiving bortezomib as the main treatment. ADMATS13 activity returned to normal in all patients with TTP after treatment, and the ADAMTS13 inhibitor turned negative. Thrombocytopenia is the most common adverse reaction after treatment, with other adverse reactions, including peripheral neuritis and abdominal pain, but ultimately all patients returned to normal. In a median follow-up of 26 (9-41) months, 5 patients maintained sustained remission, and 1 patient relapsed after 16 months of bortezomib treatment. Conclusion: Combination therapy of bortezomib and glucocorticoids has a satisfactory therapeutic effect and controllable adverse reactions for recurrent/refractory iTTP.

A combination therapy of bortezomib, CXCR4 inhibitor, and checkpoint inhibitor is effective in cholangiocarcinoma invivo.

Cholangiocarcinoma (CCA) is a biliary tree malignancy with a dismal prognosis. Tumor microenvironment (TME), including cancer-associated fibroblasts (CAFs) has been shown to be involved in drug resistance. To model the interactions between cancer cells and the TME, we established CCA complex patient-derived organoids (cPDOs) to include epithelial PDO (ePDOs) and matched CAFs. While ePDOs were sensitive to bortezomib, we found the matched cPDOs were relatively resistant. Mechanistically, this resistance was correlated with over-expression of CXCR4 in the CAF component of cPDOs. In accord with the role of CXCR4 in the resistance to bortezomib, we found that a CXCR4 inhibitor can reverse the resistance to bortezomib invivo. Furthermore, we found that the inhibition of CXCR4 allowed bortezomib to sensitize CCA to anti-PD1 treatment, with a significant reduction of tumor burden and long-term overall survival. This novel cancer/stroma/immune triple treatment holds great promise for the treatment of CCA.

Left Kidney Undifferentiated Spindle Cell Sarcoma with Myeloid Cell Leukemia-1 Amplification: Therapeutic Response to Bortezomib, Venetoclax, and Dexamethasone Therapy

Abstract The overexpression of myeloid cell leukemia-1 (MCL-1) has been identified in numerous hematologic malignancies and solid tumors. Currently, there are no selective MCL-1 inhibitors. Here, we present a case of left kidney undifferentiated spindle cell sarcoma with MCL-1 amplification. The tumor showed primary resistance to chemotherapy and immune checkpoint inhibitors. Combination therapy of bortezomib, venetoclax, and dexamethasone demonstrated a positive response, resulting in a stable tumor condition for 6 months. To our knowledge, this is the first report to mention the clinical efficacy of bortezomib, venetoclax, and dexamethasone therapy in an MCL-1-amplified solid tumor.

Rituximab Monotherapy versus Rituximab and Bortezomib Combination Therapy for Treatment of Non-paraneoplastic Autoimmune Retinopathy.

To study whether rituximab and bortezomib combination therapy is more effective than rituximab monotherapy in the treatment of non-paraneoplastic autoimmune retinopathy (npAIR). Retrospective case series involving six patients with npAIR, taking either rituximab and bortezomib combination therapy (three cases) or rituximab monotherapy (one case and two historical patients). Patients on both treatment regimens showed stability in most of the visual function parameters during the one year of follow-up. Combination therapy resulted in improvement of scotopic combined rod and cone a-wave and b-wave amplitudes in all eyes where they were available (four eyes); however, rituximab monotherapy resulted in only two eyes with stable scotopic combined rod and cone a-wave and b-wave amplitudes, while four eyes showed a decrease in both a- and b-wave amplitudes. The average improvement in b-wave amplitude (50.7% 29.4% [range, 25-90%]) was higher than the average improvement in a-wave amplitude (35.7% 9.74 [range, 25-63%]). No severe adverse effects were reported. Rituximab and bortezomib combination therapy may not be more effective than rituximab monotherapy in npAIR patients for most of the visual function parameters; however, this combination therapy may be more effective in improving scotopic combined rod and cone a- and b-wave amplitudes. This may indicate the higher efficacy of combination therapy when there is involvement of the inner retina.

A Combination Therapy of Bortezomib, CXCR4 Inhibitor and Checkpoint Inhibitor is Effective in Cholangiocarcinoma in vivo

A Combination Therapy of Bortezomib, CXCR4 Inhibitor and Checkpoint Inhibitor is Effective in Cholangiocarcinoma in vivo

Prognostic Relevance of Concordant Expression CD69 and CD56 in Response to Bortezomib Combination Therapy in Multiple Myeloma Patients

Objective Multiple myeloma is an incurable hematological malignancy. Currently, the use of proteasome inhibitors could be superior to chemotherapy-based regimen in the treatment of this disease. However, resistance to bortezomib combination therapy still occurs in some patients. So, this research work aims to assess CD69 and CD56 expression in these cases and their relation to the response to therapy. Materials and Methods Immunophenotyping by 4-color multi-parameter flow cytometry was carried out on 98 multiple myeloma cases. Clonal plasma cells were gated by co-expression of CD38 with CD138 with low SSC, negative or dim CD45. Results Double negative CD69 and CD56 (47.9%) multiple myeloma cases were associated with high serum β2 microglobulin, creatinine, calcium and low serum albumin. There was also a significant correlation between the absence of these markers with osteolytic lesions and unfavorable cytogenetic t (4;14) (p < 0.001). Moreover, there was a highly significant correlation between CD69- and CD56- with non-response to bortezomib combination therapy in multiple myeloma patients (p < 0.0001). Regression analysis for the prediction of non- response to treatment in these cases using different prognostic indicators revealed that high serum β2 microglobulin, unfavorable cytogenetic, advanced stage, and low expression of CD69 and CD56 were poor predictors of non-response. Conclusion CD69 in association with CD56 could be an independent prognostic factor in multiple myeloma cases. It could be used in the routine laboratory assessment for refining stratification and timely therapeutic decision for highly cost therapy in developing countries.

Gambogenic Acid Enhances Chemosensitivity of Multiple Myeloma to Bortezomib through p53/ROS/p38 MAPK Apoptotic Pathway

Background: Multiple myeloma (MM) is the second most prevalent hematological cancer (10%) with a five-year survival rate of only 49%. Approval of bortezomib, the first in-class proteasome inhibitor, has significantly improved outcomes of MM in the last few years; however, the almost inevitable refractory or resistance has made a cure of MM remains out of reach. Identification and validation of novel effective targeted agents are necessary. As one of the natural compounds isolated from Traditional Chinese Medicine gamboge, gambogenic acid (GNA) is a very promising antitumor agent and has been proved to have more potent anticancer effect and less systemic toxicity according to early investigations. In our previous studies, we have demonstrated that GNA could synergistically potentiate bortezomib-induced apoptosis of MM. In this study, our aim was to further explore and understand the concrete apoptotic action mechanism of GNA and bortezomib combination treatment against MM in pre-clinical models.Methods: We performed pre-clinical studies in myeloma cell lines and mouse models treated by GNA and bortezomib, alone and in combination. Cell counting kit-8 (CCK-8) assay, combination index (CI) isobologram, flow cytometry (FCM), western blot, xenograft tumor models, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), immunohistochemistry (IHC) and oxidation-sensitive fluorescent dye carboxy-DCFDA were applied in this study. The thiol antioxidant N-acetylcysteine (NAC) and p38 MAPK inhibitor SB203580 were used to detect the effect of GNA and bortezomib combination therapy on ROS, p53 and p38 MAPK.Results: Both p53 wild type cell line MM.1S and mutant type cell line RPMI 8226 myeloma cell lines were sensitive to GNA therapy. Interestingly, GNA only enhanced the chemosensitivity of bortezomib on p53 wild type cell line MM.1S. Both 0.51μM GNA combined with 2.3nM bortezomib and 0.90μM GNA combined with 4.0nM bortezomib to MM.1S cells showed a more markedly apoptotic rate of MM compared with that of the single agent group of each accordingly (p <0.01; p <0.01), and the apoptosis was presented in a dosage- and time-dependent manner. Increased apoptosis of MM.1S cells was found via the activation of PARP cleavage, p53, Caspase-3 cleavage and Bax and inhibition of Bcl-2 expression. An increased antitumor effect of combination therapy of GNA and bortezomib on MM.1S xenograft models were also observed. A significant generation of ROS was detected after exposure of GNA and bortezomib in MM.1S cells. The expression level of phospho-p38MAPK was upregulated by combination therapy compared with that of single agent (p<0.05; p<0.05). To characterize the mechanisms of action of GNA in combination with bortezomib, we pretreated MM.1S cells with NAC and SB203580. We found that the apoptosis of MM.1S cells could be inhibited by both NAC and SB203580 (p<0.01; p<0.01). However, the generation of ROS could only be inhibited by NAC (p<0.05), and the elevated expression of p53 could be inhibited neither by NAC nor SB203580. These results indicated that p53/ROS/p38 MAPK pathway is a pre-requisite for GNA to accomplish the enhancement of chemosensitivity of MM to bortezomib.Conclusions: We demonstrate that GNA could potentiate apoptosis of MM induced by bortezomib in vivo and in vitro, and p53/ROS/p38 MAPK pathway plays a central role of the apoptotic action. Thus, our data provide a persuasive rationale for the successful utilization of dual GNA and bortezomib for chemotherapy in MM patients in the future. DisclosuresNo relevant conflicts of interest to declare.

Everolimus Shows Synergistic Anti-Myeloma Effects with Bortezomib Via the AKT/mTOR Pathway

Introduction: Multiple myeloma (MM) is characterized by the proliferation of malignant plasma cells and a subsequent overabundance of monoclonal paraprotein (M protein). Everolimus ,as an oral mammalian target of rapamycin (mTOR) inhibitor, plays an important role in multiple myeloma. In the phase I trial explored the use of everolimus in relapsed and/or refractory multiple myeloma patients ,the median time to progression was 90 days (range, 13 to 278 days),and no dose-limiting toxicity was observed at daily dose of 10 mg. At the same time, the observed responses are promising in some testing combination strategies. The pre-clinical activity of pan-histone deacetylase inhibitor LBH589 in combination with everolimus caused potent G0/G1 arrest and induced pronounced apoptosis, the combination led to down regulation of pStat3, cyclins, CDKs and XIAP and up regulation of pro-apoptotic Bcl-2 family proteins. Everolimus enhances the cytotoxicity of bendamustine in multiple myeloma cells through a network of pro-apoptotic and cell-cycle-progression regulatory proteins.Down regulation of vascular endothelial cell growth factor and everolimus synergistic antitumor activity in multiple myeloma cells. Furthermore, In a phase I study of everolimus in combination with lenalidomide in relapsed or refractory multiple myeloma patients, the overall response rate was 65% and median progression-free survival was 5.5 months. Bortezomib was the first therapeutic proteasome inhibitor to be tested in humans with MM. However, the combination of bortezomib and everolimus for the treatment of MM is still less reported.Methods: To evaluate the in vitro and in vivo anti-tumor activity of the combination of everolimus with bortezomib.CCK-8 was used to explore the proliferation of MM cells. Flow cytometry was used to determine the effect on apoptosis of cells.Western blot and Immunohistochemical staining was used to determine the epression of proteins.Results: In our study, the experimental results demonstrated that everolimus combined with bortezomib suppressed cell proliferation. Treatment with 20 nM everolimus in combination with 10 nM bortezomib for 72h achieved the lowest cell survival rate in both U266 and LP-1 MM cell lines. The combination of everolimus and bortezomib was synergistic in both cell lines indicated by combination index (CI) values of <0.8.Flow cytometry was used to determine the effect on apoptosis of bortezomib in combination with everolimus. everolimus alone and bortezomib alone induced approximately 22.5% and 17.2% apoptosis, combination treatment induced28.8% apoptosis in U266 cells, and the results were 15.6%,10.0% and 16.7% in LP-1 cells. Western blot was used to explore the mechanisms. The expression of AKT1, mTOR, p70S6K1, 4EBP1 and NF-kB was significantly down regulated while the expression of Caspase-3was significantly up regulated in combination group than other alone group. Furthermore, Synergistic antitumor effect of everolimus and bortezomib was observed in the animal model carrying the myeloma xenograft on the 25th day after tumor implantation . The results of immunohistochemical staining further demonstrated that the expression of AKT1, mTOR, p70S6K1, 4EBP1 and NF-kB was significantly down regulated and the expression of Caspase-3 was significantly up regulated in combination group.Conclusion:Our results shows synergistic antitumor effects of the combination therapy of bortezomib and everolimus induced myeloma cell apoptosis in vitro and in vivo xenograft mouse model ,which mainly through the inhibition of the AKT/mTOR pathway. Our results provided provide a rationale application for the combinatorial treatment of MM with proteasome inhibitor agents and mTOR inhibitors in future clinical practice. DisclosuresNo relevant conflicts of interest to declare.

Severe but reversible pulmonary hypertension in scleromyxedema and multiple myeloma: a case report

BackgroundScleromyxedema is a progressive, systemic connective tissue disorder characterized by fibro-mucous skin lesions and increased serum monoclonal immunoglobulin levels. Pulmonary involvement occurs in a subset of patients, though the overall prevalence of pulmonary lesions in scleromyxedema is unknown. Since pulmonary hypertension presumably occurs in these patients due to disease progression and development of additional conditions, treatment of the underlying plasma cell dyscrasia and connective tissue disorder may improve pulmonary hypertension symptoms.Case presentationAn elderly patient with scleromyxedema developed pulmonary hypertension refractory to vasodilator and diuretic therapy and subsequently multiple myeloma that responded to a combination therapy of bortezomib, cyclophosphamide, and dexamethasone treatment.ConclusionsTreatment of the underlying disease(s) that contributed to pulmonary hypertension development with anti-neoplastic agents like bortezomib may improve cardiopulmonary symptoms secondary to reducing abnormal blood cell counts and paraprotein levels.

Safety and Efficacy of Venetoclax in Relapsed Refractory Multiple Myeloma: A Systematic Review and Meta-Analysis

Background:Management of relapsed or refractory multiple myeloma (RRMM) is challenging. Venetoclax (ABT-199) is an oral selective inhibitor of an anti-apoptotic protein Bcl-2 that showed activity in preclinical studies, especially for t(11;14) MM cell lines or in the cells with high bcl-2 expression. We conducted a systematic review and meta-analysis to evaluate the outcomes of venetoclax in RRMM.Method:Literature databases (Medline, Embase, and Cochrane) were searched for studies published up to June 19, 2018. Our search strategy included MeSH terms and key words for multiple myeloma and venetoclax including trade names and generic names. CMA software v.3 was used for analysis. Random-effects model was applied.Results:163 patients (n=115 in dose escalation, n=48 in safety expansion) were identified from two clinical trials (phase Ib study by Moreau, P. et al. 2017, n=66 and phase I/II study by Kumar, S. et al. 2017, n=66) and one retrospective study (Galligan, D. et al. 2017, n=31). The median age was 63, 64, N/A in phase Ib, phase I/II and retrospective study, respectively. 47 patients (29%) had t(11;14). Other cytogenetic aberrations were del(17p) [n<25]; t(4;14) [n=5]; del(13q) [n=41]; t(14;16) [n<5]; t(14;20) [n<5]. 124 patients (76%) were refractory to bortezomib and/or lenalidomide; most patients had ≥3 prior therapies. Venetoclax doses escalated from 50 mg/day to 1200 mg/day in phase Ib and phase I/II studies. Safety expansion doses were 800 mg and 1200 mg in phase Ib and phase I/II studies, respectively. Median dose of venetoclax for the retrospective study was 800 mg daily. Bortezomib and dexamethasone doses from phase Ib study were 1.3 mg/m2 subcutaneous and 20 mg, respectively. The median duration on venetoclax and median time on study ranged from 2 to 6 months. Median duration of response (DOR) and median time-to-progression (TTP) were reported higher with combination therapy of bortezomib and dexamethasone (9.7 months and 9.5 months, respectively). 62% of patients have discontinued the therapy due to: progressive disease (48%), adverse events (6%), and various other reasons (8%). There were 13 deaths; 6 were due to disease progression. Most common side effect from three studies was gastrointestinal problems such as nausea, diarrhea and vomiting. The median duration of response was 9.7, 9.7, 2 months and the median time to progression was 9.5, 2.6, NA months for phase Ib, phase I/II and retrospective study, respectively. The pooled overall response rate (ORR) for all patients was 43% (n=163) with the highest rate (67%) being reported from phase Ib study using combined venetoclax, bortezomib and dexamethasone (Figure 1 and 2). Among 44 patients with t(11;14), ORR was 40% and 78% in phase I/II and phase Ib studies, respectively. Twenty-eight patients who expressed high-bcl2 showed ORR rates of 80% and 94%, whereas 50 patients who had low-bcl2 level showed ORR rates of 8% and 59% in phase I/II and phase Ib studies, respectively (Table 1).Conclusion:Single-agent venetoclax showed an ORR of 21%, the addition of bortezomib produced an ORR of 32%, and the addition of bortezomib and dexamethasone improved an ORR to 67%. Better ORR was observed in patients with t(11;14) and with high-bcl2 expression. The highest median DOR (9.7 months) and TTP (9.5 months) were reported with a combination therapy of venetoclax, bortezomib and dexamethasone. Most reported adverse events were related to gastrointestinal system. More clinical studies evaluating the combination therapies using venetoclax are needed. DisclosuresNo relevant conflicts of interest to declare.

Abstract LB-360: JNKs-mediated phosphorylation of human stromal xbp1s regulates multiple myeloma growth &amp; osteolysis

Abstract Spliced X-box binding protein-1 (XBP1s) is a major effector of the unfolded protein response (UPR) signaling. We previously reported that human XBP1s in bone marrow stromal cells plays an essential role in regulating stromal support of multiple myeloma bone disease (MMBD). Here we report that human XBP1s (hXBP1s) is a physiological &amp; direct phosphorylation substrate of JNKs. This phosphorylation greatly increases hXBP1s protein degradation by the E3 ubiquitin ligase β-TrCP. Mutation of the phosphorylation site of JNKs to alanine largely prevents JNK phosphorylation of XBP1s &amp; JNK-induced protein degradation of hXBP1s. Further, we found that bone marrow stromal cells (BMSCs) harboring this XBP1s mutant are resistant to JNK phosphorylation and provided significantly greater support of MM growth and MM-induced bone destruction both in vitro &amp; in vivo, compared with counterparts expressing WT hXBP1s. Finally, we observed that JNK-mediated phosphorylation of hXBP1s is associated with favorable therapeutic responses of MM patients to combination therapy of bortezomib, &amp;/or dexamethasone &amp;/or thalidomide, MM drugs known to stimulate JNK. These results suggest p-hXBP1sJNK is a potential predictive biomarker for MM patients' response to the drug treatment. Taken together, our study provides the first evidence that hXBP1s is a novel physiological &amp; direct target of JNK phosphorylation and demonstrates the pathophysiological significance of this event in the hXBP1s-mediated bone microenvironment support of MM growth and MM-induced bone destruction. Citation Format: Risheng Chen, Guoshuang Xu, Wissam Beaino, Kai Lui, Xuemei Zeng, Nathan Yates, Rong Chong, Konstas Verdelis, G. David Roodman, Denise Toscani, Nicola Giuliani, Yan Lin, Carolyn J. Anderson, Hongjiao Ouyang. JNKs-mediated phosphorylation of human stromal xbp1s regulates multiple myeloma growth &amp; osteolysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-360.

658. Bortezomib Treatment Sensitizes Oncolytic Virus Treated Tumors to NK Cell Immunotherapy

Background: Bortezomib, a proteasome inhibitor and oncolytic herpes simplex virus-1 (oHSV) are currently FDA-approved and continue to be evaluated in several human cancers. Various combinatorial treatment modalities are being investigated to enhance the efficacy of each treatment. In this study, bortezomib-mediated oHSV killing sensitization and anti-tumor immunity were evaluated. Experimental Design: The synergistic interaction between oHSV and bortezomib was calculated using Chou-Talalay analysis. Western blot, flow cytometry, and caspase 3/7 activity assays were used to evaluate the induction of necroptotic cell death, JNK activation, and apoptosis. Production of reactive oxygen species (ROS) was measured. Inhibitors/shRNA targeting ROS, JNK and RIP1 kinase (RIPK1) were utilized to investigate the mechanism of cell killing. Natural killer (NK) cells isolated from normal human blood and co-cultured with tumor cells at an Effect/Target ratio of 2:1. Q-PCR, ELISA, and FACS analysis were used to evaluate NK cell activation. Intracranial tumor xenografts were utilized to evaluate anti-tumor efficacy. Results: Combination treatment with bortezomib and oHSV induced necroptotic cell death with increased production of mitochondrial ROS and phosphorylation of JNK. Inhibitors/shRNA of RIPK1 and JNK rescued synergistic cell killing. Combination treatment also increased HMGB1 and IL-1α secretion and significantly enhanced NK cell activation and tumor cell killing. Moreover, combinatorial therapy enhanced NK cell therapy. Conclusions: This study provides a significant rationale for triple combination therapy of bortezomib, oHSV, and NK cells to achieve synergistic efficacy, leading to future clinical testing of oHSV with bortezomib in patients.

The Identification of Novel Therapies for the Treatment of Follicular Dendritic Cell Sarcoma

IntroductionFollicular dendritic cell sarcoma (FDCS) is a rare malignant neoplasm arising from dendritic cells of the lymphoid follicles. The inciting event that leads to the development of malignancy remains unknown. The prevalent therapeutic approach involves surgical excision with the possibility of radiation therapy. However, most initial responders develop eventual recurrence. Furthermore, due to the rarity of the malignancy, there are no official recommendations for optimal FDCS therapy. To further elucidate possible therapies for FDCS, we assessed the effects of multiple agents in vitro on the cell viability of patient primary cells and employed our patient-derived xenograft (PDX) model to validate the efficacy of these agents in an in vivo model system.MethodsA 53-year-old female with highly metastatic FDCS, who had been refractory to multiple treatments, presented at the hospital with hypotension, weakness, and anorexia. FDCS samples were isolated from the patient's pleural fluid, and an in vitro primary patient cell culture was established and a subset of the patient cells were engrafted into SCID mice implanted with a human fetal bone chip to create the PDX model. A series of in vitro drug screens conducted with MTS cell viability and Annexin V apoptosis assays identified the therapies that decreased the cell viability of these cells. After passaging the cells for 3 generations, and based on the in vitro results, the mice were administered intravenous treatment with DMSO control (1%, n=2), bortezomib (0.5 mg/kg, n=3), carfilzomib (1 mg/kg, n=3), or combination bortezomib with CTX (0.5 mg/kg and 10 mg/kg, respectively, n=3) twice a week for 3 weeks. The average days of survival, tumor volume, and tumor mass were determined in vivo.ResultsThe clinical pathology report showed that the FDCS case was rare, with the immunophenotypes CD21- CD23- and weakly positive CD35, which was also confirmed in our PDX model. The MTS assay demonstrated that the proteasome inhibitors carfilzomib and bortezomib as well as Bruton's tyrosine kinase inhibitor ibrutinib and the SINE XP01 antagonist KPT-330 inhibited the growth of the freshly isolated FDCS cells derived from either the patient or the PDX mice. The Annexin V-binding assay demonstrated carfilzomib, bortezomib, and KPT-330 significantly induced apoptosis of both the patient and PDX-derived FDCS cells. CTX is the primary chemotherapy drug administered to FDCS patients; therefore, we combined CTX with bortezomib, the most effective anti-tumor drug observed in our in vitro studies, to investigate the therapeutic effects of this novel combination in our PDX model. Our in vivo results validated the in vitro data and demonstrated that the bortezomib and CTX combination therapy significantly inhibited tumor growth in PDX mice compared with the proteasome inhibitors bortezomib or carfilzomib alone.ConclusionThe data presented here suggest the potential of utilizing parallel in vitro drug screening and in vivo PDX tumor studies to determine possible therapies for rare malignancies. The combination therapy of bortezomib and CTX is a promising modality to treat relapsed FDCS. However, the patient died of hypotension and weakness after receiving bortezomib plus CHOP. DisclosuresPham:Amgen, Onyx, Millennium: Research Funding. Wang:Janssen: Honoraria; Pharmacyclics, Janssen, Celgene, Oncopep, Kite, Juno: Research Funding.

Synergistic effects of cisplatin and proteasome inhibitor bortezomib on human bladder cancer cells.

The proteasome inhibitor bortezomib is a promising novel agent in bladder cancer therapy; however, inducible cytoprotective mechanisms may limit its potential efficacy. To date, the cellular and molecular effects of proteasome inhibitors on bladder cancer cells have been poorly characterized. Despite the consistent rate of initial responses, cisplatin treatment typically results in the development of chemoresistance, leading to therapeutic failure. Therefore, the present study aimed to characterize the molecular mechanisms underlying the anti-proliferative effects of cisplatin and bortezomib combination therapy on the human T24 bladder cancer cell line, by analyzing the protein expression levels of apoptotic genes. Cytotoxic effects were measured using a water-soluble tetrazolium salt-1 assay, and the apoptosis-associated molecules were examined using western blot analysis and ELISA. It was observed that combined administration of cisplatin and bortezomib induced upregulation of caspase-3, -8 and -9, B-cell lymphoma-2 (Bcl-2)-like 11 and Bcl-2-interacting killer, but downregulated Bcl-2 and Bcl-extra large protein expression levels in T24 cells in a dose-dependent manner. Furthermore, enhanced protein expression of caspase-8 and -9, in line with the significantly increased caspase-3 activation, was detected when the cells were treated with a combination of cisplatin and bortezomib, compared with that of either agent alone. Bortezomib appeared to synergize with cisplatin to promote apoptosis via the extrinsic and intrinsic apoptotic pathways. Taken together, the results of the current study provide the preclinical framework for additional evaluation of the effects of combining bortezomib with other agents to induce apoptosis in bladder cancer cells.

Tumor Lysis Syndrome in Light Chain Multiple Myeloma Treated with Bortezomib Combination Therapy

Tumor Lysis Syndrome in Light Chain Multiple Myeloma Treated with Bortezomib Combination Therapy

Curcumin and its analogue induce apoptosis in leukemia cells and have additive effects with bortezomib in cellular and xenograft models.

Combination therapy of bortezomib with other chemotherapeutics is an emerging treatment strategy. Since both curcumin and bortezomib inhibit NF-κB, we tested the effects of their combination on leukemia cells. To improve potency, a novel Mannich-type curcumin derivative, C-150, was synthesized. Curcumin and its analogue showed potent antiproliferative and apoptotic effects on the human leukemia cell line, HL60, with different potency but similar additive properties with bortezomib. Additive antiproliferative effects were correlated well with LPS-induced NF-κB inhibition results. Gene expression data on cell cycle and apoptosis related genes, obtained by high-throughput QPCR, showed that curcumin and its analogue act through similar signaling pathways. In correlation with in vitro results similar additive effect could be obsereved in SCID mice inoculated systemically with HL60 cells. C-150 in a liposomal formulation given intravenously in combination with bortezomib was more efficient than either of the drugs alone. As our novel curcumin analogue exerted anticancer effects in leukemic cells at submicromolar concentration in vitro and at 3 mg/kg dose in vivo, which was potentiated by bortezomib, it holds a great promise as a future therapeutic agent in the treatment of leukemia alone or in combination.

Vorinostat, Bortezomib, Cyclophosphomide, Thalidomide, and Dexamethasone in Relapsed/Refractory Multiple Myeloma Patients

The combination of vorinostat, a histone deacetylase (HDAC) inhibitor, is synergistic with proteasome inhibitors and IMIDs based upon preclinical and clinical data. Phase III trials with vorinostat in relapsed myeloma failed to demonstrate benefit due to excess toxicity that precluded chronic administration of the agent allowing patients to realize the clinical benefits. Herein we report on our experience combining vorinostat, or adding vorinostat to current treatments in the context of refractory myeloma.Methods: Forty RRMM pts that received vorinostat (V) (200mg orally daily on days 1-14) and bortezomib (B) (1.3 mg/m2 IV/SQ days 1,4,8, and 11) combinations, every 28 days from May 2008 until May 2014 at Emory University were reviewed. Cohort 1 consisted of 22 RRMM pts that received VBCyTD regimen (V,B, cyclophosphamide (Cy) (300 mg orally flat dose days 1, 8 and 15), thalidomide (T) (100 mg daily) and dexamethasone (D) 40 mg orally weekly), while cohort 2 consisted of 18 RRMM pts that received other combinations (VBCyD+lenalidomide (R): 4 pts; VBRD: 4 pts; VBCyD: 2 pts; VBD: 4 pts; VBTD: 4 pts and VCyTD+carfilzomib (Ca): 2 pts). The objectives are response assessment by IMWG criteria, progression-free survival (PFS) and overall survival (OS). Drug related adverse events (AEs) ≥grade 3 (CTCAE v3.0) were summarized.Results: Twenty-one males and nineteen females (median age at diagnosis: 56 years [range 28-89], median age at initiation of V treatment: 62 years [range 33-91]) that were heavily pretreated (median lines of therapy: 7 [range 3-14] were included in the analysis. Ninety-five percent of pts were B refractory and 85% pts were R refractory; 97.5% and 15% of pts underwent prior autologous and allogeneic SCT, respectively. High risk cytogenetic abnormalities were seen in 40% of pts. Time from diagnosis to initiation of V combination therapy is 58.5 months (range 18-138). The overall clinical benefit rate (≥SD) was 72.5%. Figure 1 illustrates response rates from both cohorts. Median PFS for cohort 1 is 3 months (95% CI 0.5-5.51) and for cohort 2 is 2 months (95% CI 0.8-3.2), respectively. At a median follow-up of 26 months from the time of V initiation, median OS for cohort 1 is 6 months (95% CI 0-13.6) and for cohort 2 is 3 months (95% CI 1.4-4.7). Median overall survival from diagnosis for these cohorts is 80 months (95% CI 70.2-89.8) and 70 (95% CI 55.6-84.4) months, respectively. ≥Grade 3 AEs include fatigue (15%); generalized weakness (12.5%); neutropenia (15%); and thrombocytopenia (35%).Conclusions: In heavily pretreated relapsed/refractory multiple myeloma patients with limited therapeutic options, vorinostat and bortezomib combination therapy offers clinical benefit with good response rates and acceptable tolerability, likely due to lower doses of vorinostat used. This data further supports the activity of HDAC inhibitors in the context of refractory myeloma. [Display omitted] DisclosuresGleason:Celgene: Consultancy; Novartis: Consultancy. Heffner:Amgen: Honoraria, Research Funding; Biotest: Honoraria, Research Funding; Dana Farber CI: Honoraria, Research Funding; Genentech: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; Idera: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Pharmacyclics: Honoraria, Research Funding; Onyx: Honoraria, Research Funding; Spectrum: Honoraria, Research Funding; Talon Therapeutics: Honoraria, Research Funding. Lonial:Millennium: The Takeda Oncology Company: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Onyx Pharmaceuticals: Consultancy, Research Funding.

Phase I/II trial assessing bendamustine plus bortezomib combination therapy for the treatment of patients with relapsed or refractory multiple myeloma

Bendamustine, active in multiple myeloma (MM), is a bifunctional mechlorethamine derivative with alkylating properties. Bortezomib, approved to treat MM, is effective in combination with alkylators. The tolerability and efficacy of bendamustine plus bortezomib in relapsed/refractory MM was assessed in an open-label, dose-escalating, phase I/II study. Patients aged ≥18years received intravenous bendamustine 50, 70, or 90mg/m(2) (days 1 and 4) plus bortezomib 1·0mg/m(2) (days 1, 4, 8, and 11) for up to eight 28-day cycles. No dose-limiting toxicity was observed after cycle 1; bendamustine 90mg/m(2) plus bortezomib 1·0mg/m(2) was designated the maximum tolerated dose (MTD). The most common grade 3/4 adverse events were leucopenia (58%), neutropenia (50%), lymphopenia (45%), and thrombocytopenia (30%). Primary efficacy measure was overall response rate (ORR), which was the combined complete response (CR), very good partial response (VGPR), partial response (PR), and minimal response (MR). ORR was 48% (one CR, two VGPR, nine PR, and seven MR) for all 40 enrolled patients, 52% (16/31) at the MTD (90mg/m(2) ), and 42% and 46% for prior use of bortezomib (n=31) or alkylators (n=28) respectively. Bendamustine plus bortezomib was well tolerated with promising efficacy in this heavily pretreated population.

Phase I Trial of Vorinostat Combined With Bortezomib for the Treatment of Relapsing and/or Refractory Multiple Myeloma

Preclinical studies have shown that targeted combination therapy consisting of vorinostat and bortezomib has antitumor activity in multiple myeloma (MM). We examined this drug combination in advanced relapsing and/or refractory MM patients (n = 34). Although the maximum tolerated dose was not reached, the study found this combination regimen generally well tolerated and clinically active in relapsed and/or refractory MM patients. Development of targeted therapies for MM has improved response rates and increased patient survival, but ultimately the disease becomes refractory and progresses. Vorinostat combined with bortezomib has demonstrated synergistic antiproliferative and proapoptotic activity in preclinical models of MM. The objectives of this study were to determine the maximum tolerated dose for vorinostat with bortezomib in patients with advanced MM and to evaluate the clinical benefit of this new drug combination. Patients ≥ 18 years old with relapsed and/or refractory MM were enrolled into escalating dose cohorts of vorinostat and bortezomib combination therapy. Thirty-four patients were enrolled and were evaluable for safety and efficacy analyses. All patients reported adverse events, 89% of which were mild to moderate in severity. Thirteen patients experienced 29 serious adverse events, 12 (41%) of which were considered drug-related. The maximum tolerated dose was not reached. Partial responses were observed in 9 (27%) patients. Minimal responses were observed in 2 additional patients (6%), and another 20 patients (59%) experienced disease stabilization. Vorinostat with bortezomib is generally well-tolerated and has clinical activity in patients with relapsed and/or refractory MM. Response rates were similar in patients previously exposed to bortezomib and patients who were naive to bortezomib therapy.