scholarly journals ROR1 Targeted Immunoliposomal Delivery of OSU-2S Show Selective Cytotoxicity in t(1;19) Translocated B-ALL

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3798-3798
Author(s):  
Swagata Goswami ◽  
Chi-Ling Chiang ◽  
Kevan Zapolnik ◽  
Zhiliang Xie ◽  
James L. Lee ◽  
...  
Keyword(s):  
Research Funding ◽  
Hematological Malignancies ◽  
Cell Lymphoma ◽  
Tumor Burden ◽  
Leukemic Cells ◽  
State University ◽  
Research Support ◽  
University Patents ◽  
Relative Viability

The receptor tyrosine kinase ROR1 is uniquely expressed on and required for many hematological malignancies such as t(1;19) positive acute lymphoblastic leukemia (ALL) and chronic lymphocytic leukemia (CLL). The t(1;19) is one of the most frequent translocations in B-ALL, observed in both adult and pediatric patients. The translocation has intermediate prognosis on its own, but is associated with a poor prognosis in the unbalanced der(19)t(1;19) form in pediatric ALL, and in the context of hyperdiploid B-ALL. While leukemic cell dependence on ROR1 is known, ROR1 lacks kinase activity making it difficult to target therapeutically. However, we have previously shown that ROR1 can be targeted to deliver therapeutic payload specifically to leukemic cells in CLL, sparing the normal cells from toxic side effects. This encouraged us to develop ROR1 directed immunoliposomal nanoparticles encapsulating a novel small molecule OSU-2S. OSU-2S is a non-immunosuppressive derivative of the sphingosine analogue FTY720, with potent anti-tumor activity against multiple hematological malignancies including CLL, mantle cell lymphoma (MCL) and canine B-cell lymphoma. OSU-2S demonstrated potent dose dependent cytotoxicity in patient derived B-ALL samples with different cytogenetic backgrounds including translocations t(4;11), t(9;22) and t(1;19) as well as hyperdiploid, hypodiploid and normal cytogenetic background [n=7, p= 0.0032 (0 vs 2.5µM), mean decrease in relative viability= 44.51±12.12%] as assessed by Annexin V/Propidium Iodide staining. We confirmed ROR1 expression on t(1;19) translocated patient samples by flow cytometry, and synthesized ROR1 targeted OSU-2S immunoliposomal nanoparticles (2A2-OSU-2S-ILP) (mean size= 186.9 +/- 0.8 nm, mean concentration= 1.38*1013 particles/ml). 2A2-OSU-2S-ILP was selectively cytotoxic to t(1;19) translocated ALL, including unbalanced der(19)t(1;19), from relapsed patients aged 29-37, but not ROR1-ve, t(1;19) non translocated ALL, as compared to control IgG-OSU-2S-ILP, or 2A2/IgG immunoliposomes without OSU-2S [n=3, p= 0.04, mean decrease in relative viability (IgG-OSU-2S-ILP vs 2A2-OSU-2S-ILP)= 35.14±7.36%]. Similar results were seen in ROR1+ve 697 cells, a B-ALL cell line carrying t(1;19) translocation, where 2A2-OSU-2S-ILP showed selective cytotoxicity [n=8, p=0.004, mean decrease in relative viability (IgG-OSU-2S-ILP vs 2A2-OSU-2S-ILP)= 61.62±14.63%]. To assess the effect of 2A2-OSU-2S-ILP on t(1;19) positive ALL in-vivo, we used a disseminated cell line derived xenograft model. Immunocompromised NSG mice were engrafted with 697 cells, treated with 2A2-OSU-2S-ILP or IgG-OSU-2S-ILP for 14 days and tumor burden was assessed in the spleen and bone marrow. 2A2-OSU-2S-ILP treatment significantly reduced the number of human CD45+CD19+ cells in the bone marrow as compared to IgG-OSU-2S-ILP cohort (n=6 per cohort, p=0.022, mean decrease in 697 cells in marrow= 1.751 ± 0.6372 million cells/ femur). There was also a trend towards decreased tumor burden in spleen (mean decrease in 697 cells in spleen= 1.883 ± 0.9729 million cells). Together, these data show the ability of ROR1 targeted liposomal nanoparticles to selectively deliver its payload to leukemic cells in t(1;19) translocated B-ALL, sparing toxicity to the normal cells. Ongoing studies are directed towards understanding the mechanistic basis of OSU-2S mediated therapeutic benefit in B-ALL in-vitro and in-vivo. [This work was supported by NIH-R01-CA197844-01. SG is supported by Pelotonia Graduate Fellowship] Disclosures Baskar: NIH: Patents & Royalties: ROR1 mAb 2A2. Rader:NIH: Patents & Royalties: ROR1 mAb 2A2. Byrd:Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; BeiGene: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; Acerta: Research Funding; Novartis: Other: Travel Expenses, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau. Bhatnagar:Novartis and Astellas: Consultancy, Honoraria; Cell Therapeutics, Inc.: Other: Research support; Karyopharm Therapeutics: Other: Research support. Muthusamy:Ohio State University: Patents & Royalties: OSU-2S.

scholarly journals Targeting PRMT5 to Circumvent Acquired Ibrutinib Resistance in Mantle Cell Lymphoma

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4065-4065 ◽  
Author(s):  
Shelby Sloan ◽  
Fiona Brown ◽  
JI Hyun Chung ◽  
Alexander Prouty ◽  
Esther Wheeler ◽  
...  
Keyword(s):  
Research Funding ◽  
Disease Burden ◽  
Cell Lymphoma ◽  
Ex Vivo ◽  
Ohio State University ◽  
State University ◽  
University Patents ◽  
Mantle Cell ◽  
Ibrutinib Resistance ◽  
Dimethyl Arginine

Mantle cell lymphoma (MCL) is an incurable B-cell malignancy characterized by genetic dysregulation of cyclin D1 and activation of signaling pathways driving uncontrolled MCL cell proliferation and survival. Ibrutinib is an FDA-approved irreversible inhibitor of Bruton's tyrosine kinase (BTK), a downstream target of the B-cell receptor (BCR) pathway. While ibrutinib exhibits significant single-agent therapeutic activity in patients with relapsed/refractory MCL, the vast majority of MCL patients on ibrutinib progress with aggressive disease and short survival (3-8 mo). Although ~80% of chronic lymphocytic leukemia patients with acquired ibrutinib resistance have mutations in BTK and PLCγ2, this is uncommon in MCL suggesting alternative mechanisms driving this resistant phenotype. Understanding drug-resistance mechanisms and developing effective therapies for ibrutinib resistant (IR) MCL are urgently needed. The major type II protein arginine methyltransferase enzyme, PRMT5, catalyzes symmetric dimethylation of arginine residues on histone tails (H3R8 and H4R3) and other proteins. PRMT5 regulates a vast array of biologic functions including RNA processing, DNA damage response, signal transduction, and gene expression. Amplified PRMT5 activity drives the expression and activity of key oncogenes (MYC, CYCLIND1, NOTCH1) while silencing expression and activity of tumor suppressors (ST7, RBL2, and p53). Our group has shown PRMT5 is overexpressed and dysregulated in MCL and strategies aimed at selectively targeting PRMT5 show anti-tumor activity in preclinical lymphoma models. Here we describe the development of a novel patient derived xenograft (PDX) of IR-MCL and explore PRMT5 inhibition as an alternative therapeutic option to circumvent IR. Peripheral blood mononuclear cells from a 75 yo male patient diagnosed with acquired classic IR-MCL were engrafted intravenously into NSG mice. After 5 passages, all mice engrafted with 107 MCL cells developed histologically confirmed MCL infiltrating kidney, lymph nodes, bone marrow, spleen and peripheral blood. Circulating human CD5+/CD19+ cells were detectable and quantifiable by flow cytometry by day 21 post-engraftment. Karyotype analysis confirmed the hallmark t(11;14)(q13;q32) of MCL while retaining nearly all cytogenetic abnormalities present in the patient's primary tumor including a deletion of chromosome 9, associated with deletion of MTAP, a therapeutic vulnerability for PRMT5-targeted therapy. Whole exome sequencing confirmed genomic stability with successive passages. Ex vivo cytotoxicity assays and protein pathway analysis further confirmed resistance to ibrutinib (IC50 >1 µM) with maintained hyper-phosphorylation of AKT (Ser473) and ERK (Thr202/Tyr204). Western blot analysis showed elevated levels of c-MYC, CYCLIND1, BCL2, and pERK. After validation of circulating disease at day 25 post engraftment, mice were treated with either a novel small molecule inhibitor of PRMT5 (PRT382, 10 mg/kg orally 4 days on 3 days off) or ibrutinib (75 mg/kg administered in drinking water, n=5 mice per treatment group). Treatment of this PDX model with PRT382 resulted in significantly decreased disease burden and improved median survival compared to control animals from 48 to 83 days, respectively (p=0.0045). We found no significant difference in survival (p= 0.6540) or circulating disease burden with ibrutinib therapy compared to control group. The full BTK occupancy of ibrutinib treated mice was validated using fluorescence resonance energy transfer-based assay. Ex vivo PDX MCL cells from PRT382-treated mice showed loss of symmetric dimethyl arginine with preservation of asymmetric dimethyl arginine levels, reduced H4(Sme2)R3 epigenetic marks, and elevated levels of BCL2, MYC, and pAKT/pERK. We developed a cell line (SEFA) allowing for in vitro mechanistic studies. We are currently investigating potential mechanisms responsible for circumventing IR-MCL by integrating genome-wide changes to chromatin accessibility and whole transcriptome analysis. This IR-MCL PDX mouse model serves as a useful tool to investigate mechanisms of drug resistance, provides a platform to explore novel pre-clinical therapeutic strategies to circumvent IR and demonstrates the therapeutic activity of PRMT5 targeted therapy in this aggressive disease. Disclosures Byrd: Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Ohio State University: Patents & Royalties: OSU-2S; Genentech: Research Funding; BeiGene: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Genentech: Research Funding; Acerta: Research Funding; Acerta: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; BeiGene: Research Funding; Genentech: Research Funding; BeiGene: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau. Vaddi:Prelude Therapeutics: Employment. Scherle:Prelude Therapeutics: Employment. Baiocchi:Prelude: Consultancy.

scholarly journals Rapid Dose Escalation of Venetoclax in Patients with Relapsed/Refractory Chronic Lymphocytic Leukemia Previously Treated with B-Cell Receptor Inhibitor Therapy

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3045-3045 ◽  
Author(s):  
Kristin Koenig ◽  
Emily Dotson ◽  
Shane Sheredy ◽  
Seema A. Bhat ◽  
John C. Byrd ◽  
...  
Keyword(s):  
B Cell ◽  
Dose Escalation ◽  
Research Funding ◽  
Tumor Lysis Syndrome ◽  
Cell Receptor ◽  
Tumor Burden ◽  
Ohio State University ◽  
Lymphocytic Leukemia ◽  
State University ◽  
University Patents

Background B-cell receptor signaling inhibition (BCRi) is an effective treatment (trtmt) for patients (pts) with chronic lymphocytic leukemia (CLL), but resistance develops. Venetoclax selectively inhibits anti-apoptotic protein B-cell lymphoma 2 (BCL-2), and has demonstrated efficacy in relapsed/refractory CLL pts, particularly after BCRi. Venetoclax is started at 20 mg daily and escalated weekly over 5 weeks to the goal dose to avoid acute tumor lysis syndrome. However, we observed that many pts with relapsed/refractory CLL relapsing on BCRi progress more quickly than this schedule allows; they may progress while still taking BCRi or vigorously after its discontinuation. Given the need to promptly attain goal venetoclax dose in this population, we developed a rapid dose escalation scheme for venetoclax and reviewed our experience to understand the feasibility, safety, and efficacy of this approach in a properly equipped university setting. Methods We retrospectively evaluated adult pts with relapsed/refractory CLL presenting to The Ohio State University who were treated with a "rapid dose escalation" of venetoclax. Charts were reviewed for previous and concomitant CLL treatments, tumor burden, prognostic factors, performance status, and co-morbidities. Venetoclax dosing was planned for a shorter time period than the 5 weeks described in the label dosing. The dose was increased as quickly as tolerated following the customary doses (20mg, 50mg, 100mg, 200mg, then 400mg). We reviewed the evaluated safety and efficacy outcomes with this approach. Results We treated 34 pts with rapid venetoclax dose escalation. Median age at venetoclax start was 54 years old and were 73.5% men. Pts had a median of 5 previous CLL trtmts (range 2-18). The most recent trtmt was single-agent BCRi in 18 cases, which overlapped with venetoclax in the majority. Only 6 pts had high tumor burden and the majority had low or medium tumor burden. Cytogenetic abnormalities at venetoclax start included: 17 (50.0%) pts with 17p deletion, 5 (14.7%) with 13q deletion, 6 (17.6%) with 11q deletion, and 3 (8.8%) with trisomy 12. Fifty percent of pts had a complex karyotype, and 76.5% had unmutated IGVH status. 24 (80%, n=30 pts that had testing done) pts had confirmed BTK/PLCу2 mutations. The mean time to goal venetoclax dose was 9.6 days (range 4-31); all but 1 pt reached goal dose. Eighteen (52.9%) pts developed tumor lysis syndrome (TLS) by lab criteria at doses from 20-400 mg, 5 pts developed TLS by clinical criteria, and 1 pt experienced grade 3 severity TLS (per Cairo-Bishop definition). Only 4 pts had an elevated uric acid requiring rasburicase. Seventy-three percent of pts achieved at least a partial remission, and 4 pts each had stable or progressive disease. Three pts died within 30 days: 1 from uncontrolled bleeding and neutropenia, 1 due to neutropenic sepsis with invasive fungal infection and gastric perforation, and 1 due to neutropenic septic shock and respiratory failure. Time to best response was mean 50.7 days (range 2-428). Median time to subsequent trtmt was 279.5 days (range 73-430). 23 pts (67.6%) had not progressed at 1 year, and 26 (76.5%) were surviving at 1 year. Conclusion/summary Rapid dose escalation of venetoclax in this pt population is safe and feasible. Despite a high percentage of patients developing TLS (52.9%), all patients recovered without lasting complications and all but one were able to achieve the goal dose of venetoclax. This dosing scheme achieved disease control with 67.6% remaining progression-free at 1 year and the majority of pts surviving. It is reasonable to implement venetoclax rapid dose escalation in the proper hospital setting with ample ancillary support. This approach may be needed for CLL patients with rapidly progressive disease on BCRi. Disclosures Dotson: Abbvie: Consultancy. Bhat:Pharmacyclics: Consultancy; Janssen: Consultancy. Byrd:Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; Acerta: Research Funding; BeiGene: Research Funding; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Genentech: Research Funding; Acerta: Research Funding; BeiGene: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau. Woyach:Janssen: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; AbbVie: Research Funding; Karyopharm: Research Funding; Loxo: Research Funding; Morphosys: Research Funding; Verastem: Research Funding. Awan:Genentech: Consultancy; Sunesis: Consultancy; Gilead: Consultancy; Abbvie: Consultancy, Speakers Bureau; Janssen: Consultancy; Pharmacyclics: Consultancy, Research Funding; AstraZeneca: Consultancy, Speakers Bureau. Rogers:AbbVie: Research Funding; Genentech: Research Funding; Janssen: Research Funding; Acerta Pharma: Consultancy. OffLabel Disclosure: Venetoclax- we will be suggesting a faster increase from starting to maximum/goal dose than the dosing label recommends. This is in order to achieve faster disease control.

scholarly journals The Protein Kinase C Inhibitor MS-553 for the Treatment of Chronic Lymphocytic Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2077-2077
Author(s):  
Elizabeth M. Muhowski ◽  
Amy M. Lehman ◽  
Sean D. Reiff ◽  
Janani Ravikrishnan ◽  
Rose Mantel ◽  
...  
Keyword(s):  
Research Funding ◽  
Ohio State University ◽  
Lymphocytic Leukemia ◽  
State University ◽  
Advisory Committees ◽  
University Patents ◽  
Kinase C ◽  
Hla Dr ◽  
Bcr Signaling ◽  
Equity Ownership

Introduction: Treatment of chronic lymphocytic leukemia (CLL) has been transformed by small molecule inhibitors targeting the B-cell receptor (BCR) signaling cascade. The first-in-class small molecule inhibitor of Bruton's Tyrosine Kinase (BTK), ibrutinib, is FDA approved as a frontline therapy for CLL. However, resistance to BTK inhibition has emerged in patients through acquisition of mutations in BTK or its immediate downstream target, PLCG2, emphasizing the need for alternative targets and therapies. BCR signaling remains intact in the presence of these mutations, making targeted inhibition of proteins downstream of BTK an attractive therapeutic strategy. Protein kinase C-β (PKCβ) is a downstream member of the BCR signaling pathway that we have previously demonstrated as an effective therapeutic target in CLL. MS-553 is a potent, ATP-competitive, reversible inhibitor of several PKC isoforms including PKCβ. Therefore, we evaluated the effects of MS-553 in primary CLL cells. Methods: Primary CLL cells were isolated by negative selection and treated with increasing concentrations of MS-553 to a maximum dose of 10 µM. BCR signaling changes were interrogated by change in target protein phosphorylation by immunoblot following a 24 hour drug incubation with and without phorbol ester stimulation (90 minutes) in CLL samples. Inhibition of CpG-mediated activation of CLL cells was measured using flow cytometry (CD86 and HLA-DR) in ibrutinib refractory patient samples at baseline and post-relapse due to the emergence of the p.C481S BTK mutation. CCL3 and CCL4 expression was measured by ELISA after 24 hours in primary CLL cells in the presence or absence of anti-IgM ligation. TNFα expression was also measured by ELISA in negatively selected, healthy donor T cells treated with MS-553 for 24 hours with or without anti-CD3 and anti-CD28 stimulation. Results: At 24 hours, 5 µM MS-553 inhibited downstream BCR signaling in primary CLL cells, demonstrated by 31% reduced phosphorylation of PKCβ (p=0.08, n=5) and several of its downstream targets including GSK3β (40%, p<.01, n=5) , ERK (46%, p=0.02, n=4) , and IκBα (56%, p=0.04, n=5) compared to vehicle treated, stimulated samples. CpG-mediated TLR9 stimulation increases expression of CD86 and HLA-DR in primary CLL cells. In baseline samples from ibrutinib treated patients, 10 µM MS-553 decreased expression of CD86 by 34% and HLA-DR by 91%. In matched patient samples post-relapse due to ibrutinib resistance, MS-553 (10 µM) maintained the ability to decrease expression of CD86 (49%) and HLA-DR (84%). Pro-inflammatory cytokine expression by primary CLL cells stimulated with anti-IgM decreased in the presence of 5 µM MS-553, with CCL3 decreasing by 36% (p=0.06, n=5) and CCL4 decreasing by 79% (p<.01, n=4) compared to vehicle treated, stimulated controls. TNFα expression by healthy T cells increased with anti-CD3 and anti-CD28 stimulation; 1 µM MS-553 reduced TNFα expression by 97% compared to vehicle treated, stimulated controls (p<.01, n=9). Conclusions: MS-553 is a novel and potent inhibitor of PKC demonstrating in vitro efficacy in CLL. MS-553 is able to inhibit BCR signaling by blocking phosphorylation of PKCβ and its downstream targets. CpG-mediated activation is reduced with MS-553 treatment in ibrutinib refractory patient samples both at baseline and post-relapse. Inflammatory signaling by primary CLL cells is further abrogated by MS-553 in its ability to decrease CCL3 and CCL4 cytokine expression. In an ongoing phase I clinical trial of MS-553, patient samples show a potent and dose dependent decrease in PKCβ activity as measured by a clinical biomarker assay. Together, our results suggest that MS-553 targets PKCβ in primary CLL to inhibit signaling and survival, establishing MS-553 as a potential therapeutic for treating CLL. These data justify continued preclinical and clinical work in the development of MS-553 for the treatment of CLL. Disclosures Niesman: MingSight Pharmaceuticals, Inc.: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Zhang:MingSight Pharmaceuticals, Inc.: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Byrd:BeiGene: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Ohio State University: Patents & Royalties: OSU-2S; Ohio State University: Patents & Royalties: OSU-2S; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding; Novartis: Other: Travel Expenses, Speakers Bureau; Genentech: Research Funding; Acerta: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Genentech: Research Funding; Acerta: Research Funding; Novartis: Other: Travel Expenses, Speakers Bureau; BeiGene: Research Funding; BeiGene: Research Funding. Woyach:Verastem: Research Funding; Loxo: Research Funding; Morphosys: Research Funding; Janssen: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; AbbVie: Research Funding; Karyopharm: Research Funding.

scholarly journals Targeting Antibody Checkpoint Fcgriib Using Monoclonal Antibody BI-1206 to Overcome Therapeutic Resistance in Mantle Cell Lymphoma

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 35-35
Author(s):  
Alexa A Jordan ◽  
Joseph McIntosh ◽  
Yang Liu ◽  
Angela Leeming ◽  
William Lee ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Tumor Growth ◽  
Research Funding ◽  
Cell Lymphoma ◽  
Single Agent ◽  
Publicly Traded ◽  
In Vivo Efficacy ◽  
Mantle Cell ◽  
Xenograft Models

Mantle cell lymphoma (MCL) is a rare but aggressive B-cell non-Hodgkin's lymphoma that represents 6% of all lymphomas in the United States. Recent therapies including anti-CD20 antibody rituximab, BTK inhibitors, and BCL-2 inhibitors alone or in combination have shown great anti-MCL efficacy. However, primary and acquired resistance to one or multiple therapies commonly occurs, resulting in poor clinical outcome. Therefore, resistance to such therapies is currently an unmet clinical challenge in MCL patients. Therapeutic strategies to overcome this resistance holds promise to significantly improve survival of refractory/relapsed MCL patients. Recent studies showed Fc gamma receptors (FcγRs) play important roles in enhancing the efficacy of antibody-based immunotherapy. In particular, FcgRIIB (CD32B), an inhibitory member of the FcγR family, is implicated in the immune cell desensitization and tumor cell resistance through the internalization of therapeutic antibodies such as rituximab. Based on our flow cytometry analysis, we demonstrated that FcgRIIB is highly expressed on the cell surface of MCL cell lines (n=10) and primary MCL patient samples (n=22). This indicates that FcgRIIB may play an important role in MCL malignancy and identifies FcgRIIB is a potential therapeutic target for the treatment of MCL. To address this, we tested the in vivo efficacy of BI-1206, a fully humanized monoclonal antibody targeting FcgRIIB, alone, or in combination with clinically approved or investigational drugs including rituximab, ibrutinib and venetoclax. In the first in vivo cohort, BI-1206, as a single agent, dramatically inhibited the tumor growth of ibrutinib-venetoclax dual-resistant PDX tumor models, suggesting that targeting FcgRIIB by BI-1206 alone has high anti-MCL activity in vivo. Next, we assessed whether BI-1206 can boost anti-MCL activity of antibody-based therapy such as rituximab in combination with ibrutinib or venetoclax using additional mice cohorts of cell line-derived xenograft and patient-derived xenograft models. BI-1206 significantly enhanced the in vivo efficacy of ibrutinib plus rituximab, and venetoclax plus rituximab, on tumor growth inhibition, including the JeKo-1 derived xenograft models, previously proven to be partially resistant to ibrutinib and venetoclax in vivo. This tumor-sensitizaton effect was further confirmed in the ibrutinib and venetoclax dual-resistant PDX models of MCL where BI-1206 was combined with venetoclax and rituximab. More detailed mechanistic studies are currently ongoing to reveal the mechanism of action of BI-1206-based combinations or as single therapy with the possibility that BI-1206 itself may have a cytotoxic anti-tumor direct activity in MCL. In conclusion, BI-1206 as single agent showed potent efficacy in overcoming ibrutnib-venetoclax dual resistance. Moveover, BI-1206 enhanced the in vivo efficacy of ibrutinib plus rituximab and venetoclax plus rituximab and overcomes resistance to these treatments resulting in enhanced anti-tumor effects. Disclosures Karlsson: BioInvent International AB: Current Employment. Mårtensson:BioInvent International AB: Current Employment, Current equity holder in publicly-traded company. Kovacek:BioInvent International AB: Current Employment, Current equity holder in publicly-traded company. Teige:BioInvent International AB: Current Employment, Current equity holder in publicly-traded company. Frendéus:BioInvent International AB: Current Employment, Current equity holder in publicly-traded company. Wang:Pulse Biosciences: Consultancy; Loxo Oncology: Consultancy, Research Funding; Kite Pharma: Consultancy, Other: Travel, accommodation, expenses, Research Funding; BioInvent: Research Funding; Juno: Consultancy, Research Funding; Beijing Medical Award Foundation: Honoraria; OncLive: Honoraria; Verastem: Research Funding; Molecular Templates: Research Funding; Dava Oncology: Honoraria; Guidepoint Global: Consultancy; Nobel Insights: Consultancy; Oncternal: Consultancy, Research Funding; InnoCare: Consultancy; Acerta Pharma: Research Funding; VelosBio: Research Funding; MoreHealth: Consultancy; Targeted Oncology: Honoraria; OMI: Honoraria, Other: Travel, accommodation, expenses; Celgene: Consultancy, Other: Travel, accommodation, expenses, Research Funding; AstraZeneca: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Pharmacyclics: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Janssen: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Lu Daopei Medical Group: Honoraria.

CDDO and CDDO-Im Reduce Tumor Burden in a Transgenic Mouse Model of CLL.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3477-3477
Author(s):  
Juan M. Zapata ◽  
Christina L. Kress ◽  
Marina Konopleva ◽  
Maryla Krajewska ◽  
Mark Hyer ◽  
...  
Keyword(s):  
B Cells ◽  
Transgenic Mice ◽  
B Cell ◽  
B Cell Lymphoma ◽  
Chemotherapeutic Agents ◽  
Tumor Burden ◽  
Leukemic Cells ◽  
Medium Size ◽  
Control Group

Abstract Transgenic mice over-expressing in B lymphocytes both Bcl-2 and a TRAF2 mutant lacking the N-terminal RING and zinc finger domains (TRAF2DN), which mimics TRAF1, develop small B cell lymphoma and leukemia that have remarkably similar characteristics to human chronic lymphocytic leukemia (CLL). TRAF2DN/Bcl-2 mice develop over time leukemia, severe splenomegaly, and lymphadenopathy, which are associated with monoclonal and oligoclonal B cell neoplasms. The lifespan of TRAF2DN/Bcl-2 mice is markedly reduced compared to Bcl-2 and TRAF2DN single transgenics or wild-type littermates. The expanded B cell population in the blood of leukemic TRAF2DN/Bcl-2 double transgenic mice is primarily comprised of small-medium size, non-cycling B220M/IgMH/IgDL/CD21L/CD23−/CD11b+/CD5+ cells that were Bcl-6 negative, consistent with a B-1 phenotype, closely resembling their human CLL counterparts. Indeed, these B cells showed comparable proliferation rates to normal B-cells, but exhibited markedly increased survival and were resistant to apoptosis induced by chemotherapeutic agents and glucocorticoids. We studied the effects of synthetic triterpenoid 2-Cyano-3,12-Dioxooleana-1,9-Dien-28-Oic Acid (CDDO) and its imidazolide derivative (CDDO-Im) on cultured B-cells from the TRAF2DN/Bcl-2 transgenic mice. Both CDDO and CDDO-Im efficiently induced apoptosis of these cells in vitro, although CDDO-Im was approximately 10-times more potent than CDDO (LD50: 0.35μM CDDO-Im vs 3.8 μM CDDO). To study the effect of CDDO and CDDO-Im in vivo, groups of TRAF2DN/Bcl-2 mice that had developed leukemia were injected i.v. with liposomes alone or liposomes containing either CDDO or CDDO-Im, at a dose of 20 mg/kg/day. Each mouse received a total of nine injections administered over a period of 22 days. The concentration of B cells in the blood of these mice was monitored daily after each injection, using a mini-FACS (Guava Technologies, Inc.). CDDO-treated mice showed a steady reduction in the number of leukemic cells in blood during the treatment and this tendency was maintained 10 days after the last treatment. In contrast, CDDO-Im treated mice showed a striking increase in the concentration of B cells in blood (B220+ events) immediately after the first inoculation. One mouse of this group died after the first injection, and 2 more mice died after 5 injections. Only 2 mice treated with CDDO-Im survived the full treatment, showing a striking reduction of leukemic cells in blood by the end of the treatment. Administration of empty liposomes had no inhibitory effect on the leukemia, and mice in this control group had massive splenomegaly (1431±323 mg; n=3) and severe disseminated lymphadenopathy. In contrast, CDDO-treated mice had less severe splenomegaly (938±234; n=4) but still had severe lymphadenopathy. CDDO-Im treated mice showed a dramatic reduction in the spleen size that was evident also in those mice that died after 5 injections (474±185 mg; n=4) and had no signs of lymphadenopathy. Although preliminary, these results indicate that in vivo administration of CDDO and CDDO-Im reduced the tumor burden in a transgenic model of CLL, and illustrate the potential of triterpenoids as single agents for the treatment of CLL.

MLN9708 Elicits Pharmacodynamic Response in the Bone Marrow Compartment and Has Strong Antitumor Activity in a Preclinical Intraosseous Model of Plasma Cell Malignancy.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1834-1834 ◽  
Author(s):  
Edmund Lee ◽  
Bret Bannerman ◽  
Michael Fitzgerald ◽  
Jennifer Terkelsen ◽  
Daniel Bradley ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Antitumor Activity ◽  
Plasma Cell ◽  
Research Funding ◽  
Ex Vivo ◽  
Xenograft Model ◽  
Tumor Burden ◽  
Human Multiple Myeloma ◽  
Cell Malignancy

Abstract Abstract 1834 Poster Board I-860 Introduction The clinical success of VELCADE® (bortezomib) for Injection has validated the proteasome as a therapeutic target for the treatment of human cancer. The novel proteasome inhibitor MLN9708 is a potent, reversible, and specific inhibitor of the b5 site of the 20S proteasome identified in preclinical studies. MLN9708 is currently in human clinical development for both hematological and non-hematological malignancies. Here we describe the pharmacodynamic (PD) response of MLN9708 in the murine bone marrow compartment and its strong antitumor activity in an intraosseous xenograft model of plasma cell malignancy. Materials MLN9708 immediately hydrolyzes to MLN2238, the biologically active form, upon exposure to aqueous solutions or plasma. MLN2238 was used for all preclinical studies described below. Methods It has been previously shown that double transgenic iMycCa/Bcl-XL mice develop de novo plasma cell malignancies (J. Clin. Invest. 113:1763-1773, 2004) in which neoplastic plasma cell development is driven by the targeted expression of the transgene Myc (c-myc; myelocytomatosis oncogene) and Bcl-x (Bcl2l1; encodes the oncoprotein Bcl-XL). DP54 is a plasma cell tumor cell line derived from the bone marrow of a syngeneic mouse previously inoculated with an iMycCa/Bcl-XL tumor (Cancer Res. 67:4069-4078, 2007). In vitro, DP54 cells express both the Myc and Bcl-XL transgenes, various plasma cell and B-cell markers including CD38, CD138 and B220, and has gene expression profile very similar to human multiple myeloma. To establish a preclinical intraosseous model of plasma cell malignancy for efficacy studies, freshly dissociated DP54-Luc cells (constitutively expressing firefly luciferase under a mouse Ig-k promoter) were aseptically injected into the bone marrow space of the upper shaft of the right tibia of NOD-SCID mice. Once tumor growth has been established, mice were randomized into treatment groups and then treated intravenously (IV) with vehicle, bortezomib (at 0.8 mg/kg twice weekly [BIW]) or MLN2238 (at 11 mg/kg BIW) for 3 consecutive weeks. Tumor burden was measured by bioluminescent imaging. Results MLN2238 strongly inhibited proteasome activity in the blood and bone marrow compartments of mice (maximum b5 inhibition of 84% and 83%, respectively). In vivo, when DP54 cells were aseptically injected into the bone marrow space of the mouse tibia, signs of bone erosion in the tibia, femur and cranial sagittal sultures (as determined by ex-vivo mCT imaging) were observed which resembled osteolytic lesions frequently seen in human multiple myeloma. Dissemination of DP54-Luc cells after intratibia inoculations were detected by in vivo bioluminescent and confirmed by ex vivo imaging where luminescent tumor nodules were detected in the spleen, kidneys, intestine, lymph nodes and bones including right tibia, spine and cranium. To assess the antitumor activity of MLN2238 in the bone marrow compartment, an efficacy study was performed using the DP54-Luc intraosseous xenograft model of plasma cell malignancy. Tumor burden (bioluminescence), osteolytic lesions (mCT) and overall survival after treatment with bortezomib and MLN2238 will be presented. Conclusion The novel proteasome inhibitor MLN9708 demonstrates strong activity in the bone marrow compartment in vivo. MLN9708 is currently in human clinical development for both hematological and solid tumor indications. Disclosures Lee: Milllennium: Employment, Equity Ownership. Bannerman:Milllennium: Employment. Terkelsen:Milllennium: Employment. Bradley:Milllennium: Employment, Equity Ownership, Research Funding. Li:Milllennium: Employment. Li:Milllennium: Employment. Janz:Milllennium: Research Funding. Van Ness:Milllennium: Research Funding. Manfredi:Milllennium: Employment. Kupperman:Milllennium: Employment.

FTY720 Demonstrates Promising in-Vitro and in-Vivo Pre-Clinical Activity by Down-Modulation of Cyclin D1 and Pakt in Mantle Cell Lymphoma.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3728-3728
Author(s):  
Lapo Alinari ◽  
Qing Liu ◽  
Ching-Shih Chen ◽  
Fengting Yan ◽  
James T Dalton ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cyclin D1 ◽  
Mantle Cell Lymphoma ◽  
Cell Line ◽  
Cell Lymphoma ◽  
Tumor Burden ◽  
Time Dependent ◽  
Control Group ◽  
Mantle Cell

Abstract Abstract 3728 Poster Board III-664 Over-expression of Cyclin D1 and constitutive phosphorylation of Akt has been implicated in the pathogenesis of mantle cell lymphoma (MCL). Here we describe FTY720 (fingolimod), an immunosuppressive agent currently being explored in phase III studies in renal transplantation and multiple sclerosis patients, to mediate time- and dose-dependent cell death in primary MCL cells (6 patients) and MCL cell lines, Jeko and Mino. FTY720-induced apoptosis was associated with reactive oxygen species (ROS) generation, Bax up-regulation but not associated with caspase 3 activation in MCL. FTY720 treatment resulted in time-dependent down-modulation of Cyclin D1 and phospho Akt (p-Akt) protein level, two critical disease-relevant molecules in the pathogenesis of MCL. Consistent with the modulation of Cyclin D1, FTY720-induced cell cycle arrest with accumulation of cells in G0/G1 and G2/M phases of the cell cycle with concomitant decrease in S phase entry. Importantly, FTY720 treatment was also associated with a time-dependent phospho Erk (p-Erk) induction in Mino and Jeko cells. To determine the in vivo efficacy of FTY720, we developed a preclinical, in vivo xenograft model of human MCL where MCL cell lines (Jeko, Mino and SP53) were engrafted into severe combined immune deficient (SCID) mice. Cell dose titration trials identified 4 × 107 Mino or Jeko cells injected intravenously via tail vein to result in consistent engraftment and fatal tumor burden in all mice. All mice engrafted with 4 × 107 Jeko cells developed a disseminated disease within 3 weeks and had a median survival of 28 days (compared to 43 days for Mino and 51 days for SP53). Because the Jeko cell line was established from the peripheral blood of a patient with blastic variant MCL and demonstrated a more resistant phenotype to several immuno-chemoterapeutic compounds, this cell line was chosen to create a more stringent in vivo preclinical model. SCID mice were treated with the monoclonal antibody TMβ1 to deplete murine NK cells, engrafted with 4 × 107 Jeko cells and observed daily for signs of tumor burden. Ten mice/group were treated starting at day 15 post-engraftment with intraperitoneal injection of 100 μl of saline or FTY720 (5 mg/kg resuspended in 100 μl of saline), every day, for two weeks. The median survival for FTY720-treated mice (N=10) was 38 days (95% CI:30-39) compared to 26.5 days (95% CI: 26-27 days) for the control group mice (N=10). The results from the log-rank test indicated an overall statistical significant difference in survival functions between the FTY720 treatment and the control group (p=0.001). These results provide the first evidence for a potential use of FTY720 in targeting key pathways that are operable in the pathogenesis of MCL and warrant the further investigation of FTY720 in combination with other agents in clinical trials treating patients with MCL. Disclosures: No relevant conflicts of interest to declare.

Phase II Randomized, Multicenter Study of Lenalidomide Vs Best Investigator’s Choice in Relapsed/Refractory Mantle Cell Lymphoma: Results of the MCL-002 (SPRINT) Study

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 626-626 ◽  
Author(s):  
Marek Trneny ◽  
Thierry Lamy ◽  
Jan Walewski ◽  
Wojciech Jurczak ◽  
David Belada ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Phase Ii ◽  
Research Funding ◽  
Cell Lymphoma ◽  
Tumor Burden ◽  
Advisory Committees ◽  
First Response ◽  
Mantle Cell ◽  
Grade 3 ◽  
Prognostic Profile

Abstract Introduction: Mantle cell lymphoma (MCL) is an aggressive non-Hodgkin’s lymphoma with poor outcome, especially after failure of first-line treatment. Lenalidomide, an immunomodulatory drug with antineoplastic and antiproliferative effects, has shown activity in single-arm phase II studies of patients with relapsed/refractory (R/R) MCL. The present controlled randomized study compared the efficacy and safety of lenalidomide vs investigator’s choice (IC) in patients with R/R MCL. Methods: MCL-002 (SPRINT), a European multicenter, open-label, phase II study enrolled patients with up to 3 relapses or who failed prior therapy and were ineligible for intensified treatment or stem cell transplantation (NCT00875667). Oral lenalidomide was given at 25 mg/day on days 1-21 of each 28-day cycle until progressive disease (PD) or intolerability. The IC treatment consisted of single-agent therapy with cytarabine, rituximab, gemcitabine, fludarabine, or chlorambucil. Patients who progressed on IC per investigator judgment were allowed to crossover to lenalidomide. The primary endpoint was progression-free survival (PFS); secondary endpoints included overall response rate (ORR), time to first response, duration of response (DOR), overall survival (OS), and safety. Response assessments were centrally reviewed using the modified IWG criteria. Results: 254 patients with R/R MCL were randomized 2:1 to lenalidomide (n=170) or IC (n=84). Patients had median age 68.5 years, were predominantly male (73%), and had received a median of 2 prior therapies. 91% had stage III/IV disease at diagnosis, with 34% high-risk MIPI, 43% high tumor burden, and 20% bulky disease at baseline. Overall, patients on the lenalidomide arm had a worse prognostic profile than the IC arm due to higher tumor burden and disease risk (&gt;5 percentage points for a number of parameters). After a median time of 2.9 months, 39 patients (46%) from the IC arm crossed over to lenalidomide due to PD. Overall, 84 patients remain on lenalidomide (15 having crossed over from IC) and 11 patients on IC without PD. At a median follow-up time on study of 15.9 months, the risk reduction for PFS was 39% (HR=0.61 [95% CI, 0.44-0.84]; P=0.004; Table) in favor of lenalidomide (median PFS: 8.7 months lenalidomide vs 5.2 months IC). ORR was significantly improved for lenalidomide vs IC (40% vs 11%; CR/CRu 5% vs 0%). Median time to first response was 4.3 months for lenalidomide (not reached for IC). Median DOR (16.1 vs 10.4 months) and OS on mature data (27.9 vs 21.2 months) were longer for lenalidomide vs IC. Efficacy results were consistent among subgroups. Safety data in 250 patients receiving ≥1 dose showed more dose reductions in lenalidomide-treated patients (41%) vs IC (17%), due in part to a longer median duration of lenalidomide treatment vs IC, and to strict dose modification rules for lenalidomide. The most common grade 3/4 adverse events (AEs) were neutropenia (lenalidomide 44% vs IC 34% [without increased risk of infection]), thrombocytopenia (18% vs 28%), and leukopenia (8% vs 11%). Tumor flare reaction occurred in lenalidomide patients only (10%; 2% grade ≥3); 1 patient in each arm experienced tumor lysis syndrome. Invasive second primary malignancies were identified in 4% and 5% of lenalidomide and IC treated patients, respectively. Conclusions: The MCL-002 study demonstrated a statistically significant and clinically meaningful improvement in PFS for lenalidomide over best IC monotherapy in patients with advanced R/R MCL despite a worse prognostic profile in the lenalidomide arm at baseline. In addition, ORR and CR rates, TTR, DOR, and OS were improved for lenalidomide over IC. The DOR has been remarkably consistent in various studies with lenalidomide in MCL patients. The safety profile for lenalidomide was as expected and no new safety signals were identified. The results of this first randomized, controlled study of lenalidomide showed superior efficacy compared to IC in patients with R/R MCL with a manageable toxicity profile. Table Efficacy of lenalidomide vs IC in R/R MCL Efficacy Lenalidomide (n=170) IC (n=84) P PFS (Lenalidomide vs IC)  Median PFS, mo (95% CI) 8.7 (5.54-12.14) 5.2 (3.67-6.95)  Sequential HR (95% CI) 0.61 (0.44-0.84)  Sequential log-rank test p-value 0.004 ORR, n (%) 68 (40) 9 (11) &lt;0.001 CR/CRu, n (%) 8 (5) 0 (0) 0.043 Median DOR, mo 16.1 10.4 0.421 Median OS, mo 27.9 21.2 0.52 Disclosures Trneny: Celgene, Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Research Funding. Walewski:Celgene: Consultancy, Other, Research Funding; Janssen-Cilag: Consultancy; Mundipharma : Consultancy, Research Funding; Roche: Consultancy, Honoraria, Other, Research Funding. Jurczak:Celgene, Eisai, Gilead, Janssen, Pharmacyclics, Pfizer, Roche, Novartis, Spectrum, Takeda, Teva: Research Funding. Belada:Celgene: Research Funding. Mayer:Janssen Research & Development: Research Funding; Roche: Research Funding; GlaxoSmithKline: Research Funding; Celgene: Research Funding. Biyukov:Celgene: Employment. Patturajan:Celgene: Employment. Casadebaig Bravo:Celgene: Employment. Arcaini:Celgene, Roche, Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Development of a Human Therapeutic L-Cyst(e)Ine-Degrading Enzyme for the Treatment of Hematological Malignancies

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1587-1587
Author(s):  
Giulia Agnello ◽  
Susan Alters ◽  
Joseph Tyler ◽  
Jinyun Liu ◽  
Peng Huang ◽  
...  
Keyword(s):  
Research Funding ◽  
Hematological Malignancies ◽  
Ex Vivo ◽  
Redox Balance ◽  
Lymphocytic Leukemia ◽  
Employment Equity ◽  
Equity Ownership ◽  
Antioxidant Mechanisms

Abstract Cancer cells experience higher intrinsic oxidative stress than their normal counterparts and acquire adaptive antioxidant mechanisms to maintain redox balance. This increased antioxidant capacity has been correlated to malignant transformation, metastasis and resistance to standard anticancer drugs. This enhanced antioxidant state also correlates with cancer cells being more vulnerable to additional oxidative insults, therefore disruption of adaptive antioxidant mechanisms may have significant therapeutic implications. Hematological malignancies including Chronic Lymphocytic Leukemia (CLL), Acute Lymphocytic Leukemia (ALL), Acute Myeloid Leukemia (AML) and Multiple Myeloma (MM) are critically dependent on the cellular antioxidant glutathione (GSH), consistent with the higher intrinsic oxidative stress. L-cysteine is the rate-limiting substrate for GSH biosynthesis and adequate levels of cysteine are critical to maintain the intracellular homeostasis of GSH. CLL and a subset of ALL cells have been reported to rely on the stromal supply of cysteine to increase the synthesis of GSH in order to maintain redox balance, which in turn promotes cell survival and fosters drug resistance. One approach to target this cancer specific dependency is by therapeutic depletion of amino acids via enzyme administration; a clinically validated strategy for the treatment of ALL. Aeglea BioTherapeutics Inc. has developed a bioengineered cysteine and cystine degrading enzyme (Cyst(e)inase, AEB3103) and evaluated its therapeutic efficacy against hematological malignancies in in vitro, ex vivo and in vivo pre-clinical studies. The TCL1-TG:p53 -/- mouse model exhibits a drug resistant phenotype resembling human CLL with unfavorable cytogenetic alterations and highly aggressive disease progression. AEB3103 greatly decreased the viability of TCL1-TG:p53 -/- cells cultured in vitro, whereas the CLL therapeutic, fludarabine, showed minimal cytotoxic effects. In vivo treatment of TCL1-TG:p53 -/- mice with AEB3103 resulted in an increase in median survival time (7 months, p<0.0001) compared to the untreated control group (3.5 months, p<0.001) and a fludarabine treated group (5.3 months, p<0.001). These results indicate a superior therapeutic effect of AEB3103 compared to fludarabine. Additionally, evaluation of AEB3103 in in vitro 2D cultures of patient-derived CLL and MM cells, and in ex vivo 3D cultures of cells derived from ALL and AML PDx models resulted in significant cell growth inhibition with therapeutically relevant IC50 values. Collectively these results demonstrate the sensitivity of hematological malignancies to modulation of GSH levels via AEB3103-mediated cyst(e)ine depletion. Disclosures Agnello: Aeglea BioTherapeutics: Employment. Alters:Aeglea BioTherapeutics: Employment, Equity Ownership. Tyler:Aeglea BioTherapeutics: Employment, Equity Ownership. Huang:Aeglea BioTherapeutics: Research Funding. Stone:Aeglea Biotherapeutics: Consultancy, Equity Ownership, Research Funding; University of Texas at Austin: Employment, Patents & Royalties: I am an inventor of technology related to this abstract. Georgiou:Aeglea Biotherapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Lowe:Aeglea BioTherapeutics: Employment, Equity Ownership. Rowlinson:Aeglea BioTherapeutics: Employment, Equity Ownership.

scholarly journals The Synergistic Anticancer Effect of a Combination of Chidamide and Etoposide Against NK/T Cell Lymphoma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3987-3987
Author(s):  
Wenting Song ◽  
Zhan Chen ◽  
Cunzhen Shi ◽  
Yuyang Gao ◽  
Xiaoyan Feng ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
T Cell ◽  
Histone Acetylation ◽  
Hematological Malignancies ◽  
Cell Lymphoma ◽  
Dna Damaging Agents ◽  
Etoposide Treatment

Abstract Natural killer/T cell lymphoma (NKTCL) is a highly aggressive hematological malignancy. However, there is currently no consensus on first-line therapies for refractory/relapsed patients. Chidamide is a self-researched and developed HDACs inhibitor, and when combined with DNA-damaging agents, exhibited a clinical synergistic effect for the treatment of some solid tumors and hematological malignancies. Thus in this study, a series of in vitro and in vivo experiments were conducted to explore the efficacy and potential mechanisms of combined chidamide and etoposide treatment in NKTCL. We demonstrated that chidamide or etoposide alone dose- and time-dependently inhibited the cell viability of NKTCL cell lines, YT, NKYS and KHYG-1. Functional experiments suggested that combined chidamide and etoposide treatment exerted synergistic antiproliferation effect and enhanced cell apoptotic death both in vitro and in vivo. Furthermore, the expression of DNA damage related proteins was detected and we also examined the alternations in histone acetylation, cell cycle progression, and mitochondrial membrane potential (MMP). The results suggested that increased histone acetylation, cell cycle arrest at the G2/M phase and loss of MMP, converging to greater DNA damage, might account for the synergism of the combination of chidamide and etoposide in NKTCL. Taken together, our study supplements the clinical application of combining HDACs inhibitors and DNA-damaging agents on treating hematological malignancies but also provide an experimental basis for improved therapeutic efficacy and decreased complications for patients with NKTCL. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

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