FcRL5 as a Target of Antibody-Drug Conjugates for the Treatment of Multiple Myeloma.

Abstract Abstract 3836 Poster Board III-772 Antibody-drug conjugates (ADCs), potent cytotoxic drugs linked to antibodies via specialized chemical linkers, provide a means to increase the effectiveness of chemotherapy by targeting the drug to neoplastic cells while reducing side effects. Target selection is a key component to the success of an ADC. In addition to expression on the tumor, the target should have limited expression on normal tissues. The most prevalent and best-studied surface antigens on multiple myeloma (MM) cells, CD138, CD38, CD72, and CD56, all have relatively broad expression patterns that may lead to target-dependent toxicities with ADCs. We have previously shown that FcRL5/FcRH5/IRTA2 is expressed only on B-cells and plasma cells. Here we show that FcRL5 is expressed on the surface of MM cells from 85% of patients and thus could be a target for antibody and ADC treatments of MM. As experience in humans with anti-CD20 antibodies suggests that depletion of B-cells does not present a major safety issue, FcRL5 appears to have an excellent expression pattern as an ADC target for MM. Internalization of target antigens is known to increase the efficacy of ADCs and we found that FcRL5 is internalized upon antibody binding, an ideal trait. We made two different ADCs consisting of anti-FcRL5 antibodies 1) conjugated through cysteines to monomethylauristatin E (MMAE) by a maleimidocaproyl-valine-citrulline-p-aminobenzyloxycarbonyl (MC-vcPAB) linker that is designed to be cleaved by cathepsins (Anti-FcRL5-MC-vcPAB-MMAE); and 2) conjugated via lysines to the maytansinoid DM4 through a disulified linker designed to be cleaved by reducing conditions (anti-FcRL5-SPDB-DM4). These ADCs were tested for cell killing in vitro and in xenograft studies using OPM2 cells stably expressing FcRL5. While unconjugated anti-FcRH5 and control ADCs were not effective, anti-FcRL5-MC-vcPAB-MMAE and anti-FcRL5-SPDB-DM4 were effective at killing this MM cell line both in vitro and in vivo. Furthermore, the anti-FcRL5-SPDB-DM4 conjugate was effective in a SCID-rabbit bone model of MM using the LD cell line. These data suggest that FcRL5 ADCs could be an effective treatment for MM. Disclosures: Polson: Genentech, Inc.: Employment, Equity Ownership. Zheng:Genentech, Inc.: Employment, Equity Ownership. Elkins:Genentech, Inc.: Employment, Equity Ownership. Lau:Genentech, Inc.: Employment, Equity Ownership. Go:Genentech, Inc.: Employment, Equity Ownership. Scales:Genentech, Inc.: Employment, Equity Ownership. Yu:Genentech, Inc.: Employment, Equity Ownership. Chesi:Genentech, Inc.: Consultancy; Amgen: Consultancy; Celgene: Consultancy; Merck: Research Funding. Bergsagel:Genentech, Inc.: Consultancy; Amgen: Consultancy; Celgene: Consultancy; Merck: Research Funding. Ebens:Genentech, Inc.: Employment, Equity Ownership, Patents & Royalties.

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Phase 1 Study of CB-839, a First-in-Class, Glutaminase Inhibitor in Patients with Multiple Myeloma and Lymphoma

Blood ◽

10.1182/blood.v126.23.3059.3059 ◽

2015 ◽

Vol 126 (23) ◽

pp. 3059-3059 ◽

Cited By ~ 6

Author(s):

Dan T. Vogl ◽

Anas Younes ◽

Keith Stewart ◽

Keith William Orford ◽

Mark Bennett ◽

...

Keyword(s):

Multiple Myeloma ◽

Research Funding ◽

Blood Platelets ◽

Safety Data ◽

Employment Equity ◽

Efficacy Data ◽

Trough Concentrations ◽

Equity Ownership

Abstract Background: Malignant cells alter metabolism in order to enable their highly anabolic state. In addition to a massive increase in glycolysis, malignant cells frequently become dependent on glutamine to feed the TCA cycle and provide key building blocks for cell growth and proliferation. CB-839 is a first-in-class potent and selective inhibitor of glutaminase (GLS), the first step in glutamine metabolism, that has broad in vitro and in vivo anti-tumor activity in solid and heme malignancies, including multiple myeloma. GLS inhibition with CB-839 induces apoptosis and/or growth arrest in multiple myeloma and lymphoma cell lines and is synergistic with pomalidomide and lenalidomide in vitro and as well as in multiple myeloma xenograft models in vivo. Methods: CX-839-002 is an ongoing Ph1 evaluation of escalating doses of CB-839 in patients with relapsed/refractory multiple myeloma (MM) or non-Hodgkins lymphoma (NHL) with the primary objective of assessing the safety profile and selecting a recommended Phase 2 dose (RP2D). Pharmacokinetics (PK) was monitored on Days 1 and 15. Initially, CB-839 was given three times daily (TID) without food, but based on PK and safety data generated across three Ph1 studies in patients with solid and heme malignancies, the drug is now being given twice daily (BID) with meals. Results: Safety data are available for a total of 14 patients (9 MM, 4 follicular lymphoma, 1 diffuse large B cell lymphoma) that have enrolled to date during the dose escalation (100-400 mg TID and 600 mg BID). The patients have received a median of 7 prior lines of systemic therapy. CB-839 has been well tolerated with only three subjects experiencing a Gr3/4 AEs considered possibly related to study drug and there have been no discontinuations due to AEs. A similar tolerability profile has been observed across three Ph1 studies for CB-839. With a total of 119 pts treated with CB-839 across the three studies, Gr3/4 drug-related AEs have occurred in 16 subjects (13%) and 4.3% of discontinuations were due to AEs. Reversible, asymptomatic elevations in transaminases have been the primary Gr3 AEs, occurring primarily on the TID schedule in 6/59 (10.2%) pts; only one occurred among 60 pts (1.7%) receiving the BID regimen. BID dosing with 600 mg was determined to be the RP2D and combination studies with pomalidomide and dexamethasone have been initiated. The half-life of CB-839 is ~4 hr, exposure increases with dose, and trough concentrations generally remain above the target threshold of 200 ng/mL for patients receiving the RP2D. Six of 8 MM pts that received ≥ 400 mg TID achieved steady state (D15) trough concentrations above the PK target threshold while 0 of 5 pts that received ≤ 250 mg TID achieved the PK threshold. Pharmacodynamic assessment of GLS activity in MM patients was consistent with a broader PK/PD assessment (across all 3 Ph1 studies), which established clear exposure-dependent inhibition of the target in peripheral blood platelets 4 hr after the first dose of CB-839, with >90% inhibition being maintained for most patients at the RP2D. Preliminary efficacy data include confirmed stable disease in 4 of 9 evaluable MM patients. Updated efficacy data and correlative studies on clinical samples will also be presented. The first pt treated with the combination of CB-839 and pomalidomide/dexamethasone (Pd) during dose escalation received 400 mg CB-839 BID, pomalidomide at 4 mg/day (D1-21) and dexamethasone at 40 mg on Days 1, 8, 15 and 22 of each 28-day cycle. This pt had a 71% decreased in urine M-protein and an 83% reduction in serum free light chain after the first 2 cycles of treatment. This pt had 11 prior lines of therapy but not pomalidomide and had two stem cell transplants and was progressing rapidly prior to study entry. The pt has tolerated the combination well and is continuing on study. Conclusions: CB-839 has been well tolerated at and above doses that produced robust inhibition of GLS in blood platelets and in tumors. Dosing BID with food has improved the PK profile and mitigated the frequency and severity of LFT elevations, which was the primary safety signal using TID dosing. Strong preclinical combination data, an excellent clinical safety profile, and initial data with CB-839 combined with Pd provide a strong rationale for continued development of CB-839 this combination in pts with relapsed/refractory multiple myeloma. Disclosures Vogl: Constellation Pharmaceuticals: Research Funding; Calithera Biosciences: Research Funding; Celgene Corporation: Consultancy; Acetylon Pharmaceuticals, Inc.: Research Funding; Millennium Pharmaceuticals: Research Funding; GSK: Research Funding. Younes:Celgene: Honoraria; Curis: Research Funding; Sanofi-Aventis: Honoraria; Seattle Genetics: Honoraria, Research Funding; Novartis: Research Funding; Janssen: Honoraria; Takeda Millenium: Honoraria; Bristol Meyer Squibb: Honoraria; Bayer: Honoraria; Incyte: Honoraria; Johnson and Johnson: Research Funding. Orford:Calithera Biosciences: Employment, Equity Ownership. Bennett:Calithera Biosciences: Employment, Equity Ownership. Siegel:Celgene Corporation: Consultancy, Speakers Bureau; Amgen: Speakers Bureau; Takeda: Speakers Bureau; Novartis: Speakers Bureau; Merck: Speakers Bureau. Berdeja:Curis: Research Funding; Acetylon: Research Funding; Novartis: Research Funding; Janssen: Research Funding; Takeda: Research Funding; BMS: Research Funding; Array: Research Funding; MEI: Research Funding; Abbvie: Research Funding; Celgene: Research Funding; Onyx: Research Funding.

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Single Cell-Level Signaling Profiling of Acute Myeloid Leukemia Following Treatment with Axl Kinase Inhibitor BGB324

Blood ◽

10.1182/blood.v126.23.4931.4931 ◽

2015 ◽

Vol 126 (23) ◽

pp. 4931-4931

Author(s):

Monica Hellesøy ◽

Katarzyna Wnuk-Lipinska ◽

Anna Boniecka ◽

Eline Milde Nævdal ◽

Hakon Reikvam ◽

...

Keyword(s):

Signal Transduction ◽

Overall Survival ◽

Cell Line ◽

Research Funding ◽

Xenograft Model ◽

Employment Equity ◽

In Vitro Response ◽

Equity Ownership ◽

Dose Dependent

Abstract Axl is a member of the Tyro3, Axl, Mer (TAM) receptor tyrosine kinase family that regulate a wide range of cellular functions, including cell survival, proliferation, migration/invasion and adhesion. Axl has been shown to play a key role in the survival and metastasis of many tumors, and has also been found to be upregulated and constitutively active in human AML. Indeed, Axl has been reported as an independent prognostic marker and a potential novel therapeutic target in AML. BGB324 is a first-in-class highly selective small molecule inhibitor of Axl. BGB324 has been shown to be safe and well tolerated in clinical safety studies in healthy volunteers at doses up to 1500 mg/day with a predictable PK profile and long plasma half-life, and is currently in phase I b clinical trials for AML and non-small cell lung cancer. In this study, we use phosphoflow cytometry to measure changes in signal transduction nodes in single AML cells treated with BGB324. We are applying this approach to monitor signaling profiles in primary AML cells harvested from patients undergoing BGB324 treatment. Results: The human AML cell line MOLM13 was treated in vitro with BGB324 (0.5 and 1µM for 1 hour) and analyzed for signal transduction changes by phosphoflow cytometry. We found a significant reduction in phosphorylation of Axl (pY779), Akt(pS473), Erk1/2(pT202/Y204) and PLCɣ1(pY783). Next we established a systemic MOLM13 preclinical AML model in NOD/SCID mice. The mice were treated with 25 or 50 mg/kg BGB324 until moribund (up to 16 days). We found a dose-dependent and significant increase in overall survival in BGB324-treated mice. We further investigated intracellular signaling in BGB324-treated cells in vivo. Mice carrying systemic AML disease (MOLM13) were treated with BGB324 at 50mg/kg for 4 days, and we monitored CD33/45-positive MOLM13 cells harvested from spleen and bone marrow by flow cytometry. BGB324-treated mice showed a significant reduction in pErk and pPLCɣ1 relative to mice in the control group. PBMCs from peripheral blood of AML patients treated with BGB324 400 mg x1 at day 1 and 2, and thereafter 100 mg daily were collected for single cell signal profiling of signal transduction changes by conventional flow cytometry (phospho-flow) and mass cytometry (CyTOF). Preliminary phopho-flow analyses show decrease of pAkt(T308) and pPLCgamma1(Y783) in one patient. Further analyses are ongoing and will be presented. Figure 1. In vitro response to 1 hour BGB324 treatment in human AML cell line MOLM13 at 0.5 and 1µM doses. Response was evaluated in pAxl, pErk1/2, pAkt and pPLCγ1. n=3, *p≤0.05, **p≤0.005. Figure 1. In vitro response to 1 hour BGB324 treatment in human AML cell line MOLM13 at 0.5 and 1µM doses. Response was evaluated in pAxl, pErk1/2, pAkt and pPLCγ1. n=3, *p≤0.05, **p≤0.005. Figure 2. Dose-dependent response in overall survival in a MOLM13 systemic xenograft model (n=10). Figure 2. Dose-dependent response in overall survival in a MOLM13 systemic xenograft model (n=10). Figure 3. Response to BGB324-treatment in pErk, pPLCγ1 and pAkt in CD33/CD45-positive cells harvested from spleens (left) and bone marrows (right) of mice with systemic MOLM13 xenografts. n=5, *p≤0.05, **p≤0.005. Figure 3. Response to BGB324-treatment in pErk, pPLCγ1 and pAkt in CD33/CD45-positive cells harvested from spleens (left) and bone marrows (right) of mice with systemic MOLM13 xenografts. n=5, *p≤0.05, **p≤0.005. Disclosures Hellesøy: BerGenBio AS: Other: Previous employee. Stock option holder. Wnuk-Lipinska:BerGenBio AS: Employment. Boniecka:BerGenBio AS: Employment. Nævdal:BerGenBio AS: Employment. Loges:BerGenBio: Honoraria, Other: travel support, Research Funding. Cortes:Teva: Research Funding; BMS: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; BerGenBio AS: Research Funding; Ariad: Consultancy, Research Funding; Astellas: Consultancy, Research Funding; Ambit: Consultancy, Research Funding; Arog: Research Funding; Celator: Research Funding; Jenssen: Consultancy. Lorens:BerGenBio AS: Employment, Equity Ownership. Micklem:BerGenBio AS: Employment, Equity Ownership. Gausdal:BerGenBio AS: Employment. Gjertsen:Haukeland University Hospital: Research Funding.

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The PI3K Inhibitor GDC-0941 Synergizes with Standard of Care Therapies to Induce Growth Inhibition and Apoptosis of Multiple Myeloma Cells.

Blood ◽

10.1182/blood.v114.22.3788.3788 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3788-3788

Author(s):

Veerendra Munugalavadla ◽

Leanne Berry ◽

Changchun Du ◽

Sanjeev Mariathasan ◽

Dion Slaga ◽

...

Keyword(s):

Multiple Myeloma ◽

Research Funding ◽

Single Agent ◽

Standard Of Care ◽

Rational Approach ◽

Current Standard ◽

Employment Equity ◽

Specific Flow ◽

Equity Ownership

Abstract Abstract 3788 Poster Board III-724 Multiple myeloma (MM) is a malignancy characterized by clonal expansion and accumulation of long-lived plasma cells within the bone marrow. Phosphatidylinositol 3' kinase (PI3K) -mediated signaling is frequently dysregulated in cancer and controls fundamental cellular functions such as cell migration, growth, survival and development of drug resistance in many cancers, including MM, and therefore represents an attractive therapeutic target. Here, we demonstrate in vitro, that a potent and selective pan-isoform PI3Kinhibitor, GDC-0941, modulates the expected pharmacodynamic markers, inhibits cell-cycle progression and induces apoptosis; overcomes resistance to apoptosis in MM cells conferred by IGF-1 and IL-6; and is additive or synergistic with current standard of care drugs including dexamethasone, melphalan, lenolidamide and bortezomib. In cell lines we find sensitivity to GDC-0941 is positively correlated with pathway activation as determined by phospho-AKT-specific flow-cytometry and Western-blot analysis. Preliminary results indicate apoptosis of MM cells is correlated with increased expression of the proapoptotic BH3-only protein BIM; mechanisms of increased apoptosis in MM will be further explored and an update presented. We further extend these in vitro findings to show that GDC-0941 has activity as a single agent in vivo and combines well with standard of care agents in several murine xenograft models to delay tumor progression and prolong survival. Our results suggest that GDC-0941 may combine well with existing therapies, providing a framework for the clinical use of this agent, and a rational approach to improving the efficacy of myeloma treatment. Disclosures: Munugalavadla: Genentech: Employment, Patents & Royalties. Berry:Genentech: Employment, Patents & Royalties. Du:Genentech, Inc.: Employment, Equity Ownership. Mariathasan:Genentech: Employment, Patents & Royalties. Slaga:Genentech: Employment, Patents & Royalties. Sun:Genentech Inc.: Employment. Chesi:Genentech, Inc.: Consultancy; Amgen: Consultancy; Celgene: Consultancy; Merck: Research Funding. Bergsagel:Genentech: Consultancy; Amgen: Consultancy; Celgene: Consultancy; Merck: Research Funding. Ebens:Genentech, Inc.: Employment, Equity Ownership, Patents & Royalties.

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Antibody Drug Conjugates Targeted to CD45 or CD117 Enable Allogeneic Hematopoietic Stem Cell Transplantation in Animal Models

Blood ◽

10.1182/blood-2018-99-119432 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 3324-3324

Author(s):

Rahul Palchaudhuri ◽

Sharon L. Hyzy ◽

Jennifer L Proctor ◽

Hillary L Adams ◽

Bradley R Pearse ◽

...

Keyword(s):

Bone Marrow ◽

Stem Cell ◽

Employment Equity ◽

Hematopoietic Stem ◽

Antibody Drug Conjugates ◽

Post Transplant ◽

Donor Chimerism ◽

Drug Conjugates ◽

Equity Ownership ◽

Antibody Drug

Abstract Introduction Targeted antibody drug conjugates (ADCs) to mouse CD45 or mouse CD117 have recently been shown to effectively prepare immunocompetent mice for whole bone marrow transplants (Palchaudhuri et al. Nature Biotech 2016 34:738-745; and Czechowicz et al. Blood 2016 128:493). This new targeted approach to conditioning using ADCs has the potential to expand the utility of transplantation if it can be successfully translated to humans. The anti-CD45 or anti-CD117 antibodies used previously were coupled to saporin (SAP), a ribosome-inhibiting protein, which once internalized elicits cytotoxicity in a cell cycle-independent manner. Both anti-CD45-saporin (CD45-SAP) and anti-CD117-saporin (CD117-SAP) ADCs have been shown to effectively deplete bone marrow hematopoietic stem cells (HSCs) as single dosed agents, creating vacancies that enable efficient autologous HSC engraftment (>95% long-term donor chimerism). Results To further investigate and develop the utility of these tool ADCs in murine transplant models, we explored CD45-SAP (1.9 mg/kg, iv) and CD117-SAP (1 mg/kg, iv) in an allogeneic minor mismatch transplant model (Balb/c donor into DBA/2 recipients). The ADCs were used alone or in combination with an additional immune depleting agent, clone 30F11 (25 mg/kg, IP), a naked anti-CD45 antibody that mimics ATG by relying on effector function to enable potent peripheral B- and T -cell depletion. In addition to the lymphodepleting antibody, we included post-transplant Cytoxan (200 mg/kg, IP) to prevent GvHD. To compare the CD45-SAP and CD117-SAP to conventional conditioning methods, we investigated sub-lethal total body irradiation (TBI, 2Gy) or pre-transplant Cytoxan (200 mg/kg, IP) in combination with the immunosuppressants. Conditioned mice were transplanted with 2x107 whole bone marrow cells, and chimerism assessed over 12 weeks. CD45-SAP or CD117-SAP in combination with immunosuppressants (30F11 and post-transplant Cytoxan) enabled >85% peripheral donor chimerism at 12 weeks post-transplantation. Multilineage reconstitution was observed in the T-, B- and myeloid cell compartments with >80%, >90% and >90% donor chimerism respectively in both CD45-SAP and CD117-SAP groups. In contrast, 2Gy TBI in combination with immunosuppressants (30F11 and post-transplant Cytoxan) resulted in only 5% donor engraftment. Multi-dosing with 30F11 (QDx3) plus 2Gy TBI and post-transplant Cytoxan increased the peripheral donor chimerism to 40%. Pre-transplant Cytoxan plus 30F11 (QDx3) and post-transplant Cytoxan yielded 20% donor chimerism. For all groups, stem cell chimerism in the bone marrow matched the peripheral chimerism. Conclusion These results indicate anti-CD45 or anti-CD117 ADCs may be used in combination with immunosuppression to enable highly efficient allogeneic transplants in a minor mismatch model (>85% donor chimerism). CD45-SAP and CD117-SAP were more effective at conditioning versus 2Gy TBI or pre-transplant Cytoxan. Future experiments will investigate anti-CD45 and anti-CD117 ADCs in additional allogeneic models. Disclosures Palchaudhuri: Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties; Harvard University: Patents & Royalties. Hyzy:Magenta Therapeutics: Employment, Equity Ownership. Proctor:Magenta Therapeutics: Employment, Equity Ownership. Adams:Magenta Therapeutics: Employment, Equity Ownership. Pearse:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Sarma:Magenta Therapeutics: Employment, Equity Ownership. Aslanian:Magenta Therapeutics: Employment, Equity Ownership. Gillard:Magenta Therapeutics: Employment, Equity Ownership. Lamothe:Magenta Therapeutics: Employment, Equity Ownership. Burenkova:Magenta Therapeutics: Employment, Equity Ownership. Brooks:Magenta Therapeutics: Employment, Equity Ownership. Gabros:Magenta Therapeutics: Employment, Equity Ownership. McDonagh:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Boitano:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Cooke:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties.

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Concomitant Suppression of IKZF1, IRF4 and MYC Contribute to the Anti-Tumor Activity of the BET Inhibitor, Cpi-0610, in Disease Models of Multiple Myeloma

Blood ◽

10.1182/blood.v128.22.3320.3320 ◽

2016 ◽

Vol 128 (22) ◽

pp. 3320-3320 ◽

Cited By ~ 1

Author(s):

Ka Tat Siu ◽

Janani Ramachandran ◽

Andrew J. Yee ◽

Homare Eda ◽

Loredana Santo ◽

...

Keyword(s):

Multiple Myeloma ◽

Board Of Directors ◽

Research Funding ◽

Employment Equity ◽

Advisory Committees ◽

Bet Inhibitor ◽

Bet Inhibitors ◽

Equity Ownership ◽

Anti Tumor Activity

Abstract Inhibition of the bromodomain and extra-terminal (BET) proteins is a promising therapeutic strategy for various hematologic malignancies. Previous studies suggest that BET inhibitors constrain tumor cell proliferation and survival mainly through suppression of MYC transcription and activity. However, suppression of the transcription of additional genes also contributes to the anti-tumor activity of BET inhibitors but is less well understood. Here we investigated the therapeutic potential of CPI-0610, a novel BET inhibitor that is currently in a phase I clinical trial in relapsed multiple myeloma (MM) (ClinicalTrials.gov Identifier: NCT02157636). CPI-0610 displays potent in vitro cytotoxicity against MM cell lines and patient-derived MM cells by inducing G1 cell cycle arrest and caspase-dependent apoptosis. Furthermore, CPI-0610-mediated BET inhibition overcomes the protective effects conferred by cytokines and bone marrow stromal cells. We also confirmed the in vivo efficacy of CPI-0610 in a MM xenograft mouse model. CPI-0610 significantly delayed tumor growth and increased the survival of MM-bearing SCID mice. Our study found IKZF1 and IRF4 to be among the primary targets of CPI-0610, along with MYC. These findings indicate that BET inhibition not only results in a robust reduction of MYC transcription and activity but also suppresses the expression of IKZF1 and IRF4 in MM. Given that immunomodulatory drugs stabilize cereblon and facilitate Ikaros degradation in MM cells, we combined it with CPI-0610. Combination studies of CPI-0610 with lenalidomide or pomalidomide show in vitro synergism, in part due to concomitant suppression of IKZF1, IRF4, and MYC, providing a rationale for clinical testing of this drug combination in MM patients. Disclosures Mertz: Constellation Pharmaceuticals, Inc.: Employment, Equity Ownership. Sims:Constellation Pharmaceuticals, Inc.: Employment, Equity Ownership. Cooper:Constellation Pharmaceuticals, Inc.: Employment, Equity Ownership. Raje:Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Merck: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Research Funding; Eli Lilly: Research Funding.

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CC-220 Is a Potent Cereblon Modulating Agent That Displays Anti-Proliferative, Pro-Apoptotic and Immunomodulatory Activity on Sensitive and Resistant Multiple Myeloma Cell Lines

Blood ◽

10.1182/blood.v128.22.1591.1591 ◽

2016 ◽

Vol 128 (22) ◽

pp. 1591-1591 ◽

Cited By ~ 4

Author(s):

Chad C Bjorklund ◽

Jian Kang ◽

Ling Lu ◽

Michael Amatangelo ◽

Hsiling Chiu ◽

...

Keyword(s):

Multiple Myeloma ◽

Transcription Factors ◽

Cell Line ◽

Cell Lines ◽

Clinical Investigation ◽

Single Agent ◽

Immunomodulatory Activity ◽

Employment Equity ◽

Equity Ownership

Abstract Background: CC-220 is a Cereblon (CRBN) binding compound currently under clinical investigation for systemic lupus erythematosus. Comparable to other Cereblon-binding agents, ex vivo treatment of CC-220 on B-cells, T-cells and monocytes leads to the degradation of the hematopoietic transcription factors Ikaros (IKZF1) and Aiolos (IKZF3).(1) Currently, CC-220 is being investigated in a phase Ib/IIa study CC-220-MM-001 (clintrial.gov trial #NCT02773030) as a single agent, or in combination with dexamethasone in relapsed/refractory multiple myeloma (RRMM) in patients who may have previously been exposed to pomalidomide. Here, we provide pre-clinical data and mechanistic rationale for the clinical development of CC-220 in heavily pre-treated RRMM. Results: In order to evaluate the ability of CC-220 effects on MM cells in vitro, we generated a large panel of MM cell lines (~69) that consist of 5 categories, including lenalidomide-sensitive (LS; n=26), intrinsically lenalidomide-resistant (ILR; n=7), acquired lenalidomide-resistant (ALR; n=12), acquired lenalidomide/dexamethasone-dual-resistant (ALDR; n=12), and acquired-pomalidomide-resistant (APR; n=12). Cell proliferation by 3H-thymidine incorporation at concentration between 0.01-100 μM was assessed by the area under the curve (AUC) for both CC-220 and pomalidomide. The average AUC was significantly reduced by 65% vs. 52% (p<0.01) for LS, 33% vs. 20% (p<0.01) for ILR, 30% vs. 20% (p<0.01) for ALR, 25% vs.10% (p<0.01) for ALDR, and 23% vs. 8% (ns) for PR cells for CC-220 vs. pomalidomide respectively. Apoptosis was analyzed by flow cytometry and AnnV+/ToPro3+ staining where CC-220 significantly (p<0.01) induced an average of 36% apoptotic cells compared to 30% for pomalidomide in LS cells, and 18% vs. 6% (p<0.5) in PS cells. Importantly, CC-220 showed anti-proliferative and pro-apoptotic activity in PR cells where Cereblon was still expressed. Additionally, both proliferation inhibition and apoptosis were synergistically enhanced across all cell line categories when CC-220 was used in combination with dexamethasone. We next evaluated the immunmodulatory effects on peripheral blood mononuclear cell (PBMCs)-stimulated killing of MM cells. Following a 72 hr incubation with CD3-stimulated PBMCs, CC-220 significantly induced the death of MM cells (~60%, across all cell type categories) within 4 hr, at concentrations more than 10-fold lower than pomalidomide. The observed CC-220-stimulated PBMC co-culture killing of MM cells closely correlated with dose-dependent increases in IL-2 secretion and Granzyme B release. Notably, CC-220 induced PBMC-mediated death of MM cells lacking observable Cereblon protein expression. Lastly, we evaluated the mechanism of action of CC-220 in MM cells in vitro. In the absence of Cereblon, as shown by shRNA knockdown or downregulation in a subset of PR cells, there is very little if any cell autonomous activity of CC-220, implicating Cereblon-dependency for its effects. Downstream of Cereblon, CC-220 stimulates the complete proteasomal degradation of both Ikaros and Aiolos in as little as 6 hr. Measurement of the half maximal time for 50% degradation of both Ikaros and Aiolos is kinetically faster from 1.9-2.9 vs. 2.4-6.9 hr depending on the MM cell line at a 10-fold lower dose for CC-220 compared to pomalidomide, respectively. CC-220 is also more efficient than pomalidomide at causing downregulation of the c-Myc/IRF4 axis, which has been shown to be essential for the cytotoxic effect of pomalidomide.(2) Conclusions: CC-220 is a potent anti-proliferative and pro-apoptotic compound that shows activity in several MM cell line categories with differing sensitivity to lenalidomide, pomalidomide and dexamethasone. Importantly, CC-220 induces PBMC-mediated killing of all MM cell lines regardless of the level of Cereblon expression and cell autonomous sensitivity. Mechanistically CC-220 acts through binding of Cereblon, leading to the degradation of the hematopoietic transcription factors Ikaros and Aiolos, followed by disruption of the MM promoting c-Myc/IRF4 axis. Taken together, these data support the clinical investigation of CC-220 in relapsed/refractory MM patients,who have previously been exposed to pomalidomide. Disclosures Bjorklund: Celgene Corporation: Employment, Equity Ownership. Kang:Celgene Corporation: Employment, Equity Ownership. Lu:Celgene Corporation: Employment, Equity Ownership. Amatangelo:Celgene: Employment, Equity Ownership. Chiu:Celgene Corporation: Employment, Equity Ownership. Gandhi:Celgene Corporation: Employment, Equity Ownership. Pourdehnad:Celgene Corporation: Employment, Equity Ownership. Klippel:Celgene Corporation: Employment, Equity Ownership. Thakurta:Celgene: Employment, Equity Ownership.

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A Phase 1/2 Trial of TH-302 and Dexamethasone without or with Bortezomib (TBorD) in Patients with Relapsed/Refractory Multiple Myeloma

Blood ◽

10.1182/blood.v124.21.2142.2142 ◽

2014 ◽

Vol 124 (21) ◽

pp. 2142-2142

Author(s):

Jacob P. Laubach ◽

Noopur S. Raje ◽

Andrew J. Yee ◽

Philippe Armand ◽

Robert L. Schlossman ◽

...

Keyword(s):

Multiple Myeloma ◽

Board Of Directors ◽

Research Funding ◽

Progressive Disease ◽

Response Rate ◽

Phase 1 ◽

Employment Equity ◽

Advisory Committees ◽

Equity Ownership

Abstract Background: TH-302 is a 2-nitroimidazole prodrug of the DNA alkylator bromo-isophosphoramide mustard that is selectively activated under hypoxic conditions. TH-302 has demonstrated anti-myeloma activity in preclinical models both in vitro and in vivo, as well as synergistic cytotoxic activity with bortezomib (Bor) in vitro. An ongoing Phase 1/2 study (NCT01522872) investigates TH-302 with dexamethasone (dex) without Bor or with Bor (TBorD) in patients (pts) with relapsed/refractory multiple myeloma (RR MM). The maximum-tolerated dose (MTD) of TH-302 plus dex was previously established at 340 mg/m2. We report preliminary results from pts treated at the MTD of TH-302 plus dex; enrollment in the TBorD arm is ongoing. Methods: The Phase 1/2 open-label multicenter study investigates IV TH-302 (240-480 mg/m²) plus PO dex (40 mg) with or without Bor (1.3 mg/m2) on Days 1, 4, 8 and 11 of a 21-day cycle. At the MTDs, Simon two-stage designs are implemented to pursue a regimen of TH-302 plus dex if ≥25% response rate or discontinue if ≤5% (90% power, 10% alpha), and pursue TBorD if ≥50% response rate or discontinue if ≤25% (85% power, 10% alpha). Treatment at the MTD of TH-302 plus dex, and establishment of the MTD of TH-302 in TBorD, is ongoing. Results: 24 pts (19 male, 5 female) with median age 65 years (range: 53 – 86) were enrolled at the 340 mg/m2 MTD of the TH-302 plus dex biweekly regimen. Ten pts had 18 severe adverse events (SAEs), of which 9 were related to TH-302, including 3 pts with cellulitis and 2 pts with pneumonia. Of 17 pts assessable for response at the time of abstract submission, 3 pts achieved a partial response (PR) and 2 pts achieved a minimal response (MR) for an overall response rate of 18% (PR) and a clinical benefit rate of 29% (PR+MR). Nine pts achieved stable disease and 3 pts had progressive disease. Eight pts are undergoing treatment; 16 pts discontinued: progressive disease (10), subject decision (4), AE (1) and alternative therapy (1). The initial dose escalation with TBorD has been completed at 240 mg/m2 TH-302, with enrollment ongoing at 340 mg/m2 TH-302. Conclusions: TH-302 can be administered at 340 mg/m2 biweekly with dex. Preliminary clinical activity has been noted in pts with heavily pre-treated RR MM. Data from the complete cohort of pts treated with dex and initial patients treated with TBorD will be updated and presented at the meeting. Disclosures Laubach: Onyx: Research Funding; Novartis: Research Funding; Millenium: Research Funding; Celgene: Research Funding. Raje:Acetylon: Research Funding; Eli Lilly: Research Funding; Millenium: Consultancy; Celgene: Consultancy; Onyx: Consultancy; Novartis: Consultancy; Amgen: Consultancy. Schlossman:Millennium: Consultancy. Matous:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Onyx: Speakers Bureau; Millenium: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Seattle Genetics: Speakers Bureau. Reynolds:Threshold: Honoraria. Shain:Onyx/Amgen: Research Funding; Celgene: Research Funding; Envision/Celgene: Speakers Bureau; L&M Healthcare/Onyx/Amgen: Speakers Bureau. Zackon:Millenium: Speakers Bureau. Mar:Threshold: Employment. Handisides:Threshold: Employment, Equity Ownership. Kroll:Threshold: Employment, Equity Ownership. Anderson:Celgene: Consultancy; Millenium: Consultancy; Onyx: Consultancy; Gilead: Consultancy; Sanofi Aventis: Consultancy; BMS: Consultancy; Oncopep/Acetylon: Equity Ownership. Richardson:Millenium: Membership on an entity's Board of Directors or advisory committees; JNJ: Membership on an entity's Board of Directors or advisory committees. Ghobrial:Millennium/Takeda: Membership on an entity's Board of Directors or advisory committees; Onyx: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees.

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Targeting RON receptor tyrosine kinase for treatment of advanced solid cancers: antibody–drug conjugates as lead drug candidates for clinical trials

Therapeutic Advances in Medical Oncology ◽

10.1177/1758835920920069 ◽

2020 ◽

Vol 12 ◽

pp. 175883592092006

Author(s):

Hang-Ping Yao ◽

Sreedhar Reddy Suthe ◽

Xiang-Min Tong ◽

Ming-Hai Wang

Keyword(s):

Clinical Trials ◽

Tyrosine Kinase ◽

Receptor Tyrosine Kinase ◽

Targeted Therapeutics ◽

Antibody Drug Conjugates ◽

Drug Candidates ◽

Drug Conjugates ◽

Ron Receptor ◽

Antibody Drug

The recepteur d’origine nantais (RON) receptor tyrosine kinase, belonging to the mesenchymal-to-epithelial transition proto-oncogene family, has been implicated in the pathogenesis of cancers derived from the colon, lung, breast, and pancreas. These findings lay the foundation for targeting RON for cancer treatment. However, development of RON-targeted therapeutics has not gained sufficient attention for the last decade. Although therapeutic monoclonal antibodies (TMABs) targeting RON have been validated in preclinical studies, results from clinical trials have met with limited success. This outcome diminishes pharmaceutical enthusiasm for further development of RON-targeted therapeutics. Recently, antibody–drug conjugates (ADCs) targeting RON have drawn special attention owing to their increased therapeutic activity. The rationale for developing anti-RON ADCs is based on the observation that cancer cells are not sufficiently addicted to RON signaling for survival. Thus, TMAB-mediated inhibition of RON signaling is ineffective for clinical application. In contrast, anti-RON ADCs combine a target-specific antibody with potent cytotoxins for cancer cell killing. This approach not only overcomes the shortcomings in TMAB-targeted therapies but also holds the promise for advancing anti-RON ADCs into clinical trials. In this review, we discuss the latest advancements in the development of anti-RON ADCs for targeted cancer therapy including drug conjugation profile, pharmacokinetic properties, cytotoxic effect in vitro, efficacy in tumor models, and toxicological activities in primates.

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Highly Differentiated Anti-CD47 Antibody, AO-176, Potently Inhibits Hematologic Malignancies Alone and in Combination

Blood ◽

10.1182/blood-2019-126298 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 1844-1844

Author(s):

John Richards ◽

Myriam N Bouchlaka ◽

Robyn J Puro ◽

Ben J Capoccia ◽

Ronald R Hiebsch ◽

...

Keyword(s):

Multiple Myeloma ◽

Combination Therapy ◽

Tumor Growth ◽

Growth Inhibition ◽

Tumor Cells ◽

Tumor Growth Inhibition ◽

Employment Equity ◽

Equity Ownership

AO-176 is a highly differentiated, humanized anti-CD47 IgG2 antibody that is unique among agents in this class of checkpoint inhibitors. AO-176 works by blocking the "don't eat me" signal, the standard mechanism of anti-CD47 antibodies, but also by directly killing tumor cells. Importantly, AO-176 binds preferentially to tumor cells, compared to normal cells, and binds even more potently to tumors in their acidic microenvironment (low pH). Hematological neoplasms are the fourth most frequently diagnosed cancers in both men and women and account for approximately 10% of all cancers. Here we describe AO-176, a highly differentiated anti-CD47 antibody that potently targets hematologic cancers in vitro and in vivo. As a single agent, AO-176 not only promotes phagocytosis (15-45%, EC50 = 0.33-4.1 µg/ml) of hematologic tumor cell lines (acute myeloid leukemia, non-Hodgkin's lymphoma, multiple myeloma, and T cell leukemia) but also directly targets and kills tumor cells (18-46% Annexin V positivity, EC50 = 0.63-10 µg/ml) in a non-ADCC manner. In combination with agents targeting CD20 (rituximab) or CD38 (daratumumab), AO-176 mediates enhanced phagocytosis of lymphoma and multiple myeloma cell lines, respectively. In vivo, AO-176 mediates potent monotherapy tumor growth inhibition of hematologic tumors including Raji B cell lymphoma and RPMI-8226 multiple myeloma xenograft models in a dose-dependent manner. Concomitant with tumor growth inhibition, immune cell infiltrates were observed with elevated numbers of macrophage and dendritic cells, along with increased pro-inflammatory cytokine levels in AO-176 treated animals. When combined with bortezomib, AO-176 was able to elicit complete tumor regression (100% CR in 10/10 animals treated with either 10 or 25 mg/kg AO-176 + 1 mg/kg bortezomib) with no detectable tumor out to 100 days at study termination. Overall survival was also greatly improved following combination therapy compared to animals treated with bortezomib or AO-176 alone. These data show that AO-176 exhibits promising monotherapy and combination therapy activity, both in vitro and in vivo, against hematologic cancers. These findings also add to the previously reported anti-tumor efficacy exhibited by AO-176 in solid tumor xenografts representing ovarian, gastric and breast cancer. With AO-176's highly differentiated MOA and binding characteristics, it may have the potential to improve upon the safety and efficacy profiles relative to other agents in this class. AO-176 is currently being evaluated in a Phase 1 clinical trial (NCT03834948) for the treatment of patients with select solid tumors. Disclosures Richards: Arch Oncology Inc.: Employment, Equity Ownership, Other: Salary. Bouchlaka:Arch Oncology Inc.: Consultancy, Equity Ownership. Puro:Arch Oncology Inc.: Employment, Equity Ownership. Capoccia:Arch Oncology Inc.: Employment, Equity Ownership. Hiebsch:Arch Oncology Inc.: Employment, Equity Ownership. Donio:Arch Oncology Inc.: Employment, Equity Ownership. Wilson:Arch Oncology Inc.: Employment, Equity Ownership. Chakraborty:Arch Oncology Inc.: Employment, Equity Ownership. Sung:Arch Oncology Inc.: Employment, Equity Ownership. Pereira:Arch Oncology Inc.: Employment, Equity Ownership.

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