Carfilzomib Platform Study Using The LAGκ-1A Multiple Myeloma Xenograft Model

Introduction We previously demonstrated that severe combined immunodeficient (SCID) mice bearing the human multiple myeloma (MM) xenograft LAGκ-1A treated with single agent carfilzomib or the alkylating agent (AA) cyclophosphamide (CY) did not show a reduction in tumor growth compared to vehicle-treated mice. In contrast, carfilzomib with CY resulted in a significant decrease in tumor size and IgG levels when compared to mice treated with single agent carfilzomib or CY or vehicle alone. We have also shown that the combination of carfilzomib and another AA, bendamustine, decreased tumor size and IgG levels, when compared to mice treated with single agents or vehicle alone. However, no data is available regarding sequencing of the proteasome inhibitors (PI) carfilzomib or bortezomib with the AA melphalan (MEL). Thus, we used our SCID-hu MM models to evaluate the sequencing of these drugs with MEL. These studies are critical as both PIs are now being used to treat MM. Thus, we evaluated the response, toxicity and survival of animals treated sequentially with these drugs. Methods Each naïve SCID mouse was surgically implanted with a 20 – 40 mm3 MM tumor piece into the left hind limb superficial gluteal muscle. Seven days post–implantation mice were randomized into treatment groups based on human immunoglobulin (Ig) G levels. Carfilzomib stock solution (2 mg/ml) was diluted to 3 mg/kg using 5% dextrose and administered twice weekly on two consecutive days via intravenous (i.v.) injection. Bortezomib stock solution (1 mg/ml) was diluted to 0.25 mg/kg using NaCl and administered twice weekly (Thursdays and Saturdays) via i.v. injection. MEL stock solution (3 mg/ml) was diluted to 1 mg/kg using PBS and administered once weekly via intraperitoneal injection. Mice (n = 10/group) were initially treated with carfilzomib or MEL alone until tumor progression. Progression was defined as an increase in paraprotein equal to or above 25% confirmed on one consecutive assessment. Mice initially treated with carfilzomib were randomized to continue to receive single agent carfilzomib, add in MEL alone or combine it with ongoing carfilzomib, substitute single agent bortezomib, or discontinue treatment altogether. A similar treatment strategy was evaluated with mice treated initially with MEL. At progression, these animals were continued on single agent MEL, carfilzomib added alone or with continuation of MEL, or discontinued treatment. Tumor size was measured using standard calipers and human IgG levels with an ELISA (Bethyl Laboratories, Montgomery, TX). This study was conducted according to protocols approved by the Institutional Animal Care and Use Committee. Results When carfilzomib was administered first, followed by the addition of MEL, a modest nonsignificant reduction in tumor size was observed compared to either drug alone. In addition, substitution of single agent bortezomib for carfilzomib showed no effect on tumor size. However, when MEL was administered first and carfilzomib was added after disease progression, at days 35 and 42 (end of study) post tumor implantation, mice treated with the combination showed a reduction in tumor volume compared to mice that discontinued melphalan (P = 0.0378 and P = 0.0105, respectively) whereas mice treated with carfilzomib alone showed no reduction in tumor size following progression from MEL. Notably, throughout the study there was a trend toward smaller tumors in mice receiving this combination when compared to mice receiving single agent treatment with carfilzomib or MEL alone or vehicle. Similar effects were observed on human IgG levels. Overall, all mice survived combination or single agent treatment with these agents. Conclusions These in vivo studies using our human MM LAGκ–1A SCID–hu model show that animals progressing from initial MEL treatment show a reduction in MM tumor burden when carfilzomib is added to MEL at progression. In contrast, mice progressing from initial carfilzomib treatment did not benefit from the addition of MEL at disease progression. No drug-related deaths occurred in any treatment group. This study demonstrates that using a different MM model (LAGκ-1A), that the PI carfilzomib can produce anti-tumor effects among mice progressing from single-agent MEL treatment, providing further support for the use of this PI as an agent that can help overcome drug resistance in MM. Disclosures: Berenson: Onyx Pharmaceuticals: Consultancy, Honoraria, Research Funding, Speakers Bureau.

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Carfilzomib Overcomes Resistance to Bortezomib in the Human Lagk-1A Multiple Myeloma Xenograft Model

Blood ◽

10.1182/blood.v124.21.5720.5720 ◽

2014 ◽

Vol 124 (21) ◽

pp. 5720-5720 ◽

Cited By ~ 2

Author(s):

Eric Sanchez ◽

Mingjie Li ◽

Abigail Gillespie ◽

Nika M Harutyunyan ◽

Gigi Garzio ◽

...

Keyword(s):

Multiple Myeloma ◽

Tumor Progression ◽

Disease Progression ◽

Tumor Size ◽

Tumor Volume ◽

Single Agent ◽

Xenograft Model ◽

Scid Mice ◽

Human Igg ◽

To Receive

Abstract Introduction: We previously demonstrated that when carfilzomib (CFZ) was administered first to SCID mice bearing our human multiple myeloma (MM) xenografts, followed by the addition of melphalan (MEL) at the time of disease progression, a modest further reduction in tumor size was observed compared with continuing CFZ or adding MEL alone. In addition, substitution of single agent bortezomib (BOR) for CFZ showed no anti-MM effects. However, when MEL was administered first and CFZ was added after disease progression, mice treated with the combination showed a reduction in tumor volume compared with mice that discontinued MEL. Mice treated with CFZ alone showed no reduction in tumor size. Throughout the study, there was a trend toward smaller tumors among mice in which MEL was followed by the addition of CFZ when compared to mice in which MEL was continued or discontinued and treated with single-agent CFZ or vehicle alone. In the current study, we evaluated the anti-MM effects of CFZ, MEL and BOR for severe combined immunodeficient (SCID) mice progressing from BOR+MEL treatment using our human MM xenograft model LAGk-1A. Methods: Each SCID mouse was surgically implanted with a 20 – 40 mm3 LAGk-1A tumor piece into the left hind limb muscle. Seven days post-implantation mice were randomized into treatment groups based on human immunoglobulin (Ig) G levels. Carfilzomib stock solution (2 mg/ml) was diluted to 3 mg/kg using 5% dextrose and administered twice weekly on two consecutive days (Sundays and Mondays) via intravenous (i.v.) injection.Bortezomib stock solution (1 mg/ml) was diluted to 0.25 mg/kg using NaCl and administered twice weekly (Sundays and Tuesdays) via i.v. injection.MEL stock solution (3 mg/ml) was diluted to 1 mg/kg using PBS and administered once weekly (Fridays) via intraperitoneal injection. Mice (n = 10/group) were initially treated with the combination of BOR + MEL until tumor progression. Progression was defined as an increase in paraprotein > 25% confirmed on one consecutive assessment. After tumor progression, mice initially treated with BOR + MEL were randomized to continue to receive BOR + MEL, receive MEL only (discontinue BOR), receive BOR only (discontinue MEL), substitute BOR with CFZ, discontinue BOR + MEL and add in CFZ alone, or discontinue treatment altogether. Tumor size was measured using standard calipers and human IgG levels with an ELISA (Bethyl Laboratories, Montgomery, TX). This study was conducted according to protocols approved by the Institutional Animal Care and Use Committee. Results: Following progression from the combination of BOR + MEL among mice bearing LAGk-1A, substitution of these drugs with single agent CFZ alone did not produce a reduction in tumor volume when compared with mice continuing to receive BOR + MEL. However, significantly smaller tumors were observed when mice progressing from BOR + MEL were switched to CFZ + MEL compared with mice continued on BOR alone (P = 0.0044) or animals switched to CFZ alone (P = 0.05). There was a trend throughout the study toward smaller tumors in mice receiving CFZ + MEL when compared to mice continuing on BOR + MEL, receiving BOR, CFZ or vehicle alone or discontinuing BOR + MEL. Following progression from BOR + MEL, similar anti-MM effects were observed on human IgG (paraprotein) levels among animals treated with CFZ + MEL when compared to mice continuing BOR + MEL, receiving BOR alone switching to CFZ alone or discontinuing both BOR and MEL. Conclusions: These in vivo studies using our human MM xenograft model, LAGk-1A, show that SCID mice progressing from initial BOR + MEL treatment show a reduction in MM tumor burden when BOR is replaced with CFZ at the time of disease progression, and these tumors are significantly smaller than among mice continued on BOR + MEL. These studies demonstrate that once tumors progress from BOR + MEL treatment, CFZ can replace BOR and produce anti-tumor effects. A recent clinical trial confirms our preclinical findings and shows that most MM patients refractory to BOR in combination with other agents, including MEL, will respond to the substitution of CFZ for BOR (Berenson et al., Leukemia 2014). Disclosures No relevant conflicts of interest to declare.

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Effects of Oprozomib in Combination with Pomalidomide and/or Dexamethasone on Human Multiple Myeloma Tumors Growing in SCID Mice

Blood ◽

10.1182/blood.v126.23.5349.5349 ◽

2015 ◽

Vol 126 (23) ◽

pp. 5349-5349 ◽

Cited By ~ 1

Author(s):

Eric Sanchez ◽

Mingjie Li ◽

Abigail Gillespie ◽

Puja Mehta ◽

Suzie Vardanyan ◽

...

Keyword(s):

Multiple Myeloma ◽

Tumor Size ◽

Research Funding ◽

Single Agent ◽

Xenograft Model ◽

Tumor Burden ◽

Scid Mice ◽

Human Multiple Myeloma ◽

Minimal Reduction

Abstract Introduction: Oprozomib (OPZ) is an irreversible, orally administered proteasome inhibitor (PI).It decreases tumor burden and prevents tumor-related bone loss in preclinical multiple myeloma (MM) studies. In recently published clinical trials, the combination of the PI carfilzomib with the immunomodulatory agent (IMiD) lenalidomide and dexamethasone (Dex) has shown high response rates with durable responses for previously treated and untreated MM patients. Carfilzomib with the IMiD pomalidomide (Pom) and Dex for the treatment of RRMM patients shows promising results (Shah et al, 2013). We evaluated OPZ in combination with Pom and Dex using two of our human MM xenograft models in severe combined immunodeficient (SCID) mice. Methods: Each SCID mouse (n=10/group) was surgically implanted with a 20 - 40 mm3 MM tumor piece into the hind limb. Seven days post-implantation mice were randomized into treatment groups based on human immunoglobulin (Ig) G levels. OPZ stock solution (4 mg/ml) was diluted to 40 mg/kg using 1% carboxymethylcellulose (CMC) and administered twice weekly on two consecutive days via oral gavage.Dex stock solution (10 mg/ml) was diluted to 1 mg/kg using NaCl and administered daily via intraperitoneal injection.Pom stock solution (1 mg/ml) was diluted to 10 mg/kg using 1% CMC and administered daily via oral gavage. Tumor size was measured using calipers and IgG levels by ELISA. Results: Using our human MM model LAGk-1A, treatment with single agent OPZ or Pom produced a minimal reduction in tumor volume when compared with vehicle-treated mice, whereas Dex alone or OPZ + Pom produced more anti-MM effects, and no differences were observed between these two groups. Mice treated with OPZ + Dex or Pom + Dex also showed greater anti-MM activity than OPZ + Pom or Dex alone but the differences were not significant. All three agents together resulted in much smaller tumors when compared to OPZ + Pom on days 35, 42, 49 and 56 (P = 0.0006, P = 0.0001, P = 0.0002 and P < 0.0001, respectively). The same triplicate resulted in a smaller tumors when compared to OPZ + Dex on days 35, 42, 49, 56, and 63 (P = 0.0112, P = 0.0030, P = 0.0060, P = 0.0035 and P = 0.0021, respectively). Although Pom + Dex had some anti-MM effects when compared to the three single agents and one of the doublets (OPZ + Pom), mice receiving the triplicate demonstrated markedly smaller tumors when compared with Pom + Dex on days 35, 42, 49, 56, 63, 70, and 77 (P = 0.0250, P = 0.0018, P < 0.0001, P = 0.0014, P = 0.0018, P = 0.0017 and P = 0.0014, respectively). Mice receiving Pom + Dex had to be euthanized on day 77, whereas mice receiving all three drugs had very small tumors at study termination. We obtained similar results in a second MM xenograft model that produces IgG (LAGλ-1). Although day 21 post-tumor implantation mice receiving Pom alone had lower IgG levels compared with vehicle-treated mice (P = 0.0053), mice receiving OPZ + Pom had smaller tumors when compared to Pom alone (P = 0.0387), OPZ alone (P = 0.0004), or vehicle-treated mice (P = 0.0001). Although mice receiving Pom alone had a reduction in tumor size when compared with vehicle-treated mice (P = 0.0021), mice receiving OPZ + Pom had smaller tumors when compared with Pom alone (P = 0.0081), OPZ alone (P = 0.0007), or vehicle-treated mice (P < 0.0001). Mice receiving the triplicate showed smaller tumors on day 28 compared with mice treated with either the doublets of Pom + Dex (P = 0.0120) or OPZ + Pom (P = 0.0043). Conclusions: These in vivo human MM xenograft studies show that the combination of OPZ + Pom + Dex shows greater anti-MM activity than doublets (Pom + Dex, OPZ + Dex or OPZ + Pom) or single agents, and provides further support for this three drug combination to treat MM. Disclosures Tang: Onyx: Research Funding. [email protected]:Onyx: Consultancy, Honoraria, Research Funding, Speakers Bureau.

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A Multicenter Phase II Study of Perifosine (KRX-0401) Alone and in Combination with Dexamethasone (Dex) for Patients with Relapsed or Relapsed/Refractory Multiple Myeloma (MM).

Blood ◽

10.1182/blood.v108.11.3582.3582 ◽

2006 ◽

Vol 108 (11) ◽

pp. 3582-3582 ◽

Cited By ~ 3

Author(s):

Paul Richardson ◽

S. Lonial ◽

A. Jakubowiak ◽

J. Wolf ◽

A. Krishnan ◽

...

Keyword(s):

Multiple Myeloma ◽

Adverse Events ◽

Single Agent ◽

Gene Array ◽

In Vivo Studies ◽

Cell Transplant ◽

Prior Therapy ◽

Grade 3

Abstract Perifosine is an oral, novel synthetic alkylphospholipid, with multiple effects on signal transduction pathways, including inhibition of Akt and activation of JNK. Preclinical in vitro studies showed that perifosine induces significant cytotoxicity in both multiple myeloma(MM) cell lines and patient MM cells resistant to conventional therapies, and augments dexamethasone(dex), doxorubicin, melphalan and bortezomib-induced MM cell cytotoxicity. In vivo studies showed significant antitumor activity in a human plasmacytoma mouse model. PhaseI studies in solid tumors have shown that perifosine is well tolerated at a dose of up to150mg daily, with responses also seen. We report preliminary results of a PhaseII trial of perifosine, alone and in combination with dex, in patients(pts) with relapsed or relapsed/refractory MM. Pts received 150mg of perifosine daily for a 21-day(d) cycle, and were assessed by serum and/or urine electrophoresis. Eligible pts had relapsed or relapsed/refractory MM with measurable disease. Pts were permitted bisphosphonate treatment. Concomitant steroids(prednisone>10 mg/d), serum creatinine of >3.0 mg/dL, and hemoglobin<8.0g/dL within 14 d of enrollment were exclusion criteria. Progressing pts, documented on 2 occasions at least one week apart, had dex 20 mg twice per week added to perifosine. Toxicities were assessed by NCI-CTCAE, v3.0. 40 pts (22 men and 18 women, median age 61 y, range 38–78) have been treated to date. All had relapsed/refractory MM, with a median of 4 lines of prior treatment (range 1–9). Prior therapy included dex(100%), thalidomide(100%), bortezomib(73%), lenalidomide(28%) and stem cell transplant(73%). Among 25 pts currently evaluable for response, best response(EBMT criteria) to single agent perifosine after≥2 cycles was stable disease(<25% reduction in M-protein) in 6 pts(24%). Dex was added in 15 of 25 pts with PD, with 9 pts evaluable for response on the combination: 3 pts(33%) achieved MR and 2(22%) pts achieved SD. The most common adverse events included nausea (45%, 3% grade 3); vomiting (40%); diarrhea(40%); fatigue(24%, 3% grade 3), and increased creatinine(55%, 11% grade 3/4 in the context of PD and light chain nephropathy). 2 pts had G3 neutropenia which resolved. Dose reduction(150 to 100 mgs/d) was required in 11 pts and 4 pts discontinued treatment due to adverse events. Attributable toxicities otherwise proved manageable with appropriate supportive care and perifosine was generally well tolerated, with no peripheral neuropathy or DVT seen. Perifosine as monotherapy and in combination with dex has activity in pts with advanced, relapsed/refractory MM, achieving MR and/or stabilization of disease in 55% of evaluable pts to date. It was generally well tolerated, although caution in pts with renal dysfunction is warranted. PK, IHC and gene array studies are ongoing. Future studies evaluate perifosine at other dosing schedules and in combination with other agents including bortezomib.

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Efficacy of NK-92 Against Human Multiple Myeloma in a NOD/SCID Gamma Null Mouse Model

Blood ◽

10.1182/blood.v118.21.1854.1854 ◽

2011 ◽

Vol 118 (21) ◽

pp. 1854-1854

Author(s):

Brenna E. Swift ◽

Brent A. Williams ◽

Yoko Kosaka ◽

Joaquín Martínez-López ◽

Xinghua Wang ◽

...

Keyword(s):

Multiple Myeloma ◽

Flow Cytometry ◽

Mouse Model ◽

Disease Progression ◽

Cell Line ◽

Xenograft Model ◽

Tumor Burden ◽

Clinical Disease ◽

Nsg Mice

Abstract Abstract 1854 Introduction: Human NK cell lines NK-92 and KHYG-1 exhibit cytotoxicity against a broad range of tumor types in vitro, including multiple myeloma (MM). To further test efficacy of the NK lines against MM, we developed a bioluminescent mouse model that recapitulates clinical MM using the human U266 MM cell line transduced to express GFP and luciferase (U266eGFPluc) to monitor disease progression in vivo and assess bone marrow (BM) engraftment. Results: In a pilot study in which 2×106 U266 cells were injected intravenously into NOD.Cg-Prkdcscid IL2rgtm1Wjl/SzJ (NSG) mice, CD138+ MM cells engrafted in BM, with no detectable engraftment in the liver, lungs, spleen, heart, or kidneys by anti-CD138 immunohistochemistry staining at 10 weeks. We used the U266eGFPluc bioluminescent NSG mouse model to evaluate efficacy of NK-92 cell therapy in vivo. We gave 10×106 NK-92 cells every 5 days to a total dose of 50×106 cells 7 days after MM injection. Tumor burden was monitored weekly by bioluminescence imaging 4 weeks after MM inoculation using the IVIS Imaging System, and LivingImage™ Software was used to acquire images and quantify bioluminescence. We showed that U266eGFPluc cells localized to BM and spine, reflecting MM pathophysiology. Disease burden in the NK-92 treated group was consistently lower than controls over time and significantly lower at 8 weeks (Dorsal and Ventral Mann-Whitney p=0.0381) whereas for KHYG-1, the signal increased slightly over control, but was not significant at 8 weeks (Mann-Whitney Dorsal p=0.540 and Ventral p=0.247). Clinical disease progression in MM control mice correlated with IVIS signal intensity at week 11 (r2=0.4; F test p=0.0279). Engraftment was determined by sacrificing mice at 10 weeks and analyzing BM for GFP+ cells by flow cytometry. Engraftment of MM cells in BM was as follows (mean+/− SEM): control (5 +/− 1.9%), NK-92 (0.24 +/− 0.19%) and KHYG-1 (5.2 +/− 1.6%) showing a trend toward a significant decrease in mean engraftment for the NK-92 group versus control (unpaired student's t test p=0.055), but not for KHYG-1 (p=0.939). One of 6 control mice had low engraftment with U266eGFPluc at 10 weeks increasing the variance of the control mean. There was a statistically significant decrease in median engraftment in the NK-92 group (Mann-Whitney p=0.019), but not for KHYG-1 (p =0.792) (Figure). GFP BM engraftment corresponded with bioluminescence detected in R and L BM by IVIS. Presence of NK cells in BM was detected in only 1/3 NK-92 mice tested (0.2%) and in none of the KHYG-1 mice at 10 weeks. To assess biodistribution of KHYG-1 we injected 10×106 CFSE-labeled KHYG-1 via tail vein into healthy NSG mice. Blood and organ samples were collected 8 and 24 hours later and analyzed by flow cytometry. We detected CFSE-labeled KHYG-1 primarily in liver, blood and lung, less in kidney, and none in heart, spleen or BM. Conclusion: We have established a human MM cell line xenograft model in NSG mice comparable to clinical disease. Treatment efficacy can be monitored in live NSG mice by IVIS imaging technology and tumor burden at sacrifice can be determined by GFP detection. MM progression was reduced by NK-92, but not KHYG-1 as measured by bioluminescence and reduction of engrafted U266eGFPluc cells. We have shown that a MM xenograft model can screen for in vivo efficacy of immune therapies for MM. Our results indicate that NK-92 is a potentially effective therapy for MM. Disclosures: No relevant conflicts of interest to declare.

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Lycorine Downregulates HMGB1 to Inhibit Autophagy and Enhances Bortezomib Activity in Multiple Myeloma

Blood ◽

10.1182/blood.v128.22.3265.3265 ◽

2016 ◽

Vol 128 (22) ◽

pp. 3265-3265

Author(s):

Mridul Roy ◽

Long Liang ◽

Xiaojuan Xiao ◽

Yuanliang Peng ◽

Yuhao Luo ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Conflicts Of Interest ◽

Single Agent ◽

Xenograft Model ◽

Hmgb1 Expression ◽

Resistant Cells

Abstract Multiple myeloma (MM) is the second most prevalent hematologic malignancy, characterized by the infiltration of malignant plasma cells into bone marrow. In spite of current efficient therapeutic regimens, which have significantly increased patients overall survival, the major features inevitably present in MM are the intrinsic and acquired resistance with nearly universal relapse. In addition, the diverse heterogeneous characteristics of this largely incurable disease emphasize the importance of innovative therapies and identification of more effective drugs. Autophagy removes defective cellular organelles, protein aggregates, and intracellular microbes and is associated with cell survival and tumor maintenance. Inhibition of autophagy enhances sensitivity of a number of anticancer agents and induces cell death in MM. High-mobility group box-1 (HMGB1) protein plays an important subcellular localization-dependent role during autophagy. The importance of HMGB1 for induction of autophagy and tumor development has made this protein as a novel target for cancer therapy. Lycorine is a natural alkaloid with significant anti-cancer activity. While previous studies mainly showed lycorine as a potential apoptosis inducer, recent studies stated that apoptosis is not the primary underlying anti-proliferative mechanism of this compound. This led the interest to investigate the role of lycorine on other cell maintenance systems, such as autophagy. In addition single-agent efficacy of lycorine or in combination with other anti-MM agents has not been evaluated in vivo. Herein we investigated the anti-MM effect of lycorine and the role of this natural agent on regulation of autophagy in vitro and in vivo. We found that lycorine inhibits proliferation and induces apoptosis in MM cells with less sensitivity to the normal B-cell at the same concentrations. We also found that lycorine promisingly inhibits autophagy, the mechanism that MM cells use to survive and defeat treatment. We identified HMGB1, an important regulator of autophagy, as the most aberrantly expressed protein after lycorine treatment. Furthermore, we characterized HMGB1 as a critical mediator of lycorine activity against MM. Gene expression profiling (GEP) analysis showed that higher expression of HMGB1 is linked with the poor prognosis of MM. We further confirmed this correlation in human bone marrow CD138+ primary myeloma cells and MM cell lines. Mechanistically, by activating the proteasomal degradation of HMGB1, lycorine induces a rapid turnover of HMGB1. This led to decreased Bcl-2 phosphorylation by MEK-ERK pathway and increased association of Bcl-2 with Beclin-1 resulting in autophagy inhibition and growth attenuation. In addition, we observed higher HMGB1 expression in bortezomib resistant cells. The combination of bortezomib plus lycorine was highly efficient against MM cells and MM cells grown in bone marrow micro-environment. Lycorine showed the capability of inhibiting bortezomib induced autophagy as well as re-sensitizing resistant cells to bortezomib. In agreement with our in vitro observations, in vivo study using human MM xenograft model showed that lycorine is well tolerated, inhibits HMGB1 expression and thereby autophagy and induces enhanced bortezomib activity. These observations indicated lycorine as an effective autophagy inhibitor and revealed that lycorine alone or in combination with bortezomib is a potential therapeutic strategy. Our study supports the feasibility of lycorine in anti-MM treatment and provides a preclinical framework for combining lycorine with bortezomib in clinical setting. Disclosures No relevant conflicts of interest to declare.

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Using SCID-Hu Models to Evaluate the Sequencing of Bortezomib Therapy for Multiple Myeloma (MM)

Blood ◽

10.1182/blood.v116.21.5012.5012 ◽

2010 ◽

Vol 116 (21) ◽

pp. 5012-5012

Author(s):

Eric Sanchez ◽

Mingjie Li ◽

Cathy Wang ◽

Zhi-Wei Li ◽

Haiming Chen ◽

...

Keyword(s):

Disease Progression ◽

Single Agent ◽

Pegylated Liposomal Doxorubicin ◽

Initial Therapy ◽

Scid Mice ◽

In Vivo Studies ◽

Mouse Serum ◽

Control Group ◽

Treatment Groups

Abstract Abstract 5012 Introduction: Although many previous studies from our laboratory and others have used mice bearing human MM to evaluate bortezomib (BORT) alone and in combination regimens, no data exist on the sequential treatment using BORT with conventional anti-MM agents in mice bearing human MM tumors who have progressed from their initial treatment with a variety of anti-MM agents including BORT. In this study, we treated severe combined immunodeficient (SCID) mice bearing one of our human MM tumors LAGκ-1A with single agent bortezomib BORT, melphalan (MEL), dexamethasone (DEX) or pegylated liposomal doxorubicin (PLD) until disease progression and then evaluated subsequent use of combination therapies. Progression was defined as an increase in paraprotein equal to or above 25% compared to the prior time point evaluated 1 week previously. Following progression, LAGκ-1A-bearing SCID mice were assigned to receive no treatment, continue the initial therapy, substitution of initial therapy by another conventional anti-MM agent BORT, MEL, DEX, or PLD, or continue the initial therapy in combination with another anti-MM agent. An untreated control group was also included in these studies. Methods: Tumors were allowed to grow for 7 days at which time human IgG levels were detectable in the mouse serum, and mice were blindly assigned into one of five treatment groups. Initial single agent therapy was administered as follows: BORT intravenously (i.v.) twice weekly at 0.5 mg/kg, DEX (1.25 mg/kg) daily by intraperitoneal (i.p.) injection, MEL i.p. weekly at 1.5 mg/kg, or PLD 0.2 mg/kg on three consecutive days weekly by i.p. injection. Following disease progression, mice were randomized into one of the above mentioned treatment groups. Tumor size and IgG levels were measured using calipers and a hIgG specific immune assay on a weekly basis. Results: Following progression from single-agent BORT, mice treated with the combination of BORT + DEX or DEX alone showed similar anti-MM effects. In contrast, after mice progressed from single-agent DEX, BORT alone did not show significant anti-MM effects compared to mice continued on DEX alone or who received no further treatment whereas the addition of BORT to DEX produced a marked anti-MM effect. Following disease progression from MEL treatment alone, treatment with BORT alone or in combination with MEL produced similar anti-MM activity. However, among mice progressing from single agent BORT, the addition or substitution with MEL showed no anti-MM effects; and in fact, reduced the efficacy of BORT when compared to mice remaining on the drug alone following disease progression. Following disease progression from single agent PLD treatment, BORT therapy alone showed anti-MM effects; however, the addition of BORT to PLD did not show any anti-MM activity. In addition, mice progressing from BORT treatment alone who then received either PLD alone or in combination with BORT actually showed enhanced tumor growth compared to continuing BORT alone. Conclusions: Results from these in vivo studies using our SCID-hu models of human MM suggest that the sequencing of drugs following progression from initial therapy has a dramatic impact on responsiveness of the human myeloma cells growing in SCID mice. These studies suggest that this approach can be used to optimize in what order and specific combinations of anti-MM drugs should be administered following disease progression which should improve outcomes for patients with MM. Disclosures: Hilger: Millennium Pharmaceuticals, Inc.: Employment. Hibner:Millennium Pharmaceuticals, Inc.: Employment. Berenson:Millennium Pharmaceuticals, Inc.: Consultancy, Honoraria, Research Funding, Speakers Bureau.

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Pharmacodynamic, pharmacokinetic, and phase 1a study of bisthianostat, a novel histone deacetylase inhibitor, for the treatment of relapsed or refractory multiple myeloma

Acta Pharmacologica Sinica ◽

10.1038/s41401-021-00728-y ◽

2021 ◽

Author(s):

Yu-bo Zhou ◽

Yang-ming Zhang ◽

Hong-hui Huang ◽

Li-jing Shen ◽

Xiao-feng Han ◽

...

Keyword(s):

Multiple Myeloma ◽

Drug Targets ◽

Single Agent ◽

Hdac Inhibitors ◽

Preclinical Study ◽

Parp Cleavage ◽

Rpmi 8226 ◽

Ongoing Phase

AbstractHDAC inhibitors (HDACis) have been intensively studied for their roles and potential as drug targets in T-cell lymphomas and other hematologic malignancies. Bisthianostat is a novel bisthiazole-based pan-HDACi evolved from natural HDACi largazole. Here, we report the preclinical study of bisthianostat alone and in combination with bortezomib in the treatment of multiple myeloma (MM), as well as preliminary first-in-human findings from an ongoing phase 1a study. Bisthianostat dose dependently induced acetylation of tubulin and H3 and increased PARP cleavage and apoptosis in RPMI-8226 cells. In RPMI-8226 and MM.1S cell xenograft mouse models, oral administration of bisthianostat (50, 75, 100 mg·kg-1·d-1, bid) for 18 days dose dependently inhibited tumor growth. Furthermore, bisthianostat in combination with bortezomib displayed synergistic antitumor effect against RPMI-8226 and MM.1S cell in vitro and in vivo. Preclinical pharmacokinetic study showed bisthianostat was quickly absorbed with moderate oral bioavailability (F% = 16.9%–35.5%). Bisthianostat tended to distribute in blood with Vss value of 0.31 L/kg. This distribution parameter might be beneficial to treat hematologic neoplasms such as MM with few side effects. In an ongoing phase 1a study, bisthianostat treatment was well tolerated and no grade 3/4 nonhematological adverse events (AEs) had occurred together with good pharmacokinetics profiles in eight patients with relapsed or refractory MM (R/R MM). The overall single-agent efficacy was modest, stable disease (SD) was identified in four (50%) patients at the end of first dosing cycle (day 28). These preliminary in-patient results suggest that bisthianostat is a promising HDACi drug with a comparable safety window in R/R MM, supporting for its further phase 1b clinical trial in combination with traditional MM therapies.

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Efficacy and Biomarker Analysis of Adavosertib in Differentiated Thyroid Cancer

Cancers ◽

10.3390/cancers13143487 ◽

2021 ◽

Vol 13 (14) ◽

pp. 3487

Author(s):

Yu-Ling Lu ◽

Ming-Hsien Wu ◽

Yi-Yin Lee ◽

Ting-Chao Chou ◽

Richard J. Wong ◽

...

Keyword(s):

Thyroid Cancer ◽

Cell Lines ◽

Differentiated Thyroid Cancer ◽

Xenograft Model ◽

In Vivo Studies ◽

Follicular Thyroid Cancer ◽

Biomarker Analysis ◽

Cancer Tumor

Differentiated thyroid cancer (DTC) patients are usually known for their excellent prognoses. However, some patients with DTC develop refractory disease and require novel therapies with different therapeutic mechanisms. Targeting Wee1 with adavosertib has emerged as a novel strategy for cancer therapy. We determined the effects of adavosertib in four DTC cell lines. Adavosertib induces cell growth inhibition in a dose-dependent fashion. Cell cycle analyses revealed that cells were accumulated in the G2/M phase and apoptosis was induced by adavosertib in the four DTC tumor cell lines. The sensitivity of adavosertib correlated with baseline Wee1 expression. In vivo studies showed that adavosertib significantly inhibited the xenograft growth of papillary and follicular thyroid cancer tumor models. Adavosertib therapy, combined with dabrafenib and trametinib, had strong synergism in vitro, and revealed robust tumor growth suppression in vivo in a xenograft model of papillary thyroid cancer harboring mutant BRAFV600E, without appreciable toxicity. Furthermore, combination of adavosertib with lenvatinib was more effective than either agent alone in a xenograft model of follicular thyroid cancer. These results show that adavosertib has the potential in treating DTC.

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Combined Inhibition of AKT and KIT Restores Expression of Programmed Cell Death 4 (PDCD4) in Gastrointestinal Stromal Tumor

Cancers ◽

10.3390/cancers13153699 ◽

2021 ◽

Vol 13 (15) ◽

pp. 3699

Author(s):

Marya Kozinova ◽

Shalina Joshi ◽

Shuai Ye ◽

Martin G. Belinsky ◽

Dinara Sharipova ◽

...

Keyword(s):

Cell Death ◽

Gastrointestinal Stromal Tumor ◽

Cell Lines ◽

Synergistic Effects ◽

Single Agent ◽

Xenograft Model ◽

Stromal Tumor ◽

In Vivo Studies ◽

Preclinical Model ◽

Kit Mutation

The majority of gastrointestinal stromal tumor (GIST) patients develop resistance to the first-line KIT inhibitor, imatinib mesylate (IM), through acquisition of secondary mutations in KIT or bypass signaling pathway activation. In addition to KIT, AKT is a relevant target for inhibition, since the PI3K/AKT pathway is crucial for IM-resistant GIST survival. We evaluated the activity of a novel pan-AKT inhibitor, MK-4440 (formerly ARQ 751), as monotherapy and in combination with IM in GIST cell lines and preclinical models with varying IM sensitivities. Dual inhibition of KIT and AKT demonstrated synergistic effects in IM-sensitive and -resistant GIST cell lines. Proteomic analyses revealed upregulation of the tumor suppressor, PDCD4, in combination treated cells. Enhanced PDCD4 expression correlated to increased cell death. In vivo studies revealed superior efficacy of MK-4440/IM combination in an IM-sensitive preclinical model of GIST compared with either single agent. The combination demonstrated limited efficacy in two IM-resistant models, including a GIST patient-derived xenograft model possessing an exon 9 KIT mutation. These studies provide strong rationale for further use of AKT inhibition in combination with IM in primary GIST; however, alternative agents will need to be tested in combination with AKT inhibition in the resistant setting.

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