HGG-29. VENETOCLAX SYNERGIZES WITH RADIATION THERAPY FOR THE TREATMENT OF DIPG

Abstract Background and Rationale Diffuse intrinsic pontine glioma (DIPG) is one of the most aggressive pediatric brain tumors. Currently, the main treatment for DIPG is radiation and it’s only a palliative care, as the tumor eventually becomes resistant to radiation. In this study we found that radiation leads to an increase in anti-apoptotic BH3 proteins mainly BCL2 in DIPG. Previous studies in other tumor types have shown that increase in these pro-survival BCL2 family members are associated with treatment resistance and poor prognosis. Therefore, we hypothesize that inhibition of BCL2 using a small-molecule inhibitor, venetoclax that crosses the blood-brain barrier, will represent a possible therapeutic strategy to overcome radiation resistance in DIPG. Approach: For in vitro studies, DIPG cells were exposed to different radiation doses (0–10 Gy) and the magnitude of the sensitizing effect of venetoclax (with IC15) was calculated by clonogenic assay. Evaluated BCL2 family proteins by western and cytotoxicity by cleaved caspase incucyte assays. For in vivo studies, NSG mice orthotopically engrafted with a human H3K27M-DIPG luciferase-expressing cells in the pons were exposed to a focal fractionated radiation of 2Gy/day for 3 days. Mice were randomized into 2 groups based on bioluminescence IVIS signal intensity; each group receiving either venetoclax (15 mg/kg, by i.p) 3 days/week for 10 weeks or vehicle. Decrease in tumor burden was measured by IVIS and survival was evaluated compared to vehicle treated mice. Results Single agent venetoclax showed no significant activity against DIPG tumors in in vitro and in vivo DIPG xenografts. Single-agent radiation cleared the tumor burden but only transiently. Combination of radiation with venetoclax showed considerable synergistic anti-tumor effect in vitro and in vivo leading to a significant increase in animal survival beyond either single agent treatments. The metabolic reprogramming that results in this enhanced cell-killing effect will be discussed.

Download Full-text

Nano-encapsulated tryptanthrin derivative for combined anticancer therapy via inhibiting indoleamine 2,3-dioxygenase and inducing immunogenic cell death

Nanomedicine ◽

10.2217/nnm-2019-0074 ◽

2019 ◽

Vol 14 (18) ◽

pp. 2423-2440 ◽

Cited By ~ 1

Author(s):

Canyu Yang ◽

Bing He ◽

Qiang Zheng ◽

Dakuan Wang ◽

Mengmeng Qin ◽

...

Keyword(s):

Cell Death ◽

Single Agent ◽

Tumor Burden ◽

Antitumor Efficacy ◽

In Vivo Studies ◽

Immunogenic Cell Death ◽

Indoleamine 2,3 Dioxygenase ◽

Tumor Tissues

Aim: We developed a polycaprolactone-based nanoparticle (NP) to encapsulate tryptanthrin derivative CY-1-4 and evaluated its antitumor efficacy. Materials & methods: CY-1-4 NPs were prepared and evaluated for their cytotoxicity and associated mechanisms, indoleamine 2,3-dioxygenase (IDO)-inhibitory ability, immunogenic cell death (ICD)-inducing ability and antitumor efficacy. Results: CY-1-4 NPs were 123 nm in size. In vitro experiments indicated that they could both induce ICD and inhibit IDO. In vivo studies indicated that a medium dose reduced 58% of the tumor burden in a B16-F10-bearing mouse model, decreased IDO expression in tumor tissues and regulated lymphocytes subsets in spleen and tumors. Conclusion: CY-1-4 is a potential antitumor candidate that could act as a single agent with combined functions of IDO inhibition and ICD induction.

Download Full-text

Multi-Center Phase II Study of Perifosine (KRX-0401) Alone and in Combination with Dexamethasone (dex) for Patients with Relapsed or Relapsed/Refractory Multiple Myeloma (MM): Promising Activity as Combination Therapy with Manageable Toxicity.

Blood ◽

10.1182/blood.v110.11.1164.1164 ◽

2007 ◽

Vol 110 (11) ◽

pp. 1164-1164 ◽

Cited By ~ 10

Author(s):

Paul Richardson ◽

S. Lonial ◽

A. Jakubowiak ◽

A. Krishnan ◽

J. Wolf ◽

...

Keyword(s):

Phase Ii ◽

Stable Disease ◽

Single Agent ◽

Gene Array ◽

In Vivo Studies ◽

Significant Activity ◽

Prior Therapy ◽

Best Response

Abstract INTRODUCTION: Perifosine (peri) is an oral, novel synthetic alkylphospholipid, with multiple effects on signal transduction pathways, including inhibition of Akt and activation of JNK. In vitro studies showed that peri induces cytotoxicity in both MM cell lines and patient (pt) MM cells resistant to conventional therapies, and augments dexamethasone (dex) and bortezomib-induced MM cell cytotoxicity (Hideshima T. et. al. BLOOD 2006). In vivo studies showed antitumor activity in a human plasmacytoma mouse model. Here we report the results of a phase II trial of peri, alone and + dex, in pts with relapsed or relapsed / refractory MM. METHODS: Pts received 150 mg of peri daily for a 21 day (d) cycle, and were assessed every cycle by serum- and/or urine-electrophoresis. Eligible pts had symptomatic relapsed or relapsed / refractory MM. Pts were permitted to receive bisphosphonate treatment. Concomitant steroids (prednisone > 10 mg/d), creatinine of > 3.0 mg/dL, and hemoglobin < 8.0 g/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 peri. Toxicities were assessed by NCI-CTCAE, v3.0. RESULTS: 64 pts (35 M/ 29 F, median age 62, range 38–79) have been treated to date. Median lines of prior treatment was 4 (range 1–11); 32 (50%) pts had relapsed and refractory MM. Prior therapy included dex (95%), thalidomide (89%), bortezomib (73%), lenalidomide (30%) and ASCT (61%). Among 48 pts currently evaluable for response, best response (EBMT criteria) to single agent peri after ≥ 2 cycles was MR in 1 pt, stable disease (< 25% reduction in M-protein) in 22 pts (46%). Dex was added in 37 pts with PD, with 31 pts evaluable for response on the combination as follows: Peri + Dex N (%) Duration (wks) PR 4 (13%) 17, 24, 44+, 46+ MR 8 (25%) 3+, 12+, 19, 21, 25, 30, 32, 55+ Stable Disease 15 (47%) 6+ − 46 (median 12)* *4 pts ongoing at 6, 9, 11 and 24 wks Most common adverse events included nausea (74%, 8% G3); vomiting (61%, 5% G3); diarrhea (65%, 2% G3); fatigue (31%, 2% G3), increased creatinine (51%, 7% G3/4 in the context of PD and light chain nephropathy but reversible) and anemia (63%, 5% G3). 10 pts had G3/4 neutropenia which resolved. Dose reduction was required to 100 mg/d (n=16) or to 50 mg/d (n=4). 9 pts discontinued treatment due to side effects. Attributable toxicities otherwise proved manageable with supportive care and no peripheral neuropathy or DVT seen. CONCLUSION: Perifosine as monotherapy has modest activity, but in combination with dex showed significant activity in pts with relapsed/refractory MM, achieving PR + MR in 38%, and/or stabilization of disease in 47% 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. Other novel studies with peri in combination with bortezomib and with lenalidomide +/−dex are underway.

Download Full-text

Inhibition of Human Lymphoma Cell Growth by the PKC-Beta Selective Inhibitor Enzastaurin (LY317615) in Combination with Multiple Therapeutic Agents.

Blood ◽

10.1182/blood.v112.11.1595.1595 ◽

2008 ◽

Vol 112 (11) ◽

pp. 1595-1595

Author(s):

Randall M Rossi ◽

Marlene Balys ◽

Dean Franklin ◽

Valerie Grose ◽

Richard I Fisher ◽

...

Keyword(s):

Single Agent ◽

Large Cell ◽

Therapeutic Agents ◽

In Vivo Studies ◽

Therapeutic Drugs ◽

Potential Synergy ◽

Size Growth ◽

Reduce Tumor Growth

Abstract Previous studies in our lab have shown that the PKC-beta inhibitor, enzastaurin (LY317615), when used to treat a panel of human diffuse large cell lymphoma (DLCL) lines, was able to induce cell death in vitro and substantially reduce tumor growth in xenograft assays. These findings support the hypothesis that activation of PKC contributes to tumor cell survival and proliferation, which has been implicated in the pathogenesis of human B cell lymphomas. Specifically, PKC-beta activation is increased in tumor cells from patients with poor prognosis DLCL, suggesting that PKC-beta may be a target for therapeutic intervention. In the present study, we have explored the interaction of enzastaurin with a panel of well characterized therapeutic agents to evaluate whether its anti-tumor activity can potentially be enhanced. Drugs were chosen for analysis based either on known single agent activity in lymphoma, or by preclinical evaluation indicating potential synergy with enzastaurin. For in vitro culture assays (48–72 hr treatment), the addition of gemcitabine, rapamycin, or bortezomib, increased the cytotoxicity of enzastaurin from 2 to 7 fold. This effect was evident with multiple human DLCL cell lines, (OCI-Ly3, 7, 10, 19, and SUDHL-4, and 6), as well as two independent primary DLCL cultures. For in vivo studies, subcutaneous transplantation of the DLCL cell line OCI-Ly19, (previously engineered to express luciferase which allows for real time in vivo imaging), or a primary DLCL isolate, into immune deficient NOD/SCID mice formed reproducible tumors. Recipient animals were separated into uniform cohorts when the tumors were of <=500 cubic mm in size. The animals were then simultaneously or sequentially treated with enzastaurin, (150 mg/kg b.i.d. via oral gavage) and a secondary drug, either gemcitabine, (2.5 or 5.0 mg/kg 1x/3 days IP), bortezomib, (0.4 mg/kg twice weekly IP), rapamycin, (1.0 mg/kg, daily IP), or rituxan, (5 mg/kg, weekly IP). Imaging and analysis of tumor volumes showed that addition of either rituxan or rapamycin provided no additional benefit in comparison to enzastaurin alone during the course of treatment. In contrast, the combination of either gemcitabine or bortezomib with enzastaurin demonstrated significantly reduced tumor volumes in comparison to enzastaurin alone (17% to 38% greater decrease with enzastaurin + gemcitabine, and 50% greater decrease in tumor volume with enzastaurin + bortezomib). These data suggest that the use of enzastaurin in combination with existing therapeutic drugs (gemcitabine or bortezomib) has the potential to limit tumor size/growth while lowering dose levels and thereby reducing potential side effects associated with traditional treatments.

Download Full-text

The Novel Aurora Kinase Inhibitor ENMD-2076 Has Potent Single Agent Activity against Multiple Myeloma (MM) in Vitro and in Vivo, and Shows Synergistic Activity in Combination with Lenalidomide

Blood ◽

10.1182/blood.v112.11.3660.3660 ◽

2008 ◽

Vol 112 (11) ◽

pp. 3660-3660 ◽

Cited By ~ 1

Author(s):

Xiaojing Wang ◽

Anthony L. Sinn ◽

Attaya Suvannasankha ◽

Colin D. Crean ◽

Li Chen ◽

...

Keyword(s):

Multiple Myeloma ◽

Caspase 3 ◽

Kinase Inhibitor ◽

Single Agent ◽

Synergistic Activity ◽

Significant Activity ◽

Aurora A Kinase ◽

Free Base

Abstract ENMD-2076 is a novel, orally-active molecule that has been shown to have significant activity against Aurora A kinase as well as multiple receptor tyrosine kinases (RTK). We investigated the single agent activity of ENMD-2076 against MM cells in vitro and in vivo, and in combination with lenalidomide. ENMD-2076 free base showed significant cytotoxicity against MM cells with a mean LC50 of 3.84±0.86 μM at 48 hours in vitro. Cytotoxicity was associated with cleavage of caspase 3, 8, 9 and PARP, and loss of mitochondrial membrane potential as early as 6 hours. ENMD-2076 free base inhibited c-kit, FGFR-1, 3 and VEGFR1 and subsequently inhibition of downstream targets phosphorylated (p)-BAD, p-Foxo1a and p-GSK-3β was observed at 6 hours. NOD/SCID mice implanted with H929 human plasmacytoma xenografts and treated for 30 days with 50, 100, 200mg/kg/d ENMD-2076 showed a dose-dependent inhibition of tumor growth (Figure 1), with minimal toxicity as assessed by the stable weight of treated animals. Immunohistochemical staining of tumors from sacrificed animals showed significant reduction in Ki67 at all dose levels of treatment compared to control tumors. An increase in cleaved caspase-3 was observed on Western blot from the lysates of H929 tumors obtained from treated animals. ENMD-2076 free base also showed synergistic cytotoxic activity when combined with lenalidomide against H929, MM1.R and MM1.S cells as assessed by MTT assay and Annexin-V/PI staining. Using the Chou-Talalay method, the combination indices (CI) were < 1 for all three cell lines across a range of concentrations of ENMD-2076 free base (0.25–1.0 μM) plus lenalidomide (2.5–10 μM) indicating synergistic activity (CI=0.362 H929; CI=0.315 MM1.R; CI=0.415 MM1.S). Our results provide rationale for the investigation of ENMD-2076 alone and in combination with lenalidomide in patients with multiple myeloma. Figure Figure

Download Full-text

An in vivo model to evaluate donor-dependent cytokine release in response to single-agent or combination immune-oncology therapies.

Journal of Clinical Oncology ◽

10.1200/jco.2020.38.15_suppl.3114 ◽

2020 ◽

Vol 38 (15_suppl) ◽

pp. 3114-3114

Author(s):

Kyle Draheim ◽

Jing Jiao ◽

Jiwon Yang ◽

Danying Cai ◽

Mingshan Cheng ◽

...

Keyword(s):

Cancer Cells ◽

Checkpoint Inhibitors ◽

Single Agent ◽

Tumor Burden ◽

Cytokine Release ◽

Humanized Mouse ◽

Human Pbmc ◽

Immune Oncology

3114 Background: Although immune-oncology therapies such as checkpoint inhibitor, bi-specific antibody and CAR-T cell therapies are successfully used for cancer therapy, they can have very severe adverse effects such as cytokine release syndrome (CRS). The animal models and in vitro human PBMC assays presently in use do not reliably predict CRS in patients. Currently, the only widely accepted predictors of CRS are cancer burden and therapeutic dose. Despite this, most pre-clinical assays that evaluate CRS do not incorporate cancer cells and the safety of drug combinations has not been widely explored. A predictive assay that identifies patient/cancer/therapy combinations at risk for developing CRS upfront in addition to treatment efficacy would improve the safety of immune-oncology drug development. Methods: We have developed sensitive in vivo humanized mouse models for quantitating CRS that are rapid, reproducible and able to show variation among PBMC donors. The NSG mouse and its derivatives are engrafted with cancer cells and human PBMCs. Mice are then dosed with checkpoint inhibitors or bi-specific antibodies as a single therapy or in combination. Cytokine release is evaluated 2-6 hours post dosing. This assay can be modified to also evaluate efficacy by using luciferase labeled cancer cells and monitoring tumor burden using the Xenogen IVIS imaging system. Results: For all therapy groups, each cytokine tested (including human IFN-γ, IL-2, IL-6, IL-10 and TNF) was upregulated 2-6 hours after drug treatment, but different PBMC donors had various cytokines release levels. Cytokine release levels correlated with a dose response, PBMC engraftment levels and tumor burden. We can demonstrate additive and synergistic cytokine release in the combination treated groups and compare efficacy versus single agents. Our in vivo method was able to determine CRS missed in the in vitro testing method. Conclusions: We have developed a rapid, sensitive and reproducible novel in vivo PBMC humanized mouse model that can differentiate human PBMC donors based on individual safety response to single agent and combination therapeutics of immune checkpoint inhibitors and bispecific T-cell-engaging antibodies. Additionally, this assay can utilize luciferase labelled cell lines to measure treatment efficacy. Using this assay, we can potentially evaluate both cytokine release and efficacy of current immune-oncology therapies as single agents and in combination. This assay has immediate utility in current and future drug development.

Download Full-text

Effect of inducing HR deficiency using AVB500, a receptor tyrosine kinase AXL inhibitor, on response to olaparib in uterine serous cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2020.38.15_suppl.e18108 ◽

2020 ◽

Vol 38 (15_suppl) ◽

pp. e18108-e18108

Author(s):

Michael Driscoll Toboni ◽

Barbara Blachut ◽

Mary M Mullen ◽

Jo'an Tankou ◽

Hollie M Noia ◽

...

Keyword(s):

Treatment Period ◽

Cell Lines ◽

Day Treatment ◽

Parp Inhibitor ◽

Tumor Burden ◽

Scid Mice ◽

In Vivo Studies ◽

Treatment Groups

e18108 Background: Evidence suggests DNA repair is a therapeutic target in endometrial cancer (EC). Given this, we determined whether combination therapy with AVB500, an AXL inhibitor, could improve response in a uterine serous cancer (USC) model. Methods: Two USC cell lines (ARK1 & ARK4) were treated with AVB500 (Aravive Biologics, Houston, TX) in combination with the poly ADP ribose polymerase (PARP) inhibitor, olaparib. Colony forming assays were assessed after 4 days of treatment with either AVB500 alone, olaparib alone or combination treatment (olaparib + AVB500); colonies were stained and absorbance was obtained to calculate relative cell viability using Graph Pad Prism. Baseline homologous recombination (HR) status was determined after radiating cells with 10Gy and identifying RAD51 foci by immunofluorescence (IF). Cell lines were considered to be HR proficient if over 30% of the cells expressed RAD51 ( > 5 foci per cell). IF was conducted using a Leica confocal microscope and foci were quantified using FociCounter. In vivo studies were performed using NOD-SCID mice injected with 1 x 107 ARK1 cells intraperitoneally followed by treatment q3 days for a 14 and 21 day treatment period. Treatment groups were vehicle control, AVB500 alone, olaparib alone and olaparib with AVB500. Results: The absorbance for olaparib + AVB500 was significantly less than the olaparib only group in two assays involving ARK1s (0.417nm vs 0.756nm, p = 0.001; 0.320nm vs 0.620nm, p = 0.008) as well as in ARK4s (0.186nm vs 0.641nm, p = 0.003). The HR assay indicated both cell lines were HR proficient. After baseline HR proficiency was established, the cell lines were pretreated with AVB500 prior to radiation. When compared to cells without treatment with AVB500, IF showed a decrease in RAD51 foci per cell in ARK1 (2.7 vs 7.3, p = 0.0003) and ARK4 (6.3 vs 13.0, p = 0.0054). The proportion of ARK1 cells expressing RAD51 decreased to 21%, indicating HR deficiency. Lastly, NOD-SCID mice receiving olaparib + AVB500 had less tumor weight than those treated with olaparib alone (0.008g vs 0.138g, p = 0.002) and AVB500 alone (0.008g vs 0.145g, p = 0.0006) in a 14 day and a 21 day treatment period (0.212g vs 0.586g, p = 0.027 and 0.212 vs 0.494g, p = 0.005, respectively). Conclusions: HR proficient USC cell lines treated in vitro and in vivo with the combination of AVB500 and olaparib demonstrate an improved response to olaparib or AVB500 alone with a greater decrease in tumor burden. AVB500 appears to induce HR deficiency. Additional therapeutic and mechanistic experiments are ongoing.

Download Full-text

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.

Download Full-text

Liposome-Imipramine Blue Inhibits Sonic Hedgehog Medulloblastoma In Vivo

Cancers ◽

10.3390/cancers13061220 ◽

2021 ◽

Vol 13 (6) ◽

pp. 1220

Author(s):

Tobey J. MacDonald ◽

Jingbo Liu ◽

Bing Yu ◽

Anshu Malhotra ◽

Jenny Munson ◽

...

Keyword(s):

Sonic Hedgehog ◽

Clinical Investigation ◽

Single Agent ◽

Treatment Resistance ◽

Current Therapy ◽

Molecular Alteration ◽

Term Administration ◽

And Migration

Sonic hedgehog subtype of medulloblastoma (SHH MB) with metastasis or specific clinical or molecular alteration shas a poor prognosis and current therapy results in long-term cognitive impairment in the majority of survivors. Thus, a great need exists for new targeted therapeutic approaches to more effectively treat SHH MB in children. Imipramine blue (IB), a novel molecule with anti-tumor properties, inhibits the NADPH oxidase (NOX) family of enzymes, which are critical for SHH MB survival and treatment resistance. In this study, IB was encapsulated within a liposome to form a liposomal nanoparticle, Liposome-IB (Lipo-IB). This complex has the ability to cross the blood–brain barrier and be preferentially taken up by tumor cells within the brain. We demonstrated in vitro that Lipo-IB treatment caused a dose-dependent decrease in SHH MB cell viability and migration. Short-term administration of single agent Lipo-IB treatment of SHH MB in vivo significantly inhibited tumor growth, reduced the tumor volume, including a complete tumor response, and improved survival compared to control treated mice, without any observable toxicity. We conclude that Lipo-IB is a potential novel nanoparticle-based therapeutic for the treatment of SHH MB that warrants further preclinical safety and efficacy testing for development towards clinical investigation.

Download Full-text

Preclinical evaluation of strasseriolides A–D, potent antiplasmodial macrolides isolated from Strasseria geniculata CF-247,251

Malaria Journal ◽

10.1186/s12936-021-03993-8 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Frederick Annang ◽

Guiomar Pérez-Moreno ◽

Caridad Díaz ◽

Victor González-Menéndez ◽

Nuria de Pedro Montejo ◽

...

Keyword(s):

Drug Interaction ◽

Liver Microsomes ◽

In Vivo Studies ◽

Significant Activity ◽

In Vivo Efficacy ◽

Preclinical Evaluation ◽

Drug Drug Interaction ◽

Further Development

Abstract Background Malaria is a global health problem for which novel therapeutic compounds are needed. To this end, a recently published novel family of antiplasmodial macrolides, strasseriolides A–D, was herein subjected to in vivo efficacy studies and preclinical evaluation in order to identify the most promising candidate(s) for further development. Methods Preclinical evaluation of strasseriolides A–D was performed by MTT-based cytotoxicity assay in THLE-2 (CRL-2706) liver cells, cardiotoxicity screening using the FluxOR™ potassium assay in hERG expressed HEK cells, LC–MS-based analysis of drug-drug interaction involving CYP3A4, CYP2D6 and CYP2C9 isoforms inhibition and metabolic stability assays in human liver microsomes. Mice in vivo toxicity studies were also accomplished by i.v. administration of the compounds (vehicle: 0.5% HPMC, 0.5% Tween 80, 0.5% Benzyl alcohol) in mice at 25 mg/kg dosage. Plasma were prepared from mice blood samples obtained at different time points (over a 24-h period), and analysed by LC-MS to quantify compounds. The most promising compounds, strasseriolides C and D, were subjected to a preliminary in vivo efficacy study in which transgenic GFP-luciferase expressing Plasmodium berghei strain ANKA-infected Swiss Webster female mice (n = 4–5) were treated 48 h post-infection with an i.p. dosage of strasseriolide C at 50 mg/kg and strasseriolide D at 22 mg/kg for four days after which luciferase activity was quantified on day 5 in an IVIS® Lumina II imager. Results Strasseriolides A–D showed no cytotoxicity, no carditoxicity and no drug-drug interaction problems in vitro with varying intrinsic clearance (CLint). Only strasseriolide B was highly toxic to mice in vivo (even at 1 mg/kg i.v. dosage) and, therefore, discontinued in further in vivo studies. Strasseriolide D showed statistically significant activity in vivo giving rise to lower parasitaemia levels (70% lower) compared to the controls treated with vehicle. Conclusions Animal efficacy and preclinical evaluation of the recently discovered potent antiplasmodial macrolides, strasseriolides A–D, led to the identification of strasseriolide D as the most promising compound for further development. Future studies dealing on structure optimization, formulation and establishment of optimal in vivo dosage explorations of this novel compound class could enhance their clinical potency and allow for progress to later stages of the developmental pipeline.

Download Full-text

Anti-Myeloma Activity of Selective PI-3K/PDK/mTOR Inhibitor BEZ235.

Blood ◽

10.1182/blood.v110.11.1185.1185 ◽

2007 ◽

Vol 110 (11) ◽

pp. 1185-1185 ◽

Cited By ~ 2

Author(s):

Douglas W. McMillin ◽

Joseph Negri ◽

Jake Delmore ◽

Patrick Hayden ◽

Nicholas Mitsiades ◽

...

Keyword(s):

Cell Lines ◽

Mtor Inhibitor ◽

Mononuclear Cells ◽

Single Agent ◽

In Vivo Studies ◽

Cross Resistance ◽

Bone Lesions ◽

Normal Donor

Abstract Context: The PI3K-Akt-mTOR pathway has been a promising target for the treatment of multiple myeloma (MM). Major cytokine/growth factor receptor cascades (e.g. IGF-1/IGF-1R or IL-6/IL-6R) mediate, at least in part, their proliferative, anti-apoptotic or drug resistance effects through PI3K-Akt-mTOR activation and their downstream effectors. Therefore blocking this signaling pathway at one, or preferably more, of its molecular levels is considered to have promising therapeutic potential for MM. The small molecular mass compound NVP-BEZ235 (Novartis Pharma, Basel Switzerland) allows a multi-targeted, yet selective, inhibition of the PI-3K/Akt/mTOR signaling axis at the level of PI-3K and mTOR and was tested in our pre-clinical MM models. Methods/Results: A panel of human MM cell lines was tested for their in vitro response to NVP-BEZ235 using MTT colorimetric survival assays. All MM cell lines tested exhibited dose- and time-dependent decrease of their viability upon exposure to NVP-BEZ235 (IC50= 25–800 nM for 24–48hrs), without evidence of potential cross-resistance between conventional or novel anti-MM agents and NVP-BEZ235. Indeed, MM cells highly sensitive (IC50 <25 nM) to NVP-BEZ235 (e.g. MM.1S, MM.1R, Dox40 and KMS-12-PE) included both lines known to be sensitive as well as others which are resistant to dexamethasone, cytotoxic chemotherapy, thalidomide and/or its immunomodulatory derivatives (IMIDs). A longitudinal assessment of viability of MM-1S and OPM-2 MM cells during a 48-hr incubation with pharmacologically relevant concentrations of NVP-BEZ235 (25– 400nM) showed rapid commitment to and induction of MM cell death. This result, coupled with the observation that normal donor peripheral blood mononuclear cells (PBMCs) were less sensitive (IC50 >800 nM) than all MM cell lines tested, suggest that this compound exhibits a rapid and tumor-selective effect at clinically relevant conditions. This observation is further supported by our preliminary in vivo studies which suggest anti-MM activity of the drug in a model of diffuse MM bone lesions in SCID/NOD mice. Optimization of dosing and schedule to improve overall survival of NVP-BEZ235 treated mice is ongoing. To provide a more comprehensive framework for possible clinical applications of NVP-BEZ235 for MM treatment, we evaluated a series of combinations of this agent with conventional (e.g. dexamethasone, doxorubicin) and novel (e.g. bortezomib, immunodulatory thalidomide derivatives) anti-MM agents. Given the very potent single-agent activity of NVP-BEZ235 at even low nM concentrations, formal statistical documentation of synergy was not observed, but encouragingly no evidence of antagonism with any of these anti-MM agents was observed, indicating that combinations of NVP-BEZ235 with the aforementioned anti-MM agents can be feasible in clinical settings. Conclusion: The dual PI3K/mTOR inhibitor NVP-BEZ235 induces MM cell killing at sub-μM concentrations, with significantly higher sensitivity of MM cells compared to normal tissues, suggesting that this kinase inhibitor merits further consideration for possible testing as treatment option for MM patients. Further in vitro and in vivo studies are ongoing to further support the translation of these observations to clinical trials in MM.

Download Full-text