High Antitumor Activity Research Articles

Redox‐responsive core cross‐linked micelles of poly(ethylene oxide)‐b‐poly(furfuryl methacrylate) by Diels‐Alder reaction for doxorubicin release

ABSTRACTRedox‐responsive core cross‐linked (CCL) micelles of poly(ethylene oxide)‐b‐poly(furfuryl methacrylate) (PEO‐b‐PFMA) block copolymers were prepared by the Diels‐Alder click‐type reaction. First, the PEO‐b‐PFMA amphiphilic block copolymer was synthesized by the reversible addition‐fragmentation chain transfer polymerization. The hydrophobic blocks of PFMA were employed to encapsulate the doxorubicin (DOX) drug, and they were cross‐linked using dithiobismaleimidoethane at 60 °C without any catalyst. Under physiological circumstance, the CCL micelles demonstrated the enhanced structural stability of the micelles, whereas dissociation of the micelles took place rapidly through the breaking of disulfide bonds in the cross‐linking linkages under reduction environment. The core‐cross‐linked micelles showed fine spherical distribution with hydrodynamic diameter of 68 ± 2.9 nm. The in vitro drug release profiles presented a slight release of DOX at pH 7.4, while a significant release of DOX was observed at pH 5.0 in the presence of 1,4‐dithiothreitol. MTT assays demonstrated that the block copolymer did not have any practically cytotoxicity against the normal HEK293 cell line while DOX‐loaded CCL micelles exhibited a high antitumor activity towards HepG2 cells. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3741–3750

Current status and future prospect of internal medicine treatment for advanced esophageal cancer

Esophageal cancer (EC) is one of common malignant tumors, and the incidence and mortality of EC in China rank the first place in the world. Because of the occult onset, the early atypical symptoms, and the lack of effective early diagnostic methods, most of patients are diagnosed at an advanced stage of the disease and lost the chance of surgery. Comprehensive treatment including palliative medical treatment, molecular targeted therapy, immunotherapy and so on is appropriate for these patients. How to choose the chemotherapy regimen and formulate reasonable treatment plan has become a hot spot in clinical research. Molecular targeted drugs have become a new developmental direction in cancer treatment because of their high specificity and antitumor activity, but the effects on esophageal cancer remain controversial. With the development of immune check point blockade treatment, breakthrough has been made in tumor immunotherapy, which has become an important means in cancer comprehensive treatment and shown a good prospect of treatment.

2-DEOXY-D-GLUCOSE ENHANCES DICHLOROACETATE ANTITUMOR ACTION AGAINST LEWIS LUNG CARCINOMA

Aerobic glycolysis that supports high proliferation rate and survival of tumor cells in unfavorable conditions is among fundamental features of tumor metabolism. The search for active modulators of energetic metabolism capable of suppressing tumor growth and metastasis could result in higher effectiveness of anticancer therapy. To study antitumor and antimetastatic activity of the modulators of energetic metabolism dichloroacetate (DCA) and 2-deoxy-D-glucose (2DG) used in combination treatment of Lewis lung carcinoma (LLC). As experimental tumor model, LLC/R9 variant was used. DCA and 2DG were administered per os to С57Bl/6 mice 5 times per week for 3 weeks at a total dose of 1.5 and 0.98 g/kg, respectively, as single agents or in combination starting from the following day after tumor cell transplantation. Growth of primary tumor and number and volume of lung metastases were registered. Lactate and pyruvate content was determined by enzymatic methods using lactate dehydrogenase. Electron paramagnetic resonance was used for analyzing the functional state of the components of mitochondrial respiratory chain. Engulfing activity and reactive oxygen species (ROS) production in tumor-associated CD14(+) cells was analyzed by flow cytometer with the use of FITC-labeled staphylococcus, and by spectrofluorometry with the use of 2.7-dichlorofluorescein diacetate, respectively. DCA administered as a single agent did not affect primary tumor growth but decreased the number and volume of lung metastases by 60% (p < 0.05) and 90% (p < 0.05), respectively. In mice treated with 2DG only, primary tumor volume as well as the number and volume of lung metastases were not affected. Combination treatment with DCA and 2DG resulted in the decrease of primary tumor volume, the number and volumes of lung metastases by 70; 46, and 90%, respectively (p < 0.05). High antitumor activity of DCA + 2DG was associated with 31% decrease (p < 0.05) of lactate content in tumor tissue and 120% increase (p < 0.01) of ROS production in CD14(+) cells recruited to the region of tumor growth. 2DG that possesses neither antitumor nor antimetastatic activity against LLC/R9 significantly enhanced antitumor activity of DCA with accompanying inhibition of glycolysis and increase of cytotoxic activity of CD14(+) cells infiltrating tumor tissue. Taking into account significant antimetastatic activity of DCA this substance could be considered as a promising antimetastatic agent.

NEW COMPOUND N1,N1′-(2′′-BROMO-2′′-CHLOROETHENYL)-BIS-(5-FLUOROURACIL) AS THE ACTIVE ANTITUMOR AGENT FOR SARCOMA 180

The problem of how to treat malignant tumors and the search for effective low-toxic anticancer drugs are among the most important in modern medicine and other chemical and biological sciences, including pharmaceutical chemistry. The arsenal of anticancer drugs occupies a prominent position as medications related to heterocyclic systems (cancer of the digestive system and other areas). In this regard, further development towards new derivatives of purine and pyrimidine series are of significant scientific interest and justify the relevance, novelty, and scientific practical significance of this study. Synthesis of 5-fluorouracil bis-derivative was performed with a halogen-containing pharmacophore group to compose a molecule that was studied for its physical, chemical, and biological properties. Synthesis of 5-fluorouracil bis-derivative is a typical example of substitution reactions with a heteroatom of the uracil molecule (N1) as the second component in the reaction involving halothane, a known inhaled anesthetic. The reaction was carried out in a solvent system of benzene-dimethylformamide-diethyl ether, under conditions of phase transfer catalysis with dibenzo-18-crown-6 (DB 18C6) complex (alkaline medium), by heating (14 h), followed by purification, and drying of the products. The structure of the synthesized compound was confirmed by elemental analysis, infrared, and proton nuclear magnetic resonance (1H NMR) spectroscopy. By varying the reaction conditions, a synthesized compound of high purity was obtained with increased practical output of up to 50%. The toxicity and antitumor activity of the synthesized compound were investigated. The new substance, 5-fluorouracil bis-derivative, was found to have high antitumor activity, reducing the Sarcoma 180 tumor by 51.7% (activity criterion &gt; 50%). This suggests the synthesized compound is suitable as a physiologically active treatment and its further study as a potential vehicle for anti-tumor treatment in patients is recommended.

Five novel dinuclear copper(II) complexes: Crystal structures, properties, Hirshfeld surface analysis and vitro antitumor activity study

Five dinuclear copper(II) complexes have been synthesized with three kinds of Schiff bases and Cu(NO3)2·H2O in different solvent systems: [Cu2(bdhc)(CH3OH)(NO3)(dmf)2] (1), [Cu2(bdhc)(CH3CH2OH)(NO3)(dmf)2] (2) [Cu2(bchc)(CH3CH2OH)(NO3)(dmf)2] (3), [Cu2(bchc)(CH3OH)(NO3)(dmf)2] (4), [Cu2(bbhc)(H2O)(dmf)2]·NO3·H2O (5) (H3bdhc is 1,5-bis(3,5-dibromosalicylidene)-carbohydrazide, H3bchc is 1,5-bis(3,5-dichlorosalicylidene)-carbohydrazide, H3bbhc is 1,5-bis(5-bromosalicylidene)-carbohydrazide). All the compounds were characterized by IR spectroscopy, Element analysis and X-ray single-crystal diffraction. The anti-proliferative activity of 1–5 was evaluated against a panel of human tumor cells while 3 exhibited a high antitumor activity against T-24, A549, SK-OV-3 and MGC-803. A detailed analysis of Hirshfeld surface and 2D fingerprint plot revealed that 1–5 were supported mainly by H⋯H, C-H⋯X (X=Cl, Br) and O⋯H intermolecular interactions. Fluorescence properties indicate that all the complexes exist fluorescence concentration self-quenching effect. The magnetic properties of 1 from 2 to 300Kare also discussed.

Robust, tumor-homing and redox-sensitive polymersomal doxorubicin: A superior alternative to Doxil and Caelyx?

Pegylated liposomal doxorubicin (Lipo-Dox) is one of the few clinically used cancer nanomedicines. Here we show that tumor-homing, redox-responsive and reversibly crosslinked multifunctional biodegradable polymersomes are a better alternative to liposomes for Dox delivery. Cyclic peptide cNGQGEQc-decorated polymersomes (cNGQ-PS) are easily prepared with a small size and high Dox loading. Dox-loaded cNGQ-PS (cNGQ-PS-Dox) shows superb stability with minimal drug leakage under physiological conditions while spontaneous disassembly and quick drug release in response to 10mM glutathione. MTT assays, flow cytometry and confocal microscopy clearly display efficient receptor-mediated internalization of cNGQ-PS-Dox, fast intracellular drug release, and high antitumor activity in α3β1 integrin-overexpressing A549 lung cancer cells. Intriguingly, cNGQ-PS-Dox presents a remarkably high maximum-tolerated dose of over 100mg/kg, over 6-fold higher than Lipo-Dox. The in vivo pharmacokinetics and biodistribution studies reveal that cNGQ-PS-Dox has a long circulation time and significantly enhanced tumor accumulation (8.60%ID/g) as compared to Lipo-Dox and non-targeting PS-Dox controls. Notably, cNGQ-PS-Dox shows superior treatment of both subcutaneous and orthotopic A549 human lung cancer bearing nude mice to Lipo-Dox, resulting in effective tumor suppression, significantly improved survival time, and markedly reduced adverse effects. cNGQ-PS appears to be a clinically viable system for targeted lung cancer chemotherapy.

Synthesis and characterization of mesoporous magnetic nanocomposites wrapped with chitosan gatekeepers for pH-sensitive controlled release of doxorubicin

Multifunctional nanocarriers based on the Fe3O4 nanoparticles core and mesoporous silica shell (mSiO2) were synthesized for controlled drug release through magnetic targeting and pH-sensitive performances. The developed Fe3O4@mSiO2 nanocarriers exhibited a suitable size (63nm) and good magnetic responsibility, doxorubicin (DOX) could be successfully loaded into the mesoporous of Fe3O4@mSiO2 via electrostatic interaction, and the drug loading content and loading efficiency are 29.3% and 93.6%, respectively. The chitosan (CS) was employed to wrap the Fe3O4@mSiO2-DOX as the blocking agent to inhibit premature drug release, and the final CS/Fe3O4@mSiO2-DOX exhibited excellent pH-sensitivity, 86.1% DOX was released within 48h at pH4.0. Furthermore, all the release behaviors fit the Higuchi model very well and a purely diffusion-controlled process played a major role on DOX release from CS/Fe3O4@mSiO2-DOX. In addition, MTT assays in human liver hepatocellular carcinoma cells (HepG2) demonstrated that the CS/Fe3O4@mSiO2-DOX had high anti-tumor activity, while the Fe3O4@mSiO2 nanocarriers were practically non-toxic. Thus, our results revealed that the CS/Fe3O4@mSiO2-DOX could play an important role in the development of intracellular delivery nanodevices for cancer therapy.

Synthesis and characterization of magnetic mesoporous core–shell nanocomposites for targeted drug delivery applications

Magnetic mesoporous nanocomposites are emerging as a significant new material to improve the effectiveness of cancer treatment and enhance the availability of drug therapy. Thus, the core–shell structure magnetic mesoporous nanocomposites (Fe3O4@SiO2@LDH) were synthesized with an average diameter of about 100 nm and used as methotrexate (MTX) carriers for cancer therapy. As an important biological material, Fe3O4@SiO2@LDH exhibited higher superparamagnetic behavior and biocompatibility, and the drugs can be loaded in the channels of the mesoporous silica and the interlayer of layered double hydroxides (LDH). The embedding rate of magnetic mesoporous silica (Fe3O4@SiO2) and LDH were 60.32 % and 0.67 %, respectively, and the release rate of the drug delivery systems (Fe3O4@SiO2@LDH-MTX) was 66.81 %. In addition, LDH as a kind of pH-sensitive material was adopted for controlled drug release and WST-1 assays in cancer cells (Hela) demonstrated that Fe3O4@SiO2@LDH-MTX presented high anti-tumor activity, while the carriers were nearly non-toxic. Therefore, all the results suggested that the magnetic nanocomposites can be employed to deliver MTX, and would be applied in the field of cancer therapy in the future.

Facile synthesis of magnetic-/pH-responsive hydrogel beads based on Fe3O4 nanoparticles and chitosan hydrogel as MTX carriers for controlled drug release

In the present study, methotrexate (MTX)-encapsulated magnetic-/pH-responsive hydrogel beads based on Fe3O4 nanoparticles and chitosan were successfully prepared through a one-step gelation process, which is a very facile, economic and environmentally friendly route. The developed hydrogel beads exhibited homogeneous porous structure and super-paramagnetic responsibility. MTX can be successfully encapsulated into magnetic chitosan hydrogel beads, and the drug encapsulation efficiency (%) and encapsulation content (%) were 93.8 and 6.28%, respectively. In addition, the drug release studies in vitro indicated that the MTX-encapsulated magnetic chitosan hydrogel beads had excellent pH-sensitivity, 90.6% MTX was released from the magnetic chitosan hydrogel beads within 48 h at pH 4.0. WST-1 assays in human liver hepatocellular carcinoma cells (HepG2) demonstrated that the MTX-encapsulated magnetic chitosan hydrogel beads had good cytocompatibility and high anti-tumor activity. Therefore, our results revealed that the MTX-encapsulated magnetic chitosan hydrogel beads would be a competitive candidate for controlled drug release in the area of targeted cancer therapy in the near future.

Adoptively transferred natural killer cells maintain long-term antitumor activity by epigenetic imprinting and CD4+ T cell help

ABSTRACTNatural killer (NK) cell infusions can induce remissions in subsets of patients with different types of cancer. The optimal strategies for NK cell activation prior to infusion are still under debate. There is recent evidence that NK cells can acquire long-term functional competence by preactivation with the cytokines IL-12/15/18. The mechanisms supporting the maintenance of long-term NK cell antitumor activity are incompletely under-stood. Here, we show that NK cells preactivated in vitro with IL-12/15/18, but not with IL-15 alone, maintained high antitumor activity even 1 mo after transfer into lymphopenic RAG-2−/−γc−/− mice. The NK cell intrinsic ability for IFNγ production coincided with demethylation of the conserved non-coding sequence (CNS) 1 in the Ifng locus, previously shown to enhance transcription of Ifng. In a xenograft melanoma mouse model, human IL-12/15/18-preactivated NK cells rejected tumors more efficiently. In RAG-2−/−γc−/− mice, co-transfer of CD4+ T cells further improved the long-term competence of NK cells for IFNγ production that was dependent on IL-2. CD4+ T cell activation during homeostatic proliferation required macrophages and further promoted the long-term NK cell antitumor activity. Thus, NK cells can “remember” a previous exposure to cytokines by epigenetic imprinting resulting in a remarkable stability of the IFNγ-producing phenotype after adoptive transfer. In addition, our results support combination of cytokine-preactivated NK cells with CD4+ T cell activation upon lymphopenic conditioning to achieve long-term NK cell effector function for cancer immunotherapy.

Abstract 330: Development of a highly selective B/CRAF kinase inhibitor that exhibits antitumor activities in RAS and BRAF mutant tumors with minimal paradoxical activation

Abstract The mitogen-activated protein kinase (MAPK) signaling pathway is frequently activated in human cancers due to genetic alterations that can occur at multiple nodes in the pathway, the most prevalent of which are mutations in RAS or BRAF. While BRAFV600 mutant tumors are effectively treated with existing RAF inhibitors, RAS mutant cancers and tumors expressing atypical BRAF mutants remain an unmet medical need. Emerging biology has demonstrated that the CRAF kinase functions as a critical mediator of mutant KRAS-driven cell proliferation and tumor development. CRAF was also shown to be the mediator of feedback-mediated pathway reactivation following MEK inhibitor treatment in KRAS mutant cancers. Hence selective inhibitors that potently inhibit the activity of CRAF could be both effective in blocking mutant RAS-driven tumorigenesis and in alleviating feedback activation. We have developed a type II ATP-competitive inhibitor that inhibits both B- and CRAF kinase activities at picomolar IC50 values in biochemical assays with high selectivity profile against a panel of 456 human kinases. The inhibitor not only inhibits MAPK signaling activity in tumor models harboring BRAFV600 mutation, but also inhibits mutant N- and KRAS-driven signaling with minimum paradoxical activation, likely due to its activity in inhibiting both RAF monomers and dimers with similar potencies. Correspondingly, profiling data of the inhibitor in a panel of 480 human cancer cell lines shows that it has higher antitumor activities in cell lines harboring BRAF or RAS mutations as compared to those that are wild-type. The inhibitor is orally bioavailable, it demonstrates a direct PK/PD relationship and causes tumor regression in multiple cell line and primary human tumor derived xenograft models that have BRAF, NRAS or KRAS mutations with good tolerability. Thus, we have developed a next generation RAF inhibitor with unique biochemical and cellular properties that enables its antitumor activities in RAS mutant tumors. Citation Format: Wenlin Shao, Yuji Mishina, Yun Feng, Giordano Caponigro, Savithri Ramurthy, Vesselina Cooke, Lesley Griner, Gisele Nishiguchi, Alice Rico, Ben Taft, Matthew Burger, Huw Tanner, Valery Polyakov, Brent Appleton, John Tellew, Richard Zang, Mohammad Hekmat-Nejad, Payman Amiri, Mallika Singh, Darrin Stuart. Development of a highly selective B/CRAF kinase inhibitor that exhibits antitumor activities in RAS and BRAF mutant tumors with minimal paradoxical activation. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 330.

Multifunctional pH-Responsive Folate Receptor Mediated Polymer Nanoparticles for Drug Delivery.

Multifunctional pH-responsive folate receptor mediated targeted polymer nanoparticles (TPNps) were developed for docetaxel (DTX) delivery based on poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)poly (β-amino ester) (P123-PAE) and poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)-folate (P123-FA) copolymers. The DTX was loaded into the TPNps with a decent drug loading content of 15.02 ± 0.14 wt%. In vitro drug release results showed that the DTX was released from the TPNps at a pH-dependent manner. Tetrazolium dye (MTT) assay revealed that the bland polymer nanoparticles displayed almost nontoxicity at 200 μg/mL concentration. However, the DTX-loaded TPNps showed high anti-tumor activity at low IC50 (0.72 μg/mL) for MCF-7 cells following 48 h incubation. Cellular uptake experiments revealed that the TPNps had higher degree of cellular uptake than nontargeted polymer nanoparticles, indicating that the nanoparticles were internalized into the cells via FA receptor-mediated endocytosis. Moreover, the cellular uptake pathways for the FA grafted polymer were involved in energy-dependent, clathrin-mediated and caveolae-mediated endocytosis. The cell killing effect and cellular uptake of the DTX-TPNps by the MCF-7 cells were all enhanced by about two folds at pH 5.5 when compared with pH 7.4. The TPNps also significantly prolonged the in vivo retention time for the DTX. These results suggest that the biocompatible pH responsive folate-modified polymer nanoparticles present a promising safe nanosystem for intracellular targeted delivery of DTX.

Magnetic targeted drug delivery carriers encapsulated with pH-sensitive polymer: synthesis, characterization and in vitro doxorubicin release studies

Targeted and efficient delivery of drug to tumor is one of the crucial issues in cancer therapy. In this work, we have successfully designed and prepared the pH-sensitive magnetic nanoparticles (MNPs) as targeted anticancer drug carriers, in which the MNPs were coated by poly(acrylic acid) (PAA) and the obtained PAA@MNPs exhibited a size within 100 nm, good stability, and superparamagnetic responsibility (Ms 45.97 emu/g). Doxorubicin (DOX) can be successfully loaded onto MNPs via electrostatic interaction, and the drug loading content and loading efficiency are 26.4 and 88.1%, respectively. Moreover, the release studies showed that the drug-loaded carriers (MNPs-DOX) had excellent pH sensitivity, 75.6% of the loaded DOX was released at pH 4.0 within 48 h. Importantly, MTT assays in HUVEC and MCF-7 cells demonstrated that MNPs-DOX exhibited high anti-tumor activity, while the PAA@MNPs were practically nontoxic. Thus, our results revealed that PAA@MNPs would be a competitive candidate for biomedical application and MNPs-DOX could be used in targeted cancer therapy.

Doxorubicin-Functionalized Silica Nanoparticles Incorporated into a Thermoreversible Hydrogel and Intraperitoneally Administered Result in High Prostate Antitumor Activity and Reduced Cardiotoxicity of Doxorubicin.

Described here is an anticancer material based on colloidal mesoporous silica nanoparticles (MSNs) functionalized with doxorubicin (DOX), and incorporated into Pluronic F127 hydrogels for prolonged release, with a potential therapeutic application for prostate cancer treatment. The MSNs have spherical morphology, size of about 60 nm, surface area of 970 cm2 g-1 and average pore width of 2.0 nm. A high colloidal stability for the MSNs in the physiological medium used for in vivo administration (NaCl 0.9% w/v) could be attained in the presence of PF127 (from 5 to 18 wt %), where depletion repulsion forces prevent MSN agglomeration. By conjugating DOX, MSN and PF127 (18 wt %) in NaCl 0.9%, the hybrid system has a gelation temperature of 21 °C, which allowed its in vivo administration in the liquid form and further in situ gelation, generating a drug depot system inside the animals after peritoneal injection. The systems were tested in rats with chemically induced prostate cancer and, after this treatment, histopathological analyses confirmed (i) a reduction in the frequency of aggressive tumors; (ii) that the antitumor effect was dependent on MSN concentration; and most importantly (iii) the reduction of DOX intrinsic cardiotoxicity, indicating that the MSNs play a cardioprotective effect.

A novel dual-responsive core-crosslinked magnetic-gold nanogel for triggered drug release

A facial approach was reported to prepare a novel dual-responsive core-crosslinked nanogel and investigated for the triggered methotrexate (MTX) release. Nanogels with core-shell architecture were synthesized by decoration of Au/Fe3O4 core/shell NPs using poly(ethylene glycol)-b-poly((N,N-dimethylamino)ethyl methacrylate-co-2-hydroxyethyl methacrylate)-maleic acid (PEG-b-P(DMAEMA-co-HEMA)-MA) for crosslinking and autoreduction processes. The second block containing amino groups and maleate groups as the inner shell was used for the reduction of HAuCl4 (auric cation) in the presence of Fe3O4 NPs and as a crosslinker agent, respectively. Furthermore, to improve the long-term dispersibility of the nanogels, poly(ethylene glycol) was preferred as outer shell even under high ionic strength. After that, NIPAAm was polymerized from the vinyl double bonds for fabricating the thermo and pH-responsive core-crosslinked nanogels. MTX (an anti-cancer agent) was successfully loaded (the loading capacity of 37%) into the nanogels by both ionic interaction and entrapment in polymeric network in the inner shell. The triggered MTX release ability of the synthesized nanocarriers was proved through the comparison of in-vitro drug release at simulated physiological condition and tumor tissue environment. MTT assay showed that MTX-loaded nanocarriers revealed high antitumor activity in MCF7 cell line after incubation following 24 and 48h. It was concluded that the developed nanogels have many promising qualities as an efficient carrier for the targeted MTX delivery to cancer tissues.

Using lymph node swelling as a potential biomarker for successful vaccination.

There is currently a lack of biomarkers to help properly assess novel immunotherapies at both the preclinical and clinical stages of development. Recent work done by our group indicated significant volume changes in the vaccine draining right lymph node (RLN) volumes of mice that had been vaccinated with DepoVaxTM, a lipid-based vaccine platform that was developed to enhance the potency of peptide-based vaccines. These changes in lymph node (LN) volume were unique to vaccinated mice.To better assess the potential of volumetric LN markers for multiple vaccination platforms, we evaluated 100 tumor bearing mice and assessed their response to vaccination with either a DepoVax based vaccine (DPX) or a water–in-oil emulsion (w/o), and compared them to untreated controls. MRI was used to longitudinally monitor LN and tumor volumes weekly over 4 weeks. We then evaluated changes in LN volumes occurring in response to therapy as a potential predictive biomarker for treatment success.We found that for both vaccine types, DPX and w/o, the %RLN volumetric increase over baseline and the ratio of RLN/LLN were strong predictors of successful tumor suppression (LLN is left inguinal LN). The area under the curve (AUC) was greatest, between 0.75-0.85, two (%RLN) or three (RLN/LLN) weeks post-vaccination. For optimized critical thresholds we found these biomarkers consistently had sensitivity >90% and specificity >70% indicating strong prognostic potential. Vaccination with DepoVax had a more pronounced effect on draining lymph nodes than w/o emulsion vaccines, which correlated with a higher anti-tumor activity in DPX-treated mice.

Design and Synthesis of Potent in Vitro and in Vivo Anticancer Agents Based on 1-(3',4',5'-Trimethoxyphenyl)-2-Aryl-1H-Imidazole.

A novel series of tubulin polymerization inhibitors, based on the 1-(3′,4′,5′-trimethoxyphenyl)-2-aryl-1H-imidazole scaffold and designed as cis-restricted combretastatin A-4 analogues, was synthesized with the goal of evaluating the effects of various patterns of substitution on the phenyl at the 2-position of the imidazole ring on biological activity. A chloro and ethoxy group at the meta- and para-positions, respectively, produced the most active compound in the series (4o), with IC50 values of 0.4-3.8 nM against a panel of seven cancer cell lines. Except in HL-60 cells, 4o had greater antiproliferative than CA-4, indicating that the 3′-chloro-4′-ethoxyphenyl moiety was a good surrogate for the CA-4 B-ring. Experiments carried out in a mouse syngenic model demonstrated high antitumor activity of 4o, which significantly reduced the tumor mass at a dose thirty times lower than that required for CA-4P, which was used as a reference compound. Altogether, our findings suggest that 4o is a promising anticancer drug candidate that warrants further preclinical evaluation.

IMpassion130: a Phase III randomized trial of atezolizumab with nab-paclitaxel for first-line treatment of patients with metastatic triple-negative breast cancer (mTNBC).

TPS1104 Background: Treatment for mTNBC is limited, with chemotherapy the mainstay (bevacizumab is approved in > 80 countries). Atezolizumab (atezo; MPDL3280A), a humanized anti-PDL1 antibody, inhibits PD-L1 binding to PD-1 and B7.1 but leaves PD-L2/PD-1 binding intact. mTNBC has high levels of tumor-infiltrating immune cells, increased PD-L1 expression and high mutation rates that may generate immunogenic neoantigens, making it a good candidate for PD-L1–targeted therapy. It is hypothesized that atezo’s single-agent activity in TNBC could be enhanced with chemotherapy by exposing the immune system to high levels of tumor antigens and modulating T-cell and NK cell functions. Nab-paclitaxel (pac) has high antitumor activity that may favorably alter the immune microenvironment, and atezo + nab-pac resulted in promising activity and tolerable safety. A Phase III multicenter, randomized, double-blind, placebo-controlled trial (IMpassion130) has been initiated to evaluate atezo + nab-pac in first-line mTNBC. Methods: Patients (pts) will be randomized 1:1 to receive atezo (840 mg) or placebo on days 1 and 15 plus nab-pac (100 mg/m2) on days 1, 8 and 15 of a 28-day cycle. Stratification factors include presence of liver metastases and prior taxane therapy. Pts will have histologically documented locally advanced TNBC or mTNBC, no prior systemic therapy for advanced TNBC, ECOG PS 0–1 and measurable disease (RECIST v1.1). Pts with known CNS disease (except asymptomatic treated metastases), autoimmune disease or prior immune checkpoint blockade therapy are excluded. Coprimary endpoints include progression-free survival (PFS) and overall survival (OS). Other endpoints include response rate and duration and safety. Tumor biopsies will be obtained at baseline and progression to assess biomarkers of response and immune escape. PD-L1 expression will be centrally evaluated using the SP142 IHC assay. PFS and OS will be compared between study arms using the stratified log-rank test. Hazard ratios for progression or death will be estimated with a stratified Cox proportional hazards model. This trial will enroll 900 pts at > 270 sites globally. Clinical trial information: NCT02425891.

Impact of disease burden on long-term outcome of 19-28z CAR modified T cells in adult patients with relapsed B-ALL.

7003Background: We have previously reported high anti-tumor activity of CD19-targeted 19-28z chimeric antigen receptor (CAR) modified T cells in adult patients (pts) with relapsed or refractory (R/...

508. IL-33/ST2 Triggering of IL-9-Secreting T Cells: From Proteomics to Therapeutics

As one of the most validated immunotherapies to date, allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative option for high-risk hematological malignancies, particularly acute myeloid leukemia (AML). The immunotherapeutic activity of allo-HCT is known as the graft-vs-leukemia (GVL) activity. However, GVL activity is often accompanied by T-cell reactivity to allo-antigens in normal host tissues, which leads to graft-versus-host disease (GVHD), another major cause of death after HCT. Therefore, there is a great unmet need to improve the current process of allo-HCT through increasing the GVL activity and decreasing GVHD. We have shown that an elevated plasma level of soluble (s)ST2 in HCT patients is a risk factor for severe GVHD. ST2 blockade reduces sST2-producing T cells while maintaining protective membrane (m)ST2-expressing T cells such as type 2 T cells and regulatory T cells during aGVHD. A novel IL-9 producing T helper subset, Th9, expresses mST2. Furthermore, Th9 cells and IL-9 producing CD8 cytotoxic (Tc9) cells have higher antitumor activity than Th1 and Tc1 cells in melanoma models. Interestingly, we found that the addition of IL-33 during T9 differentiation (T9IL-33) increased expression of mST2 and PU.1, a transcription factor that promotes IL-9 production in both CD4 and CD8 T cells. Adoptive transfer of T9IL-33 cells with bone marrow cells in a murine model of HCT resulted in less severe GVHD compared to transfer of T9IL-33 cells generated from ST2−/− or IL-9−/− T cells. Furthermore, cytolytic molecules implicated in anti-leukemic activity (granzyme B and perforin) were upregulated in WT T9IL-33 cells while ST2−/− T9IL-33 cells did not. WT T9IL-33 cells also exhibited higher anti-leukemic activity when cultured with a retrovirally transduced MLL-AF9 leukemic cells in comparison to ST2−/− T9IL-33 in in vitro cytolytic assays. In vivo GVL experiments with MLL-AF9 AML and adoptive transfer of T9IL-33 cells resulted in increased survival compared to syngeneic mice, allo-HCT mice transferred with T1 cells, or T9 cells or T9IL-33 cells generated from ST2−/− or IL-9−/− T cells (Figure 1Figure 1). Human T9 cells are poorly studied. Here we demonstrate that IL-33 has the same impact on human T cells through enhancing IL-9 and Granzyme B production compared to T9 cells as well as demonstrated higher in vitro anti-leukemic cytolytic activity when incubated with MOLM14, an aggressive AML tumor cell line expressing FLT3/ITD mutations. Importantly, CD8α expression was upregulated in WT T9IL-33 (both CD4 and CD8) cells in comparison to ST2−/− T9IL-33 cells, and CD8α blockade with neutralizing antibody during allogeneic specific T9IL-33 differentiation reduced cytotoxicity of both murine T9IL-33, and human T9IL-33 cells as compared to the cell blocked with isotype control, suggesting that CD8α was associated with MHC-restricted cytolytic activity in T9IL-33 cells. Altogether, our observations demonstrated that adoptive transfer of T9IL-33 cells represents a promising cellular therapy following HCT.View Large Image | Download PowerPoint Slide