Single Intratumoral Injection Research Articles

Efficient Gene Silencing in Brain Tumors with Hydrophobically Modified siRNAs.

Glioblastoma (GBM) is the most common and lethal form of primary brain tumor with dismal median and 2-year survivals of 14.5 months and 18%, respectively. The paucity of new therapeutic agents stems from the complex biology of a highly adaptable tumor that uses multiple survival and proliferation mechanisms to circumvent current treatment approaches. Here, we investigated the potency of a new generation of siRNAs to silence gene expression in orthotopic brain tumors generated by transplantation of human glioma stem-like cells in athymic nude mice. We demonstrate that cholesterol-conjugated, nuclease-resistant siRNAs (Chol-hsiRNAs) decrease mRNA and silence luciferase expression by 90% in vitro in GBM neurospheres. Furthermore, Chol-hsiRNAs distribute broadly in brain tumors after a single intratumoral injection, achieving sustained and potent (>45% mRNA and >90% protein) tumor-specific gene silencing. This readily available platform is sequence-independent and can be adapted to target one or more candidate GBM driver genes, providing a straightforward means of modulating GBM biology in vivoMol Cancer Ther; 17(6); 1251-8. ©2018 AACR.

Efficacy of paclitaxel/dexamethasone intra-tumoral delivery in treating orthotopic mouse breast cancer

The effect of topical co-administration of promoter drugs with paclitaxel to increase anti-tumor effects of paclitaxel was investigated. Mice with orthotopic 4T1-Luc breast cancer received single intra-tumoral injection of a polymeric formulation with paclitaxel and a specific promoter drug. Several promoter drugs were evaluated, including: dexamethasone, losartan, nicotinamide, Azone, and oleic acid. Dexamethasone exhibited the highest effect on paclitaxel anti-tumor activity, in a dose-dependent fashion. However, this effect was accompanied by systemic effects of dexamethasone, and inability to prevent tumor metastasis to the lungs. Topical co-administration of promoter drugs with anti-cancer agents can enhance their anti-tumor effects. Further investigations are needed to identify the most efficient combinations of promoter and anti-cancer drugs, and their suitability for the clinical management of the breast cancer disease.

Adoptive Transfer of IL13Rα2-Specific Chimeric Antigen Receptor T Cells Creates a Pro-inflammatory Environment in Glioblastoma.

In order to fully harness the potential of immunotherapy with chimeric antigen receptor (CAR)-modified Tcells, pre-clinical studies must be conducted in immunocompetent animal models that closely mimic the immunosuppressive malignant glioma (MG) microenvironment. Thus, the goal of this project was to study the invivo fate of Tcells expressing CARs specific for the MG antigen IL13Rα2 (IL13Rα2-CARs) in immunocompetent MG models. Murine Tcells expressing IL13Rα2-CARs with a CD28.ζ (IL13Rα2-CAR.CD28.ζ) or truncated signaling domain (IL13Rα2-CAR.Δ) were generated by retroviral transduction, and their effector function was evaluated both invitro and invivo. IL13Rα2-CAR.CD28.ζ Tcells' specificity toward IL13Rα2 was confirmed through cytokine production and cytolytic activity. Invivo, a single intratumoral injection of IL13Rα2-CAR.CD28.ζ Tcells significantly extended the survival of IL13Rα2-expressing GL261 and SMA560 glioma-bearing mice; long-term survivors were resistant to re-challenge with IL13Rα2-negative and IL13Rα2-positive tumors. IL13Rα2-CAR.CD28.ζ Tcells proliferated, produced cytokines (IFNγ, TNF-α), and promoted a phenotypically pro-inflammatory glioma microenvironment by inducing a significant increase in the number of CD4+ and CD8+ T cells and CD8α+ dendritic cells and a decrease in Ly6G+ myeloid-derived suppressor cells (MDSCs). Our data underline the significance of CAR Tcell studies in immunocompetent hosts and further validate IL13Rα2-CAR Tcells as an efficacious therapeutic strategy for MG.

Intratumoral administration of IL2- and TNF-based fusion proteins cures cancer without establishing protective immunity.

The combination of tumor-targeting IL2- and TNF-based antibody-cytokine fusions has exhibited encouraging results in mouse and men. Here, we studied their combination to assess efficacy and mechanism of action in four different immunocompetent mouse models of cancer. Mice receiving a single intratumoral injection of F8-IL2, F8-TNF or the combination were investigated for tumor-infiltrating leukocytes and rechallenged when cured. In three models, a proportion of treated animals could be cured, most probably by infiltrating NK and CD8+ T cells. Most of the cured mice did not acquire protective immunity when rechallenged with the same tumor cell line. Immunocompetent mouse tumor models may not be adequate enough to predict the search for more efficacious therapy regimens.

Abstract LB-A30: Hafnium oxide nanoparticles with radiotherapy induce immunogenic cell death

Abstract Background - Between 70 to 90% of patient have "cold" tumors, i.e. devoid or poorly infiltrated by immune cells, rendering inoperative their treatment by immune checkpoint inhibitors. To allow these patients to benefit from these therapies, it is fundamental to prime an antitumor immune response. Radiotherapy (RT) has demonstrated its ability to induce the immunogenic cell death (ICD), a crucial event allowing the priming of the antitumor immune response. Meanwhile, a new class of material with high electron density, hafnium oxide, was designed at the nanoscale (HfO2-NP) to efficiently absorb ionizing radiation and increase the radiation dose deposition from within the tumor cells and increase killing of cancer cells. Here, we compared the ability of HfO2-NP and RT to RT alone to kill cancer cells and induce immunogenic cell death. Methods - A panel of human and mouse cancer cell lines (mesenchymal and epithelial origin, radiosensitive and radioresistant) were treated or not with HfO2-NP, then irradiated by X-rays. Impact of the treatments on apoptosis and necrosis was assessed by FACS analysis (Annexin V/Propidium iodide). In addition, the production of the DAMPs characteristic of the ICD (secreted adenosine triphosphate (ATP), ecto-calreticulin (ecto-CALR), and extracellular High Mobility Group Box 1 (HMGB1)) and of two additional DAMPs (ecto-heat shock protein 70 (ecto-HSP70) and 90 (ecto-HSP90)) were determined. The ENLITEN ATP Assay system was used to measure the secreted-ATP. Ecto-(CRT, HSP70 and HSP90) were assessed by FACS analysis and HMGB1 by ELISA assay. Results - For all the tested cell lines treated with HfO2-NP and RT, a marked increase of apoptosis and necrosis was demonstrated, compared to cells treated with RT alone. In addition, higher levels of DAMPs (ecto-CRT, ecto-HSP70, ecto-HSP90, secreted ATP and extracellular HMGB1) were measured in the cancer cells treated with HfO2-NP and RT when compared to cancer cells exposed to RT. Conclusion - HfO2-NP has demonstrated its capacity to kill cancer cells more efficiently than radiotherapy alone. HfO2-NP, administered via a single intratumor injection, is currently evaluated in clinical trials including soft tissue sarcoma (phase II/III), head and neck, prostate, liver and rectum cancers (phase I) and would permit to improve the local control of tumors, a crucial parameter for the cure and survival of patients. Here, we further show that the superior ability of HfO2-NP and RT treatment to generate ICD would prime an antitumor immune response with more effectiveness than RT alone can do, converting the tumor into an actual in situ vaccine. Thus, this transformation by HfO2-NP of immunologically “cold” tumors into “hot” tumors would open a new avenue for the use of immune checkpoint inhibitors across oncology, particularly for non- and poor-responder patients. Citation Format: Julie Marill, Naeemunnisa Mohamed, Audrey Darmon, Laurent Levy, Elsa Borghi, Agnès Pottier, Sébastien Paris. Hafnium oxide nanoparticles with radiotherapy induce immunogenic cell death [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr LB-A30.

Biodegradable multi-walled carbon nanotubes trigger anti-tumoral effects.

Carbon nanotubes are of huge biotechnological interest because they can penetrate most biological barriers and, inside cells, can biomimetically interact with the cytoskeletal filaments, triggering anti-proliferative and cytotoxic effects in highly dividing cells. Unfortunately, their intrinsic properties and bio-persistence represent a putative hazard that relapses their application as therapies against cancer. Here we investigate mild oxidation treatments to improve the intracellular enzymatic digestion of MWCNTs, but preserving their morphology, responsible for their intrinsic cytotoxic properties. Cell imaging techniques and confocal Raman spectroscopic signature analysis revealed that cultured macrophages can degrade bundles of oxidized MWCNTs (o-MWCNTs) in a few days. The isolation of nanotubes from these phagocytes 96 hours after exposure confirmed a significant reduction of approximately 30% in the total length of these filaments compared to the control o-MWCNTs extracted from the cell culture medium, or the intracellular pristine MWCNTs. More interestingly, in vivo single intratumoral injections of o-MWCNTs triggered ca. 30% solid melanoma tumour growth-inhibitory effects while displaying significant signs of biodegradation at the tumoral/peri-tumoral tissues a week after the therapy has had the effect. These results support the potential use of o-MWCNTs as antitumoral agents and reveal interesting clues of how to enhance the efficient clearance of in vivo carbon nanotubes.

TMOD-12. AN ONCOLYTIC MEASLES VIRUS SENSITIVE GROUP 3 MEDULLOBLASTOMA MODEL IN IMMUNE-COMPETENT MICE

Modified measles virus (MV) has demonstrated oncolytic efficacy in xenograft models of multiple tumor types using human cells in immune-deficient mice. However, MV does not grow in murine cells, thus, no murine tumor cell line that is oncogenic, grows in immune-competent mice, and is infectable by MV exists. The lack of such a model prevents an examination of the effect of anti-MV immunity and other possible effects of the immune system on MV oncotherapy. We have developed a murine Group 3 medulloblastoma cell line that allows replication of, and is killed by, MV in-vivo. Cerebellar stem cells isolated from P6 human CD46-transgenic immune-competent mice were transduced to express Sendai virus C-protein, c-Myc-Td tomato and GFI1B-GFP proteins. The cell line stably expresses higher levels of C-myc and GFI1B proteins but identical levels of N-myc and p53 when compared to unmodified cerebellar stem cells. Measles virus infects and replicates in the cell line, and cells are killed in a dose and time dependent manner with 55%, 85% and 92% cell death at MOI of 0.1, 1 and 10 respectively after 96h of MV infection. The cells express stem cell makers and NPR3, an established marker for the group 3 subtype of medulloblastoma. This cell line is highly tumorigenic when orthotopically implanted into the brain of syngeneic immune-competent mice. A single intratumoral injection of MV results in significant prolongation of median survival compared to mice injected with heat-killed virus (P=0.0027). Sixty percent of MV-treated mice did not die during the period of study and showed no evidence of tumor at autopsy. Autopsy of brains from inactivated virus treated animals revealed tumors resembling group 3 medulloblastoma in all mice. This is the first cell line and tumor model of any type available for testing the effect of an intact immune system on MV therapy.

A hydrogel matrix prolongs persistence and promotes specific localization of an oncolytic adenovirus in a tumor by restricting nonspecific shedding and an antiviral immune response.

Currently, intratumoral injection of an oncolytic adenovirus (Ad) is the conventional administration route in clinical trials. Nonetheless, the locally administered Ad disseminates to the surrounding nontarget tissues and has short biological activity due to immunogenicity of Ad, thus necessitating multiple injections to achieve a sufficient therapeutic index. In the present study, a tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-expressing oncolytic Ad (oAd-TRAIL) was encapsulated in a gelatin hydrogel (oAd-TRAIL/gel) to enhance and prolong antitumor efficacy of the virus after a single intratumoral injection. oAd-TRAIL/gel showed greater antitumor efficacy than naked oAd-TRAIL did due to enhanced and prolonged intratumoral accumulation of Ad up to a 20-day period, showing potent induction of apoptosis and inhibition of tumor cell proliferation. Furthermore, the gel system effectively prevented shedding of oncolytic Ad from the injection site to hepatic and other healthy tissues. oAd-TRAIL/gel treatment resulted in a markedly weaker antiviral immune response against Ad relative to naked oAd-TRAIL, further contributing to prolonged persistence of the oncolytic Ad in tumor tissue. Moreover, the hydrogel matrix preserved oAd-TRAIL's ability to induce an antitumor immune response, resulting in higher intratumoral infiltration by CD4+/CD8+ T cells. Taken together, these findings show that single intratumoral administration of the Ad/hydrogel modality may prolong and potentiate the therapeutic efficacy of Ad, modulate the immune reaction in favor of the virotherapy, and enhance intratumoral localization of the virus, ultimately overcoming limitations of oncolytic virotherapy revealed in recent clinical trials.

Blockade of transforming growth factor-β signaling enhances oncolytic herpes simplex virus efficacy in patient-derived recurrent glioblastoma models.

Despite the current standard of multimodal management, glioblastoma (GBM) inevitably recurs and effective therapy is not available for recurrent disease. A subset of tumor cells with stem-like properties, termed GBM stem-like cells (GSCs), are considered to play a role in tumor relapse. Although oncolytic herpes simplex virus (oHSV) is a promising therapeutic for GBM, its efficacy against recurrent GBM is incompletely characterized. Transforming growth factor beta (TGF-β) plays vital roles in maintaining GSC stemness and GBM pathogenesis. We hypothesized that oHSV and TGF-β inhibitors would synergistically exert antitumor effects for recurrent GBM. Here we established a panel of patient-derived recurrent tumor models from GBMs that relapsed after postsurgical radiation and chemotherapy, based on GSC-enriched tumor sphere cultures. These GSCs are resistant to the standard-of-care temozolomide but susceptible to oHSVs G47Δ and MG18L. Inhibition of TGF-β receptor kinase with selective targeted small molecules reduced clonogenic sphere formation in all tested recurrent GSCs. The combination of oHSV and TGF-βR inhibitor was synergistic in killing recurrent GSCs through, in part, an inhibitor-induced JNK-MAPK blockade and increase in oHSV replication. In vivo, systemic treatment with TGF-βR inhibitor greatly enhanced the antitumor effects of single intratumoral oHSV injections, resulting in cures in 60% of mice bearing orthotopic recurrent GBM. These results reveal a novel synergistic interaction of oHSV therapy and TGF-β signaling blockade, and warrant further investigations aimed at clinical translation of this combination strategy for GBM patients.

A phase 1 trial of NBTXR3 nanoparticles activated by intensity-modulated radiation therapy (IMRT) in the treatment of advanced-stage head and neck squamous cell carcinoma (HNSCC).

6080 Background: Functionalized hafnium oxide nanoparticles (NBTXR3) have been developed as selective radioenhancers, which may represent a breakthrough approach for the local treatment of solid tumors. The high electron density of the nanoparticles, when exposed to radiotherapy (RT), allow the absorption/deposition of a high radiation dose within the tumor cells, to physically kill the cells and possibly improve outcome. A phase I trial was implemented for the treatment of locally advanced HNSCC in patients (pts) older than 65 years who cannot receive cisplatin. Methods: Pts received a single intratumor (IT) injection of NBTXR3, volume dose levels escalated at 5%, 10%, 15% and 22% of baseline tumor volume, followed by RT (IMRT, 70Gy/ 35 fractions / 7 weeks). Primary endpoints included feasibility of the IT implantation and safety. Secondary endpoints included IT residency of NBTXR3 using CT scan and RECIST 1.1 response. Results: Enrollment was completed for volume 5%, 10%, and 15% (11 pts) and 1 patient at volume dose level 22%. Feasibility of the IT injection was confirmed. The treatment was easily administered, was safe with no SAE, or early DLT, which allowed the pts for completion of the planned RT schedule. Adverse events related to the injection procedure included grade 1-2 injection pain (1 pt), and tumor hemorrhage (1 pt). Results demonstrated that a single injection of NBTXR3 provides adequate bioavailability of NBTXR3 IT over seven weeks of RT. No leakage of NBTXR3 to the adjoining healthy tissues was observed. Preliminary results of antitumor activity according to RECIST 1.1 are presented below: 11 evaluable pts, 10 showed complete or partial response (RECIST 1.1) including, 1/5 complete response at dose levels ≤ 10% and 3/6 complete responses at dose levels > 10% Follow up results with duration of response and tolerance will be disclosed. Conclusions: Injection of NBTXR3 was safe and well tolerated. All pts received the planned RT. Clinical trial information: NCT01946867.

Phase 1b open-label randomized study of the oncolytic adenovirus DNX-2401 administered with or without interferon gamma for recurrent glioblastoma.

2002 Background: DNX-2401 is a replication-competent, tumor-selective, oncolytic adenovirus with enhanced infectivity that causes durable tumor control by killing tumor cells and eliciting antitumor immunity. To increase immune activation, a phase 1b randomized study of intratumoral DNX-2401 alone versus DNX-2401 with interferon gamma (IFN) was conducted. Methods: A total of 27 patients with biopsy-confirmed glioblastoma at first or second recurrence received a single intratumoral injection of 3e10 vp DNX-2401. Patients were randomized in a 2:1 ratio to receive 50 mcg/m2 of subcutaneous IFN (Actimmune) Q3W initiated 14 days after DNX-2401 or to be followed without further treatment for safety and survival. Results: Twenty-seven (27) patients were enrolled following first (59%) or second (41%) recurrence having previously failed surgery, radiation, and temozolomide (100%). The median longest tumor diameter was 40 mm (range 20-77 mm). Patients were randomized to DNX-2401 followed by IFN (n = 18) or to DNX-2401 alone (n = 9). Due to the poor tolerability of IFN, the median duration of treatment was only 6 weeks (range 0-30 weeks), and two patients did not initiate treatment as scheduled due to early clinical deterioration. The most frequent grade 3-4 AEs across treatment groups were fatigue, headache, and seizures consistent with pre-existing symptoms, underlying disease and/or surgery. Based upon a preliminary intent-to-treat analysis, IFN did not appear to provide additional benefit. However, OS-12 and OS-18 for all patients enrolled was 33% and 22%, respectively regardless of treatment assignment. Three patients remain alive at 19, 21, and 22 months (DNX-2401, n = 1; DNX-2401 + IFN, n = 2). Interestingly, 50% of patients with a baseline tumor diameter of ≤ 42 mm survived beyond 12 months, potentially identifying a sub-population of patients that may live longer following intratumoral DNX-2401. Conclusions: DNX-2401 was well tolerated as monotherapy. Although the addition of IFN did not improve survival, clinical activity following a single injection of DNX-2401 is encouraging and supports an ongoing Phase II study of DNX-2401 for recurrent glioblastoma. Clinical trial information: NCT02197169.

Thermally Triggered in Situ Assembly of Gold Nanoparticles for Cancer Multimodal Imaging and Photothermal Therapy.

The assembly of gold nanoparticles (AuNPs) to AuNP assemblies is of interest for cancer therapy and imaging. Herein we introduce a new and general paradigm, thermally triggered AuNP assembly, for the development of novel intelligent platforms for cancer photothermal therapy (PTT) and multimodal imaging. Site-specific conjugation of a thermally sensitive elastin-like polypeptide (ELP) to AuNPs yields thermally sensitive ELP-AuNPs. Interestingly, ELP-AuNPs can in situ form AuNP assemblies composed of short necklace-like gold nanostructures at elevated temperatures and thus show strong near-infrared light absorption and high photothermal effect. These thermally responsive properties of ELP-AuNPs enable simultaneous photothermal/photoacoustic/X-ray computed tomographic imaging and PTT of melanoma after single intratumoral injection of ELP-AuNPs. The thermally triggered assembly of a variety of nanoparticles with optical, electronic, and magnetic properties into nanoparticle assemblies may open new ways for the establishment of intelligent platforms for various applications in biomedicine.

Antitumor efficacy of Auger electron emitter 111In delivered by modular nanotransporter into the nuclei of cells with folate receptor overexpression.

A new modular nanotransporter (MNT) for the delivery of anticancer agents into the nuclei of cells with folate receptor overexpression was created. An effective method for acceding labeling of this MNT with Auger electron emitter 111In has been developed. A significant therapeutic effect was observed after a single intratumoral injection of the new 111In-labeled MNT to mice grafted with human cervical carcinoma characterized by folate receptor overexpression.

Abstract A28: Adenoviruses up-regulate IL17F, but not IL17A, and activate NK cells, with potential impact on oncolytic adenovirus efficacy

Abstract Oncolytic viruses (OVs) are a new class of anti-cancer agent. They infect and replicate selectively within malignant cells, whilst sparing normal cells. OVs disrupt chemokine and cytokine networks, which may influence clinical efficacy. This study investigates the role of innate immune responses, in particular IL17F and Natural Killer cells (NK), on the efficacy of oncolytic adenoviruses. A transcriptional array (Qiagen RT2 Profiler) of 84 human chemokines and cytokines revealed highly consistent changes (r=0.623, p<0.0001) following infection of ovarian cancer lines (TOV21G, OVCAR4) by the E1A CR2-deleted oncolytic adenovirus dl922-947. The most highly upregulated cytokine in both cells was IL17F (fold change=166.9 in TOV21G, p<0.0001, and 97.6 in OVCAR4, p<0.05), whilst CXCL1 and CCL2 were the most down-regulated. Similarly, an increase in IL17F transcription was seen after dl922-947 infection in HeLa cells (fold change=4.3, p<0.05) and after Ad5 wild-type infection in OVCAR4 (fold change=18.3, p<0.01). By ELISA, an increase in IL17F production was also observed after dl922-947 infection in TOV21G (mean IL17F was 4930pg/106 cells for dl922-947 versus 1167pg/106 for mock infection, n=2 in triplicates, p<0.05). We also observed increased transcription (median fold-change=91.5, p<0.05) and translation (median 2086pg/106 for dl922-947 vs 1381pg/106 for mock infection, p<0.05) of IL17F in 6 primary lines derived from ascites of patient with ovarian cancer, suggesting immediate clinical relevance of our findings. As human adenoviruses do not replicate in mice, HeLa subcutaneous xenografts in CD1 nu/nu mice were used to evaluate the infiltration of immune cells after dl922-947 infection. Tumors were harvested 48 hours following a single intra-tumoral injection of dl922-947 (1010 particles). IL17F transcription increased significantly in virus-treated tumors (mean fold-change=1 for mock-infected, n=5, vs 10.7 for dl922-947-infected, n=7), accompanied by a significant neutrophil infiltration (as detected by NIMP-R14, which binds Ly6G and Ly6C; median histoscores 2 and 16.5 for mock and dl922-947 infected tumors, respectively, p<0.05). We are currently generating TOV21G IL17F-/- cells using CRISPR-Cas9 technology, which will be used to evaluate potential changes in dl922-947 efficacy in vitro and in vivo. NK have potential impact on oncolytic virus efficacy (1). The interaction between NK and dl922-947 was evaluated in vitro using peripheral blood NK from health donors. Significant increases in CD107a+ NK, a degranulation marker, and interferon-Υ production were observed after co-culture with dl922-947-infected TOV21G, compared to co-culture with mock-infected TOV21G, by flow cytometry and ELISA, respectively (CD107a in 9.0% vs 1.8% of total NK, p<0.01 and interferon-Υ were 8559 +/-356pg/mL vs 4 +/-1pg/mL, respectively). Furthermore, Ad-CMV-GFP, an E1-deleted Ad5 vector, infects ovarian cancer lines but not NK-92 cells (92% vs 0% infected, respectively, p<0.001), suggesting the activation observed was not due to direct infection of NK by Ad5. We will investigate alteration of NK cytotoxicity against ovarian cancer cells after exposure to dl922-947 infection by calcein cytotoxicity assays, using both peripheral blood NK and NK from ascites of women with ovarian cancer. Any change in efficacy of dl922-947 with or without NK depletion in vivo will be assessed using ovarian cancer (TOV21G) intraperitoneal xenografts in CD1 nu/nu mice. To conclude, adenovirus infection leads to distinctive changes in chemokines and cytokines, as well as activation of NK. In particular, IL17F, but not IL17A, was up-regulated after adenovirus infection. The influence of these observations on oncolytic adenovirus efficacy is currently being evaluated. 1. Alvarez-Breckenridge CA, et al. Nat Med. 2012 Dec;18(12):1827-34. Citation Format: Elaine YL Leung, Melanie Weigert, Josephine Walton, Darren Ennis, Dimitris Athineos, Suzanne Dowson, Chris Hansell, Karen Blyth, Gerard Graham, Iain McNeish. Adenoviruses up-regulate IL17F, but not IL17A, and activate NK cells, with potential impact on oncolytic adenovirus efficacy. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr A28.

First-in-Human Study Testing a New Radioenhancer Using Nanoparticles (NBTXR3) Activated by Radiation Therapy in Patients with Locally Advanced Soft Tissue Sarcomas

Purpose: This phase I study aimed to determine the recommended dose (RD), safety profile, and feasibility of a procedure combining intratumoral injection of hafnium oxide nanoparticles (NBTXR3; a radioenhancer) and external beam radiotherapy (EBRT) for preoperative treatment of adults with locally advanced soft tissue sarcoma (STS).Experimental Design: Patients had a preoperative indication of EBRT for STS of the extremity or trunk. Baseline tumor volume (TV) was calculated by MRI. NBTXR3 was injected percutaneously into tumors at 53.3 g/L. Dose escalation was based on four levels equivalent to 2.5%, 5%, 10%, and 20% of baseline TV. NBTXR3 was visualized in the tumor 24 hours postinjection, and EBRT was initiated (50 Gy over 5 weeks). Surgery was performed 6 to 8 weeks after EBRT completion.Results: Twenty-two patients completed NBTXR3 injection, EBRT, and surgery and were followed for a median 22 months (range, 6-40). At NBTXR3 20% of TV, two dose-limiting toxicities occurred: injection-site pain and postoperative scar necrosis. The RD was defined as 10%. No leakage of NBTXR3 into surrounding tissues occurred; intratumor NBTXR3 levels were maintained during radiotherapy. At the RD, median tumor shrinkage was 40% (range 71% shrinkage, 22% increase); median percentage of residual viable tumor cells was 26% (range, 10%-90%). Patients receiving 20% of TV demonstrated pathologic complete responses. Seven grade 3 adverse events occurred, which were reversible.Conclusions: A single intratumoral injection of NBTXR3 at 10% of TV with preoperative EBRT was technically feasible with manageable toxicity; clinical activity was observed. Clin Cancer Res; 23(4); 908-17. ©2016 AACR.

A reconstituted thermosensitive hydrogel system based on paclitaxel-loaded amphiphilic copolymer nanoparticles and antitumor efficacy

Combination delivery systems composed of injectable hydrogels and drug-incorporated nanoparticles are urgently in regional cancer chemotherapy to facilitate efficient delivery of chemotherapeutic agents, enhance antitumor efficiency, and decrease side effects. Here, we developed a novel thermosensitive amphiphilic triblock copolymer consisting of methoxy poly(ethylene glycol), poly(octadecanedioic anhydride), and d,l-lactic acid oligomer (PEOALA), built a combination system of thermosensitive injectable hydrogel PTX/PEOALAGel based on paclitaxel (PTX)-loaded PEOALA nanoparticles (NPs). PTX/PEOALAGel could be stored as freeze-dried powders of paclitaxel-loaded PEOALA NPs, which could be easily redispersed into the water at ambient temperature, and form a hydrogel at the injected site in vivo. The in vitro cytotoxicity of PTX/PEOALAGel showed no obvious cytotoxicity in comparison with Taxol® against MCF-7 and HeLa cells. However, the in vivo antitumor activity showed that a single intratumoral injection of the PTX/PEOALAGel formulation was more effective than four intravenous (i.v.) injections of Taxol® at a total dosage of 20 mg/kg in inhibiting the growth of MCF-7 tumor-bearing Balb/c mice, and the inhibition could be sustained for more than 17 d. The pharmacokinetic study demonstrated that the intratumoral injection of PTX/PEOALAGel could greatly decrease the systemic exposure of PTX, as confirmed by the rather low plasma concentration, and prolonged circulation time and enhanced tumor PTX accumulation, implying fewer off-target side effects. In summary, the PTX/PEOALAGel combination local delivery system could enhance tumor inhibition effect and tumor accumulation of PTX, and lower the systemic exposure. So, the reconstituted PTX/PEOALAGel system could potentially be a useful vehicle for regional cancer chemotherapy.

Doxorubicin Conjugated to Glutathione Stabilized Gold Nanoparticles (Au-GSH-Dox) as an Effective Therapeutic Agent for Feline Injection-Site Sarcomas-Chick Embryo Chorioallantoic Membrane Study.

Feline injection-site sarcomas are malignant skin tumours with a high local recurrence rate, ranging from 14% to 28%. The treatment of feline injection-site sarcomas includes radical surgery, radiotherapy and/or chemotherapy. In our previous study it has been demonstrated that doxorubicin conjugated to glutathione-stabilized gold nanoparticles (Au-GSH-Dox) has higher cytotoxic effects than free doxorubicin for feline fibrosarcoma cell lines with high glycoprotein P activity (FFS1, FFS3). The aim of the present study was to assess the effectiveness of intratumoural injection of Au-GSH-Dox on the growth of tumours from the FFS1 and FFS3 cell lines on chick embryo chorioallantoic membrane. This model has been utilized both in human and veterinary medicine for preclinical oncological studies. The influence of intratumoural injections of Au-GSH-Dox, glutathione-stabilized gold nanoparticles and doxorubicin alone on the Ki-67 proliferation marker was also checked. We demonstrated that the volume ratio of tumours from the FFS1 and FFS3 cell lines was significantly (p < 0.01) decreased after a single intratumoural injection of Au-GSH-Dox, which confirms the positive results of in vitro studies and indicates that Au-GSH-Dox may be a potent new therapeutic agent for feline injection-site sarcomas.

Facile fabrication of a resveratrol loaded phospholipid@reduced graphene oxide nanoassembly for targeted and near-infrared laser-triggered chemo/photothermal synergistic therapy of cancer in vivo.

Resveratrol (Res) has emerged as an extremely promising natural molecule due to its vast therapeutic prospects. However, the potential of the drug is immensely hindered by several limiting factors including poor water solubility, limited chemical stability and high metabolization. Herein we report a facile synthesis of a Res-loaded folate-terminated PEG-phospholipid coated reduced graphene oxide nanoassembly (FA-PEG-Lip@rGO/Res) by simply sonicating Res and rGO in FA-PEG linked liposome (FA-PEG-liposome) suspensions. The as-obtained FA-PEG-Lip@rGO/Res exhibits a nanoscale size (148 ± 7 nm), a negative surface potential (-23.6 mV), an excellent drug loading (69.5 ± 4.3%), a high drug entrapment efficiency (86.9 ± 5.6%), good monodispersity and controlled release. Additionally, the nanoassembly can protect Res from UV-light induced instability. Owing to the folate mediated targeted delivery, the robust FA-PEG-Lip@rGO/Res can deliver loaded Res to human MCF-7 breast cancer cells with high specificity and excellent efficiency. The cell toxicity viability shows that unloaded FA-PEG-Lip@rGO has no cytotoxicity, confirming its suitability as a drug vehicle. Furthermore, a systematic in vivo study shows that, under near-infrared (NIR) laser irradiation, FA-PEG-Lip@rGO/Res exhibits highly efficient combined chemotherapy and photothermal therapy to eradicate xenografted tumor with a single dose intratumoral (i.t.) injection. Thus, a facile, stable, biocompatible, and highly-effective Res delivery system has been developed, which may greatly advance the application of Res in biomedical research.

Combination of bacteriolytic therapy with magnetic field for Ehrlich tumour treatment.

Referable to the limited response of the current available cancer treatment modalities, new effective cancer fighting treatments are needed. This work investigates the efficiency of intratumoural injection of Pseudomonas aeruginosa bacteria combined with a local tumour exposure to extremely low frequency square pulsed magnetic field (ELF SPMF) in the mouse Ehrlich tumour. 64 Ehrlich ascites tumour-implanted female albino BALB/C mice were equally split up into 4 groups. Group 1 (GP1) was the positive control group. Group 2 (GP2) received a single intratumoural injection of P. aeruginosa bacteria. Group 3 (GP3) was exposed to ELF SPMF for tumour local exposure. Group 4 (GP4) was treated with P. aeruginosa intratumoural injection followed by local exposure of the tumour to ELF SPMF. Treatment monitoring was evaluated using ultrastructural examination, flow cytometry analysis in addition to the measurement of tumour dielectric properties. Tumour cell apoptosis was obvious in GP2 and GP4, but, with higher severity and percentages in GP2. Tumour biophysical properties revealed a significant increase in static conductivity σS of GP2, and decreases in dielectric increment Δɛ´of both GP2 and GP4 compared to the GP1. Unfortunately, GP2 mice showed severe signs of toxicity. We advocate the utilization of the combination of P. aeruginosa and SPMF to yield the most effective antitumour agent with less bacteria-related toxicity.

Mesoporous carbon nanoshells for high hydrophobic drug loading, multimodal optical imaging, controlled drug release, and synergistic therapy.

Loading and controlled release of sufficient hydrophobic drugs to tumor cells has been the bottleneck in chemotherapy for decades. Herein we report the development of a fluorescent and mesoporous carbon nanoshell (FMP-CNS) that exhibits a loading capacity for the hydrophobic drug paclitaxel (PTX) as high as ∼80 wt% and releases the drug in a controllable fashion under NIR irradiation (825 nm) at an intensity of 1.5 W cm-2. The high drug loading is primarily attributed to its mesoporous structure and to the supramolecular π-stacking between FMP-CNSs and PTX molecules. The FMP-CNS also exhibits wavelength-tunable and upconverted fluorescence properties and thus can serve as an optical marker for confocal, two-photon, and near infrared (NIR) fluorescence imaging. Furthermore, our in vitro results indicate that FMP-CNSs demonstrate high therapeutic efficacy through the synergistic effect of combined chemo-photothermal treatment. In vivo studies demonstrate marked suppression of tumor growth in mice bearing rat C6 glioblastoma after administration with a single intratumoral injection of PTX-loaded FMP-CNS.