Search

BACKGROUND Colorectal cancer (CRC) is the third most commonly diagnosed cancer (10% of new cases in 2020) and the second leading cause of cancer-related death (9.4%) worldwide. CRC is often detected at late stages, with 38% of metastasis cases at diagnosis. This makes the development of efficient treatments crucial. Recent tremendous progress sets immunotherapy as a treatment option and opens multiple ways to address therapeutic challenges in CRC. Accordingly, we have previously developed therapeutic cancer vaccine based on stimulated tumor cells (STC) technology, that have already shown efficacy in immunocompetent mouse models. Same strategy was used in this study to generate the STC-1010 therapeutic vaccine, a novel human therapeutic CRC vaccine derivate from 3 human CRC cell lines, HCT116, HT29 and LOVO exposed to irradiation, heat shock, chemotherapy agents and haptenized. METHODS We evaluate STC-1010 for its potential to favor an immune stimulatory response on human monocytes-derived dendritic cells (moDCs) from 2 different donors through i) a derived Mixed Lymphocyte Reaction (dMLR) assay, ii) the assessment of their cytokine profile, iii) the evaluation of their capacity to activate autologous CD8+ T cells and finally iv) to promote apoptosis of three CRC cell lines (HCT116, HT29 and LS-174T). RESULTS We showed that STC-1010 induced IL-8 and IL-12 production, and reduced IL-10 during moDCs maturation. In addition, dendritic cells (DCs) exposed to STC-1010 during the maturation enhanced Interferon gamma (IFNg) production by CD8+ T cells (p=0,06 for donor 1 and p=0,0004 for donor 2) and amplified their anti-tumor activity, in combination with LPS/IFNg and CD40L. CD8+ T cells primed with STC-1010-treated DCs promote massive apoptosis of HCT116 and HT29 cells compared to the condition without STC-1010 (p CONCLUSION Taken together, our results showed that Brenus STC-1010 human vaccine is an efficient strategy to educate immune system and promote the CRC cells death in vitro lending further support in favor of STC technology based on physical or chemical stimulation and haptenization to generate human cancer therapeutic vaccine. Citation Format: Alban Bessede, George Alzeeb, Corinne Tortorelli, Jean-Philippe Guegan, Christophe Rey, Lionel Chalus, Benoit Pinteur, Paul Bravetti, Antoine Italiano. STC-1010 a new therapeutic vaccine promotes tumor cell death [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB224.

BACKGROUND: Colorectal cancer (CRC) is the second-most deadly cancer. Therapeutic resistance to immuno-oncology drives the need for new treatments. Stimulated tumor cell (STC) vaccine (Brenus Pharma) is composed of selected tumor cell lines, stimulated to overexpress tumor-associated or tumor-specific antigens and neoantigens including resistance factors. Haptenization of these proteins forms an immunogenic complex which stimulate the immune system to recognize and target the patient’s tumor cells expressing same resistance factors. We report in vivo results of STC-1010 vaccine, on human CRC adenocarcinoma from HT29 cell using chorioallantoic membrane (CAM) assay developed by Inovotion in immune reactive model. METHODS: This study was carried out in 2 steps: Firstly, three batches of naïve chicken embryos were stimulated by injections of STC1010 at Embryo Development Day (EDD) 11 and EDD13. At EDD18 of each batch, chicken peripheral blood mononuclear cells (PBMCs) were collected and used as anti-tumor reagent to treat respectively, at EDD 11, EDD 13 and EDD16 chicken embryos xenografted with HT29 cells. Activation of PBMCs was evaluated by IL2 and IL12 secretion quantified by ELISA. At EDD18, i.e., 9 days post-graft, in ovo anti-tumor efficacy was evaluated by tumor weight, metastatic invasion (qPCR analysis of human Alu sequence in lower CAM) and quantification of tumor-infiltrating by CD8, CD4, IFN-gamma, Perforin and TNF-alpha. RESULTS: Compared to negative control, STC-1010 vaccine induced: 1) significant increase of IL-12 and IL-2 secretion in peripheric blood during the generation of all three batches of PBMCs, confirming previous results (IL-12: +52%, p=0.0003 ; IL-2: +482%, p=0.0033); 2) a significant expression of IFN-gamma in tumor (+130,83%, p=0.0185); 3) a tendency to increase infiltrating cells: CD4+: +79,2%, CD8+: +29,4% , Perforin: +105,5%, TNFα : +78,63% confirmed by immunohistochemistry and translated into 4) a significant increase of tumor necrosis (p = 0.0267); and 5) a tendency of metastasis regression (-49%); with 6) no embryonic toxicity/mortality (daily evaluation of embryonic viability) induced by STC-1010. CONCLUSION: This in ovo study confirms efficacy of the STC-1010 observed in previous CRC syngeneic models and gives more insight about STC mechanism of action with the activation and maturation of dendritic cells, induction of CD8+ and LTh1 against tumor as the main driver of the response, all without toxicity. Inovotion’s CAM model could be used for indication screening and as a pre-proof-of-concept before syngeneic model study. Citation Format: Yan Wang, Arnaud Peyronnier, Benoit Pinteur, Lionel Chalus, Corinne Tortorelli, Paul Bravetti, Jean Viallet, François Ghiringhelli, Philippe Fornies. Inovative in vivo (in ovo) CAM model to predict efficacy and mode of action of a new antitumor vaccine stc-1010 on human colorectal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6791.

BACKGROUND: Colorectal cancer (CRC) is the second most common solid organ cancer. Immunotherapy has recently emerged as a promising treatment for the MSI-H/dMMR metastatic CRC. However, MSS patients still cannot benefit from this therapy. STC therapeutic vaccine (Brenus Pharma) is composed of selected tumor cell lines, stimulated to overexpress TAA/TSA and neoantigens including resistant factors that are further haptenized to form immunogenic hapten-protein complex. This educates the immune system to recognize and target the patient’s tumor cells expressing the same resistance factors. We report results of the transcriptomic changes induced by the different treatment and culture conditions on each cell line; highlighting the potential of this three cell lines vaccine to sensitize immunotherapy-resistant tumors to anti-PD1 therapy. STUDY DESIGN and METHODS: In this study, three cell lines have been cultured: HCT116, HT29, and LoVo. Each of these cell lines has been subjected to four growth conditions: RCB) the parental cell line cultured in standard medium 10% SVF or MCB) 2% SVF; DSA) MCB condition plus low-dose irradiation and heat shock or DSB) cultured with chemotherapy exposure. STC-1010 vaccine (DP) is the mix of the haptenized DSA and DSB culture conditions of these three cell lines. Total RNA of all those samples have been extracted and sequenced on Illumina NextSeq 500. Sequences have been aligned against the GRCh38 reference genome using Kallisto v0.46.1 software. Differential abundance and enrichment analyses have been performed with DESeq2 v1.34.0 and clusterProfiler v4.2.0 R packages, respectively. RESULTS: A first overview of the whole-transcriptome shows that each cell line has its very own profile and that the DP condition reflects a balanced mixture of the three transcriptomes. HT29-DSA condition displays 1048 differentially expressed genes (DEG) compared to MCB condition and altered 59 pathways, whereas the HT29-DSB condition shows 1288 DEG and altered 46 pathways. Both conditions show an overexpression of DNA repair pathways. LoVo-DSA condition displays 1044 DEG compared to MCB condition and altered 59 pathways, especially DNA repair pathways. HT29-DSB condition shows 1791 DEG and altered 130 pathways, mostly impacting the tumor immunity. HCT116-DSA condition displays 407 DEG compared to MCB condition and altered 72 pathways, especially DNA repair pathways. HCT116-DSB condition shows 1824 DEG and altered 51 pathways. Both conditions show an overexpression of pathways involved in tumor immunity. CONCLUSION: Brenus STC vaccine based on physical and chemical stimulations and haptenization reveals a promising potential to sensitize MSS CRC immunotherapy resistant tumors to immune checkpoint inhibition therapy. Further studies are ongoing to profile and analyze the proteosurfaceome of each cell line. Citation Format: Corentin Richard, Sandy Chevrier, Lionel Chalus, Jeremy Forget, Benoît Pinteur, Paul Bravetti, Romain Boidot. Sensitizing potential of a novel stimulated and haptenized vaccine in immunotherapy resistant metastatic colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3566.

BACKGROUND: Metastatic colorectal cancer (mCRC) is one of the major causes of death worldwide. The relative therapeutic resistance of these populations to I/O drives the need for new treatment. STC-1010 (Brenus Pharma) therapeutic vaccine is developed by tumor cells stimulation to induce overexpression of TAA and neoantigens to mimic mCRC resistant cancer cells allowing education of the immune system to target the patient’s tumor cells harboring the same resistance factors. We report results of a study evaluating efficacy and safety of a 3 cell lines-based product namely “3CL-SH” (made of CT26, CMT93 and LTPA) physical stimulated (S=irradiation and heat shock) and haptenized (H) with immunostimulant in an anti-PD1 resistant MC38 colorectal tumor model grafted with its TME. METHODS: Female C57BL/6 mice bearing MC38 tumor model grown in vivo under anti-PD1 selection pressure (anti-PD1; 12.5 mg/kg; qw) to obtain MC38 resistant to anti-PD1 treatment (MC38 antiPD1R). Two sampled tumors from these mice were cut into fragment of 2 mm2 and reimplanted in the right flank of naïve syngenic mice. 5 groups (15 mice per group) were allocated to: G1) Control group: Isotype/placebo/vehicle G2) Anti-PD1/placebo/vehicule G3) Anti PD1/placebo-GM-CSF/endoxan G4) Isotype/3CL-SH-GM-CSF/endoxan G5) Anti-PD1/3CL-SH-GM-CSF/endoxan. Endoxan, vehicule and antibodies were administered by IP, vaccine or placebo subcutaneously. Overall survival (OS) and tumour growth (TG) were recorded until 1600 mm3 or safety endpoint. 5 mice per group were euthanized and sampled for immunophenotyping. In parallel, we conducted the identification and relative quantification of proteins expressed in 3CL-SH by LC-MS/MS and flow cytometry. RESULTS: Flow cytometry analysis shows that HSP-70 expression was significantly upregulated in each of the three cell lines of the 3CL-SH compared to untreated cells. LC-MS/MS analysis demonstrated that cell lines of 3CL-SH display overexpression of membrane proteins of interest such as Lamp 1, MDR1A/B and Fas Receptor. The group treated with 3CL-SH significantly improves the survival of mice bearing MC38PD1R tumor model vs the control group (Log-rank Mantel-Cox test, pvalue=0.0368) and we observed a non-benefit of the combination of 3CL-SH and anti-PD1 drug in concomitant injections. The immunophenotyping data show statistical increase in the infiltration of anti-tumor populations (CD8+ T cells, M1) in the tumors treated with 3CL-SH but also an increase in M2. No side effect or inflammatory reaction towards the 3CL-SH is evidenced. CONCLUSION: The 3CL-SH treatment presents a promising antitumor efficacy on the aggressive MC38 PD1R model, resulting in a significative gain of survival and anti-tumoral changes in the immune infiltrate of treated animals. More studies are needed to evaluate the benefit of a combination with ICI. Citation Format: Céline Gongora, Elsa Kress, Claudine Vermot-Desroches, Lionel Chalus, Jeremy Forget, Benoît Pinteur, Paul Bravetti, Charles Dumontet, Antoîne Italiano. Antitumor activity of a novel allogeneic colorectal cancer vaccine in C57BL/6 mice bearing MC38 anti-PD1 resistant colon carcinoma syngeneic model with TME [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2051.

BACKGROUND: Metastatic colorectal cancer (mCRC) is a major cause of death. Unmet medical need in immunotherapy is high for MSS patients and still present for MSI-H/dMMR patients. STC vaccine (Brenus Pharma) is composed of selected tumor cell lines, stimulated to overexpress TAA/TSA and neoantigens including resistant factors that are further haptenized to form immunogenic hapten-protein complex to educate the immune system to recognize and target the patient's tumor cells expressing the same resistance factors. We report results of two studies aiming to A) evaluate efficacy of a one cell line-based product (CT26) physical stimulated (S=irradiation and heat shock) and/or haptenized (H) w/o immunostimulant (IS=cyclophosphamide + mGM-CSF w/o BCG) and to B) investigate a potential increase of antitumoral effect of 3 cell lines vaccine (3CL-SH made of CT26, CMT-93, LTPA). STUDY DESIGN and METHODS: Female BALB/c mice were subcutaneously grafted with 5.104 CT26-WT cells. In study A, 9 groups (10 mice per group) are allocated to: G1) Control group, G2) IS, G3) CT26-S, G4) CT26-H, G5) CT26-SH, G6) CT26-S+IS, G7) CT26-H+IS, G8) CT26-SH+IS, G9) CT26-SH+IS+BCG. In study B, 5 groups (20 mice per group) are allocated to: G1) Control group, G2) CT26-SH + IS, G3) 3CL-SH, G4) 3CL-SH + IS once a week for 3 weeks and G5) 3CL-SH + IS twice a week for 4 weeks. Treatments were administered subcutaneously. Overall survival (OS) and tumor growth (TG) were recorded until 1000 mm3, safety endpoint or on D41 (study A) or D50 (study B). RESULTS: Stimulated cell-based treatments with IS (CT26-SH + IS) significantly increases OS compared to control group (Study A: G1/G8 p=0.0046 & study B: G1/G2 p=0.0023). Best mOS among groups is observed with 3CL-SH+IS (Study B: G1/G4 p CONCLUSION: Brenus STC vaccine based on physical stimulation and haptenization demonstrated a significant anticancer effect in mice with immunostimulant and confirmed a better efficacy of the 3 cell lines vaccine versus a single cell line vaccine. Further studies are ongoing to test the efficacy of STC vaccine in PD1 resistant preclinical model and in combination with SOC. Citation Format: Céline Gongora, Jacqueline Taleb, Benoît Pinteur, Lionel Chalus, Fanny De Luca, Paul Bravetti, François Ghiringhelli. Efficacy results of a novel vaccine composed of stimulated and haptenized tumors cells in Balbc mice grafted with murine colon adenocarcinoma CT26 cells [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P003.