Specific Antitumor Immune Response Research Articles

Long-Lasting, Fine-Tuned Anti-Tumor Activity of Recombinant Listeria monocytogenes Vaccine Is Controlled by Pyroptosis and Necroptosis Regulatory and Effector Molecules.

One of the main objectives of developing new anti-cancer vaccine strategies is to effectively induce CD8+ T cell-mediated anti-tumor immunity. Live recombinant vectors, notably Listeria monocytogenes, have been shown to elicit a robust in vivo CD8+ T-cell response in preclinical settings. Significantly, it has been demonstrated that Listeria induces inflammatory/immunogenic cell death mechanisms such as pyroptosis and necroptosis in immune cells that favorably control immunological responses. Therefore, we postulated that the host's response to Listeria-based vectors and the subsequent induction of CD8+ T cell-mediated immunity would be compromised by the lack of regulatory or effector molecules involved in pyroptosis or necroptosis. To test our hypothesis, we used recombinant L. monocytogenes carrying the ovalbumin gene (LM.OVA) to vaccinate wild-type (WT), caspase-1/11-/-, gsdmd-/-, ripk3-/-, and mlkl-/- C57Bl/6 mice. We performed an in vivo cytotoxicity assay to assess the efficacy of OVA-specific CD8+ T lymphocytes in eliminating target cells in wild-type and genetically deficient backgrounds. Furthermore, we evaluated the specific anti-tumor immune response in mice inoculated with the B16F0 and B16F0.OVA melanoma cell lines. Our findings demonstrated that while caspase-1/11 and GSDMD deficiencies interfere with the rapid control of LM.OVA infection, neither of the KOs seems to contribute to the early activation of OVA-specific CTL responses. In contrast, the individual deficiency of each one of these proteins positively impacts the generation of long-lasting effector CD8+ T cells.

Blockade of CD73 potentiates radiotherapy antitumor immunity and abscopal effects via STING pathway

Radiotherapy (RT) is a crucial treatment for colorectal cancer (CRC) patients, but it often fails to induce systemic antitumor immunity. CD73, an immunomodulatory factor, is upregulated after RT and associated with poor prognosis in CRC patients. This study aims to elucidate the mechanisms driving RT-induced CD73 upregulation in CRC and investigate how combining RT with CD73 blockade stimulates immune responses and induces abscopal effects. Findings revealed that RT-induced CD73 upregulation is mediated by the ataxia telangiectasia and Rad3-related (ATR) pathway and correlated with RT tolerance, as demonstrated through flow cytometry, immunofluorescence, and Western Blotting. Using flow cytometry and multicolor immunofluorescence, experiments demonstrated that in CRC subcutaneous tumor models, combination therapy reduces the infiltration of myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), and regulatory T cells (Tregs) while increasing dendritic cells (DCs) and CD8 + T cells, resulting in superior antitumor responses. Additionally, results from flow cytometry, Western Blot, and RNA sequencing demonstrated that combination therapy enhances the antigen-presenting ability of DCs and activates tumor antigen-specific CD8 + T cells, improving their function and delaying their depletion. The activation of the cGAS-STING and IFN-I pathways is crucial for this effect. In summary, the integration of RT with CD73 blockade effectively reverses the immunosuppressive TME and invigorates CD8 + T cell-driven, specific antitumor immune responses. These insights shed fresh light on the mechanisms governing the synergistic modulation of immunity by RT and CD73 blockade in CRC, offering promising avenues for the advancement of therapeutic strategies against CRC.

Tetradecanol-wrapped, CpG-loaded porous Prussian blue nanoimmunomodulator for photothermal-responsive in situ anti-tumor vaccine-like immunotherapy

Therapeutic vaccine becomes a promising strategy to fight cancer by enhancing and sustaining specific anti-tumor immune responses. However, its efficacy is often impeded by low immunogenicity, the immunosuppressive tumor microenvironment (TME), and immune-related adverse events. Herein, we introduce 1-tetradecanol (TD)-wrapped, CpG-loaded porous Prussian blue nanoparticles (pPBNPs-CpG@TD) as a nanoimmunomodulator to initiate photothermal-induced immunogenic cell death (ICD) and photothermal-responsive release of CpG for augmenting the ICD effect. It was revealed that the dual-photothermal action significantly potentiated the in situ anti-tumor vaccine-like immunotherapy in terms of enhanced immunogenicity, promoted dendritic cell maturation, and increased T lymphocyte infiltration, consequently eliciting a robust immune response for inhibiting both primary and rechallenge tumors on a subcutaneous 4T1 tumor-bearing mouse model. The development and use of photoactive nanoimmunomodulators represents a novel and effective strategy to boost immunogenicity and counteract immunosuppressive TME, marking a significant advancement in the realm of ICD-driven in situ anti-tumor vaccine-like immunotherapy.

T Cell-Engaging Bispecific Antibodies Targeting gp100 and PRAME: Expanding Application from Uveal Melanoma to Cutaneous Melanoma.

Uveal melanoma represents a rare and aggressive subtype of melanoma with limited treatment options and poor prognosis, especially in the metastatic setting. Tebentafusp, a bispecific fusion protein, offers a promising therapeutic approach by targeting gp100, an antigen highly expressed in uveal melanoma cells, and redirecting T cell-mediated cytotoxicity towards tumor cells. This review provides an overview of the preclinical and clinical data on tebentafusp in the management of metastatic uveal melanoma. We summarize the mechanism of action, clinical efficacy, safety profile, and ongoing research efforts surrounding this innovative immunotherapy. Preclinical studies have demonstrated the ability of tebentafusp to induce potent and specific anti-tumor immune responses against gp100-expressing uveal melanoma cells. Clinical trials have shown encouraging results, with tebentafusp exhibiting meaningful clinical activity in a subset of patients with metastatic uveal melanoma. Importantly, tebentafusp has also demonstrated a manageable safety profile. By specifically targeting tumor cells expressing gp100, tebentafusp offers a promising therapeutic avenue for individuals with metastatic uveal melanoma, meeting a significant clinical need in this context. Continued clinical trials will provide additional insights into the impact of tebentafusp on treatment-resistant metastatic cutaneous melanoma. Furthermore, we are exploring the potential of T cell engagers directed against the cancer testis antigen PRAME, which could have widespread utility in the treatment of cutaneous melanoma as well as other PRAME-expressing malignancies.

TG6050, an oncolytic vaccinia virus encoding interleukin-12 and anti-CTLA-4 antibody, favors tumor regression via profound immune remodeling of the tumor microenvironment

BackgroundTG6050 was designed as an improved oncolytic vector, combining the intrinsic properties of vaccinia virus to selectively replicate in tumors with the tumor-restricted expression of recombinant immune effectors to modify...

INT-1B3, an LNP formulated miR-193a-3p mimic, promotes anti-tumor immunity by enhancing T cell mediated immune responses via modulation of the tumor microenvironment and induction of immunogenic cell death.

microRNAs (miRNAs) are small, non-coding RNAs that regulate expression of multiple genes. MiR-193a-3p functions as a tumor suppressor in many cancer types, but its effect on inducing specific anti-tumor immune responses is unclear. Therefore, we examined the effect of our lipid nanoparticle (LNP) formulated, chemically modified, synthetic miR-193a-3p mimic (INT-1B3) on anti-tumor immunity. INT-1B3 inhibited distant tumor metastasis and significantly prolonged survival. INT-1B3-treated animals were fully protected against challenge with autologous tumor cells even in absence of treatment indicating long-term immunization. Protection against autologous tumor cell challenge was hampered upon T cell depletion and adoptive T cell transfer abrogated tumor growth. Transfection of tumor cells with our miR-193a-3p mimic (1B3) resulted in tumor cell death and apoptosis accompanied by increased expression of DAMPs. Co-culture of 1B3-transfected tumor cells and immature DC led to DC maturation and these mature DC were able to stimulate production of type 1 cytokines by CD4+ and CD8+ T cells. CD4-CD8- T cells also produced type 1 cytokines, even in response to 1B3-transfected tumor cells directly. Live cell imaging demonstrated PBMC-mediated cytotoxicity against 1B3-transfected tumor cells. These data demonstrate for the first time that miR-193a-3p induces long-term immunity against tumor development via modulation of the tumor microenvironment and induction of immunogenic cell death.

MDB-50. CAR-T CELL-DERIVED EXOSOMES LOADED WITH THERAPEUTIC SIRNA IS A PROMISING TECHNIQUE IN THE TREATMENT OF SUBGROUP 3 MEDULLOBLASTOMA

Abstract Medulloblastoma (MB) is a childhood life-threatening tumor that occurs in the cerebellum. This tumor showed resistance against several types of immunotherapies like anti-PD1, cancer vaccines, monoclonal antibodies (mAbs), and even CAR-T cells. Subgroup 3 MB is the worst threatening subtype that poorly responds to treatment. Interestingly, our data showed that the HLX gene a transcription factor that regulates cell growth is highly expressed in G3-MB and associated with poor prognosis. The siRNA-HLX inhibited tumor growth in vitro and in vivo and promisingly showed long survival in the immunocompetent mouse model. We developed CAR-T-Exosomes that can pass brain-blood barriers (BBB) and deliver therapeutic siRNA to the brain tumor. Further analysis revealed that CAR-T-Exosomes contain T cell cytotoxicity materials that can destroy tumor cells and induce anti-tumor immune response. Promisingly, the expression of HLX was significantly inhibited in the tumor cells and the anti-tumor immune response was enhanced. CAR-T-Exosomes have high safety and can induce anti-tumor response without stimulation of immunotoxicity side effects like cytokine release syndrome (CRS). In this study, we are highlighting anti-EPHA2-CAR-Exosomes as a highly specific type of tumor CAR-T-Exos immunotherapy due to a very low expression of EPHA2 in normal cells and overexpression in medulloblastoma, particularly G3-MB. Therefore, we speculate significant inhibition of tumor growth and activation of CTL effector cells in the tumor microenvironment. This study provides a new biological technique for delivering tumor suppressor RNAs and developing specific anti-tumor immune responses. Indeed, the promising safety of anti-EPHA2-CAR-T cell exosomes compared to cell-based immunotherapy.

Self‐Delivered Transformable Nanosystem Capable of Enhancing Photodynamic Effectiveness and Multi‐Target Ameliorating Immunosuppression for Treatment of Breast Cancer and Lung Metastasis

AbstractHomogeneous distribution and adequate accumulation of photosensitizer in tumor are essential for effective photodynamic therapy (PDT). However, the intricate tumor microenvironment (TME) often poses great challenges to the deep penetration and retention of therapeutic agents in tumor. Moreover, the important effect of PDT to induce specific antitumor immune response is impeded by multiple immunosuppressive mechanisms within TME. Confronting these issues, here a rationally designed nanosystem (SUN‐NPA) with acid‐responsive sphere‐to‐fiber transformation ability by leveraging the characters of drug molecules is proposed to achieve self‐delivery of photosensitizer Chlorin e6 (Ce6) and two small‐molecule immunomodulators, metformin (MET) and sunitinib (SUN). The spatiotemporal controlled transformation enables homogeneous distribution and high accumulation of drugs to achieve enduring PDT and complete tumor elimination. Meanwhile, the co‐delivered MET and SUN alleviate tumor immunosuppression from multiple aspects, effectively synergizing with PDT to ignite potent host immune response and long‐lasting immunological memory against tumor cells. The artful integration of enhanced PDT and activated antitumor immunity realized by SUN‐NPA leads to the significant inhibition of tumor growth and metastasis, exhibiting great potential for oncotherapy.

Mycobacterium smegmatis enhances shikonin-induced immunogenic cell death-an efficient in situ tumor vaccine strategy.

Tumor vaccines are a promising avenue in cancer immunotherapy. Despite the progress in targeting specific immune epitopes, tumor cells lacking these epitopes can evade the treatment. Here, we aimed to construct an efficient in situ tumor vaccine called Vac-SM, utilizing shikonin (SKN) to induce immunogenic cell death (ICD) and Mycobacterium smegmatis as an immune adjuvant to enhance in situ tumor vaccine efficacy. SKN showed a dose-dependent and time-dependent cytotoxic effect on the tumor cell line and induced ICD in tumor cells as evidenced by the CCK-8 assay and the detection of the expression of relevant indicators, respectively. Compared with the control group, the in situ Vac-SM injection in mouse subcutaneous metastatic tumors significantly inhibited tumor growth and distant tumor metastasis, while also improving survival rates. Mycobacterium smegmatis effectively induced maturation and activation of bone marrow-derived dendritic cells (DCs), and in vivo tumor-draining lymph nodes showed an increased maturation of DCs and a higher proportion of effector memory T-cell subsets with the Vac-SM treatment, based on flow cytometry analysis results. Collectively, the Vac-SM vaccine effectively induces ICD, improves antigen presentation by DCs, activates a specific systemic antitumor T-cell immune response, exhibits a favorable safety profile, and holds the promise for clinical translation for local tumor immunotherapy.

TIGIT+ NK cells in combination with specific gut microbiota features predict response to checkpoint inhibitor therapy in melanoma patients

BackgroundComposition of the intestinal microbiota has been correlated to therapeutic efficacy of immune checkpoint inhibitors (ICI) in various cancer entities including melanoma. Prediction of the outcome of such therapy, however, is still unavailable. This prospective, non-interventional study was conducted in order to achieve an integrated assessment of the connection between a specific intestinal microbiota profile and antitumor immune response to immune checkpoint inhibitor therapy (anti-PD-1 and/or anti-CTLA-4) in melanoma patients.MethodsWe assessed blood and stool samples of 29 cutaneous melanoma patients who received immune checkpoint inhibitor therapy. For functional and phenotypical immune analysis, 12-color flow cytometry and FluoroSpot assays were conducted. Gut microbiome was analyzed with shotgun metagenomics sequencing. To combine clinical, microbiome and immune variables, we applied the Random Forest algorithm.ResultsA total of 29 patients was analyzed in this study, among whom 51.7% (n = 15) reached a durable clinical benefit. The Immune receptor TIGIT is significantly upregulated in T cells (p = 0.0139) and CD56high NK cells (p = 0.0037) of responders. Several bacterial taxa were associated with response (e.g. Ruminococcus torques) or failure (e.g. Barnesiella intestinihominis) to immune therapy. A combination of two microbiome features (Barnesiella intestinihominis and the Enterobacteriaceae family) and one immune feature (TIGIT+ CD56high NK cells) was able to predict response to ICI already at baseline (AUC = 0.85; 95% CI: 0.841–0.853).ConclusionsOur results reconfirm a link between intestinal microbiota and response to ICI therapy in melanoma patients and furthermore point to TIGIT as a promising target for future immunotherapies.

Multifunctional hybrid oncolytic virus-mimicking nanoparticles for targeted induce of tumor-specific pyroptosis and enhanced anti-tumor immune response in melanoma

Pyroptosis, a newly discovered form of programmed cell death, has emerged as a promising antitumor approach by releasing pro-inflammatory cytokines and immunogenic substances upon cell rupture. However, non-specific pyroptosis potentially causes systemic damage to healthy tissues, and the heterogeneity of tumors limits the anti-tumor effect of pyroptosis. To address these challenges, we propose a simple yet powerful method for creating multifunctional hybrid oncolytic virus-mimicking nanovesicles (HVMNVs) that possess tumor-targeting capabilities, adjuvant activity, and the ability to evade immune clearance induced by virus modification. Based on this multifunctional nanovesicle, we developed a functional nanoparticle (HVMNVs@Fe-C) that significantly enhances the tumor targetability and cell uptake efficiency of the extremely small iron oxide nanoparticles (ESIONPs) and carbonyl cyanide m-chlorophenyl hydrazone (CCCP), leading to rapid tumor pyroptosis. More importantly, HVMNVs@Fe-C ingeniously achieves a synergistic effect by incorporating the adjuvantic and tumor-targeting properties of oncolytic viruses with the cell lytic and pro-inflammatory functions of pyroptosis in a single nanoparticle. This leads to a cascade of specific anti-tumor immune responses and reprogramming of the immunosuppressive tumor microenvironment, resulting in excellent tumor inhibition efficacy against primary melanoma growth and pulmonary metastasis. Overall, our novel strategy offers considerable promise for precisive targeted delivery and cancer immunotherapy.

Dendritic Cells Pulsed with Tumor Lysates Induced by Tetracyanotetra(aryl)porphyrazines-Based Photodynamic Therapy Effectively Trigger Anti-Tumor Immunity in an Orthotopic Mouse Glioma Model.

Research in the past decade on immunogenic cell death (ICD) has shown that the immunogenicity of dying tumor cells is crucial for effective anticancer therapy. ICD induction leads to the emission of specific damage-associated molecular patterns (DAMPs), which act as danger signals and as adjuvants to activate specific anti-tumor immune responses, leading to the elimination of tumor cells and the formation of long-term immunological memory. ICD can be triggered by many anticancer treatment modalities, including photodynamic therapy (PDT). However, due to the variety of photosensitizers used and the lack of a universally adopted PDT protocol, there is a need to develop novel PDT with a proven ICD capability. In the present study, we characterized the abilities of two photoactive dyes to induce ICD in experimental glioma in vitro and in vivo. One dye was from the tetracyanotetra(aryl)porphyrazine group with 9-phenanthrenyl (pz I), and the other was from the 4-(4-fluorobenzyoxy)phenyl (pz III) group in the aryl frame of the macrocycle. We showed that after the photosensitizers penetrated into murine glioma GL261 cells, they localized predominantly in the Golgi apparatus and partially in the endoplasmic reticulum, providing efficient phototoxic activity against glioma GL261 cells upon light irradiation at a dose of 20 J/cm2 (λex 630 nm; 20 mW/cm2). We demonstrated that pz I-PDT and pz III-PDT can act as efficient ICD inducers when applied to glioma GL261 cells, facilitating the release of two crucial DAMPs (ATP and HMGB1). Moreover, glioma GL261 cells stimulated with pz I-PDT or pz III-PDT provided strong protection against tumor growth in a prophylactic subcutaneous glioma vaccination model. Finally, we showed that dendritic cell (DC) vaccines pulsed with the lysates of glioma GL261 cells pre-treated with pz-I-PDT or pz-III-PDT could act as effective inducers of adaptive anti-tumor immunity in an intracranial orthotopic glioma mouse model.

OS01.4.A A DETECTABLE ANTITUMOR IMMUNE RESPONSE IS PRESENT IN GLIOMAS, BUT IS PROFOUNDLY DAMPED BY CHEMOTHERAPY

Abstract BACKGROUND Until now, immunotherapy has been disappointing in gliomas. Promising results in cancer neoantigen (NeoAg)-directed vaccines have been seen, but final outcomes remain poor. We need a better comprehension of the factors associated with effectively immunogenic NeoAgs along with clinical features that correlate with detectable immune responses. MATERIAL AND METHODS We prospectively enrolled glioma patients from our institution in the IDeATIon project (NCT03706625) exploring tumors occurring in immunosuppressed conditions or in immune-privileged sites such as the CNS. We performed whole exome and RNA sequencing of tumor samples along with patients HLA typing. Using state of the art algorithms and personalized filters, we predicted cancer NeoAg sequences and expression. Peripheral blood mononuclear cells (PBMC) were collected in a subset of patients, and their reactivity to NeoAg-derived peptides was assessed ex vivo using ELISpot assays to validate in silico-predicted immunogenicity. RESULTS We enrolled 36 prospective glioma patients (IDH mutant, n=10; IDH wildtype, n=26). To test the ability of our pipeline to identify the most immunologically relevant NeoAgs among others, we privileged the inclusion of mismatch-repair (MMR)-deficient (MMRd) gliomas (n=21, of which 12 post-temozolomide and 9 de novo), given their expected high NeoAg burden. The median number of predicted immunogenic NeoAgs from 21 patients with both WES and RNASeq data was 274 and was higher for MMRd gliomas (1540 vs. 58, p<0.001). Tumor mutational burden and the number of predicted NeoAgs were correlated (ρ=0.81, p<0.001). Ex vivo PBMC responses were assessed for best ranked peptides (median 48 peptides/patient, range 12-62) in 18 patients (10 MMRd). NeoAg-specific T-cell responses (>50 spot forming units/10e6 PBMC) were detected in 72% (13/18) of patients, including MMRd cases (8/10). All non-responder patients (5/5) were under treatment with cytotoxic chemotherapies (CHT) at the time of blood sampling, compared to 15% (2/13) of responders (p=0.003). Conversely, NeoAg-specific responses were seen in 100% (11/11) of patients not under CHT. CONCLUSION We developed and validated in vitro a robust and reliable pipeline for the identification of effectively immunogenic neoantigens using validated algorithms and personalized filters. Our results suggest that in the absence of CHT, a specific antitumor immune response is present in the majority of gliomas and may represent a therapeutic lever.

Promises of oncolytic viral therapy for adult and children with brain glioma.

The purpose of this review is to give an overview of early clinical studies addressing the safety and efficacy of oncolytic immunovirotherapy in adults and children with brain gliomas, and to highlight the extensive potential for the development of this therapeutic alternative. The lack of curative treatments and poor prognosis of high-grade glioma patients warrants research on innovative therapeutic alternatives such as oncolytic immunovirotherapy. Engineered modified oncolytic viruses exert both a direct lytic effect on tumor cells and a specific antitumor immune response. Early clinical trials of different DNA and RNA oncolytic viruses, mainly Herpes Simplex Virus Type-1 and adenovirus based platforms, have consistently demonstrated an acceptable safety profile, hints of efficacy and the potential of this therapy to reshape the tumor microenvironment in both adult and pediatric patients with glioma, thus constituting the basis for the development of more advanced clinical trials. The future landscape of oncolytic immunovirotherapy is still plenty of challenges and opportunities to enable its full therapeutic potential in both adult and children with brain gliomas.

The effects of irreversible electroporation triggering anti-tumor immunity and the value of its combination with immunotherapy

Recently, interventional ablation techniques have gained prominence in tumor treatment guidelines and complement traditional approaches, such as surgery, chemotherapy, and radiotherapy. Conventional ablation techniques, such as microwave, radiofrequency, and cryoablation, have been used; however, they have certain limitations, including the risk of damaging surrounding normal tissues and the heat sink effect caused by tumor blood flow.1 Irreversible electroporation (IRE), an ablation technology independent of thermal energy, is a promising alternative.2 Clinical studies have demonstrated IRE's efficacy in treating tumors, such as pancreatic and liver tumors.3 Recent research has shown that IRE can elicit specific anti-tumor immune responses in the body.5 IRE also plays a crucial role in eliminating residual tumor cells postoperatively and preventing tumor recurrence.

Peptide Vaccines as Therapeutic and Prophylactic Agents for Female-Specific Cancers: The Current Landscape.

Breast and gynecologic cancers are significant global threats to women's health and those living with the disease require lifelong physical, financial, and social support from their families, healthcare providers, and society as a whole. Cancer vaccines offer a promising means of inducing long-lasting immune response against the disease. Among various types of cancer vaccines available, peptide vaccines offer an effective strategy to elicit specific anti-tumor immune responses. Peptide vaccines have been developed based on tumor associated antigens (TAAs) and tumor specific neoantigens which can also be of viral origin. Molecular alterations in HER2 and non-HER2 genes are established to be involved in the pathogenesis of female-specific cancers and hence were exploited for the development of peptide vaccines against these diseases, most of which are in the latter stages of clinical trials. However, prophylactic vaccines for viral induced cancers, especially those against Human Papillomavirus (HPV) infection are well established. This review discusses therapeutic and prophylactic approaches for various types of female-specific cancers such as breast cancer and gynecologic cancers with special emphasis on peptide vaccines. We also present a pipeline for the design and evaluation of a multiepitope peptide vaccine that can be active against female-specific cancers.

Hyperbranched Polymer-Based Vaccines for Cancer Immunotherapy.

Recently, several immunotherapeutic strategies are extensively studied and entered clinical investigation, suggesting their potential to lead a new generation of cancer therapy. Particularly, a cancer vaccine that combines tumor-associated antigens and immune adjuvants with a nanocarrier holds huge promise for inducing specific antitumor immune responses. Hyperbranched polymers, such as dendrimers and branched polyethylenimine (PEI) possessing abundant positively charged amine groups and inherent proton sponge effect are ideal carriers of antigens. Much effort is devoted to design dendrimer/branched PEI-based cancer vaccines. Herein, the recent advances in the design of dendrimer/branched PEI-based cancer vaccines for immunotherapy are reviewed. The future perspectives with regard to the development of dendrimer/branched PEI-based cancer vaccines are also briefly discussed.

Results of phase I-II bridging study for Nous-209, a neoantigen cancer immunotherapy, in combination with pembrolizumab as first line treatment in patients with advanced dMMR/MSI-h colorectal cancer.

e14665 Background: Microsatellite instability (MSI) is a molecular hallmark in which systemic deficiency of DNA mismatch-repair (dMMR) generates tumor-specific frameshift peptides (FSPs). Nous-209 is an off-the-shelf cancer vaccine targeting 209 FSPs selected from dMMR/MSI-H tumors (Leoni, G. et al., 2020). Treatment options for unresectable dMMR/MSI-H tumors have improved, but further efforts to increase long-term progression-free survival are needed. NOUS-209-01 Phase I demonstrated that Nous-209 and pembrolizumab is safe, well tolerated, and provides clinical benefit in advanced gastric and CRC dMMR/MSI-H tumors (Fakih et al., 2022). Moreover, Nous-209 induces durable specific anti-tumoral immune response, capable of successfully infiltrating the tumor (D’Alise et al., 2022). Here, we present data from NOUS-209-01 study Phase I-II expansion cohort at the recommended phase 2 dose (RP2D) of Nous-209 and pembrolizumab in adults with dMMR/MSI-H locally advanced unresectable or metastatic colorectal cancer (mCRC) eligible for 1st line immune checkpoint inhibition. Methods: NOUS-209-01 ( NCT04041310 ) Phase I-II bridge expansion cohort receives one GAd20-209-FSP prime intramuscularly at the 1st infusion of pembrolizumab, followed by 3 MVA-209-FSP boosts with the 2nd, 3rd and 4th pembrolizumab cycles. Patients can continue treatment with pembrolizumab for 18 months. Response assessment is evaluated every 9 (+/-1) weeks by CT imaging, according to RECIST v1.1 criteria. ctDNA assessments are at baseline, 11, 28, 49, 79 weeks and at objective progression on study. Results: Phase I-II bridge enrolled 8 patients with dMMR/MSI-H treatment-naïve mCRC. One patient had clinical progression before 1st scan and was excluded as non-evaluable and 7 were evaluable for tumor response. 5/7 (71%, CI: 95% 29.0, 96.3) patients achieved objective response: 1 (14%) complete response (CR) and 4 (57%) partial responses (PR). 2 patients (29%) had disease progression (PD) at the 1st scan. ctDNA assessments were available for 6 out of 7 patients (4 PR; 2 PD); ctDNA levels reduced >50% at week 11 in the 4 PR patients, in contrast to a 28% increase in 1 PD. Interestingly 1 PD patient had ctDNA > 50% reduction. The median follow-up at data cut-off was 7.5 months (range: 3.3-8.4), median progression free survival and median duration of response have not been reached. 6/7 (85.7%) patients had treatment emergent adverse events (TEAE), all mild or moderate grade; no TEAEs were serious or led to treatment discontinuation. Conclusions: The combination of Nous-209 and pembrolizumab is safe, well tolerated and shows encouraging clinical efficacy in patients with treatment-naive dMMR/MSI-H mCRC eligible for anti-PD-1 therapy. The study is ongoing and expanding to Phase II randomization with a new accelerated Nous-209 vaccination schedule. Clinical trial information: NCT04041310 .

The CD40 agonist HERA-CD40L results in enhanced activation of antigen presenting cells, promoting an anti-tumor effect alone and in combination with radiotherapy.

The ability to modulate and enhance the anti-tumor immune responses is critical in developing novel therapies in cancer. The Tumor Necrosis Factor (TNF) Receptor Super Family (TNFRSF) are potentially excellent targets for modulation which result in specific anti-tumor immune responses. CD40 is a member of the TNFRSF and several clinical therapies are under development. CD40 signaling plays a pivotal role in regulating the immune system from B cell responses to myeloid cell driven activation of T cells. The CD40 signaling axis is well characterized and here we compare next generation HERA-Ligands to conventional monoclonal antibody based immune modulation for the treatment of cancer. HERA-CD40L is a novel molecule that targets CD40 mediated signal transduction and demonstrates a clear mode of action in generating an activated receptor complex via recruitment of TRAFs, cIAP1, and HOIP, leading to TRAF2 phosphorylation and ultimately resulting in the enhanced activation of key inflammatory/survival pathway and transcription factors such asNFkB, AKT, p38, ERK1/2, JNK, and STAT1 in dendritic cells. Furthermore, HERA-CD40L demonstrated a strong modulation of the tumor microenvironment (TME) via the increase in intratumoral CD8+ T cells and the functional switch from pro-tumor macrophages (TAMs) to anti-tumor macrophages that together results in a significant reduction of tumor growth in a CT26 mouse model. Furthermore, radiotherapy which may have an immunosuppressive modulation of the TME, was shown to have an immunostimulatory effect in combination with HERA-CD40L. Radiotherapy in combination with HERA-CD40L treatment resulted in an increase in detected intratumoral CD4+/8+ T cells compared to RT alone and, additionally, the repolarization of TAMs was also observed, resulting in an inhibition of tumor growth in a TRAMP-C1 mouse model. Taken together, HERA-CD40L resulted in activating signal transduction mechanisms in dendritic cells, resulting in an increase in intratumoral T cells and manipulation of the TME to be pro-inflammatory, repolarizing M2 macrophages to M1, enhancing tumor control.

Therapeutic strategies to enhance immune response induced by multiple myeloma cells.

Multiple myeloma (MM)as a haematological malignancy is still incurable. In addition to the presence of somatic genetic mutations in myeloma patients, the presence of immunosuppressive microenvironment greatly affects the outcome of treatment. Although the discovery of immunotherapy makes it possible to break the risk of high toxicity and side effects of traditional chemotherapeutic drugs, there are still obstacles of ineffective treatment or disease recurrence. In this review, we discuss therapeutic strategies to further enhance the specific anti-tumor immune response by activating the immunogenicity of MM cells themselves. New ideas for future myeloma therapeutic approaches are provided.