Platform For Immunotherapy Research Articles

CRISPR-based molecule-regulatory expression platform for specific immunotherapy of cancer

IntroductionCancer is still a major challenge of human health. The abnormality of intracellular cancer-related signal pathways is an important mechanism for the occurrence of cancer.MethodsWe used a molecular-senor to act on the endogenous signal molecules within the cell to redirect the abnormal signal flows in the cell to treat cancer. Based on CRISPR-dCas12f procedures, we combined aptamers and ribozymes to construct riboswitches, which served as molecular switches to reprogram sgRNAs, so that CRISPR-dCas12f redirected the intracellular anti-cancer signal flows after sensing specific input signal molecules. In addition, the activated molecular sensors and the inhibitory molecular sensors were constructed by combining transcription factors (VP64) and transcription inhibitors (KRAB) to specifically activate and inhibit target genes of interest.ResultsOur experimental results showed that the molecular sensors that we designed and constructed specifically sensed the endogenous signal molecules and then redirect the cancer related signal networks of cancer cells. In addition, corresponding logic gates were constructed to distinguish cancer cells from normal cells and redirect anticancer signal flows to trigger specific cancer immunotherapy.ConclusionThe constructed molecular sensors constructed specifically recognized the signal molecules within the cell and redirected the endogenous signal pathway to reprogram the fate of cancer cells.

Broad applicability of the Goldspire™ platform for the treatment of solid tumors

Goldspire™ is a personalized immunotherapy platform that combines whole tumor-derived cells with antisense oligonucleotide (IMV-001) against Insulin-Like Growth Factor-1 Receptor (IGF-1R) in biodiffusion chambers (BDCs; 0.1 μm pore). BDCs are exposed to 5–6 Gy and implanted at abdominal sites for ∼48 h to deliver an antigenic payload and immunostimulatory factors to train the immune system. Lead product IGV-001 was evaluated in newly diagnosed glioblastoma (ndGBM) patients in Phase 1a and 1b trials (NCT02507583). A Phase 2b study (NCT04485949) recently completed enrollment.Preventative treatment with tumor-specific products manufactured with Goldspire limited tumor progression and extended overall survival in mice challenged with bladder, pancreatic, ovarian, colorectal, or renal carcinomas. The benefit of this immunotherapy was enhanced with anti-PD-1; combination treatment was superior to either monotherapy in orthotopic GBM and melanoma models. Lastly, Goldspire elicited immune T cell activation and memory phenotypes against patient-derived endometrial tumor-derived products in co-cultures with matching immune cells.

Haploidentical hematopoietic cell transplantation as a platform for natural killer cell immunotherapy.

An innovative approach is crucially needed to manage relapse after allogeneic hematopoietic cell transplantation (HCT) in patients with advanced hematological malignancies. This review explores key aspects of haploidentical HCT with post-transplant cyclophosphamide, highlighting the potential and suitability of this platform for natural killer (NK) cell immunotherapy. NK cells, known for their unique abilities to eliminate cancer cells, can also exhibit memory-like features and enhanced cytotoxicity when activated by cytokines. By discussing promising results from clinical trials, the review delves into the recent major advances: donor-derived NK cells can be expanded ex vivo in large numbers, cytokine activation may enhance NK cell persistence and efficacy in vivo, and post-HCT NK cell infusion can improve outcomes in high-risk and/or relapsed myeloid malignancies without increasing the risk of graft-versus-host disease, severe cytokine release syndrome, or neurotoxicity. Looking ahead, cytokine-activated NK cells can be synergized with immunomodulatory agents and/or genetically engineered to enhance their tumor-targeting specificity, cytotoxicity, and persistence while preventing exhaustion. The ongoing exploration of these strategies holds promising preliminary results and could be rapidly translated into clinical applications for the benefit of the patients.

Unveiling the functional roles of patient-derived tumour organoids in assessing the tumour microenvironment and immunotherapy.

Recent studies have established the pivotal roles of patient-derived tumour organoids (PDTOs), innovative three-dimensional (3D) culture systems, in various biological and medical applications. PDTOs, as promising tools, have been established and extensively used for drug screening, prediction of immune response and assessment of immunotherapeutic effectiveness in various cancer types, including glioma, ovarian cancer and so on. The overarching goal is to facilitate the translation of new therapeutic modalities to guide personalised immunotherapy. Notably, there has been a recent surge of interest in the co-culture of PDTOs with immune cells to investigate the dynamic interactions between tumour cells and immune microenvironment. A comprehensive and in-depth investigation is necessary to enhance our understanding of PDTOs as promising testing platforms for cancer immunotherapy. This review mainly focuses on the latest updates on the applications and challenges of PDTO-based methods in anti-cancer immune responses. We strive to provide a comprehensive understanding of the potential and prospects of PDTO-based technologies as next-generation strategies for advancing immunotherapy approaches.

A Pyroptosis-Inducing Arsenic(III) Nanomicelle Platform for Synergistic Cancer Immunotherapy.

Immunogenic cell death (ICD) could activate anti-tumor immune responses, which is highly attractive for improving cancer treatment effectiveness. Here, this work reports a multifunctional arsenic(III) allosteric inhibitor Mech02, which induces excessive accumulation of 1O2 through sensitized biocatalytic reactions, leading to cell pyroptosis and amplified ICD effect. After Mech02 is converted to Mech03, it could actualize stronger binding effects on the allosteric pocket of pyruvate kinase M2, further interfering with the anaerobic glycolysis pathway of tumors. The enhanced DNA damage triggered by Mech02 and the pyroptosis of cancer stem cells provide assurance for complete tumor clearance. In vivo experiments prove nanomicelle Mech02-HA NPs is able to activate immune memory effects and raise the persistence of anti-tumor immunity. In summary, this study for the first time to introduce the arsenic(III) pharmacophore as an enhanced ICD effect initiator into nitrogen mustard, providing insights for the development of efficient multimodal tumor therapy agents.

Immunocyte membrane-derived biomimetic nano-drug delivery system: a pioneering platform for tumour immunotherapy.

Tumor immunotherapy characterized by its high specificity and minimal side effects has achieved revolutionary progress in the field of cancer treatment. However, the complex mechanisms of tumor immune microenvironment (TIME) and the individual variability of patients' immune system still present significant challenges to its clinical application. Immunocyte membrane-coated nanocarrier systems, as an innovative biomimetic drug delivery platform, exhibit remarkable advantages in tumor immunotherapy due to their high targeting capability, good biocompatibility and low immunogenicity. In this review we summarize the latest research advances in biomimetic delivery systems based on immune cells for tumor immunotherapy. We outline the existing methods of tumor immunotherapy including immune checkpoint therapy, adoptive cell transfer therapy and cancer vaccines etc. with a focus on the application of various immunocyte membranes in tumor immunotherapy and their prospects and challenges in drug delivery and immune modulation. We look forward to further exploring the application of biomimetic delivery systems based on immunocyte membrane-coated nanoparticles, aiming to provide a new framework for the clinical treatment of tumor immunity.

Engineering Versatile Bacteria-Derived Outer Membrane Vesicles: An Adaptable Platform for Advancing Cancer Immunotherapy.

In recent years, cancer immunotherapy has undergone a transformative shift toward personalized and targeted therapeutic strategies. Bacteria-derived outer membrane vesicles (OMVs) have emerged as a promising and adaptable platform for cancer immunotherapy due to their unique properties, including natural immunogenicity and the ability to be engineered for specific therapeutic purposes. In this review, a comprehensive overview is provided of state-of-the-art techniques and methodologies employed in the engineering of versatile OMVs for cancer immunotherapy. Beginning by exploring the biogenesis and composition of OMVs, unveiling their intrinsic immunogenic properties for therapeutic appeal. Subsequently, innovative approaches employed to engineer OMVs are delved into, ranging from the genetic engineering of parent bacteria to the incorporation of functional molecules. The importance of rational design strategies is highlighted to enhance the immunogenicity and specificity of OMVs, allowing tailoring for diverse cancer types. Furthermore, insights into clinical studies and potential challenges utilizing OMVs as cancer vaccines or adjuvants are also provided, offering a comprehensive assessment of the current landscape and future prospects. Overall, this review provides valuable insights for researchers involved in the rapidly evolving field of cancer immunotherapy, offering a roadmap for harnessing the full potential of OMVs as a versatile and adaptable platform for cancer treatment.

A Dual Enhancing Strategy of Novel Nanovaccine Based on TIM3 Silencing Nanoadjuvants and Desialylated Cancer Cell Membrane Antigens for Personalized Vaccination Immunotherapy of Cancer

AbstractCancer vaccines represent a promising form of immunotherapy employed in the treatment of cancer. However, their efficiency in eliciting immune responses is limited, and satisfactory results have yet to be achieved. Optimizing adjuvants and antigens is an important approach to promoting the anti‐tumor efficacy of cancer vaccines. Here, a novel nanoadjuvant (LNP/siRNA) designed to silence T‐cell immunoglobulin and mucin‐domain containing‐3 (TIM3) and activate Toll‐like receptors (TLRs) is presented. The LNP/siRNA demonstrates significant potential in promoting dendritic cell (DC) maturation and enhancing the anti‐tumor response. Furthermore, desialylated cancer cell membrane is utilized as antigens, providing a variety of tumor antigens for DCs and enhancing their function. Additionally, they are integrated to create a core‐shell structured nanovaccine (dClip‐LNP/siRNA) through coextrusion, which collectively enhances the cross‐presentation ability of DCs, thus achieving a dual enhancement strategy. The dClip‐LNP/siRNA significantly silences TIM3 expression in DCs and promotes antigen presentation by DCs. Besides, dClip‐LNP/siRNA significantly promotes the activation of T cells in lymph nodes and induces robust and durable anti‐tumor immunity in tumor sites to eliminate established B16‐OVA tumors, prevent tumor occurrence, and suppress tumor lung metastasis. The dClip‐LNP/siRNA is also suitable for combination with adoptive OT‐I cell therapy to enhance cancer immunotherapy. The dClip‐LNP/siRNA represents a robust vaccine platform for personalized cancer immunotherapy.

NK-92 cells labeled with Fe3O4-PEG-CD56/Avastin@Ce6 nanoprobes for the targeted treatment and noninvasive therapeutic evaluation of breast cancer

Adoptive cellular immunotherapy as a promising and alternative cancer therapy platform is critical for future clinical applications. Natural killer (NK) cells have attracted attention as an important type of innate immune regulatory cells that can rapidly kill multiple adjacent cancer cells. However, these cells are significantly less effective in treating solid tumors than in treating hematological tumors. Herein, we report the synthesis of a Fe3O4-PEG-CD56/Avastin@Ce6 nanoprobe labeled with NK-92 cells that can be used for adoptive cellular immunotherapy, photodynamic therapy and dual-modality imaging-based in vivo fate tracking. The labeled NK-92 cells specifically target the tumor cells, which increases the amount of cancer cell apoptosis in vitro. Furthermore, the in vivo results indicate that the labeled NK-92 cells can be used for tumor magnetic resonance imaging and fluorescence imaging, adoptive cellular immunotherapy, and photodynamic therapy after tail vein injection. These data show that the developed multifunctional nanostructure is a promising platform for efficient innate immunotherapy, photodynamic treatment and noninvasive therapeutic evaluation of breast cancer.

Fostering collaborative care in multiple myeloma: The impact of holistic education on decision-making with antibody and CAR-T platforms.

e21008 Background: The management of multiple myeloma (MM) continues to be transformed by evidence supporting the use of CD38 antibodies and B-cell maturation antigen (BCMA) immunotherapy (chimeric antigen receptor (CAR-T) and bispecific antibodies) in newly diagnosed and relapsed/refractory MM (NDMM and RRMM), respectively. However, real-world evidence and survey data show that these approaches are under-utilized across lines of therapy and that educational outreach to patients on their use is inadequate (Puig N et al. ASH 2022. Abstract 1859; Pink S et al. ISPOR 2022. Abstract HSD44; Terpos E et al. Blood Cancer J. 2021;11:40; Adu Y et al. ASH 2023. Abstract 2418). Methods: To address these gaps, PeerView partnered with HealthTree Foundation for Multiple Myeloma to develop 4 live events and 5 online enduring activities from 06/2022 to 06/2023, to educate clinicians on the evidence and principles for integrating CD38 and BCMA antibody platforms into patient care. The activities’ core objectives focused on improving knowledge and skills for integrating CD38 antibodies and BCMA immunotherapy platforms into sequential MM treatment. Furthermore, through the partnership with HealthTree Foundation, the initiatives featured patient perspectives as well as tools and resources to foster clinician–patient communication on use of antibody and CAR-T therapy. Pre- and post-activity multiple choice questions measured changes in knowledge and skills. Responses from enduring activity learners were compared with those from a matched sample of nonparticipants. In a meta-analysis of outcomes from the 9 activities, learning objectives were grouped by key themes, with changes in knowledge and skills averaged across them. Results: Total learners: 12,248 (hematologist-oncologists/oncologists: 7,345; oncology nurses: 1,247) In all activities, learners’ knowledge and skills improved, with increases of: 35 percentage points (ppt) in knowledge of new evidence and changing practice guidelines supporting BCMA antibody platforms in RRMM (44% to 79%); 36 ppt in skills in treatment planning and evidence-based integration of CD38 and BCMA-targeting antibodies in the management of MM (52% to 88%); 46 ppt in ability to address safety considerations related to the use of antibody therapy and BCMA immunotherapy (39% to 85%); 58 ppt in patient interaction skills (eg, counseling, shared decision-making) when using antibody-based and CAR-T platforms (28% to 86%). Conclusions: Improvements in knowledge and skills, combined with a greater focus on patient-centricity, suggest that learners are poised to more effectively integrate CD38 antibodies and BCMA immunotherapy into guideline-recommended MM care that improves the overall well-being and outcomes of patients with MM.

Patient-reported experience with an immunotherapy telehealth platform.

1637 Background: The Making Telehealth Delivery of Cancer Care at Home Effective and Safe for Immunotherapy (MATCHES-IO) intervention seeks to improve the efficiency and patient experience for those treated with single agent pembrolizumab. Because pembrolizumab is administered as an outpatient infusion every 3-weeks, patients require up to 18 clinic visits per year to receive treatment, which is arduous. During the COVID-19 pandemic, the FDA granted accelerated approval for an extended interval dosing administered every 6 weeks, but despite this approval every 3-week dosing remains the standard (65% of prescriptions) as clinicians perceive this schedule enables them to identify and manage toxicity early. Telehealth may be the impetus to change the standard to the more convenient 6-week in person schedule, but evidence is needed. Methods: We conducted a single arm pragmatic trial to evaluate the efficiency and patient experience of a telehealth immunotherapy platform (MATCHES-IO) in patients with non-small cell lung, genitourinary, or melanoma cancers receiving single agent pembrolizumab. MATCHES-IO evaluates whether in-person visits for pembrolizumab therapy q6wk (rather than q3wk), with interim telehealth toxicity checks between in-person treatments, is more efficient and enhances patient experience relative to the standard q3wk infusion visits. The components of the platform include clinician-patient virtual visits, labs at home, biometric devices at home for vital sign monitoring, and electronic patient-reported outcomes to monitor for common IO-related toxicities. Patient experience was assessed after each MATCHES-IO televisit for up to two televisits. We measured experience with a patient experience survey that included the net promoter score, of how likely are they to recommend this intervention to similar patients (scale 0-10, higher score is desirable). A score of 9 or greater is considered excellent. Results: Between July 2023 and February 2024, 27 patients were enrolled, median age 68 (range 45–85), 74% white, 11% black, 11% Asian, and 41% female. Cancer types included thoracic (59% of patients), genitourinary (33%), and melanoma (7%). 19 patients (70.4%) have completed a MATCHES-IO televisit and completed the patient experience survey. The median net promoter score was 9 (range 2-10). 94% patients perceived a benefit to the MATCH-IO televisit including saved time (83% of respondents), patient convenience (83%), convenience for caregiver/family (44%), saved money (44%), and better monitoring of cancer and treatment (39%). 78% of patients found the at home visit less stressful than the in-person visit. Conclusions: Patients endorsed an enhanced experience with an immunotherapy telehealth platform for extended dosing of pembrolizumab. Further follow-up is needed to confirm these experience findings and determine whether this platform improved efficiency through fewer in-person visits.

Heterogeneous-Structure-Based AuNBs@TiO2 Nano-Photosensitizers for Computed Tomography Imaging Guided NIR-II Photodynamic Therapy and Cancer Metastatic Prevention.

Photodynamic therapy (PDT) is a minimally invasive cancer treatment that, despite its significant attention, faces limitations in penetration depth, which restrict its effectiveness. Herein, it is found that gold nanobipyramid (AuNBs) coated with TiO2 can form a core-shell heterogeneous structure (AuNBs@TiO2) with strong absorption at second near infrared (NIR-II) region. A substantial quantity of reactive oxygen species (ROS), including singlet oxygen (1O2), superoxide anion radicals, and hydroxyl radicals, can be rapidly generated when subjecting the AuNBs@TiO2 aqueous suspension to 1064nm laser irradiation. The quantum yield for sensitization of 1O2 by AuNBs@TiO2 is 0.36 at 1064nm light excitation. In addition, the Au element as high-Z atoms in the nanosystem can improve the ability of computed tomographic (CT) imaging. As compared to commercial iohexol, the AuNBs@TiO2 nanoparticle exhibits significantly better CT imaging effect, which can be used to guide PDT. In addition, the nano-photosensitizer shows a remarkable therapeutic effect against established solid tumors and prevents tumor metastasis and potentiates immune checkpoint blockade therapy. More importantly, here the great potentials of AuNBs@TiO2 are highlighted as a theranostic platform for CT-guided cancer photodynamic immunotherapy.

A Bioactive Injectable Hydrogel Regulates Tumor Metastasis and Wound Healing for Melanoma via NIR-Light Triggered Hyperthermia.

Surgical resection remains the mainstream treatment for malignant melanoma. However, challenges in wound healing and residual tumor metastasis pose significant hurdles, resulting in high recurrence rates in patients. Herein, a bioactive injectable hydrogel (BG-Mngel) formed by crosslinking sodium alginate (SA) with manganese-doped bioactive glass (BG-Mn) is developed as a versatile platform for anti-tumor immunotherapy and postoperative wound healing for melanoma. The incorporation of Mn2+ within bioactive glass (BG) can activate the cGAS-STING immune pathway to elicit robust immune response for cancer immunotherapy. Furthermore, doping Mn2+ in BG endows system with excellent photothermal properties, hence facilitating STING activation and reversing the tumor immune-suppressive microenvironment. BG exhibits favorable angiogenic capacity and tissue regenerative potential, and Mn2+ promotes cell migration in vitro. When combining BG-Mngel with anti-PD-1 antibody (α-PD-1) for the treatment of malignant melanoma, it shows enhanced anti-tumor immune response and long-term immune memory response. Remarkably, BG-Mngel can upregulate the expression of genes related to blood vessel formation and promote skin tissue regeneration when treating full-thickness wounds. Overall, BG-MnGel serves as an effective adjuvant therapy to regulate tumor metastasis and wound healing for malignant melanoma.

Mesoporous Silica Nanoparticles as an Ideal Platform for Cancer Immunotherapy: Recent Advances and Future Directions.

Cancer immunotherapy recently transforms the traditional approaches against various cancer malignancies. Immunotherapy includes systemic and local treatments to enhance immune responses against cancer and involves strategies such as immune checkpoints, cancer vaccines, immune modulatory agents, mimetic antigen-presenting cells, and adoptive cell therapy. Despite promising results, these approaches still suffer from several limitations including lack of precise delivery of immune-modulatory agents to the target cells and off-target toxicity, among others, that can be overcome using nanotechnology. Mesoporous silica nanoparticles (MSNs) are investigated to improve various aspects of cancer immunotherapy attributed to the advantageous structural features of this nanomaterial. MSNs can be engineered to alter their properties such as size, shape, porosity, surface functionality, and adjuvanticity. This review explores the immunological properties of MSNs and the use of MSNs as delivery vehicles for immune-adjuvants, vaccines, and mimetic antigen-presenting cells (APCs). The review also details the current strategies to remodel the tumor microenvironment to positively reciprocate toward the anti-tumor immune cells and the use of MSNs for immunotherapy in combination with other anti-tumor therapies including photodynamic/thermal therapies to enhance the therapeutic effect against cancer. Last, the present demands and future scenarios for the use of MSNs for cancer immunotherapy are discussed.

Genetically engineered nanomodulators elicit potent immunity against cancer stem cells by checkpoint blockade and hypoxia relief

Rapid development of checkpoint inhibitors has provided significant breakthroughs for cancer stem cell (CSC) therapy, while the therapeutic efficacy is restricted by hypoxia-mediated tumor immune evasion, especially hypoxia-induced CD47 overexpression in CSCs. Herein, we developed a genetically engineered CSC membrane-coated hollow manganese dioxide (hMnO2@gCMs) to elicit robust antitumor immunity by blocking CD47 and alleviating hypoxia to ultimately achieve the eradication of CSCs. The hMnO2 core effectively alleviated tumor hypoxia by inducing decomposition of tumor endogenous H2O2, thus suppressing the CSCs and reducing the expression of CD47. Cooperating with hypoxia relief-induced downregulation of CD47, the overexpressed SIRPα on gCM shell efficiently blocked the CD47-SIRPα “don't eat me” pathway, synergistically eliciting robust antitumor-mediated immune responses. In a B16F10-CSC bearing melanoma mouse model, the hMnO2@gCMs showed an enhanced therapeutic effect in eradicating CSCs and inhibiting tumor growth. Our work presents a simple, safe, and robust platform for CSC eradication and cancer immunotherapy.

DNA nanodevice as a multi-module co-delivery platform for combination cancer immunotherapy

A major challenge in combining cancer immunotherapy is the efficient delivery of multiple types of immunological stimulators to elicit a robust anti-tumor immune response and reprogram the immunosuppressive tumor microenvironment (TME). Here, we developed a DNA nanodevice that was generated by precisely assembling three types of immunological stimulators. The doxorubicin (Dox) component induced immunogenic cell death (ICD) in tumor cells and enhanced phagocytosis of antigen-presenting cells (APCs). Exogenous double-stranded DNA (dsDNA) could act as a molecular adjuvant to activate the stimulator of interferon genes (STING) signaling in APCs by engulfing dying tumor cells. Interleukin (IL)-12 and small hairpin programmed cell death-ligand 1 (shPD-L1) transcription templates were designed to regulate TME. Additionally, for targeted drug delivery, multiple cyclo[Arg-Gly-Asp-(d-Phe)-Cys] (cRGD) peptide units on DNA origami were employed. The incorporation of disulfide bonds allowed the release of multiple modules in response to intracellular glutathione (GSH) in tumors. The nanodevice promoted the infiltration of CD8+ and CD4+ cells into the tumor and generated a highly inflamed TME, thereby enhancing the effectiveness of cancer immunotherapy. Our research results indicate that the nanodevice we constructed can effectively inhibit tumor growth and prevent lung metastasis without obvious systemic toxicity, providing a promising strategy for cancer combination treatment.

Immortalized nanodendritic cells decorated with immune-checkpoint inhibitors for personalized cancer immunotherapy

In our study, we have designated artificial nanoDCs (anDCs) by transferring the whole DC membrane onto the gold nanoparticles (Au NPs) to overcome the limitation of DC therapy. The anDCs were optimized by varying membrane-to-substrate ratio, exhibiting similar features with natural DC in having a T cell stimulation and tumor regression even after long-term stability of up to 30 days. This versatile anDCs platform allows engineering immune-boosting agents onto their surface on demand. We further functionalized one of the immune checkpoint inhibitors (ICI), αCTLA-4, on anDCs, leading to complete tumor clearance compared to DC membrane vesicles. Surprisingly, αCTLA-4 conjugated anDC (αCTLA-4-anDC) dramatically blocked the CTLA-4 pathway and resulted in increased frequency and effector cytokine functions in cytotoxic CD8+ T cells. Thus, our anDC system can effectively induce a tumor-specific T cell immune response by sustainable and potent T cell priming ability based on the high stability of anDCs, suggesting a great potential platform for next-generation personalized cancer immunotherapy.

CXCR4-Targeted Macrophage-Derived Biomimetic Hybrid Vesicle Nanoplatform for Enhanced Cancer Therapy through Codelivery of Manganese and Doxorubicin.

Immune-cell-derived membranes have garnered significant attention as innovative delivery modalities in cancer immunotherapy for their intrinsic immune-modulating functionalities and superior biocompatibilities. Integrating additional parental cell membranes or synthetic lipid vesicles into cellular vesicles can further potentiate their capacities to perform combinatorial pharmacological activities in activating antitumor immunity, thus providing insights into the potential of hybrid cellular vesicles as versatile delivery vehicles for cancer immunotherapy. Here, we have developed a macrophage-membrane-derived hybrid vesicle that has the dual functions of transporting immunotherapeutic drugs and shaping the polarization of tumor-associated macrophages for cancer immunotherapy. The platform combines M1 macrophage-membrane-derived vesicles with CXCR4-binding-peptide-conjugated liposomes loaded with manganese and doxorubicin. The hybrid nanovesicles exhibited remarkable macrophage-targeting capacity through the CXCR4-binding peptide, resulting in enhanced macrophage polarization to the antitumoral M1 phenotype characterized by proinflammatory cytokine release. The manganese/doxorubicin-loaded hybrid vesicles in the CXCR4-expressing tumor cells evoked potent cancer cytotoxicity, immunogenic cell death of tumor cells, and STING activation. Moreover, cotreatment with manganese and doxorubicin promoted dendritic cell maturation, enabling effective tumor growth inhibition. In murine models of CT26 colon carcinoma and 4T1 breast cancer, intravenous administration of the manganese/doxorubicin-loaded hybrid vesicles elicited robust tumor-suppressing activity at a low dosage without adverse systemic effects. Local administration of hybrid nanovesicles also induced an abscessive effect in a bilateral 4T1 tumor model. This study demonstrates a promising biomimetic manganese/doxorubicin-based hybrid nanovesicle platform for effective cancer immunotherapy tailored to the tumor microenvironment, which may offer an innovative approach to combinatorial immunotherapy.

Abstract 3190: Twin Fc-immune cell engager (ICE): A novel antibody platform for cancer immunotherapy with enhanced avidity for Fcγ receptors and complement

Abstract Immunoglobulin G (IgG)-based mAbs have become a dominant class of cancer immunotherapy due to their excellent drug-like properties, long half-life, and generally safe profiles. Typical IgG-based therapeutic mAbs have strong binding to target antigens owing to the valency effect of two antigen-binding fragments (Fabs). However, the single crystallizable fragment (Fc) lacks the valency effect to engage immune effector elements. As Fcγ receptors (FcγR) such as FcγRIIa and FcγRIIIa and C1q complement component have low affinity for Fc, IgG-based mAbs require high antibody opsonization density to exhibit avidity for these low affinity Fcγ receptors and C1q. This may also account for the suboptimal efficacy of IgG-based mAbs against tumors with less abundant antigen. To enhance effector functions of IgG1 by overcoming such limitation, we devised a novel platform, Twin Fc-ICE, in which a single Fab region is attached by two Fc regions which allow for high avidity binding to Fcγ receptors and C1q. The two Fc regions of Twin Fc-ICE are arranged in parallel, not in tandem, to adopt natural topologies of multiple Fc regions presented by IgG1-opsonized targets. Supporting the avidity effect of Twin Fc-ICE for FcγR binding, we showed that CTN001, a Twin Fc-ICE with trastuzumab Fab, have markedly increased binding to FcγRs including FcγRI, FcγRIIa and FcγRIIIa compared with trastuzumab. The avid FcγR binding was further demonstrated by flow cytometry analysis of human blood which revealed significantly increased binding of CTN001 relative to trastuzumab for immune cells expressing activating FcγRs such as natural killer (NK) cells, monocytes, and dendritic cells (DCs). The monovalent antigen binding of Twin Fc-ICE requires Fab with high affinity. However, provided that high affinity is achieved, the monovalent Fab adds to the two Fc regions to maximize the Fc load on cancer cells expressing low levels of antigen. Indeed, flow cytometry analysis revealed that treatment of CTN001 alone results in higher Fc load on HER2-expressing cancer cells than combination of two anti-HER2 IgG1 mAbs, trastuzumab and pertuzumab. In consistent with increased Fc load on target cells and avid FcγR binding, CTN001 induces enhanced effector functions such as CDC, ADCC and ADCP against HER2-expressing cancer cells compared with trastuzumab, which will be presented in a separate poster. CTN001 exhibits comparable thermal stability with trastuzumab and can be readily purified to >95% purity with typical purification platforms. The serum half-life of CTN001 at 10 mg/kg intravenous dose in rats is found non-inferior to that of trastuzumab (~12 days versus ~7 days). Taken together, Twin Fc-ICE provides an optimized platform with drug-like properties, which leverages avidity effects of Fc to potentiate therapeutic efficacy of antibody. Citation Format: Eun Shik Choi, Hyunkyu Park, Jiseon Bae, Ki-June Lee, Eunmi Kim, Sujin Yoon, Deokjae Lee, Gi-Hyeok Yang. Twin Fc-immune cell engager (ICE): A novel antibody platform for cancer immunotherapy with enhanced avidity for Fcγ receptors and complement [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3190.

Abstract 6709: P329G-Engager: A novel universal antibody-based adaptor platform for cancer immunotherapy

Abstract Bispecific immune cell engagers are showing promise in cancer immunotherapy. To achieve optimal efficacy, there is a growing need for patient personalization, tackling intra-tumor heterogeneity, and simplified combination therapies. Here, we present a novel modular anti-P329G adaptor platform aiming to address these issues, which is based on the recognition of the P329G mutation in the Fc portion of a targeting adaptor antibody. This P329G mutation can serve to recruit different anti-P329G effector cell engagers, including innate cell engagers, T cell engagers, costimulators or immunocytokines. Specifically, upon identifying patient-specific tumor surface targets, the primary antigen-binding IgG1 antibodies bearing Fc-silencing P329G LALA mutations are applied. Subsequently, based on the tumor’s immune profile, the best-suited anti-tumoral effector cell type is chosen for recruitment and activation. Based on this information, the secondary antibody recognizing the P329G mutation is chosen from an array of effector cell engagers with different modes of action: P329G-T cell bispecifics (P329G-TCB), ADCC-competent P329G innate cell engagers (P329G-ICE), P329G costimulatory molecules (P329G-CD28/4-1BBL) or P329G immunocytokines (P329G-IL2v). In vitro assays showed all P329G modalities inducing anti-tumoral and/or immunomodulatory cell activity. Anti-tumoral efficacy of secondary antibodies was observed only in presence of tumor-targeted P329G adaptors, while no effect was observed in their absence. The readouts consisted of tumor killing quantification, CD4+ and CD8+ T cell activation, cytokine release and cytokine receptor signaling. As a proof of concept study in vivo, an experiment in MKN-45 (CEACAM5+)-bearing humanized mice was performed, using an anti-CEACAM5 P329G-IgG adaptor and a P329G-TCB. Both tumor volume shrinkage and T cell infiltration into the tumor confirmed anti-tumoral efficacy of the platform, as compared to a conventional CEACAM5-targeted TCB. Neither the individual P329G IgG nor the individual P329G-TCB induced anti-tumoral efficacy, validating the requirement for primary and secondary antibody binding for T cell engaging activity. These results provide in vitro and in vivo evidence that the universal P329G engager platform can be used as an efficacious cancer treatment. Ultimately, this modular approach may enable off-the-shelf personalization via combination of patient-specific antibodies and universal effector cell engagers based on the patient’s tumor target and immune profile. Citation Format: Marlena Surowka, Idil Hutter-Karakoc, Diana Darowski, Christina Claus, Claudia Ferrara Koller, Anne Freimoser-Grundschober, Thomas Hofer, Andrzej Sobieniecki, Denis Assisi, Stephane Leclair, Ekkehard Moessner, Pablo Umaña, Maria Amann, Christian Klein. P329G-Engager: A novel universal antibody-based adaptor platform for cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6709.