Tumor-associated Antigens Research Articles

Multifaceted function of B cells in tumorigenesis.

B lymphocytes (B cells) play a complex and paradoxical role in tumorigenesis. They can recognize tumor-associated antigens, present these antigens to T cells, and produce antibodies that directly target and eliminate tumor cells. This makes B cells a potentially powerful ally in combating cancer. However, B cells also exhibit immunosuppressive functions, secreting cytokines like IL-10 or generating tumor-promoting antibodies that dampen the anti-tumor immune response, and some tumor cells have even been shown to exploit B cells to promote their growth and metastasis. This dual nature of B cells presents both opportunities and challenges for tumor immunotherapy. In this review, we summarize the mechanisms underlying the multifaceted functions of B cells and their current applications in cancer immunotherapy. Furthermore, we also explore the key issues and future directions in this field, emphasizing the need for further research to fully harness the anti-tumor potential of B cells in the fight against cancer.

Rationally designed NIR-II excitable and endoplasmic reticulum-targeted molecular phototheranostics for imaging-guided enhanced photoimmunotherapy of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer characterized by an extremely poor prognosis. Photoimmunotherapy has emerged as a promising strategy for the treatment of TNBC. This approach works by selectively destroying tumor cells, releasing tumor-associated antigens, activating the immune system, and effectively inhibiting tumor proliferation and metastasis. However, the majority of current phototheranostic approaches are hindered by limited tissue penetration in the first near-infrared (NIR-I) and ultraviolet–visible (UV–Vis) regions. Additionally, due to the lack of specific subcellular targets, it may be difficult to effectively treat deep-seated lesions with ambiguous and extensive boundaries caused by TNBC metastases. Consequently, the development of effective, deep-penetrating, organelle-targeted phototheranostics is essential for enhancing treatment outcomes in TNBC. This work proposes a novel molecular design strategy of NIR-II phototheranostics to realize planar rigid conjugation and alkyl chain functionalization. The di-hexaalkyl chains in a vertical configuration on the donor (4H-cyclopenta[2,1-b:3,4-b’] dithiophene) and shielding units (fluorene) are introduced to construct a S-D-A-D-S type NIR-II phototheranostics (IR-FCD). The planar and rigid structure of IR-FCD exhibits a robust intramolecular charge transfer capability, a lower band gap, enhanced photon absorption properties, and significant steric hindrance from vertically arranged alkyl chains to minimize non-radiative energy loss. By incorporating N-(but-3-yn-1-yl)-4-methylbenzenesulfonamide at the terminus of an elongated alkyl chain, followed by self-assembly into DSPE-S-S-PEG2000, NIR-II excitable phototheranostics (IR-FCD-Ts NPs) with endoplasmic reticulum (ER) targeting capability were successfully synthesized for imaging-guided photoimmunotherapy of TNBC. The IR-FCD-Ts NPs demonstrate exceptional optical characteristics, with maximum absorption at 1068 nm (extending to 1300 nm) and emission at 1273 nm (extending to 1700 nm), along with a high molar absorption coefficient of 2.76*104 L/mol·c at 1064 nm in aqueous solution. Under exposure to 1064 nm laser irradiation, IR-FCD-Ts NPs exhibit superior photothermal properties and have the potential for photodynamic therapy. By targeting ER, thereby inducing ER stress and significantly enhancing immunogenic cell death (ICD) in tumor cells, it triggers a strong antitumor immune response and inhibits the proliferation and metastasis of TNBC.Graphical

Thermoresistant flagellin-adjuvanted cancer vaccine combined with photothermal therapy synergizes with anti-PD-1 treatment

BackgroundCancer immunotherapy, leveraging the immune system to target and eradicate cancer cells, has transformed cancer treatment paradigms. Immune checkpoint inhibitors (ICIs) are used in a wide array of cancers, but...

Comprehensive Overview on Antibody Drug Conjugates- A Promising Approach in Cancer Therapy

Chemotherapy remains a cornerstone in cancer treatment, utilizing cytotoxic agents to kill or inhibit the growth of cancer cells. However, its efficacy is often limited by systemic toxicity and the development of resistance. To address these challenges, Antibody-Drug Conjugates (ADCs) have emerged as a promising therapeutic strategy, combining the specificity of monoclonal antibodies with the potency of cytotoxic drugs. ADCs are designed to deliver targeted chemotherapy directly to cancer cells, reducing off-target effects and improving therapeutic outcomes. The structure of ADCs consists of a monoclonal antibody, a cytotoxic agent (payload), and a chemical linker. The antibody specifically binds to tumor-associated antigens, facilitating internalization of the drug, which is then released within the cancer cell to induce cell death. This selective targeting minimizes the damage to normal, healthy tissues. Since the first ADC approval in 2000, the field has rapidly advanced, with multiple ADCs receiving FDA approval for both hematological and solid tumors. Despite their potential, ADC development faces challenges such as linker stability, payload delivery, and tumor penetration. Recent advancements have led to the development of second and third-generation ADCs, which feature improved stability, efficacy, and safety profiles. The future of ADCs lies in optimizing their design, including selecting appropriate antigens, refining drug-to-antibody ratios, and enhancing intracellular delivery mechanisms. Overall, ADCs represent a transformative approach to cancer therapy, offering a more targeted, effective, and safer treatment option for cancer patients. Keywords: ADC, Cancer, Chemotherapy, Cytotoxic drug, Carrier, Linker, Target therapy, Toxicity.

Anti-Tumor Efficacy of a Mesothelin-Based Nanovaccine in a KPC Orthotopic Mouse Model of Pancreatic Cancer

Background/Objectives: Immunotherapy has shown promising results in some cancers, but its efficacy remains limited in pancreatic ductal adenocarcinoma (PDAC). Vaccines in nanoparticle form (nanovaccines) can incorporate immunostimulating components to induce a potent immune response. As mesothelin (MSLN) is a tumor-associated antigen overexpressed in PDAC, we evaluated the effect of MSLN nanovaccine in a syngeneic orthotopic KPC-PDAC mouse model. Methods: An MSLN peptide combining three MSLN epitopes and two adjuvants, poly I:C and R848, was encapsulated in PLGA–chitosan nanoparticles to generate the nanovaccine. Results: The MSLN nanovaccine was successfully taken up by dendritic cells in vitro and was found in inguinal lymph nodes 24 h after subcutaneous injection into C57BL/6 mice. Nanovaccine re-stimulation of splenocytes from vaccinated mice led to increased levels of interferon-γ in vitro compared to unstimulated splenocytes. Higher levels of MSLN-specific IgM and IgG antibodies were detected in the serum of vaccinated mice compared to that of control mice. Three vaccination regimens were tested: a prophylactic scheme that included vaccination before tumor induction and two therapeutic schemes involving early and late vaccination after tumor cell inoculation. MSLN nanovaccination inhibited KPC tumor progression and metastasis and induced higher CD8+ T cell infiltration in the tumor that developed in response to prophylactic and early therapeutic schedules but not in response to a later vaccination approach. Although the nanovaccine treatment elicited higher humoral and cellular antigen-specific responses in tumor-bearing mice for both vaccination strategies, the therapeutic vaccination also increased the expression of exhaustion markers in CD8+ T cells. Conclusions: Our results support the relevance of an MSLN-based nanovaccine as a new immunotherapy treatment for PDAC and propose an innovative method of vaccine delivery using NPs.

Motif-Directed Oxidative Folding to Design and Discover Multicyclic Peptides for Protein Recognition.

ConspectusMulticyclic peptides that are constrained through covalent cross-linkers can usually maintain stable three-dimensional (3D) structures without the necessity of incorporating noncovalently interacting cores. This configuration allows for a greater utilization of residues for functional purposes compared to larger proteins, rendering multicyclic peptides attractive molecular modalities for the development of chemical tools and therapeutic agents. Even smaller multicyclic peptides, which may lack stable 3D structures due to limited sequence-driven folding capabilities, can still benefit from the specific conformations stabilized by covalent cross-linkers to facilitate target binding. Disulfide-rich peptides (DRPs) are a class of particularly significant multicyclic peptides that are primarily composed of disulfide bonds in their interior. However, the structural diversity of DRPs is limited to a few naturally occurring and designer scaffolds, which significantly impedes the development of multicyclic peptide ligands and therapeutics. To address this issue, we developed a novel method that utilizes disulfide-directing motifs to design and discover DRPs with new structures and functions in random sequence space. Compared with traditional DRPs, these new DRPs that incorporate disulfide-directing motifs exhibit more precise oxidative folding regarding disulfide pairing and demonstrate greater tolerance to sequence manipulations. Thus, we designated these peptides as disulfide-directed multicyclic peptides (DDMPs).Over the past decade, we have developed a new class of multicyclic peptides by leveraging disulfide-directing motifs, including biscysteine motifs such as CPXXC, CPPC, and CXC (C: cysteine; P: proline; X: any amino acid), as well as triscysteine motifs that rationally combine two biscysteine motifs (e.g., CPPCXC and CPXXCXC) to direct the oxidative folding of peptides. This leads to the introduction of a novel concept known as motif-directed oxidative folding, which is valuable for the construction of peptides with multiple disulfide bonds. A large diversity of DDMPs have been designed by simply altering the disulfide-directing motifs, the arrangement of cysteine residues (i.e., cysteine patterns), and the number of random residues separating them. As the oxidative folding of DDMPs is primarily determined by disulfide-directing motifs, these peptides are intrinsically more tolerant of extensive sequence manipulations compared to traditional DRPs. Consequently, multicyclic peptide libraries with an unprecedented high degree of sequence randomization have been developed by utilizing commonly used biological display systems such as phage display. We have validated the applicability of these libraries by successfully discovering DDMPs with unique protein-like 3D structures and high affinity and specificity to various cell-surface receptors, including tumor-associated antigens, immune costimulatory receptors, and G protein-coupled receptors (GPCRs). Currently, multicyclic peptides used in clinical settings are of natural origin or derived from natural DRPs. Our studies have opened up the possibility of developing multicyclic peptides without relying on natural scaffolds, representing a pivotal breakthrough in the field of peptide ligand and drug discovery. Further investigations will facilitate the application of our DDMPs in broader fields such as bioanalysis, chemical biology, and biomedicine.

Functionalized Poly(ethylene Glycol) Diacrylate Scaffolds for In Situ Immunomodulation of Dendritic Cells Targeting Melanoma Tumor.

Various immunotherapeutic strategies are being developed to fight cancer, which is one of the leading causes of mortality. Dendritic cells (DCs), being professional antigen-presenting cells, after efficient manipulation with tumor-associated antigens, can lead to effective T-cell recruitment and activation at the tumor site, resulting in cytotoxic T-cell-mediated cancer cell killing. To circumvent the inefficiencies of ex vivo DC modification and patient infusion, an alternative strategy involving in situ DC activation has been explored here. Here, the vaccine components are tumor lysates, as antigens, and polyinosinic:polycytidylic acid (poly(I:C)), a toll-like receptor-3 (TLR3) agonist, as an adjuvant. Our in vitro studies demonstrate that complexing poly(I:C) with a carrier molecule, chitosan, enhances its stability and accessibility to TLR3 in the DC endosomal membrane. Material-based localized delivery of immunomodulatory factors is known to improve their stability and reduce their off-target side effects. Here, PEGDA-PLL-based macroporous scaffolds allow easy recruitment of host cells, thereby enabling effective interaction between the vaccine components loaded on them and the infiltrating immune cells. The vaccine components present in the scaffold facilitate efficient DC activation and migration, leading to subsequent T-cell activation and antitumor response, as shown by our in vivo studies.

Carrier-Free Nanocombo-Sensitized Photoimmunotherapy via Activation of α2-Adrenergic Receptors.

Photodynamic therapy (PDT)-based photoimmunotherapy has attracted increasing attention in the field of cancer immunotherapy. Nonetheless, monotherapy alone proves insufficient in eliciting robust and enduring tumor immunogenicity within the "cold" microenvironment of triple-negative breast cancer. Therefore, it is imperative to integrate phototherapy and immunostimulation strategies to achieve synergistic effects. Here, we developed a carrier-free nanocombo comprising a photosensitizer (chlorin e6, Ce6) and an α2-adrenergic receptor (α2-AR) agonist (guanfacine, GFC) to enhance photoimmunotherapy through α2-AR activation. Ce6 and GFC possessed the ability to self-assemble into spherical nanoparticles, with the resulting Ce6-GFC (CeG) exhibiting exceptional drug loading efficiency (approaching 100%) and long-lasting colloidal stability, along with effective in vivo tumor-targeting capabilities. Following near-infrared laser irradiation, CeG-mediated phototherapy instigated a rapid generation of reactive oxygen species, leading to membrane disruption and the release of tumor-associated antigens, thereby facilitating dendritic cell maturation. Furthermore, α2-AR agonists served to repolarize M2 tumor-associated macrophages toward the M1 phenotype via adenylyl cyclase-mediated activation of α2-AR, thereby promoting the recruitment and activation of cytotoxic T lymphocytes. As a result, the carrier-free nanocombo significantly enhanced the efficacy of photoimmunotherapy in combatting poorly immunogenic breast tumors in female mice. Our findings showcase a "killing two birds with one stone" approach that boosts tumor immunogenicity, mitigates tumor immunosuppression, and advances the field of photoimmunotherapy.

Lipid Nanoparticles and PEG: Time Frame of Immune Checkpoint Blockade Can Be Controlled by Adjusting the Rate of Cellular Uptake of Nanoparticles.

The engineerability of lipid nanoparticles (LNPs) and their ability to deliver nucleic acids make LNPs attractive tools for cancer immunotherapy. LNP-based gene delivery can be employed for various approaches in cancer immunotherapy, including encoding tumor-associated antigens and silencing of negative immune checkpoint proteins. For example, LNPs carrying small interfering RNAs can offer several advantages, including sustained and durable inhibition of an immune checkpoint protein. Due to their tunable design, modifying the lipid composition of LNPs can regulate the rate of their uptake by immune cells and the rate of gene silencing. Controlling the kinetics of LNP uptake provides additional flexibility and strategies to generate appropriate immunomodulation in the tumor microenvironment. Here, we evaluated the effects of polyethylene glycol (PEG) content ranging from 0.5 to 6 mol % on the cellular uptake of LNPs by immune cells and gene silencing of PD-L1 after intratumoral administration. We evaluated the cellular uptake and PD-L1 blockade in vitro in cell studies and in vivo using the YUMM1.7 melanoma tumor model. Cell studies showed that the rate of cell uptake was inversely correlated to an increasing mol % of PEG in a linear relationship. In the in vivo studies, 0.5% PEG LNP initiated an immediate effect in the tumor with a significant decrease in the PD-L1 expression of immune cells observed within 24 h. In comparison, the gene silencing effect of 6% PEG LNP was delayed, with a significant decrease of PD-L1 expression in immune cell subsets being observed 72 h after administration. Notably, performance of the 6% PEG LNP at 72 h was comparable to that of the 0.5% PEG LNP at 24 h. Overall, this study suggests that PEG modifications and intratumoral administration of LNPs can be a promising strategy for an effective antitumor immune response.

Engineered SH3-Derived Sherpabodies Function as a Modular Platform for Targeted T Cell Immunotherapy.

Engineered T cell therapies have emerged as a promising approach for cancer treatment, yet their application to solid tumors remains challenging due to the limited specificity and persistence of current antigen recognition strategies. Here, we introduced sherpabodies, engineered from a human SH3 domain scaffold, as a class of antibody-mimetic proteins capable of precise tumor-associated antigen recognition. A phage display library identified sherpabodies against a panel of popular tumor-associated antigens (TAA), which were subsequently incorporated into second-generation chimeric antigen receptor constructs that were termed sherpabody-guided CARs (SbCARs). These SbCARs demonstrated potent in vitro specificity and cytotoxicity against solid cancer TAAs, without cross-reactivity to closely related proteins. The modularity, versatility, and small size of sherpabodies enabled generation of multipecific SbCARs, in particular TriSbCARs with OR-logic that could robustly activate with cells expressing any or combinations of three cognate TAA targets, as well as circuits with IF-THEN logic in combination with synthetic Notch. In vivo, SbCAR T cells elicited a dose-dependent antitumor response in xenograft mouse models, highlighting their potential for therapeutic application. Furthermore, an inducible SbCAR system displayed enhanced persistence and antitumor activity when compared to constitutive CARs. These findings suggest that sherpabodies represent a versatile and promising platform for the next generation of CAR-T cell therapies, particularly for solid tumors.

Elevated serum tumor-associated antigens in patients with interstitial lung disease: a retrospective study on clinical features and prognosis

ABSTRACT Background Elevated serum tumor-associated antigens (TAAs) were reported to be common in patients with interstitial lung disease (ILD), and correlated with pulmonary involvement or malignancy development. However there were no adequate longitudinal studies on the association between elevated TAAs and various types of ILDs in Chinese patients. Research design and methods The treatment-naïve ILD patients were retrospectively enrolled. The clinical, laboratory, imaging characteristics and prognosis were analyzed and compared among those with normal and different number of elevated TAAs. Results An increase of at least one TAA was present in 169/308 (54.87%) of our patients. Both baseline alveolar and interstitial scores were much higher, and lung involvement tended to be worse during follow up in patients with two and three or more elevated TAAs than in normal TAAs. Patients with three or more elevated TAAs had the highest interstitial scores and a higher all-cause mortality during follow-up than those with one elevated TAA or normal TAAs. The occurrence of malignancy was similar in all patients. Conclusion Elevated TAAs were present in 54.87% of ILD patients and associated with lung interstitial lesions, which might be a marker for lung involvement progression, while not for malignancy development in ILD.

EPS-8 regulates human malignant melanoma development by activating the Hedgehog pathway via degradation of Ptch1.

EPS-8 regulates human malignant melanoma development by activating the Hedgehog pathway via degradation of Ptch1.

Personalized tumor vaccines based on carrier-free double-adjuvant nanoparticles and tumor-associated antigens for enhancing immune responses

Personalized tumor vaccines based on carrier-free double-adjuvant nanoparticles and tumor-associated antigens for enhancing immune responses

A CLDN18.2-Targeted Nanoplatform Manipulates Magnetic Hyperthermia Spatiotemporally for Synergistic Immunotherapy in Gastric Cancer.

Precision treatment of gastric cancer requires specific biomarkers, and CLDN18.2 emerges as a promising target for patients' stratification and therapeutic guidance. In 563 cases, 54.4% of patients are identified as CLDN18.2-positive, with CLDN18.2 expression negatively correlated with immune-related factors like PD-L1, indicating a "cold" tumor microenvironment. Here, a novel CLDN18.2 monoclonal antibody 1D5 is created with superior high specificity and affinity, and the antibody-dependent fluorescence-magnetic nanoparticle is developed for specific detection and magnetic hyperthermia (MHT). Under the assistance of sensitive fluorescence and deep-penetrating magnetic particle imaging for tracing and timing the optimal nanoparticle dosage, MHT induces robust immunogenic response via DNA mismatch repair and tumor-associated antigen release. It recruits CD11c+ dendritic cells, compensates PD-1 in CD8+ T cells, and enhances CD86+ macrophage polarization. The combination of anti-PD-1 therapy increased TNF-α and IFN-γ secretion and further boosted the cytotoxic efficacy of CD8+ T cells. Excellent therapeutic efficacy is found simultaneously on cell-derived allografts and patient-derived xenografts based on this spatiotemporally manipulated strategy, presenting a therapeutic option for enhancing responsiveness to immunotherapy for CLDN18.2-positive individuals.

Targeting mesothelin-CD24 axis repolarizes tumor-associated macrophages to potentiate PD-1 blockade therapy in high-grade serous ovarian cancer

BackgroundHigh-grade serous ovarian cancer (HGSOC) is a highly aggressive malignancy marked by an immunosuppressive tumor microenvironment that hinders effective immune responses. A key feature of this environment is the extensive...

Reprogramming the Tumor Immune Microenvironment with ICAM-1-Targeted Antibody‒Drug Conjugates and B7-H3-CD3 Bispecific Antibodies.

Reprogramming the tumor immune microenvironment (TIM) plays an important role in promoting the reversal of immune "cold" tumors into "hot" inflammatory tumors. Improving drug targeting, blocking immune checkpoints, and promoting the activation of immune cells are crucial for reprogramming the TIM. Here, an intercellular adhesion molecule 1-targeted antibody‒drug conjugate in combination with a B7-H3-CD3 bispecific antibody is selected for TIM reprogramming, which improved the efficacy of triple-negative breast cancer immunotherapy. This combination therapy improves drug targeting, blocks immune checkpoint pathways, and activates effector T cells to release cytokines, leading to immunogenic cell death and the release of tumor-associated antigens. This effect promotes the maturation of dendritic cells, infiltration and activation of cytotoxic CD8+ T cells, repolarization of M1-type macrophages, and reduction of M2-type macrophages, immune suppressor Tregs, and MDS cells, thereby reprogramming the TIM. In addition, this innovative strategy promotes the accumulation of immune cells at metastasis sites and significantly impedes the progression of lung metastatic lesions. Overall, this study provides novel insights for reprogramming the TIM using novel immunotherapeutic strategies that leverage the synergistic effects of antibody-drug conjugatesand bispecific antibodies.

Tumor-specific CD8+ T cells from the bone marrow resist exhaustion and exhibit increased persistence in tumor-bearing hosts as compared with tumor-infiltrating lymphocytes

BackgroundImmunotherapy is now an integral aspect of cancer therapy. Strategies employing adoptive cell therapy (ACT) have seen the establishment of chimeric antigen receptor (CAR)-T cells using peripheral blood lymphocytes as...

Universal Prophylactic Antitumor Vaccination Using Stem Cell Membrane-Coated Nanoparticles.

Cancer vaccines are a promising immunotherapeutic modality that function by training the immune system to recognize and destroy malignant cells. As tumor-specific and tumor-associated antigens generally cannot be identified until after a tumor has already been established, these vaccines must be applied therapeutically when strong immunosuppressive mechanisms are already in place. Building upon previous work using cell membrane coating nanotechnology, the development of a broad-spectrum prophylactic cancer nanovaccine that consists of induced pluripotent stem cell (iPSC) membrane coated around an adjuvant-loaded nanoparticle core is shown. The resulting nanostructure is capable of presenting iPSC-derived oncofetal antigens, which are oftentimes re-expressed on cancer cells but lowly present on normal adult tissues. When administered in vivo, the iPSC membrane-coated nanoparticles are highly immunostimulatory and elicit strong antitumor immunity that can successfully inhibit the growth of multiple tumor types, including five different murine tumor models and in a bilaterial heterogeneous tumor model. Overall, this work demonstrates an effective approach for engineering iPSC-based nanovaccines that can be applied broadly to prevent cancer before it occurs.

Abstract B124: Molecular mimicry of SARS-COV-2 antigens with tumor associated antigens

Abstract The entire SARS-CoV-2 proteome was scanned to predict potential T cell antigens linked to HLA-A*02:01 and homology to TAAs (tumor-associated antigens) was searched by BLAST. Viral epitopes with high affinity (<100nM) to the HLA-A*02:01 allele were predicted. Shared and variant-specific epitopes were identified. Significant homologies in amino acidic sequence have been found between SARS-CoV-2 peptides and multiple TAAs, mainly associated with breast, liver, melanoma and colon cancers. The molecular mimicry of the viral epitopes and the TAAs was found in all viral proteins, mostly the Orf 1ab and the Spike, which is included in the BNT162b2 vaccine. Predicted structural similarities confirmed the sequence homology and comparable patterns of contact with both HLA and TCR α and β chains were observed. CD8+ T cell clones cross-reactive with the paired peptides have been found by MHC class l-dextramer staining. Our results show for the first time that several SARS-COV-2 antigens are highly homologous to TAAs and cross-reactive T cells are identified in infected and BNT162b2 preventive vaccinated individuals. The implication would be that the SARS-Cov-2 pandemic could represent a natural preventive immunization for breast, liver, melanoma and colon cancers. In the coming years, real-world evidences will provide the final proof for such immunological experimental evidence. Moreover, such SARS-CoV-2 epitopes can be used to develop “multi-cancer” off-the-shelf preventive/therapeutic vaccine formulations, with higher antigenicity and immunogenicity than over-expressed tumor self-antigens, for the potential valuable benefit of thousands of cancer patients around the World. Ragone et al., Front. Immunol. 15:1398002 Citation Format: Concetta Ragone, Angela Mauriello, Beatrice Cavalluzzo, Ernesta Cavalcanti, Luigi Russo, Simona Mangano, Biancamaria Cembrola, Maria Tagliamonte, Luigi Buonaguro. Molecular mimicry of SARS-COV-2 antigens with tumor associated antigens [abstract]. In: Proceedings of the AACR IO Conference: Discovery and Innovation in Cancer Immunology: Revolutionizing Treatment through Immunotherapy; 2025 Feb 23-26; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Immunol Res 2025;13(2 Suppl):Abstract nr B124.

Abstract A009: Development of monoclonal antibodies targeting truncated O-glycans expressed specifically by cancer cells offers a novel strategy to enhance cancer immunotherapy efficacy

Abstract Glycosylation is a vital post-translational modification of proteins and lipids in mammalian cells involved in cell–matrix interactions, cell recognition, and intracellular signaling. One glycosylation pattern often disrupted during the process of carcinogenesis is O-glycosylation. This phenomenon leads to the expression of incomplete or truncated O-glycans on proteins of cancer cells, particularly in cancers of epithelial origin, including breast, ovarian, gastric, pancreatic, and colon cancers. This alteration supports tumor progression and is often linked to poor prognosis. Developing monoclonal antibodies (mAbs) targeting truncated Oglycans expressed specifically by cancer cells could be a promising strategy to enhance cancer immunotherapy efficacy, although it could be challenging. We developed two mAbs that recognize truncated O-glycans expressed specifically on tumor tissues, sparing healthy tissues. Both mAbs were generated from the Hollinshead allogeneic colorectal cancer vaccine platform containing two immunogenic synergistic tumor associated antigens (TAAs) derived from pooled specimens from 79 patients with colon cancer. This cancer vaccine platform was used as immunogen to generate these two mAbs in mice. NEO-201 is a humanized IgG1 mAb that binds to Core 1 and/or extended Core 1 O-glycans expressed by several human solid and blood tumors, as well as neutrophils, and mediates killing of cancer cells, neutrophils, regulatory T cells (Tregs) and granulocytic myeloid-derived suppressor cells (gMDSCs) via ADCC and CDC. In the ongoing phase II clinical trial (NCT03476681), combining NEO-201 with pembrolizumab in subjects with tumor resistant to checkpoint inhibitors, it has been observed that the reduction of both circulating Tregs and gMDSCs mediated by NEO-201 was associated with durable stable disease. These findings suggest that employing a mAb able to mediate the killing of both tumor cells and immunosuppressive cells expressing core 1 O-glycans can restore the efficacy of checkpoint inhibitors and enhance overall the efficacy of cancer immunotherapy. NEO-102 was a chimeric human IgG1 mAb targeting a glycosylated variant of MUC5AC expressed specifically by colorectal and pancreatic cancer. In a phase 2 study, NEO-102 showed promising results in patients with advanced, refractory colorectal cancer. However, given its low binding affinity for its target antigen, we decided to enhance the binding affinity of NEO-102. The new clone was named PB-223. PB-223 demonstrates a higher affinity for the target antigen compared to NEO-102. PB-223 binds specifically to core-2 O-glycans expressed on cancer cell lines positive for PB-223 binding in flow cytometry. IHC analysis also showed that PB-233 binds to additional tumor tissues not reactive with NEO-102, but not healthy tissues. PB-223 can also internalize into human cancer cell lines expressing core 2 O-glycans, suggesting that PB-223 may be a potential candidate for the development of safe and effective antibody-drug conjugates (ADC) for the treatment of various human carcinomas. Citation Format: Massimo Fantini, Anjum Zaki, Sharon A Mavroukakis, Philip M Arlen, Kwong Y Tsang. Development of monoclonal antibodies targeting truncated O-glycans expressed specifically by cancer cells offers a novel strategy to enhance cancer immunotherapy efficacy [abstract]. In: Proceedings of the AACR IO Conference: Discovery and Innovation in Cancer Immunology: Revolutionizing Treatment through Immunotherapy; 2025 Feb 23-26; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Immunol Res 2025;13(2 Suppl):Abstract nr A009.