Conjugate Targeting Research Articles

Modulating autophagy to boost the antitumor efficacy of TROP2-directed antibody-drug conjugate in pancreatic cancer

Pancreatic cancer, characterized by a dismal prognosis and limited treatment options, persists as a formidable challenge in oncology. Trophoblast cell surface antigen 2 (TROP2)-directed antibody-drug conjugates have achieved great success in solid tumors such as breast cancer and uroepithelial carcinoma. However, their efficacy against pancreatic cancer was insufficient in clinical trials, necessitating an imperative exploration of underlying mechanisms and new therapeutic strategies. In this study, we indicated that αTROP2-MMAE, an antibody-drug conjugate targeting TROP2, induced apoptosis through the caspase-9/PARP pathway and exerted potent antitumor effects against TROP2-positive pancreatic cancer. Simultaneously, RNA sequencing suggested significant changes in autophagy after αTROP2-MMAE treatment. The formation of autophagosomes and activation of autophagic flux were markedly induced through mechanisms associated with suppressing the activation of the Akt/mTOR pathway. The addition of pharmacological inhibitors of autophagy enhanced the cytotoxicity and apoptosis caused by αTROP2-MMAE, revealing the cytoprotective role of autophagy in TROP2-positive pancreatic cancer. In the subcutaneous xenograft model using BxPC3 cells, the combined administration of αTROP2-MMAE and an autophagy inhibitor elevated the tumor inhibition rate of αTROP2-MMAE from 71.6 % to 99.0 %, resulting in the eradication of tumors in half of the mice. Collectively, our research demonstrated for the first time the cytoprotective role of autophagy in TROP2-targeted antibody-drug conjugate therapy for pancreatic cancer, providing new perspectives for mechanistic exploration and therapeutic strategies in the treatment of pancreatic cancer.

P3.13D.01 Proteomic Characterization of Antibody Drug Conjugate Target Expression Profiles in Small Cell Lung Cancer (SCLC)

P3.13D.01 Proteomic Characterization of Antibody Drug Conjugate Target Expression Profiles in Small Cell Lung Cancer (SCLC)

Aluminum phthalocyanine tetrasulfonate conjugated to surface-modified Iron oxide nanoparticles as a magnetic targeting platform for photodynamic therapy of Ehrlich tumor-bearing mice

BackgroundPhotodynamic therapy (PDT) is a targeted treatment option for cancers that are non-responding to ordinary anticancer therapies. It involves activating a photosensitizer with a light source of a specific wavelength to destroy targeted cells and their surrounding vasculature. Aluminum phthalocyanine tetra sulfonate (AlPcS4) has gained attention as a second-generation photosensitizer for its strong absorption in the red-light region. AlPcS4 can be conjugated to magnetic iron oxide nanoparticles (IONs) to provide targeted drug delivery to the tumor cells while reducing its undesired effect on healthy tissues in other body parts. MethodsMagnetic glutamine functionalized iron oxide nanocomposites loaded with AlPcS4 (IONs-NH2-AlPcS4) were synthesized via the co-precipitation method. The conjugate (IONs-NH2-AlPcS4) was characterized by TEM, Zeta potential, DLS, FTIR, and UV–VIS absorption spectroscopy. Furthermore, its photodynamic activity was investigated using albino mice with induced Ehrlich solid tumors. ResultsAlPcS4 was successfully conjugated to IONs-NH2 with a high loading efficiency of 54±2%. The synthesized conjugate exhibited a spherical shape, with 7 ± 2 nm particle size. The In vivo experiment revealed that the albino mice with induced Ehrlich solid tumor that were treated by combined PDT and magnetic targeting conjugate exhibited significant tumor regression and notably higher levels of necrotic tissue compared to the animals in other groups. ConclusionPDT mediated by magnetic targeting significantly inhibited tumor growth with minimal adverse effects, indicating its great potential as a promising strategy for solid cancer treatment.

Synthesis of novel skipped diene-3-halocoumarin conjugates as potent anticancer and antibacterial biocompatible agents

Cancer and bacterial infections are persistent nightmares for human health, which are now aggravated by the development of new types of cancer and pathogenic bacteria, as well as their resistance to prescribed drugs. To be part of a hopeful awakening, this work aimed to synthesize four novel skipped diene-3-halocoumarin conjugates coded SDC1-SDC4 and explore their biosafe functions as anticancer and antibacterial alternatives. In the first step of their synthesis, mequinol reacts with ethyl-2-haloacetoacetate through a H2SO4-catalyzed Pechmann reaction, yielding 3-halo-6-methoxy-4-methylcoumarins. The in situ-generated Vilsmeier-Haack reagent formylated these trifunctionalized coumarins to create their 7-carbaldehyde congeners. Finally, the target conjugates were prepared by condensing the latter compounds with 2,4-pentadione through the modified Claisen-Schmidt reaction. The molecular structures involving their stereochemistry were established for SDC1-SDC4 by analyzing their spectra released from FTIR, 1H NMR, 13C NMR, and HRMS. On the other hand, the anticancer and cytotoxicity of these conjugates were investigated against eight cancer and three healthy cell lines, respectively, using an MTT-probing technique. Four pathogenic and three commensal aerobes were the microbes utilized to evaluate the antibacterial and microbiota compatibility, respectively, employing a broth microdilution methodology. The results indicated that the conjugate with the highest anticancer attribute and lowest cytotoxicity was SDC1, while SDC2 demonstrated the greatest antibacterial attribute with minimal microbiota toxicity. These findings projected the influence of a 3-position substitute of the coumarin backbone on the biological activities under research. From these, it is concluded that the chemical structures of SDC1 and SDC2 may represent potent anticancer cytocompatible and antibacterial microbiota-compatible scaffolds, respectively.

172 (PB160): Affimer® Drug Conjugates (AffDC) targeting Fibroblast Activation Protein-α deliver highly toxic warheads to the tumor microenvironment by leveraging the preCISION™ release mechanism

172 (PB160): Affimer® Drug Conjugates (AffDC) targeting Fibroblast Activation Protein-α deliver highly toxic warheads to the tumor microenvironment by leveraging the preCISION™ release mechanism

TROP2 Expression and Therapeutic Implications in Cutaneous Squamous Cell Carcinoma: Insights From Immunohistochemical and Functional Analysis.

Cutaneous squamous cell carcinoma (cSCC) is a common form of skin cancer, but treatments for advanced cases have limited efficacy. Trophoblast cell-surface antigen 2 (TROP2) is a cell-surface protein that is widely expressed in various tumours, where it exerts significant influence over critical processes such as tumour cell growth, apoptosis, migration, invasion and metastasis. Sacituzumab govitecan, an antibody-drug conjugate (ADC) targeting TROP2, is emerging as a promising strategy for anticancer therapy. In this study, we investigated TROP2 expression in cSCC tissues from 51 patients and evaluated its function in the A431 human SCC cell line. Immunohistochemical analysis revealed TROP2 expression on the plasma membrane of cSCC tissues and A431 cells. A431 cells showed sensitivity to sacituzumab govitecan with a significant concentration-dependent decrease in viable cell number. In addition, Knockdown of TROP2 resulted in decreased expression of cyclin D1 and BCL-2, along with reduced cell viability. Knockdown of TROP2 also resulted in decreased expression of vimentin, along with reduced migratory capacity. These findings suggest that TROP2 plays a crucial role in cSCC cell proliferation and migration, and highlight the potential of sacituzumab govitecan as a promising therapeutic option for cSCC.

P1.06B.06 Analysis of Antibody-Drug Conjugate Target Expression Across Genomic Subsets of Non-Small Cell Lung Cancer

P1.06B.06 Analysis of Antibody-Drug Conjugate Target Expression Across Genomic Subsets of Non-Small Cell Lung Cancer

165 (PB153): NEXUS-01, a phase 1 study of LY4052031, an antibody-drug conjugate targeting Nectin-4 in participants with advanced or metastatic urothelial carcinoma or other solid tumors (Trial in Progress)

165 (PB153): NEXUS-01, a phase 1 study of LY4052031, an antibody-drug conjugate targeting Nectin-4 in participants with advanced or metastatic urothelial carcinoma or other solid tumors (Trial in Progress)

Novel bispecific antibody-drug conjugate targeting PD-L1 and B7-H3 enhances antitumor efficacy and promotes immune-mediated antitumor responses

BackgroundAntibody-drug conjugates (ADCs) offer a promising approach, combining monoclonal antibodies with chemotherapeutic drugs to target cancer cells effectively while minimizing toxicity.MethodsThis study examined the therapeutic efficacy and potential mechanisms of...

Detection of SEZ6, a therapeutic target, in medullary thyroid carcinoma.

Seizure-related 6 homolog (SEZ6) is a cDNA that strongly associated with neuroendocrine differentiation. Recently, SEZ6 expression was found in a subset of small cell lung carcinoma (SCLC). Furthermore, ABBV-011, a novel antibody drug conjugate targeting SEZ6 has been developed and is currently in clinical trial in treating SCLC and neuroendocrine neoplasms, including medullary thyroid carcinoma (MTC). We herein presented the first evidence that SEZ6 was highly expressed in MTC. SEZ6 immunoexpression was studied in 78 MTCs and correlated with clinicopathologic characteristics, outcome, and molecular profile. SEZ6 was highly expressed in primary tumors, regional recurrence, and distant metastasis. Using two different SEZ6 antibody clones SC17.14 and 14E5, SEZ6 immunopositivity was seen in 91% to 93% of primary MTCs, 100% of regional recurrence, and 75% to 83% of distant metastasis. High level of SEZ6 immunoexpression determined using H score was associated with male sex, advance stage, and extrathyroidal thyroidal extension. There was no correlation between SEZ6 expression and outcome or RET/RAS mutation status in MTC. The frequency of SEZ6 positivity in MTC without RET/RAS mutations were 83%. SEZ6 may serve as a novel biomarker for MTCs. Although SEZ6 lacks any prognostic values in MTC, its positivity in 91% to 93% of MTCs, including MTCs without RET and RAS mutations, renders SEZ6-targetted antibody-drug conjugate therapy a promising targeted therapy for MTCs.

Preclinical Evaluation of STI-8811, a Novel Antibody-Drug Conjugate Targeting BCMA for the Treatment of Multiple Myeloma.

Treatment for patients with multiple myeloma has experienced rapid development and improvement in recent years; however, patients continue to experience relapse, and multiple myeloma remains largely incurable. B-cell maturation antigen (BCMA) has been widely recognized as a promising target for treatment of multiple myeloma due to its exclusive expression in B-cell linage cells and its critical role in the growth and survival of malignant plasma cells. Here, we introduce STI-8811, a BCMA-targeting antibody-drug conjugate (ADC) linked to an auristatin-derived duostatin payload via an enzymatically cleavable peptide linker, using our proprietary C-lock technology. STI-8811 exhibits target-specific binding activity and rapid internalization, leading to G2/M cell-cycle arrest, caspase 3/7 activation, and apoptosis in BCMA-expressing tumor cells in vitro. Soluble BCMA (sBCMA) is shed by multiple myeloma cells into the blood and increases with disease progression, competing for ADC binding and reducing its efficacy. We report enhanced cytotoxic activity in the presence of high levels of sBCMA compared with a belantamab mafodotin biosimilar (J6M0-mcMMAF). STI-8811 demonstrated greater in vivo activity than J6M0-mcMMAF in solid and disseminated multiple myeloma models, including tumor models with low BCMA expression and/or in large solid tumors representing soft-tissue plasmacytomas. In cynomolgus monkeys, STI-8811 was well tolerated, with toxicities consistent with other BCMA-targeting ADCs with auristatin payloads in clinical studies. STI-8811 has the potential to outperform current clinical candidates with lower toxicity and higher activity under conditions found in patients with advanced disease. Significance: STI-8811 is a BCMA-targeting ADC carrying a potent auristatin derivative. We report unique binding properties which maintain potent cytotoxic activity under sBCMA-high conditions that hinder the clinical efficacy of current BCMA-targeting ADC candidates. Beyond disseminated models of multiple myeloma, we observed efficacy in solid tumor models of plasmacytomas with low and heterogenous BCMA expressions at a magnitude and duration of response exceeding that of clinical comparators.

Treatment of refractory diffuse large B-cell lymphoma involving the central nervous system with polatuzumab vedotin-based regimen: a case report and literature review

Polatuzumab vedotin (Pola) is a novel antibody-drug conjugate targeting CD79b, which has been shown to be effective in treating newly diagnosed and relapsed/refractory diffuse large B cell lymphoma (DLBCL) during clinical trials. This study aims to conduct a retrospective analysis of the clinical characteristics, diagnosis, and treatment of a patient with refractory secondary central nervous system lymphoma at Beijing Hospital, alongside a review of relevant literature. This study included a 79-year-old female patient who was diagnosed with DLBCL affecting the ilium, sacrum, spinal cord, and nerve roots and had an IPI score of 5 and a high-risk score according to MSKCC. She showed a geriatric comprehensive assessment (IACA) score of 2, which was categorized under the unfit group. Her initial treatment comprised chemo-free therapy and radiotherapy, followed by progression. In the second-line treatment, a Pola-based regimen was applied, and the patient achieved a complete response, suggesting that this regimen may be a therapeutic option for patients with DLBCL involving the central nervous system.

Versatile hydrogel drug carrier loading with peptide-carbon dots conjugates for efficient targeting and synergistic suppression of breast cancer cell

Breast cancer become the most prevalent malignancy and is rising up to the first leading cause of cancer-related mortality among the female people globally. Approaches for safe, specific targeting and efficient inhibition of breast cancer cells, are urgently demanded for lifting the survival rate of breast tumor-bearing patients. Herein, a versatile hydrogel drug carrier consisting of doxorubicin (DOX)-loaded hydrogel microsphere and carbon dots (CDs)-loaded peptide nanowires (DOX@PEG/PNFs-CDs) was constructed, presenting specific targeting and synergistic anti-cancer cell potencies. The hydrogel PEG microspheres with a rich porous structure benefited the drug loading efficiency, demonstrating good biodegradability and higher drug release efficiency at acidic environment. Benefiting from the RGD group of the peptide nanowires, the drug-loaded system specific targeted onto the MDA-MB-231 cells, subsequently promoting the synergistic inhibition of the cancer cell growth by DOX and metformin derived CDs. This all-in-one smart drug carrier post a promising strategy for breast cancer treatment.

Tuning Responses to Polatuzumab Vedotin in B-cell Lymphoma.

Polatuzumab vedotin, an antibody-drug conjugate targeting CD79B, is the first new drug approved for first-line therapy of diffuse large B-cell lymphoma in more than two decades, although factors determining treatment responses to polatuzumab vedotin remain unknown. Two new studies identified central mechanisms of lower sensitivity, namely reduced accessibility of the CD79B epitope through N-linked glycosylation of CD79B and lower CD79B surface expression levels due to the activity of the KLHL6 E3 ligase. See related article by Corcoran et al., p. 1653 (6) See related article by Meriranta et al. (7).

Single-cell RNA sequencing of pediatric Hodgkin lymphoma to study the inhibition of T cell subtypes.

Pediatric classic Hodgkin lymphoma (cHL) patients have a high survival rate but suffer from severe long-term side effects induced by chemo- and radiotherapy. cHL tumors are characterized by the low fraction (0.1%-10%) of malignant Hodgkin andReed-Sternberg (HRS) cells in the tumor. The HRS cells depend on the surrounding immune cells for survival and growth. This dependence is leveraged by current treatments that target the PD-1/PD-L1 axis in cHL tumors. The development of more targeted therapies that are specific for the tumor and are therefore less toxic for healthy tissue compared with conventional chemotherapy could improve the quality of life of pediatric cHL survivors. Here, we applied single-cell RNA sequencing (scRNA-seq) on isolated HRS cells and the immune cells from the same cHL tumors. Besides TNFRSF8 (CD30), we identified other genes of cell surface proteins that are consistently overexpressed in HRS cells, such as NRXN3 and LRP8, which can potentially be used as alternative targets for antibody-drug conjugates or CAR T cells. Finally, we identified potential interactions by which HRS cells inhibit T cells, among which are the galectin-1/CD69 and HLA-II/LAG3 interactions. RNAscope was used to validate the enrichment of CD69 and LAG3 expression on T cells near HRS cells and indicated large variability of the interaction strength with the corresponding ligands between patients and between tumor tissue regions. In conclusion, this study identifies new potential therapeutic targets for cHL and highlights the importance of studying heterogeneity when identifying therapy targets, specifically those that target tumor-immune cell interactions.

437TiP An open-label, multicenter, phase II study to evaluate the safety and efficacy of BB-1701, a novel antibody drug conjugate (ADC) targeting HER2, in previously treated patients (pts) with HER2+ or HER2-low unresectable or metastatic (M) breast cancer (BC)

437TiP An open-label, multicenter, phase II study to evaluate the safety and efficacy of BB-1701, a novel antibody drug conjugate (ADC) targeting HER2, in previously treated patients (pts) with HER2+ or HER2-low unresectable or metastatic (M) breast cancer (BC)

Trastuzumab-Deruxtecan: Redefining HER2 as a Tumor Agnostic Biomarker.

Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate (ADC) targeting HER2-positive malignancies across various tumor types. Through its unique composition, T-DXd achieves selective payload delivery, inducing cell death and halting tumor progression. Clinical trials initially investigated T-DXd's efficacy in HER2-positive advanced or metastatic breast, gastric, lung, and colorectal cancers; however, recent results from the DESTINY-PanTumor02 trial further underscore T-DXd's versatility, prompting T-DXd's US FDA approval for HER2-positive (immunohistochemistry [IHC] 3+) solid tumors. Moreover, in addition to T-DXd's efficacy against brain metastasis, T-DXd is showing promising results in HER2-low and HER2-ultra-low metastatic breast cancer, indicating a broader population of patients who may benefit.

Standardization of CD30 immunohistochemistry staining among three automated immunostaining platforms.

The identification of CD30 expression by immunohistochemistry is essential for the treatment of lymphomas using an antibody-drug conjugate targeting CD30. However, no standardized protocol for CD30 staining has been available. In this study, we compared three common automated immunostaining platforms {Bond III (B III), Dako Omnis (DO) and Ventana BenchMark ULTRA (VBMU)}. A primary antibody for CD30, the Ber-H2 clone, was diluted 50- to 400-fold for B III and DO, and ready-to-use antibody was used for VBMU. An enhancement step using a linker was introduced in all protocols. First, several candidate dilutions were selected for each platform by staining six cases. These candidate conditions were then confirmed with 60 cases of various types of peripheral T-cell lymphomas (PTCLs). The concordance rates of CD30 expression among platforms differed depending on cutoff values and antibody dilutions, except for anaplastic large cell lymphoma. The concordance rates among three platforms in the evaluation of "positive" or "negative" were 100% and 97% when the cutoff values were 1% and 10% respectively, if using 400-diluted antibody in B III and 100-diluted antibody in DO. This study demonstrated the feasibility of equalizing CD30 staining of PTCLs among different platforms by adjusting protocols.

795TiP A first-in-human phase I study of LY4170156, an antibody-drug conjugate targeting folate receptor α (FRα)-expressing advanced solid tumors

795TiP A first-in-human phase I study of LY4170156, an antibody-drug conjugate targeting folate receptor α (FRα)-expressing advanced solid tumors

Expanding the repertoire of Antibody Drug Conjugate (ADC) targets with improved tumor selectivity and range of potent payloads through in-silico analysis.

Antibody-Drug Conjugates (ADCs) have emerged as a promising class of targeted cancer therapeutics. Further refinements are essential to unlock their full potential, which is currently limited by a lack of validated targets and payloads. Essential aspects of developing effective ADCs involve the identification of surface antigens, ideally distinguishing target tumor cells from healthy types, uniformly expressed, accompanied by a high potency payload capable of selective targeting. In this study, we integrated transcriptomics, proteomics, immunohistochemistry and cell surface membrane datasets from Human Protein Atlas, Xenabrowser and Gene Expression Omnibus utilizing Lantern Pharma's proprietary AI platform Response Algorithm for Drug positioning and Rescue (RADR®). We used this in combination with evidence based filtering to identify ADC targets with improved tumor selectivity. Our analysis identified a set of 82 targets and a total of 290 target indication combinations for effective tumor targeting. We evaluated the impact of tumor mutations on target expression levels by querying 416 genes in the TCGA mutation database against 22 tumor subtypes. Additionally, we assembled a catalog of compounds to identify potential payloads using the NCI-Developmental Therapeutics Program. Our payload mining strategy classified 729 compounds into three subclasses based on GI50 values spanning from pM to 10 nM range, in combination with sensitivity patterns across 9 different cancer indications. Our results identified a diverse range of both targets and payloads, that can serve to facilitate multiple choices for precise ADC targeting. We propose an initial approach to identify suitable target-indication-payload combinations, serving as a valuable starting point for development of future ADC candidates.