ATRT-15. LY6D – A CANDIDATE FOR NANOPARTICLE-BASED TARGETED THERAPIES OF ATRT

Abstract Atypical Teratoid Rhabdoid Tumors (ATRT) are aggressive brain malignancies of the infant. Despite intensive multimodal therapy, the overall prognosis remains poor, making investigations on targeted therapies crucial. Arsenic trioxide (ATO) is known to inhibit cell growth of ATRT in vitro and in vivo but its efficacy in solid tumors is limited by its adverse effects. We aimed to characterize whether a nanoparticle-based drug delivery could overcome these limitations. Therefore metal-organic frameworks containing ATO (MOF-ATO) were constructed. To improve drug specificity further, we searched for unique proteins on the surface of ATRT, in order to create antibody-drug-conjugates out of MOF-ATO and an ATRT-specific ligand. ATRT are marked by a biallelic loss of SMARCB1, which results in an activation of the repressive histone methyltransferase EZH2. After chemical inhibition of EZH2 with GSK126, a mass spectrometric based screening for differentially expressed surface proteins was performed. Treatment with ATO, as well as MOF-ATO and GSK126 each reduces the cell viability of ATRT cell lines. It results in a cell cycle arrest and an induction in apoptosis, being analysed via MTT test and flow cytometry. GSK126 treatment causes a significant upregulation of several cell surface proteins, upon them the Lymphocyte antigen 6 family member D (LY6D). Being rarely expressed on other human cells, this protein is an interesting candidate. An antibody-drug-conjugate consisting of MOF-ATO and LY6D-ligands could be a promising approach for future targeted therapies of ATRT.

Download Full-text

A Novel Antibody-Drug Conjugate (ADC) Delivering a DNA Mono-Alkylating Payload to Chondroitin Sulfate Proteoglycan (CSPG4)-Expressing Melanoma

Cancers ◽

10.3390/cancers12041029 ◽

2020 ◽

Vol 12 (4) ◽

pp. 1029

Author(s):

Ricarda M. Hoffmann ◽

Silvia Crescioli ◽

Silvia Mele ◽

Eirini Sachouli ◽

Anthony Cheung ◽

...

Keyword(s):

Tumor Regression ◽

Chondroitin Sulphate ◽

Alkylating Agents ◽

Residual Tumor ◽

Similar Efficacy ◽

Antibody Drug Conjugate ◽

Drug Conjugates ◽

Antibody Drug

Despite emerging targeted and immunotherapy treatments, no monoclonal antibodies or antibody-drug conjugates (ADCs) directly targeting tumor cells are currently approved for melanoma therapy. The tumor-associated antigen chondroitin sulphate proteoglycan 4 (CSPG4), a neural crest glycoprotein over-expressed on 70% of melanomas, contributes to proliferative signaling pathways, but despite highly tumor-selective expression it has not yet been targeted using ADCs. We developed a novel ADC comprising an anti-CSPG4 antibody linked to a DNA minor groove-binding agent belonging to the novel pyrridinobenzodiazepine (PDD) class. Unlike conventional DNA-interactive pyrrolobenzodiazepine (PBD) dimer payloads that cross-link DNA, PDD-based payloads are mono-alkylating agents but have similar efficacy and substantially enhanced tolerability profiles compared to PBD-based cross-linkers. We investigated the anti-tumor activity and safety of the anti-CSPG4-(PDD) ADC in vitro and in human melanoma xenografts. Anti-CSPG4-(PDD) inhibited CSPG4-expressing melanoma cell growth and colony formation and triggered apoptosis in vitro at low nanomolar to picomolar concentrations without off-target Fab-mediated or Fc-mediated toxicity. Anti-CSPG4-(PDD) restricted xenograft growth in vivo at 2 mg/kg doses. One 5 mg/kg injection triggered tumor regression in the absence of overt toxic effects or of acquired residual tumor cell resistance. This anti-CSPG4-(PDD) can deliver a highly cytotoxic DNA mono-alkylating payload to CSPG4-expressing tumors at doses tolerated in vivo.

Download Full-text

Targeted Fluorogenic Cyanine Carbamates Enable In Vivo Analysis of Antibody-Drug Conjugate Linker Chemistry

10.33774/chemrxiv-2021-mhj20-v2 ◽

2021 ◽

Author(s):

Syed Usama ◽

Sierra Marker ◽

Donald Caldwell ◽

Nimit Patel ◽

Yang Feng ◽

...

Keyword(s):

Near Infrared ◽

Antibody Drug Conjugate ◽

Drug Conjugates ◽

Lysosomal Accumulation ◽

Cellular Signal ◽

In Vivo Analysis ◽

Cellular Permeability ◽

Therapeutic Platform ◽

Antibody Drug

Antibody-drug conjugates (ADCs) are a rapidly emerging therapeutic platform. The chemical linker between the antibody and the drug payload plays an essential role in the efficacy and tolerability of these agents. New methods that quantitively assess cleavage efficiency in complex tissue settings could provide valuable insights into the ADC design process. Here we report the development of a near-infrared (NIR) optical imaging approach that measures the site and extent of linker cleavage in mouse models. This approach is enabled by a superior variant of our recently devised cyanine carbamate (CyBam) platform. We identify a novel tertiary amine-containing norcyanine, the product of CyBam cleavage, that exhibits dramatically in-creased cellular signal due to improved cellular permeability and lysosomal accumulation. The resulting cyanine lysosome-targeting carbamates (CyLBams) are ~50X brighter in cells, and we find this strategy is essential for high-contrast in vivo targeted imaging. Finally, we compare a panel of several common ADC linkers across two antibodies and tumor models. These studies indicate that cathepsin-cleavable linkers provide dramatically higher tumor activation relative to hindered or non-hindered disulfides – an observation that is only apparent with in vivo imaging. This strategy enables quantitative comparisons of cleavable linker chemistries in complex tissue settings with implications across the drug delivery landscape.

Download Full-text

In Vitro and In Vivo Evaluation of Cysteine Rebridged Trastuzumab–MMAE Antibody Drug Conjugates with Defined Drug-to-Antibody Ratios

Molecular Pharmaceutics ◽

10.1021/acs.molpharmaceut.5b00116 ◽

2015 ◽

Vol 12 (6) ◽

pp. 1872-1879 ◽

Cited By ~ 71

Author(s):

Penny Bryant ◽

Martin Pabst ◽

George Badescu ◽

Matthew Bird ◽

William McDowell ◽

...

Keyword(s):

In Vivo Evaluation ◽

Antibody Drug Conjugates ◽

Drug Conjugates ◽

Antibody Drug

Download Full-text

Use of an antibody-drug conjugate targeting tissue factor to induce complete tumor regression in xenograft models with heterogeneous target expression.

Journal of Clinical Oncology ◽

10.1200/jco.2013.31.15_suppl.3066 ◽

2013 ◽

Vol 31 (15_suppl) ◽

pp. 3066-3066 ◽

Cited By ~ 1

Author(s):

Esther CW Breij ◽

David Satijn ◽

Sandra Verploegen ◽

Bart de Goeij ◽

Danita Schuurhuis ◽

...

Keyword(s):

Tissue Factor ◽

Tumor Cells ◽

Tumor Regression ◽

Antibody Drug Conjugate ◽

Xenograft Models ◽

Anti Tumor Activity ◽

Complete Tumor ◽

Antibody Drug

3066 Background: Tissue factor (TF) is the main initiator of coagulation, that starts when circulating factor VII(a) (FVII(a)) binds membrane bound TF. In addition, the TF:FVIIa complex can initiate a pro-angiogenic signaling pathway by activation of PAR-2. TF is aberrantly expressed in many solid tumors, and expression has been associated with poor prognosis. TF-011-vcMMAE, an antibody-drug conjugate (ADC) under development for the treatment of solid tumors, is composed of a human TF specific antibody (TF-011), a proteaseEcleavable valine-citrulline (vc) linker and the microtubule disrupting agent monomethyl auristatin E (MMAE). Methods: TF-011 and TF-011-vcMMAE were functionally characterized using in vitro assays. In vivo anti-tumor activity of TF-011-vcMMAE was assessed in human biopsy derived xenograft models, which genetically and histologically resemble human tumors. TF expression in xenografts was assessed using immunohistochemistry. Results: TF-011 inhibited TF:FVIIa induced intracellular signaling and efficiently killed tumor cells by antibody dependent cell-mediated cytoxicity in vitro, but showed only minor inhibition of TF procoagulant activity. TF-011 was rapidly internalized and targeted to the lysosomes, a prerequisite for intracellular MMAE release and subsequent tumor cell killing by the ADC. Indeed, TF-011-vcMMAE efficiently and specifically killed TF-positive tumors in vitro and in vivo. Importantly, TF-011-vcMMAE showed excellent anti-tumor activity in human biopsyEderived xenograft models derived from bladder, lung, pancreas, prostate, ovarian and cervical cancer (n=7). TF expression in these models was heterogeneous, ranging from 25-100% of tumor cells. Complete tumor regression was observed in all models, including cervical and ovarian cancer xenografts that showed only 25-50% TF positive tumor cells. Conclusions: TF-011-vcMMAE is a promising new ADC with potent anti-tumor activity in xenograft models that represent the heterogeneity of human tumors, including heterogeneous TF expression. The functional characteristics of TF-011-vcMMAE allow efficient tumor targeting, with minimal impact on coagulation.

Download Full-text

Sortase Enzyme-Mediated Generation of Site-Specifically Conjugated Antibody Drug Conjugates with High In Vitro and In Vivo Potency

PLoS ONE ◽

10.1371/journal.pone.0131177 ◽

2015 ◽

Vol 10 (7) ◽

pp. e0131177 ◽

Cited By ~ 113

Author(s):

Roger R. Beerli ◽

Tamara Hell ◽

Anna S. Merkel ◽

Ulf Grawunder

Keyword(s):

Antibody Drug Conjugates ◽

Drug Conjugates ◽

Antibody Drug

Download Full-text

Sacituzumab govitecan, an antibody‐drug conjugate targeting trophoblast cell‐surface antigen 2, shows cytotoxic activity against poorly differentiated endometrial adenocarcinomas in vitro and in vivo

Molecular Oncology ◽

10.1002/1878-0261.12627 ◽

2020 ◽

Vol 14 (3) ◽

pp. 645-656 ◽

Cited By ~ 3

Author(s):

Emanuele Perrone ◽

Paola Manara ◽

Salvatore Lopez ◽

Stefania Bellone ◽

Elena Bonazzoli ◽

...

Keyword(s):

Cell Surface ◽

Cytotoxic Activity ◽

Surface Antigen ◽

Trophoblast Cell ◽

Cell Surface Antigen ◽

Antibody Drug Conjugate ◽

Poorly Differentiated ◽

Antibody Drug

Download Full-text

An antibody-drug conjugate directed to the ALK receptor demonstrates efficacy in preclinical models of neuroblastoma

Science Translational Medicine ◽

10.1126/scitranslmed.aau9732 ◽

2019 ◽

Vol 11 (483) ◽

pp. eaau9732 ◽

Cited By ~ 10

Author(s):

Renata Sano ◽

Kateryna Krytska ◽

Colleen E. Larmour ◽

Pichai Raman ◽

Daniel Martinez ◽

...

Keyword(s):

Cell Surface ◽

Neuroblastoma Cells ◽

In Vivo Studies ◽

Wild Type ◽

Antibody Drug Conjugate ◽

Cell Surface Antigens ◽

Drug Conjugates ◽

Bona Fide ◽

Antibody Drug

Enthusiasm for the use of antibody-drug conjugates (ADCs) in cancer therapy has risen over the past few years. The success of this therapeutic approach relies on the identification of cell surface antigens that are widely and selectively expressed on tumor cells. Studies have shown that native ALK protein is expressed on the surface of most neuroblastoma cells, providing an opportunity for development of immune-targeting strategies. Clinically relevant antibodies for this target have not yet been developed. Here, we describe the development of an ALK-ADC, CDX-0125-TEI, which selectively targets both wild-type and mutated ALK-expressing neuroblastomas. CDX-0125-TEI exhibited efficient antigen binding and internalization, and cytotoxicity at picomolar concentrations in cells with different expression of ALK on the cell surface. In vivo studies showed that CDX-0125-TEI is effective against ALK wild-type and mutant patient-derived xenograft models. These data demonstrate that ALK is a bona fide immunotherapeutic target and provide a rationale for clinical development of an ALK-ADC approach for neuroblastomas and other ALK-expressing childhood cancers such as rhabdomyosarcomas.

Download Full-text

Synthesis of site-specific antibody-drug conjugates by ADP-ribosyl cyclases

Science Advances ◽

10.1126/sciadv.aba6752 ◽

2020 ◽

Vol 6 (23) ◽

pp. eaba6752 ◽

Cited By ~ 1

Author(s):

Zhefu Dai ◽

Xiao-Nan Zhang ◽

Fariborz Nasertorabi ◽

Qinqin Cheng ◽

Jiawei Li ◽

...

Keyword(s):

Growth Factor Receptor ◽

Reaction Times ◽

Single Step ◽

Her2 Positive ◽

Site Specific ◽

Antibody Drug Conjugates ◽

Drug Conjugates ◽

Antibody Drug

Most of the current antibody-drug conjugates (ADCs) in clinic are heterogeneous mixtures. To produce homogeneous ADCs, established procedures often require multiple steps or long reaction times. The introduced mutations or foreign sequences may cause high immunogenicity. Here, we explore a new concept of transforming CD38 enzymatic activity into a facile approach for generating site-specific ADCs. This was achieved through coupling bifunctional antibody-CD38 fusion proteins with designer dinucleotide-based covalent inhibitors with stably attached payloads. The resulting adenosine diphosphate–ribosyl cyclase–enabled ADC (ARC-ADC) with a drug-to-antibody ratio of 2 could be rapidly generated through single-step conjugation. The generated ARC-ADC targeting human epidermal growth factor receptor 2 (HER2) displays excellent stability and potency against HER2-positive breast cancer both in vitro and in vivo. This proof-of-concept study demonstrates a new strategy for production of site-specific ADCs. It may provide a general approach for the development of a novel class of ADCs with potentially enhanced properties.

Download Full-text