Antibody-drug conjugates (ADCs) is a fast moving class of targeted biotherapeutics that currently combines the selectivity of monoclonal antibodies with the potency of a payload consisting of ...cytotoxic agents. For many years microtubule targeting and DNA-intercalating agents were at the forefront of ADC development. The recent approval and clinical success of trastuzumab deruxtecan (Enhertu
) and sacituzumab govitecan (Trodelvy
), two topoisomerase 1 inhibitor-based ADCs, has shown the potential of conjugating unconventional payloads with differentiated mechanisms of action. Among future developments in the ADC field, payload diversification is expected to play a key role as illustrated by a growing number of preclinical and clinical stage unconventional payload-conjugated ADCs. This review presents a comprehensive overview of validated, forgotten and newly developed payloads with different mechanisms of action.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Antibody-drug conjugates (ADCs) convey highly potent anticancer drugs to antigen-expressing tumor cells, thereby sparing healthy tissues throughout the body. Pharmacokinetics and tolerability of ADCs ...are predominantly influenced by the drug-antibody ratio (DAR) of the conjugates, which is to-date limited to a value of 3-4 drugs per antibody in ADCs under clinical investigations. Here, we report the synthesis of monodisperse (
discrete) polysarcosine compounds and their use as a hydrophobicity masking entity for the construction of highly-loaded homogeneous β-glucuronidase-responsive antibody-drug conjugates (ADCs). The highly hydrophilic drug-linker platform described herein improves drug-loading, physicochemical properties, pharmacokinetics and
antitumor efficacy of the resulting conjugates.
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IJS, KILJ, NUK, UL, UM, UPUK
We herein report the development and evaluation of a novel HER2-targeting antibody-drug conjugate (ADC) based on the topoisomerase I inhibitor payload exatecan, using our hydrophilic monodisperse ...polysarcosine (PSAR) drug-linker platform (PSARlink). In vitro and in vivo experiments were conducted in breast and gastric cancer models to characterize this original ADC and gain insight about the drug-linker structure-activity relationship. The inclusion of the PSAR hydrophobicity masking entity efficiently reduced the overall hydrophobicity of the conjugate and yielded an ADC sharing the same pharmacokinetic profile as the unconjugated antibody despite the high drug-load of the camptothecin-derived payload (drug-antibody ratio of 8). Tra-Exa-PSAR10 demonstrated strong anti-tumor activity at 1 mg/kg in an NCI-N87 xenograft model, outperforming the FDA-approved ADC DS-8201a (Enhertu), while being well tolerated in mice at a dose of 100 mg/kg. In vitro experiments showed that this exatecan-based ADC demonstrated higher bystander killing effect than DS-8201a and overcame resistance to T-DM1 (Kadcyla) in preclinical HER2+ breast and esophageal models, suggesting potential activity in heterogeneous and resistant tumors. In summary, the polysarcosine-based hydrophobicity masking approach allowsfor the generation of highly conjugated exatecan-based ADCs having excellent physicochemical properties, an improved pharmacokinetic profile, and potent in vivo anti-tumor activity.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Nanomedicine as a therapeutic approach for pregnancy-related diseases could offer improved treatments for the mother while avoiding side effects for the fetus. In this study, we evaluated the ...potential of liposomes as carriers for small interfering RNAs to placental cells. Three neutral formulations carrying rhodamine-labelled siRNAs were evaluated on an in vitro model, i.e., human primary villous cytotrophoblasts. siRNA internalization rate from lipoplexes were compared to the one in the presence of the lipofectamine reagent and assessed by confocal microscopy. Results showed cellular internalization of nucleic acid with all three formulations, based on two cationic lipids, either DMAPAP or CSL-3. Moreover, incubation with DMAPAP+AA provided a rate of labelled cells as high as with lipofectamine (53 ± 15% and 44 ± 12%, respectively) while being more biocompatible. The proportion of cells which internalized siRNA were similar when using DMAPAP/DDSTU (16 ± 5%) and CSL-3 (22 ± 5%). This work highlights that liposomes could be a promising approach for gene therapy dedicated to pregnant patients.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
We report the use of switchable lipids to improve the endosomal escape and cytosolic delivery of cell‐impermeable compounds. The system is based on a conformational reorganization of the lipid ...structure upon acidification, as demonstrated by NMR spectroscopic studies. When incorporated in a liposome formulation, the switchable lipids triggered bilayer destabilization through fusion even in the presence of poly(ethylene glycol). We observed 88 % release of sulforhodamine B in 15 min at pH 5, and the liposome formulations demonstrated high stability at pH 7.4 for several months. By using sulforhodamine B as a model of a highly polar drug, we demonstrated fast cytosolic delivery mediated by endosomal escape in HeLa cells, and no toxicity.
Switch it on! The integration of pH‐sensitive switchable lipids (see picture) into poly(ethylene glycol)‐coated liposome formulations enabled the efficient cytoplasmic delivery of polar compounds through an endosomal‐escape mechanism. The liposome formulations containing the switchable lipids were stable at pH 7.4 and upon storage but instantly destabilized at endosomal pH values (pH 5–5.5).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract As double stranded, single stranded siRNA (ss-siRNA) has demonstrated gene silencing activity but still requires efficient carriers to reach its cytoplasmic target. To better understand the ...fundamental aspect driving the complexation of ss-siRNA with nanocarriers, the interactions between surfaces of various compositions across a ss-siRNA solution were qualitatively investigated using the Surface Forces Apparatus. The results show that ss-siRNA can adsorb onto hydrophilic (positively and negatively charged) as well as on hydrophobic substrates suggesting that the complexation can occur through hydrophobic interactions and hydrogen bonding in addition to electrostatic interactions. Moreover, the binding strength and the conformation of ss-siRNA depend on the nature of the interactions between the ss-siRNA and the surfaces. The binding of ss-siRNA with nanocarriers, such as micelles or liposomes through non-electrostatic interactions was also evidenced by a SYBR® Gold cyanine dye. We evidenced the presence of interactions between the dye and oligonucleotides already complexed to non-cationic nanovectors biasing the quantification of the encapsulation. These results suggest that non-electrostatic interactions could be exploited to complement electrostatic interactions in the design of nanocarriers. In particular, the types of interaction between ss-siRNA and the carriers can be tuned to decrease the cationic charges and therefore lower its toxicity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Antibody-drug conjugates (ADCs) convey highly potent anticancer drugs to antigen-expressing tumor cells, thereby sparing healthy tissues throughout the body. Pharmacokinetics and tolerability of ADCs ...are predominantly influenced by the drug-antibody ratio (DAR) of the conjugates, which is to-date limited to a value of 3-4 drugs per antibody in ADCs under clinical investigations. Here, we report the synthesis of monodisperse (
i.e.
discrete) polysarcosine compounds and their use as a hydrophobicity masking entity for the construction of highly-loaded homogeneous β-glucuronidase-responsive antibody-drug conjugates (ADCs). The highly hydrophilic drug-linker platform described herein improves drug-loading, physicochemical properties, pharmacokinetics and
in vivo
antitumor efficacy of the resulting conjugates.
A new antibody-drug conjugate (ADC) chemical drug-linker platform based on polysarcosine enables increased drug-loading, improved pharmacokinetics and exquisite
in vivo
potency.
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IJS, KILJ, NUK, UL, UM, UPUK
A new antibody-drug conjugate (ADC) chemical drug-linker platform based on polysarcosine enables increased drug-loading, improved pharmacokinetics and exquisite
in vivo
potency.
Antibody-drug ...conjugates (ADCs) convey highly potent anticancer drugs to antigen-expressing tumor cells, thereby sparing healthy tissues throughout the body. Pharmacokinetics and tolerability of ADCs are predominantly influenced by the drug-antibody ratio (DAR) of the conjugates, which is to-date limited to a value of 3–4 drugs per antibody in ADCs under clinical investigations. Here, we report the synthesis of monodisperse (
i.e.
discrete) polysarcosine compounds and their use as a hydrophobicity masking entity for the construction of highly-loaded homogeneous β-glucuronidase-responsive antibody-drug conjugates (ADCs). The highly hydrophilic drug-linker platform described herein improves drug-loading, physicochemical properties, pharmacokinetics and
in vivo
antitumor efficacy of the resulting conjugates.
Full text
Available for:
IJS, KILJ, NUK, UL, UM, UPUK
Abstract
Folate receptor alpha (FOLR1) is a clinically validated target, that is overexpressed extracellularly in numerous solid malignancies with a high unmet medical need. Ovarian, non-small cell ...lung and breast adenocarcinomas are among indications with the highest frequency of FOLR1-positive patients with one out of two patients showing upregulated topoisomerase I expression. MBK-103, an antibody-drug conjugate targeting FOLR1, is based on Mablink’s novel proprietary hydrophilic drug-linker platform. It is comprised of: (i) an Fc-attenuated humanized IgG1 monoclonal antibody, that selectively binds to FOLR1; (ii) a polysarcosine hydrophobicity masking entity allowing for a high drug-to-antibody ratio (DAR) of 8, while improving the pharmacokinetics and tolerability of the drug; (iii) a proprietary dipeptide cleavable unit and iv) exatecan, a potent topoisomerase I inhibitor. MBK-103 showed excellent ex vivo stability in human plasma enabling a prolonged half-life, similar to that of the unconjugated monoclonal antibody. This led to an increased drug exposure, resulting in a potent antitumor efficacy observed in a collection of more than ten in vivo mouse tumor models with a diverse FOLR1 expression, already at doses as low as 1-3 mg/kg. In addition, the distinct mode of action of exatecan along with the unique characteristics of the proprietary drug-linker platform resulted in the in vivo antitumor potency obtained also in colorectal cancer models, in which tubulin-inhibiting agents exhibit only limited therapeutic effects. The compound was also very well tolerated in cynomolgus monkeys with HNSTD at 50 mg/kg and even when administered repeatedly. High conjugation yields along with 100% homogeneity are major drivers of the successful ongoing manufacturing process with planned IND submission in Q4/2023.
Citation Format: Warren Viricel, Louise Conilh, Edouard Leroy, Jean-Guillaume Lafay, Frederique Brune, Lenka Kyrych Sadilkova, Charles Dumontet. MBK-103, a potent novel conjugation platform-based antibody-drug conjugate, changing therapeutic options in folate receptor alpha positive cancer patients abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1544.
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