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Molecular Cancer Therapeutics Jun 2023MET, the cell-surface receptor for the hepatocyte growth factor/scatter factor, which is widely overexpressed in various solid cancer types, is an attractive target for...
MET, the cell-surface receptor for the hepatocyte growth factor/scatter factor, which is widely overexpressed in various solid cancer types, is an attractive target for the development of antibody-based therapeutics. BYON3521 is a novel site-specifically conjugated duocarmycin-based antibody-drug conjugate (ADC), comprising a humanized cysteine-engineered IgG1 monoclonal antibody with low pmol/L binding affinity towards both human and cynomolgus MET. In vitro studies showed that BYON3521 internalizes efficiently upon MET binding and induces both target- and bystander-mediated cell killing. BYON3521 showed good potency and full efficacy in MET-amplified and high MET-expressing cancer cell lines; in moderate and low MET-expressing cancer cell lines good potencies and partial efficacy were observed. In mouse xenograft models, BYON3521 showed significant antitumor activity upon single-dose administration in multiple non-MET-amplified tumor types with low, moderate, and high MET expression, including complete tumor remissions in models with moderate MET expression. In the repeat-dose Good Laboratory Practice (GLP) safety assessment in cynomolgus monkeys, BYON3521 was well tolerated and based on the observed toxicities and their reversibility, the highest non-severely toxic dose was set at 15 mg/kg. A human pharmacokinetics (PK) model was derived from the PK data from the cynomolgus safety assessments, and the minimal efficacious dose in humans is estimated to be in the range of 3 to 4 mg/kg. In all, our nonclinical data suggests that BYON3521 is a safe ADC with potential for clinical benefit in patients. A first-in-human dose-escalation study is currently ongoing to determine the maximum tolerated dose and recommended dose for expansion (NCT05323045).
Topics: Animals; Humans; Mice; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Cell Line, Tumor; Immunoconjugates; Immunoglobulin G; Xenograft Model Antitumor Assays
PubMed: 37042205
DOI: 10.1158/1535-7163.MCT-22-0596 -
British Journal of Cancer Apr 2023Long-term prognosis remains poor for colorectal cancer (CRC) patients with advanced disease due to treatment resistance. The identification of novel targets is essential...
BACKGROUND
Long-term prognosis remains poor for colorectal cancer (CRC) patients with advanced disease due to treatment resistance. The identification of novel targets is essential for the development of new therapeutic approaches. GPR56, an adhesion GPCR, is highly expressed in CRC tumours and correlates with poor survival. Here, we describe the generation and preclinical evaluation of a novel ADC consisting of an anti-GPR56 antibody (10C7) conjugated with the DNA-damaging payload duocarmycin.
METHODS
RNA-seq dataset analysis was performed to determine GPR56 expression in CRC subtypes. The specificity of binding, epitope mapping, and internalisation of 10C7 was examined. 10C7 was conjugated to payload and ADC cytotoxicity was assessed against a panel of CRC cell lines and tumour organoids. Antitumour efficacy was evaluated in xenograft models of CRC cell lines and patient-derived tumours.
RESULTS
High GPR56 was shown to be associated with the microsatellite stable (MSS) subtype that accounts for 80-85% of CRC. GPR56 ADC selectively induced cytotoxicity in CRC cells and tumour organoids at low nanomolar potency in a GPR56-dependent manner and showed significant antitumour efficacy against GPR56-expressing xenograft models.
CONCLUSIONS
This study provides the rationale for the future development of a GPR56-targeted ADC approach to potentially treat a large fraction of MSS CRC patients.
Topics: Humans; Cell Line, Tumor; Colorectal Neoplasms; Immunoconjugates; Prognosis; Receptors, G-Protein-Coupled
PubMed: 36759728
DOI: 10.1038/s41416-023-02192-3 -
JACS Au Dec 2022Synthetic analogues of the DNA-alkylating cytotoxins of the duocarmycin class have been extensively investigated in the past 40 years, driven by their high potency,... (Review)
Review
Synthetic analogues of the DNA-alkylating cytotoxins of the duocarmycin class have been extensively investigated in the past 40 years, driven by their high potency, their unusual mechanism of bioactivity, and the beautiful modularity of their structure-activity relationship (SAR). This Perspective analyzes how the molecular designs of synthetic duocarmycins have evolved: from (1) early SAR studies, through to modern applications for directed cancer therapy as (2) prodrugs and (3) antibody-drug conjugates in late-stage clinical development. Analyzing 583 primary research articles and patents from 1978 to 2022, we distill out a searchable A0-format "Minard map" poster of ca. 200 key structure/function-tuning steps tracing chemical developments across these three key areas. This structure-based overview showcases the ingenious approaches to tune and target bioactivity, that continue to drive development of the elegant and powerful duocarmycin platform.
PubMed: 36590260
DOI: 10.1021/jacsau.2c00448 -
Natural Product Research 2023Antibody-drug conjugates (ADCs) are one of the most rapidly expanding classes of oncology therapeutics. Till now, 11 ADCs have been approved by USFDA, with the first ADC...
Antibody-drug conjugates (ADCs) are one of the most rapidly expanding classes of oncology therapeutics. Till now, 11 ADCs have been approved by USFDA, with the first ADC approval of gemtuzumab ozogamicin (Mylotarg) in 2000. A large number of ADCs are being evaluated in different stages of clinical trials and pre-clinical studies. Interestingly, the cytotoxic warheads of the all approved ADCs, as well as clinical and preclinical candidates, belong to different classes of natural products viz. calicheamicins, auristatins, maytansinoids, camptothecin derivatives, pyrolidobenzodiazepines (PBDs), and duocarmycins, etc. Herein, a review of the natural product-based cytotoxic warheads, briefly discussing their source, modifications, and mechanism of action, has been conducted.
PubMed: 36305758
DOI: 10.1080/14786419.2022.2138872 -
Cancers Feb 2022Breast cancer is one of the most frequently diagnosed tumors and the second leading cause of cancer death in women worldwide. The use of nanosystems specifically... (Review)
Review
Breast cancer is one of the most frequently diagnosed tumors and the second leading cause of cancer death in women worldwide. The use of nanosystems specifically targeted to tumor cells (active targeting) can be an excellent therapeutic tool to improve and optimize current chemotherapy for this type of neoplasm, since they make it possible to reduce the toxicity and, in some cases, increase the efficacy of antineoplastic drugs. Currently, there are 14 nanomedicines that have reached the clinic for the treatment of breast cancer, 4 of which are already approved (Kadcyla, Enhertu, Trodelvy, and Abraxane). Most of these nanomedicines are antibody-drug conjugates. In the case of HER-2-positive breast cancer, these conjugates (Kadcyla, Enhertu, Trastuzumab-duocarmycin, RC48, and HT19-MMAF) target HER-2 receptors, and incorporate maytansinoid, deruxtecan, duocarmicyn, or auristatins as antineoplastics. In TNBC these conjugates (Trodelvy, Glembatumumab-Vedotin, Ladiratuzumab-vedotin, Cofetuzumab-pelidotin, and PF-06647263) are directed against various targets, in particular Trop-2 glycoprotein, NMB glycoprotein, Zinc transporter LIV-1, and Ephrin receptor-4, to achieve this selective accumulation, and include campthotecins, calicheamins, or auristatins as drugs. Apart from the antibody-drug conjugates, there are other active targeted nanosystems that have reached the clinic for the treatment of these tumors such as Abraxane and Nab-rapamicyn (albumin nanoparticles entrapping placlitaxel and rapamycin respectively) and various liposomes (MM-302, C225-ILS-Dox, and MM-310) loaded with doxorubicin or docetaxel and coated with ligands targeted to Ephrin A2, EPGF, or HER-2 receptors. In this work, all these active targeted nanomedicines are discussed, analyzing their advantages and disadvantages over conventional chemotherapy as well as the challenges involved in their lab to clinical translation. In addition, examples of formulations developed and evaluated at the preclinical level are also discussed.
PubMed: 35267507
DOI: 10.3390/cancers14051198 -
Yakugaku Zasshi : Journal of the... 2022Among my recent work on the syntheses of complex natural products based on the development of a novel synthetic method for the heteroaromatic skeleton, this article... (Review)
Review
Among my recent work on the syntheses of complex natural products based on the development of a novel synthetic method for the heteroaromatic skeleton, this article primarily deals with the total syntheses of (+)-CC-1065, isobatzeline A/B, and batzeline A. These syntheses were accomplished via a novel indole synthesis utilizing a ring expansion reaction of benzocyclobutenone oxime sulfonate as the key step. The 1,2-dihydro-3H-pyrrolo[3,2-e]indole segments of (+)-CC-1065 were rapidly constructed via a two-directional double-ring expansion strategy. Highly substituted pyrrolidine-fused common 5-chloro-2-methylthioindoles of isobatzeline A/B and batzeline A were constructed using a ring expansion reaction of benzocyclobutenone oxime sulfonate with NaSMe and a benzyne-mediated cyclization/functionalization reaction.
Topics: Biological Products; Chemistry, Organic; Cyclization; Duocarmycins; Indoles; Oximes; Pyrroloiminoquinones; Quinolones
PubMed: 35110456
DOI: 10.1248/yakushi.21-00199 -
Trends in Pharmacological Sciences Apr 2022A recent antimalarial screen by Alder and colleagues has uncovered a natural product, PDE-I, with DNA-binding and schizonticidal activity against Plasmodium falciparum....
A recent antimalarial screen by Alder and colleagues has uncovered a natural product, PDE-I, with DNA-binding and schizonticidal activity against Plasmodium falciparum. Parasite specificity is likely conferred by the extremely high A+T content of the P. falciparum genome. We discuss here this character as a potential target for future drugs.
Topics: Animals; Antimalarials; DNA; Humans; Malaria, Falciparum; Parasites; Plasmodium falciparum
PubMed: 35058076
DOI: 10.1016/j.tips.2022.01.003 -
Analytical Chemistry Jan 2022Quantitative analysis of antibody-drug conjugates (ADCs) involves cleavage of ADCs into smaller analytes representing different components and subsequent measurements...
Quantitative analysis of antibody-drug conjugates (ADCs) involves cleavage of ADCs into smaller analytes representing different components and subsequent measurements from multiple assays for a more comprehensive pharmacokinetic (PK) assessment. Multiple PK analytes including the drug remaining conjugated to the antibody (or antibody-conjugated drug, acDrug) and total antibody can be accessed simultaneously using a multiplex assay by proteolytic digestion of an ADC, if the sites of conjugation are homogeneous for an ADC and the linker drug is stable to proteases. Herein, a multiplexed immunoaffinity liquid chromatography-mass spectrometry (LC-MS)/MS PK assay is described involving immunoaffinity enrichment, enzymatic conversion of prodrug, trypsin digestion, and LC-MS/MS as applied to next-generation ADCs constructed from linker drugs bearing dimeric cyclopropabenzindole (CBI) payloads (duocarmycin analogues). The cytotoxic payload is chemically labile, requiring extensive optimization in sample preparation steps to stabilize the drug without modification and to convert the prodrug into a single active form of the drug. The qualification data for this assay format showed that this approach provides robust acDrug and total antibody data and can be extended to ADCs with different monoclonal antibody frameworks and linker chemistries. Applications of this multiplexed assay to support preclinical studies are presented.
Topics: Antibodies, Monoclonal; Antineoplastic Agents; Chromatography, Liquid; Immunoconjugates; Tandem Mass Spectrometry
PubMed: 34958550
DOI: 10.1021/acs.analchem.1c04338 -
Current Cancer Drug Targets 2022Aberrant expression of the MET receptor tyrosine kinase is an oncogenic determinant and a drug target for cancer therapy. Currently, antibody-based biotherapeutics...
BACKGROUND
Aberrant expression of the MET receptor tyrosine kinase is an oncogenic determinant and a drug target for cancer therapy. Currently, antibody-based biotherapeutics targeting MET are under clinical trials.
OBJECTIVE
Here, we report the preclinical and therapeutic evaluation of a novel anti-MET antibody- drug conjugate PCMC1D3-duocarmycin SA (PCMC1D3-DCM) for targeted cancer therapy.
METHODS
The monoclonal antibody PCMC1D3 (IgG1a/κ), generated by a hybridoma technique and specific to one of the MET extracellular domains, was selected based on its high specificity to human MET with a binding affinity of 1.60 nM. PCMC1D3 was conjugated to DCM via a cleavable valine-citrulline dipeptide linker to form an antibody-drug conjugate with a drug-to-antibody ratio of 3.6:1. PCMC1D3-DCM in vitro rapidly induced MET internalization with an internalization efficacy ranging from 6.5 to 17.2h dependent on individual cell lines.
RESULTS
Studies using different types of cancer cell lines showed that PCMC1D3-DCM disrupted the cell cycle, reduced cell viability, and caused massive cell death within 96h after treatment initiation. The calculated IC values for cell viability reduction were 1.5 to 15.3 nM. Results from mouse xenograft tumor models demonstrated that PCMC1D3-DCM in a single dose injection at 10 mg/kg body weight effectively delayed xenograft tumor growth up to two weeks without signs of tumor regrowth. The calculated tumoristatic concentration, a minimal dose required to balance tumor growth and inhibition, was around 2 mg/kg body weight. Taken together, PCMC1D3-DCM was effective in targeting the inhibition of tumor growth in xenograft models.
CONCLUSION
This work provides the basis for the development of humanized PCMC1D3-DCM for MET-targeted cancer therapy in the future.
Topics: Animals; Body Weight; Cell Line, Tumor; Duocarmycins; Humans; Immunoconjugates; Mice; Neoplasms; Proto-Oncogene Proteins c-met; Xenograft Model Antitumor Assays
PubMed: 34951367
DOI: 10.2174/1568009621666211222154129 -
Nature Communications Nov 2021Microbes produce a broad spectrum of antibiotic natural products, including many DNA-damaging genotoxins. Among the most potent of these are DNA alkylating agents in the...
Microbes produce a broad spectrum of antibiotic natural products, including many DNA-damaging genotoxins. Among the most potent of these are DNA alkylating agents in the spirocyclopropylcyclohexadienone (SCPCHD) family, which includes the duocarmycins, CC-1065, gilvusmycin, and yatakemycin. The yatakemycin biosynthesis cluster in Streptomyces sp. TP-A0356 contains an AlkD-related DNA glycosylase, YtkR2, that serves as a self-resistance mechanism against yatakemycin toxicity. We previously reported that AlkD, which is not present in an SCPCHD producer, provides only limited resistance against yatakemycin. We now show that YtkR2 and C10R5, a previously uncharacterized homolog found in the CC-1065 biosynthetic gene cluster of Streptomyces zelensis, confer far greater resistance against their respective SCPCHD natural products. We identify a structural basis for substrate specificity across gene clusters and show a correlation between in vivo resistance and in vitro enzymatic activity indicating that reduced product affinity-not enhanced substrate recognition-is the evolutionary outcome of selective pressure to provide self-resistance against yatakemycin and CC-1065.
Topics: Anti-Bacterial Agents; Bacterial Proteins; DNA Damage; DNA Glycosylases; DNA Repair; Duocarmycins; Multigene Family; Mutagens; Streptomyces
PubMed: 34836957
DOI: 10.1038/s41467-021-27284-7