ABSTRACT
We describe a two-step process for the synthesis of substituted bicyclo[1.1.0]butanes. A photo-Hunsdiecker reaction generates iodo-bicyclo[1.1.1]pentanes under metal-free conditions at room temperature. These intermediates react with nitrogen and sulfur nucleophiles to afford substituted bicyclo[1.1.0]butane products.
ABSTRACT
Macrocyclic pyrrolobenzodiazepine dimers were designed and evaluated for use as antibody-drug conjugate payloads. Initial structure-activity exploration established that macrocyclization could increase the potency of PBD dimers compared with non-macrocyclic analogs. Further optimization overcame activity-limiting solubility issues, leading to compounds with highly potent (picomolar) activity against several cancer cell lines. High levels of in vitro potency and specificity were demonstrated with an anti-mesothelin conjugate.
Subject(s)
Antibodies/metabolism , Antineoplastic Agents/pharmacology , Benzodiazepines/pharmacology , Macrocyclic Compounds/pharmacology , Pyrroles/pharmacology , Antibodies/chemistry , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Benzodiazepines/chemical synthesis , Benzodiazepines/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Dimerization , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Macrocyclic Compounds/chemical synthesis , Macrocyclic Compounds/chemistry , Molecular Structure , Pyrroles/chemical synthesis , Pyrroles/chemistry , Solubility , Structure-Activity RelationshipABSTRACT
The prominent role of IAPs in controlling cell death and their overexpression in a variety of cancers has prompted the development of IAP antagonists as potential antitumor therapies. We describe the identification of a series of heterodimeric antagonists with highly potent antiproliferative activities in cIAP- and XIAP-dependent cell lines. Compounds 15 and 17 further demonstrate curative efficacy in human melanoma and lung cancer xenograft models and are promising candidates for advanced studies.
Subject(s)
Antineoplastic Agents/pharmacology , Drug Discovery , Inhibitor of Apoptosis Proteins/antagonists & inhibitors , Neoplasms, Experimental/drug therapy , Proline/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Mice , Molecular Structure , Neoplasms, Experimental/pathology , Proline/chemical synthesis , Proline/chemistry , Structure-Activity RelationshipABSTRACT
Bivalent heterodimeric IAP antagonists that incorporate (R)-tetrahydroisoquinoline in the P3' subunit show high affinity for the BIR2 domain and demonstrated potent IAP inhibitory activities in biochemical and cellular assays. Potent in vivo efficacy was observed in a variety of human tumor xenograft models. The bivalent heterodimeric molecule 3 with a P3-P3' benzamide linker induced pharmacodynamic markers of apoptosis and was efficacious when administered intravenously at a dose of 1mg/kg to mice harboring A875 human melanoma tumors. Analog 5, with a polyamine group incorporated at the P2' thiovaline side chain exhibited antiproliferative activity against the P-gp expressing HCT116/VM46 cell line.
Subject(s)
Antineoplastic Agents/pharmacology , Drug Discovery , Inhibitor of Apoptosis Proteins/antagonists & inhibitors , Melanoma/drug therapy , Pancreatic Neoplasms/drug therapy , Tetrahydroisoquinolines/chemistry , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Animals , Antineoplastic Agents/chemistry , Apoptosis/drug effects , Binding Sites , Female , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Models, Molecular , Tumor Cells, Cultured , Xenograft Model Antitumor AssaysABSTRACT
Antibody-drug conjugates (ADCs) aim to take advantage of the specificity of monoclonal antibodies (mAbs) to deliver potent cytotoxic drugs selectively to antigen-expressing tumor cells. Despite the simple concept, various parameters must be considered when designing optimal ADCs, such as selection of the appropriate antigen target and conjugation method. Each component of the ADC (the antibody, linker and drug) must also be optimized to fully realize the goal of a targeted therapy with improved efficacy and tolerability. Advancements over the past several decades have led to a new generation of ADCs comprising non-immunogenic mAbs, linkers with balanced stability and highly potent cytotoxic agents. Although challenges remain, recent clinical success has generated intense interest in this therapeutic class.
Subject(s)
Antibodies, Monoclonal, Humanized/chemistry , Antibodies, Monoclonal, Humanized/therapeutic use , Antineoplastic Agents/chemistry , Antineoplastic Agents/therapeutic use , Animals , Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal, Humanized/immunology , Antineoplastic Agents/immunology , Forecasting , Humans , Neoplasms/drug therapy , Neoplasms/immunologyABSTRACT
A series of phenylacylsulfonamides has been prepared as antagonists of Bcl-2/Bcl-xL. In addition to potent binding affinities for both Bcl-2 and Bcl-xL, these compounds were shown to induce classical markers of apoptosis in isolated mitochondria. Overall weak cellular potency was improved by the incorporation of polar functionality resulting in compounds with moderate antiproliferative activity.
Subject(s)
Antineoplastic Agents/chemical synthesis , Mitochondria/drug effects , Sulfonamides/chemical synthesis , bcl-2-Associated X Protein/antagonists & inhibitors , bcl-X Protein/antagonists & inhibitors , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Cell Line, Tumor , Crystallography, X-Ray , Cytochromes c/metabolism , Humans , Hydrophobic and Hydrophilic Interactions , Mitochondria/metabolism , Models, Molecular , Sulfonamides/pharmacology , bcl-2-Associated X Protein/chemistry , bcl-X Protein/chemistryABSTRACT
5-Butyl-1,4-diphenyl pyrazole and 2-amino-5-chloro pyrimidine acylsulfonamides were developed as potent dual antagonists of Bcl-2 and Bcl-xL. Compounds were optimized for binding to the I88, L92, I95, and F99 pockets normally occupied by pro-apoptotic protein Bim. An X-ray crystal structure confirmed the proposed binding mode. Observation of cytochrome c release from isolated mitochondria in MV-411 cells provides further evidence of target inhibition. Compounds demonstrated submicromolar antiproliferative activity in Bcl-2/Bcl-xL dependent cell lines.
