ABSTRACT
KRASG12C has emerged as a promising target in the treatment of solid tumors. Covalent inhibitors targeting the mutant cysteine-12 residue have been shown to disrupt signaling by this long-"undruggable" target; however clinically viable inhibitors have yet to be identified. Here, we report efforts to exploit a cryptic pocket (H95/Y96/Q99) we identified in KRASG12C to identify inhibitors suitable for clinical development. Structure-based design efforts leading to the identification of a novel quinazolinone scaffold are described, along with optimization efforts that overcame a configurational stability issue arising from restricted rotation about an axially chiral biaryl bond. Biopharmaceutical optimization of the resulting leads culminated in the identification of AMG 510, a highly potent, selective, and well-tolerated KRASG12C inhibitor currently in phase I clinical trials (NCT03600883).
Subject(s)
Antineoplastic Agents/therapeutic use , Neoplasms/drug therapy , Piperazines/therapeutic use , Proto-Oncogene Proteins p21(ras)/antagonists & inhibitors , Pyridines/therapeutic use , Pyrimidines/therapeutic use , Pyrimidinones/therapeutic use , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Clinical Trials as Topic , Dogs , Drug Discovery , Humans , Isomerism , Madin Darby Canine Kidney Cells , Mice, Inbred BALB C , Mice, Nude , Mutation , Piperazines/chemistry , Piperazines/pharmacology , Proto-Oncogene Proteins p21(ras)/genetics , Pyridines/chemistry , Pyridines/pharmacokinetics , Pyridines/pharmacology , Pyrimidines/chemistry , Pyrimidines/pharmacology , Pyrimidinones/chemistry , Pyrimidinones/pharmacokinetics , Rats , Structure-Activity RelationshipABSTRACT
The efficacy of therapeutic antibodies that induce antibody-dependent cellular cytotoxicity can be improved by reduced fucosylation. Consequently, fucosylation is a critical product attribute of monoclonal antibodies produced as protein therapeutics. Small molecule fucosylation inhibitors have also shown promise as potential therapeutics in animal models of tumors, arthritis, and sickle cell disease. Potent small molecule metabolic inhibitors of cellular protein fucosylation, 6,6,6-trifluorofucose per-O-acetate and 6,6,6-trifluorofucose (fucostatin I), were identified that reduces the fucosylation of recombinantly expressed antibodies in cell culture in a concentration-dependent fashion enabling the controlled modulation of protein fucosylation levels. 6,6,6-Trifluorofucose binds at an allosteric site of GDP-mannose 4,6-dehydratase (GMD) as revealed for the first time by the X-ray cocrystal structure of a bound allosteric GMD inhibitor. 6,6,6-Trifluorofucose was found to be incorporated in place of fucose at low levels (<1%) in the glycans of recombinantly expressed antibodies. A fucose-1-phosphonate analog, fucostatin II, was designed that inhibits fucosylation with no incorporation into antibody glycans, allowing the production of afucosylated antibodies in which the incorporation of non-native sugar is completely absent-a key advantage in the production of therapeutic antibodies, especially biosimilar antibodies. Inhibitor structure-activity relationships, identification of cellular and inhibitor metabolites in inhibitor-treated cells, fucose competition studies, and the production of recombinant antibodies with varying levels of fucosylation are described.
Subject(s)
Fucose/metabolism , Hydro-Lyases/metabolism , Small Molecule Libraries , Animals , CHO Cells , Cricetinae , Cricetulus , Crystallography, X-Ray , Fucose/antagonists & inhibitors , Guanosine Diphosphate Mannose/metabolism , Mass Spectrometry , Molecular Structure , Surface Plasmon ResonanceABSTRACT
We report the discovery of a novel series of 2-(3-alkoxy-1-azetidinyl) quinolines as potent and selective PDE10A inhibitors. Structure-activity studies improved the solubility (pH 7.4) and maintained high PDE10A activity compared to initial lead compound 3, with select compounds demonstrating good oral bioavailability. X-ray crystallographic studies revealed two distinct binding modes to the catalytic site of the PDE10A enzyme. An ex vivo receptor occupancy assay in rats demonstrated that this series of compounds covered the target within the striatum.
Subject(s)
Phosphodiesterase Inhibitors/pharmacology , Phosphoric Diester Hydrolases/metabolism , Quinolines/pharmacology , Dose-Response Relationship, Drug , Humans , Models, Molecular , Molecular Structure , Phosphodiesterase Inhibitors/chemical synthesis , Phosphodiesterase Inhibitors/chemistry , Quinolines/chemical synthesis , Quinolines/chemistry , Solubility , Structure-Activity RelationshipABSTRACT
We reveal how a N-scan SAR strategy (systematic substitution of each CH group with a N atom) was employed for quinolinone-based S1P(1) agonist 5 to modulate physicochemical properties and optimize in vitro and in vivo activity. The diaza-analog 17 displays improved potency (hS1P(1) RI; 17: EC(50)=0.020 µM, 120% efficacy; 5: EC(50)=0.070 µM, 110% efficacy) and selectivity (hS1P(3) Ca(2+) flux; 17: EC(50) >25 µM; 5: EC(50)=1.5 µM, 92% efficacy), as well as enhanced pharmacokinetics (17: CL=0.15 L/h/kg, V(dss)=5.1L/kg, T(1/2)=24h, %F=110; 5: CL=0.93L/h/kg, V(dss)=11L/kg, T(1/2)=15 h, %F=60) and pharmacodynamics (17: 1.0mg/kg po, 24h PLC POC=-67%; 5: 3mg/kg po, 24h PLC POC=-51%) in rat.
Subject(s)
Chemistry, Physical/methods , Quinolones/pharmacology , Receptors, Lysosphingolipid/agonists , Receptors, Lysosphingolipid/chemistry , Animals , Area Under Curve , Cardiovascular Diseases/metabolism , Drug Design , Female , Humans , Immunosuppressive Agents/pharmacology , In Vitro Techniques , Kinetics , Lymphocytes/cytology , Lymphocytes/metabolism , Models, Chemical , Multiple Sclerosis/drug therapy , Quinolones/chemistry , Rats , Rats, Inbred Lew , Structure-Activity RelationshipABSTRACT
The sphingosine-1-phosphate-1 receptor (S1P1) and its endogenous ligand sphingosine-1-phosphate (S1P) cooperatively regulate lymphocyte trafficking from the lymphatic system. Herein, we disclose 4-methoxy-N-[2-(trifluoromethyl)biphenyl-4-ylcarbamoyl]nicotinamide (8), an uncommon example of a synthetic S1P1 agonist lacking a polar headgroup, which is shown to effect dramatic reduction of circulating lymphocytes (POC = -78%) in rat 24 h after a single oral dose (1 mg/kg). The excellent potency that 8 exhibits toward S1P1 (EC50 = 0.035 µM, 96% efficacy) and the >100-fold selectivity that it displays against receptor subtypes S1P2-5 suggest that it may serve as a valuable tool to understand the clinical relevance of selective S1P1 agonism.
ABSTRACT
Inhibition of the PHD2 enzyme has been associated with increased red blood cell levels. From a screening hit, a series of novel hydroxyl-thiazoles were developed as potent PHD2 inhibitors.