ABSTRACT
Reactive metabolites have been putatively linked to many adverse drug reactions including idiosyncratic toxicities for a number of drugs with black box warnings or withdrawn from the market. Therefore, it is desirable to minimize the risk of reactive metabolite formation for lead molecules in optimization, in particular for non-life threatening chronic disease, to maximize benefit to risk ratio. This article describes our effort in addressing reactive metabolite issues for a series of 3-amino-2-pyridone inhibitors of BTK, e.g. compound 1 has a value of 459pmol/mg protein in the microsomal covalent binding assay. Parallel approaches were taken to successfully resolve the issues: establishment of a predictive screening assay with correlation association of covalent binding assay, identification of the origin of reactive metabolite formation using MS/MS analysis of HLM as well as isolation and characterization of GSH adducts. This ultimately led to the discovery of compound 7 (RN941) with significantly reduced covalent binding of 26pmol/mg protein.
Subject(s)
Protein Kinase Inhibitors/chemistry , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyridones/chemistry , Agammaglobulinaemia Tyrosine Kinase , Glutathione/chemistry , Magnetic Resonance Spectroscopy , Microsomes/metabolism , Protein Kinase Inhibitors/metabolism , Protein-Tyrosine Kinases/metabolism , Pyridones/metabolism , Tandem Mass SpectrometryABSTRACT
CD73 (ecto-5'-nucleotidase) has emerged as an attractive target for cancer immunotherapy of many cancers. CD73 catalyzes the hydrolysis of adenosine monophosphate (AMP) into highly immunosuppressive adenosine that plays a critical role in tumor progression. Herein, we report our efforts in developing orally bioavailable and highly potent small-molecule CD73 inhibitors from the reported hit molecule 2 to lead molecule 20 and then finally to compound 49. Compound 49 was able to reverse AMP-mediated suppression of CD8+ T cells and completely inhibited CD73 activity in serum samples from various cancer patients. In preclinical in vivo studies, orally administered 49 showed a robust dose-dependent pharmacokinetic/pharmacodynamic (PK/PD) relationship that correlated with efficacy. Compound 49 also demonstrated the expected immune-mediated antitumor mechanism of action and was efficacious upon oral administration not only as a single agent but also in combination with either chemotherapeutics or checkpoint inhibitor in the mouse tumor model.
Subject(s)
CD8-Positive T-Lymphocytes , Neoplasms , Mice , Animals , Nucleosides , 5'-Nucleotidase , Neoplasms/drug therapy , Disease Models, Animal , Adenosine MonophosphateABSTRACT
Learnings from previous Roche p38-selective inhibitors were applied to a new fragment hit, which was optimized to a potent, exquisitely selective preclinical lead with a good pharmacokinetic profile.
Subject(s)
Drug Design , Enzyme Activation/drug effects , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Mitogen-Activated Protein Kinase 14/antagonists & inhibitors , Pyrimidines/chemical synthesis , Pyrimidines/pharmacology , Animals , Crystallography, X-Ray , Enzyme Inhibitors/chemistry , Inhibitory Concentration 50 , Models, Molecular , Molecular Structure , Pyrazoles/chemical synthesis , Pyrazoles/chemistry , Pyrazoles/pharmacology , Pyrimidines/chemistry , RatsABSTRACT
A novel series of (E)-1-((2-(1-methyl-1H-imidazol-5-yl) quinolin-4-yl) methylene) thiosemicarbazides was discovered as potent inhibitors of IKKß. In this Letter we document our efforts at further optimization of this series, culminating in 2 with submicromolar potency in a HWB assay and efficacy in a CIA mouse model.
Subject(s)
I-kappa B Kinase/antagonists & inhibitors , Protein Kinase Inhibitors/chemistry , Quinolines/chemistry , Semicarbazides/chemistry , Thiourea/analogs & derivatives , Animals , Dogs , Female , Hepatocytes/metabolism , High-Throughput Screening Assays , Humans , I-kappa B Kinase/metabolism , Macaca mulatta , Male , Mice , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Quinolines/chemical synthesis , Quinolines/pharmacokinetics , Rats , Semicarbazides/chemical synthesis , Semicarbazides/pharmacokinetics , Structure-Activity Relationship , Thiourea/chemical synthesis , Thiourea/chemistry , Thiourea/pharmacokineticsABSTRACT
A novel series of (E)-1-((2-(1-methyl-1H-imidazol-5-yl) quinolin-4-yl) methylene) thiosemicarbazides was discovered as potent inhibitors of IKKß. In this Letter we document our early efforts at optimization of the quinoline core, the imidazole and the semithiocarbazone moiety. Most potency gains came from substitution around the 6- and 7-positions of the quinoline ring. Replacement of the semithiocarbazone with a semicarbazone decreased potency but led to some measurable exposure.
Subject(s)
I-kappa B Kinase/antagonists & inhibitors , Protein Kinase Inhibitors/chemistry , Semicarbazides/chemistry , Animals , Dogs , Female , High-Throughput Screening Assays , I-kappa B Kinase/metabolism , Male , Microsomes/metabolism , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Quinolines/chemistry , Rats , Semicarbazides/chemical synthesis , Semicarbazides/pharmacokinetics , Structure-Activity RelationshipABSTRACT
A new synthesis of di- and trisubstituted pyrroles was achieved by treating in situ generated vinylogous diazoesters and readily available nitriles with a catalytic amount of silver(I) antimony hexafluoride at room temperature. This method showcased the potential of utilizing silver(I) carbenoids in preparing heterocyclic compounds.