ABSTRACT
Epidermal growth factor receptor (EGFR)-targeted therapy in non-small cell lung cancer represents a breakthrough in the field of precision medicine. Previously, we have identified a lead compound, furanopyrimidine 2, which contains a (S)-2-phenylglycinol structure as a key fragment to inhibit EGFR. However, compound 2 showed high clearance and poor oral bioavailability in its pharmacokinetics studies. In this work, we optimized compound 2 by scaffold hopping and exploiting the potent inhibitory activity of various warhead groups to obtain a clinical candidate, 78 (DBPR112), which not only displayed a potent inhibitory activity against EGFRL858R/T790M double mutations but also exhibited tenfold potency better than the third-generation inhibitor, osimertinib, against EGFR and HER2 exon 20 insertion mutations. Overall, pharmacokinetic improvement through lead-to-candidate optimization yielded fourfold oral AUC better that afatinib along with F = 41.5%, an encouraging safety profile, and significant antitumor efficacy in in vivo xenograft models. DBPR112 is currently undergoing phase 1 clinical trial in Taiwan.
Subject(s)
Antineoplastic Agents/pharmacology , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung Neoplasms/drug therapy , Protein Kinase Inhibitors/pharmacology , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Binding Sites , Cell Line, Tumor , Crystallography, X-Ray , Drug Design , Drug Resistance, Neoplasm/genetics , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/chemistry , ErbB Receptors/genetics , ErbB Receptors/metabolism , Exons , Humans , Male , Mice, Inbred ICR , Mice, Nude , Mutation , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/metabolism , Pyrimidines/chemistry , Rats , Receptor, ErbB-2 , Structure-Activity Relationship , Xenograft Model Antitumor AssaysABSTRACT
Ligand efficiency (LE) and lipophilic efficiency (LipE) are two important indicators of "drug-likeness", which are dependent on the molecule's activity and physicochemical properties. We recently reported a furano-pyrimidine Aurora kinase inhibitor 4 (LE = 0.25; LipE = 1.75), with potent activity in vitro; however, 4 was inactive in vivo. On the basis of insights obtained from the X-ray co-crystal structure of the lead 4, various solubilizing functional groups were introduced to optimize both the activity and physicochemical properties. Emphasis was placed on identifying potential leads with improved activity as well as better LE and LipE by exercising tight control over the molecular weight and lipophilicity of the molecules. Rational optimization has led to the identification of Aurora kinase inhibitor 27 (IBPR001; LE = 0.26; LipE = 4.78), with improved in vitro potency and physicochemical properties, resulting in an in vivo active (HCT-116 colon cancer xenograft mouse model) anticancer agent.
Subject(s)
Antineoplastic Agents/pharmacology , Aurora Kinase A/antagonists & inhibitors , Protein Kinase Inhibitors/pharmacology , Pyrimidines/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Aurora Kinase A/chemistry , Aurora Kinase A/metabolism , Body Weight/drug effects , Cell Proliferation/drug effects , Crystallography, X-Ray , Drug Design , Furans/chemistry , HCT116 Cells , Heterocyclic Compounds, 2-Ring/chemical synthesis , Heterocyclic Compounds, 2-Ring/chemistry , Heterocyclic Compounds, 2-Ring/pharmacology , Humans , Ligands , Lipids/chemistry , Male , Mice , Mice, Nude , Models, Chemical , Models, Molecular , Molecular Structure , Neoplasms/drug therapy , Neoplasms/metabolism , Neoplasms/pathology , Phenylurea Compounds/chemical synthesis , Phenylurea Compounds/chemistry , Phenylurea Compounds/pharmacology , Protein Binding , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/chemistry , Protein Structure, Tertiary , Pyrimidines/chemical synthesis , Pyrimidines/chemistry , Xenograft Model Antitumor AssaysABSTRACT
The Asp-Phe-Gly (DFG) motif plays an important role in the regulation of kinase activity. Structure-based drug design was performed to design compounds able to interact with the DFG motif; epidermal growth factor receptor (EGFR) was selected as an example. Structural insights obtained from the EGFR/2a complex suggested that an extension from the meta-position on the phenyl group (ring-5) would improve interactions with the DFG motif. Indeed, introduction of an N,N-dimethylamino tail resulted in 4b, which showed almost 50-fold improvement in inhibition compared to 2a. Structural studies confirmed this N,N-dimethylamino tail moved toward the DFG motif to form a salt bridge with the side chain of Asp831. That the interactions with the DFG motif greatly contribute to the potency of 4b is strongly evidenced by synthesizing and testing compounds 2a, 3g, and 4f: when the charge interactions are absent, the inhibitory activity decreased significantly.
Subject(s)
ErbB Receptors/antagonists & inhibitors , Oligopeptides/chemical synthesis , Oligopeptides/pharmacology , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , Crystallography, X-Ray , Drug Design , ErbB Receptors/genetics , Humans , Models, Molecular , Mutation , Protein Binding , Protein Conformation , Protein Kinase Inhibitors/chemistry , Real-Time Polymerase Chain Reaction , Structure-Activity RelationshipABSTRACT
BPR0L075 (2) is a potential anticancer drug candidate designed from Combretastatin A-4 (1) based on the bioisosterism principle. Metabolites of 2, proposed from in vitro human microsome studies, were synthesized, leading to the identification of metabolite-derived analogue 10 with 40-350 pM potency against various cancer cell lines. Insights gained from the major inactive metabolite of 2 led to the development of 29, with better pharmacokinetics and improved potency in the tumor xenograft model than 2.
Subject(s)
Antineoplastic Agents/chemical synthesis , Indoles/chemical synthesis , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Colchicine/metabolism , Drug Design , Humans , Indoles/metabolism , Indoles/pharmacokinetics , Indoles/pharmacology , Mice , Rats , Structure-Activity Relationship , Tubulin Modulators/chemical synthesis , Tubulin Modulators/pharmacologyABSTRACT
6-Methoxy-3-(3',4',5'-trimethoxy-benzoyl)-1H-indole (BPR0L075) is a novel synthetic indole compound with microtubule binding activity. Incubation of BPR0L075 with mouse, rat, dog, and human liver microsomes in the presence of NADPH resulted in the formation of six metabolites. Liquid chromatography-tandem mass spectrometry and comparison with the synthetic reference standards identified two metabolites (M1 and M5) as the products derived from hydroxylation on the indole moiety of the molecule. M3 was also identified as a product derived from hydroxylation, but the structure of this metabolite was not identified because of the lack of a reference standard. M2, M4, and M6 were identified as the products derived from O-demethylation. M2, 6-desmethyl-BPR0L075, was the major metabolite formed by the liver microsomes of the four species. No qualitative species difference in the metabolism of BPR0L075 was observed. There was quantitative species difference in the metabolism of BPR0L075 among the four species. Whereas mouse and rat liver microsomes metabolized BPR0L075 predominantly via O-demethylation, dog liver microsomes metabolized BPR0L075 by O-demethylation and hydroxylation to about the same extent. The rank order of intrinsic clearance rates for the conversion of BPR0L075 to 6-desmethyl-BPR0L075 was mouse > rat > human > dog. Incubation of BPR0L075 with baculovirus-insect cell-expressed human cytochrome P450 (P450) isozymes showed that CYP1A2, 2C9, 2C19, 2D6, 2E1, and 3A4 all catalyzed the O-demethylation and hydroxylation of BPR0L075 but to a different degree. Among the six P450 isozymes tested, CYP1A2 and 2D6 were most active on catalyzing the metabolism of BPR0L075. CYP1A2 catalyzed mainly the formation of M1, M2, and M3. M2 was the predominant metabolite formed by CYP2D6.