The Bruton’s tyrosine kinase (Btk) inhibitor ibrutinib has shown impressive clinical efficacy in a range of B-cell malignancies. However, acquired resistance has emerged, and second generation therapies are now being sought. Ibrutinib is a covalent, irreversible inhibitor that modifies Cys481 in the ATP binding site of Btk and renders the enzyme inactive, thereby blocking B-cell receptor signal transduction. Not surprisingly, Cys481 is the most commonly mutated Btk residue in cases of acquired resistance to ibrutinib. Mutations at other sites, including Thr474, a gatekeeper residue, have also been detected. Herein, we describe noncovalent Btk inhibitors that differ from covalent inhibitors like ibrutinib in that they do not interact with Cys481, they potently inhibit the ibrutinib-resistant Btk C481S mutant in vitro and in cells, and they are exquisitely selective for Btk. Noncovalent inhibitors such as GNE-431 also show excellent potency against the C481R, T474I, and T474M mutants. X-ray crystallographic...

Battling Btk Mutants With Noncovalent Inhibitors That Overcome Cys481 and Thr474 Mutations

Strategies for developing DNA-encoded libraries beyond binding assays

Sulfur/selenium-containing electron-rich arenes (ERAs) exist in a wide range of both approved and investigational drugs with diverse pharmacological activities. These unique chemical structures and bioactive properties, if combined with the emerging DNA-encoded chemical library (DEL) technique, would facilitate drug and chemical probe discovery. However, it remains challenging, as there is no general DNA-compatible synthetic methodology available for the formation of C–S and C–Se bonds in aqueous solution. Herein, an in-solution direct oxidative coupling procedure that could efficiently integrate sulfur/selenium into the ERA under mild conditions is presented. This method features simple DNA-conjugated electron-rich arenes with a broad substrate scope and a transition-metal free process. Furthermore, this synthetic methodology, examined by a scale-up reaction test and late-stage precise modification in a mock peptide-like DEL synthesis, will enable its utility for the synthesis of sulfur/selenium-containing DNA-encoded libraries and the discovery of bioactive agents.

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In-solution direct oxidative coupling for the integration of sulfur/selenium into DNA-encoded chemical libraries

DNA-encoded libraries (DELs) are an increasingly popular approach to finding small molecule ligands for proteins. Many DEL synthesis protocols hinge on sequential additions of monomers using split-pool combinatorial methods. Therefore, compatible protecting group strategies that allow the unmasking of reactive functionality (e.g. amines and alcohols) prior to monomer coupling, or the removal of less desirable functionality (e.g. alkenes and alkynes) are highly desirable. Hydrogenation / hydrogenolysis procedures would achieve these ends but has not been amenable to DEL chemistry. We report a catalytic hydrogen transfer reaction using Pd / C, HCONH 4 and the micelle-forming surfactant, TPGS-750-M, which gives highly efficient conversions for hydrogenolysis of Cbz-protected amines and benzyl protected alcohols and hydrogenation of nitros, halides, nitriles, aldehydes, alkenes and alkynes. Application to multicycle synthesis of an encoded compound was fully compatible with DNA-amplification and sequencing, demonstrating its applicability to DEL synthesis. This method will enable synthetic DEL sequences using orthogonal protecting groups.

On-DNA Transfer Hydrogenolysis and Hydrogenation for the Synthesis of DNA-Encoded Chemical Libraries.

Heteroaryl pyridone and aza-pyridone amide compounds with electrophilic functionality of Formula I are provided, including stereoisomers, tautomers, and pharmaceutically acceptable salts thereof, useful for inhibiting Btk, and for treating cancer and immune disorders such as inflammation mediated by Btk. Methods of using compounds of Formula I for in vitro, in situ, and in vivo diagnosis, and treatment of such disorders in mammalian cells, or associated pathological conditions, are disclosed.

Heteroaryl pyridone and aza-pyridone compounds with electrophilic functionality

Heteroaryl pyridone and aza-pyridone compounds of Formula I are provided, where one or two of X1, X2, and X3 are N, and including stereoisomers, tautomers, and pharmaceutically acceptable salts thereof, useful for inhibiting Btk kinase, and for treating immune disorders such as inflammation mediated by Btk kinase. Methods of using compounds of Formula I for in vitro, in situ, and in vivo diagnosis, and treatment of such disorders in mammalian cells, or associated pathological conditions, are disclosed.

Heteroaryl pyridone and aza-pyridone compounds as inhibitors of btk activity

DNA encoded libraries (DELs) represent powerful new technology for finding small molecule ligands for proteins and are increasingly being applied to hit finding in medicinal chemistry. Crucial to the synthesis of high quality DELs is the identification of chemical reactions for their assembly that proceed with very high conversion across a range of different substrates, under conditions compatible with DNA-tagged substrates. Many current chemistries used in DEL synthesis do not meet this requirement, resulting in libraries of low fidelity. Amide couplings are the most commonly used reaction in synthesis of screening libraries and also in DELs. The ability to carry out highly efficient, widely applicable amide couplings in DEL synthesis would therefore be highly desirable. We report a method for amide coupling using micelle forming surfactants, promoted by a modified linker, that is broadly applicable across a wide range of substrates. Most significantly, this works exceptionally well for coupling of DNA-conjugated carboxylic acids (N-to-C) with amines in solution, a procedure that is currently very inefficient. The optimisation of separate procedures for coupling of DNA-conjugated acids and amines by reagent screening and statistically driven optimisation is described. The generality of the method is illustrated by the application to a wide range of examples with unprecedented levels of conversion. The utility of the (N-to-C) coupling of DNA-conjugated acids in DEL synthesis is illustrated by the three cycle synthesis of a fully DNA-encoded compound by two cycles of coupling of an aminoester, with intermediate ester hydrolysis, followed by capping with an amine. This methodology will be of great utility in the synthesis of high fidelity DELs.

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Highly efficient on-DNA amide couplings promoted by micelle forming surfactants for the synthesis of DNA encoded libraries.

Heteroaryl pyridone and aza-pyridone compounds are provided, including stereoisomers, tautomers, and pharmaceutically acceptable salts thereof, useful for inhibiting Btk kinase, and for treating immune disorders such as inflammation mediated by Btk kinase Methods of using heteroaryl pyridone and aza-pyridone compounds for in vitro, in situ, and in vivo diagnosis, and treatment of such disorders in mammalian cells, or associated pathological conditions, are disclosed

Heteroaryl pyridone and aza-pyridone compounds

Heteroaryl pyridone and aza-pyridone compounds of Formula I are provided, where one or two of X, X, and Xare N, and including stereoisomers, tautomers, and pharmaceutically acceptable salts thereof, useful for inhibiting Btk kinase (Bruton's Tyrosine Kinase), and for treating immune disorders such as inflammation mediated by Btk kinase. Methods of using compounds of Formula I for in vitro, in situ, and in vivo diagnosis, and treatment of such disorders in mammalian cells, or associated pathological conditions, are disclosed.

Crawford James John

Papers

Heteroaryl pyridone and aza-pyridone compounds as inhibitors of btk activity

Highly efficient on-DNA amide couplings promoted by micelle forming surfactants for the synthesis of DNA encoded libraries.

Heteroaryl pyridone and aza-pyridone compounds

Heteroaryl pyridone and aza-pyridone compounds as inhibitors of bruton's tyrosine kinase