James J.-W. Duan

Discovery of N-Hydroxy-2-(2-oxo-3-pyrrolidinyl)acetamides as potent and selective inhibitors of tumor necrosis factor-α converting enzyme (TACE)

New inhibitors of tumor necrosis factor-alpha converting enzyme (TACE) were discovered using an N-hydroxy-2-(2-oxo-3-pyrrolidinyl)acetamide scaffold. The series was found to be potent in a porcine TACE (pTACE) assay with IC(50)s typically below 5 nM. For most compounds, selectivity for pTACE relative to MMP-1,-2, and -9 is at least 300-fold. Compound 2o was potent in inhibition of TNFalpha production in a human whole blood assay (WBA) with an IC(50) of 0.42 micro M.

Synthesis and structure-activity relationship of a novel, achiral series of TNF-α converting enzyme inhibitors

Replacement of the amide functionality in IM491 (N-hydroxy-(5S,6S)-1-methyl-6-[[4-(2-methyl-4-quinolinylmethoxy)anilinyl]carbonyl]5-piperidinecarboxamide) with a sulfonyl group led to a new series of alpha,beta-cyclic and beta,beta-cyclic gamma-sulfonyl hydroxamic acids, which were potent TNF-alpha converting enzyme (TACE) inhibitors. Among them, inhibitor 4b (N-hydroxy-(4S,5S)-1-methyl-5-[[4-(2-methyl-4-quinolinylmethoxy)phenyl]sulfonylmethyl]-4-pyrrolidinecarboxamide) exhibited IC50 values of < 1 nM and 180 nM in porcine TACE (pTACE) and cell assays, respectively, with excellent selectivity over MMP-1, -2, -9 and -13 and was orally bioavailable with an F value of 46% in mice.

α,β-Cyclic-β-benzamido hydroxamic acids: Novel oxaspiro[4.4]nonane templates for the discovery of potent, selective, orally bioavailable inhibitors of tumor necrosis factor-α converting enzyme (TACE)

Two novel oxaspiro[4.4]nonane beta-benzamido hydroxamic scaffolds have been synthesized in enantio- and diasteriomerically pure form. These templates proved to be exceptional platforms that have led to the discovery of potent inhibitors of TACE that are active in a cellular assay measuring suppression of LPS-induced TNF-alpha. Furthermore, these inhibitors are selective against related MMPs, demonstrate permeability in a Caco-2 assay, and display good oral bioavailability.

Discovery of pyrrolo[1,2-b]pyridazine-3-carboxamides as Janus kinase (JAK) inhibitors.

A new class of Janus kinase (JAK) inhibitors was discovered using a rationally designed pyrrolo[1,2-b]pyridazine-3-carboxamide scaffold. Preliminary studies identified (R)-(2,2-dimethylcyclopentyl)amine as a preferred C4 substituent on the pyrrolopyridazine core (3b). Incorporation of amino group to 3-position of the cyclopentane ring resulted in a series of JAK3 inhibitors (4g-4j) that potently inhibited IFNγ production in an IL2-induced whole blood assay and displayed high functional selectivity for JAK3-JAK1 pathway relative to JAK2. Further modifications led to the discovery of an orally bioavailable (2-fluoro-2-methylcyclopentyl)amino analogue 5g which is a nanomolar inhibitor of both JAK3 and TYK2, functionally selective for the JAK3-JAK1 pathway versus JAK2, and active in a human whole blood assay.

Identification of bicyclic hexafluoroisopropyl alcohol sulfonamides as retinoic acid receptor-related orphan receptor gamma (RORγ/RORc) inverse agonists. Employing structure-based drug design to improve pregnane X receptor (PXR) selectivity

We disclose the optimization of a high throughput screening hit to yield benzothiazine and tetrahydroquinoline sulfonamides as potent RORγt inverse agonists. However, a majority of these compounds showed potent activity against pregnane X receptor (PXR) and modest activity against liver X receptor α (LXRα). Structure-based drug design (SBDD) led to the identification of benzothiazine and tetrahydroquinoline sulfonamide analogs which completely dialed out LXRα activity and were less potent at PXR. Pharmacodynamic (PD) data for compound 35 in an IL-23 induced IL-17 mouse model is discussed along with the implications of a high Ymax in the PXR assay for long term preclinical pharmacokinetic (PK) studies.

Discovery of potent and efficacious pyrrolopyridazines as dual JAK1/3 inhibitors

A series of potent dual JAK1/3 inhibitors have been developed from a moderately selective JAK3 inhibitor. Substitution at the C6 position of the pyrrolopyridazine core with aryl groups provided exceptional biochemical potency against JAK1 and JAK3 while maintaining good selectivity against JAK2 and Tyk2. Translation to in vivo efficacy was observed in a murine model of chronic inflammation. X-ray co-crystal structure determination confirmed the presumed inhibitor binding orientation in JAK3. Efforts to reduce hERG channel inhibition will be described.

Discovery of highly potent, selective, covalent inhibitors of JAK3

A useful and novel set of tool molecules have been identified which bind irreversibly to the JAK3 active site cysteine residue. The design was based on crystal structure information and a comparative study of several electrophilic warheads.