A Novel Triazolopyridine-Based Spleen Tyrosine Kinase Inhibitor That Arrests Joint Inflammation.

Autoantibodies and the immunoreceptors to which they bind can contribute to the pathogenesis of autoimmune diseases such as rheumatoid arthritis (RA). Spleen Tyrosine Kinase (Syk) is a non-receptor tyrosine kinase with a central role in immunoreceptor (FcR) signaling and immune cell functionality. Syk kinase inhibitors have activity in antibody-dependent immune cell activation assays, in preclinical models of arthritis, and have progressed into clinical trials for RA and other autoimmune diseases. Here we describe the characterization of a novel triazolopyridine-based Syk kinase inhibitor, CC-509. This compound is a potent inhibitor of purified Syk enzyme, FcR-dependent and FcR-independent signaling in primary immune cells, and basophil activation in human whole blood. CC-509 is moderately selective across the kinome and against other non-kinase enzymes or receptors. Importantly, CC-509 was optimized away from and has modest activity against cellular KDR and Jak2, kinases that when inhibited in a preclinical and clinical setting may promote hypertension and neutropenia, respectively. In addition, CC-509 is orally bioavailable and displays dose-dependent efficacy in two rodent models of immune-inflammatory disease. In passive cutaneous anaphylaxis (PCA), CC-509 significantly inhibited skin edema. Moreover, CC-509 significantly reduced paw swelling and the tissue levels of pro-inflammatory cytokines RANTES and MIP-1α in the collagen-induced arthritis (CIA) model. In summary, CC-509 is a potent, moderately selective, and efficacious inhibitor of Syk that has a differentiated profile when compared to other Syk compounds that have progressed into the clinic for RA.

Aminopurine based JNK inhibitors for the prevention of ischemia reperfusion injury.

In this Letter we describe the optimization of an aminopurine lead (1) with modest potency and poor overall kinase selectivity which led to the identification of a series of potent, selective JNK inhibitors. Improvement in kinase selectivity was enabled by introduction of an aliphatic side chain at the C-2 position. CC-359 (2) was selected as a potential clinical candidate for diseases manifested by ischemia reperfusion injury.

Discovery of CC-930, an orally active anti-fibrotic JNK inhibitor.

In this Letter we describe the discovery of potent, selective, and orally active aminopurine JNK inhibitors. Improving the physico-chemical properties as well as increasing the potency and selectivity of a subseries with rat plasma exposure, led to the identification of four structurally diverse inhibitors. Differentiation based on PK profiles in multiple species as well as activity in a chronic efficacy model led to the identification of 1 (CC-930) as a development candidate, which is currently in Phase II clinical trial for IPF.