Christopher John Davis

Design and Optimization of Selective Protein Kinase C θ (PKCθ) Inhibitors for the Treatment of Autoimmune Diseases

Protein kinase C θ (PKCθ) has a central role in T cell activation and survival; however, the dependency of T cell responses to the inhibition of this enzyme appears to be dictated by the nature of the antigen and by the inflammatory environment. Studies in PKCθ-deficient mice have demonstrated that while antiviral responses are PKCθ-independent, T cell responses associated with autoimmune diseases are PKCθ-dependent. Thus, potent and selective inhibition of PKCθ is expected to block autoimmune T cell responses without compromising antiviral immunity. Herein, we describe the development of potent and selective PKCθ inhibitors, which show exceptional potency in cells and in vivo. By use of a structure based rational design approach, a 1000-fold improvement in potency and 76-fold improvement in selectivity over closely related PKC isoforms such as PKCδ were obtained from the initial HTS hit, together with a big improvement in lipophilic efficiency (LiPE).

Structure-based optimization of aminopyridines as PKCθ inhibitors

The identification of a novel series of PKCθ inhibitors and subsequent optimization using docking based on a crystal structure of PKCθ is described. SAR was rapidly generated around an amino pyridine-ketone hit; (6-aminopyridin-2-yl)(2-aminopyridin-3-yl)methanone 2 leading to compound 21 which significantly inhibits production of IL-2 in a mouse SEB-IL2 model.