Development of PI3Kγ selective inhibitors: the strategies and application

The gamma isoform of Class I PI3Ks (PI3K gamma) is primarily found in leukocytes and is essential for the function of myeloid cells, as it regulates the migration, differentiation, and activation of myeloid-lineage immune cells. Thus, PI3K gamma has been identified as a promising drug target for the treatment of inflammation, autoimmune disease, and immuno-oncology. Due to the high incidence of serious adverse events (AEs) associated with PI3K inhibitors, in the development of PI3K gamma inhibitors, isoform selectivity was deemed crucial. In this review, an overview of the development of PI3K gamma selective inhibitors in the past years is provided. The isoform selectivity of related drugs was achieved by different strategies, including inducing a specificity pocket by a propeller-shape structure, targeting steric differences in the solvent channel, and modulating the conformation of the Asp-Phe-Gly DFG motif, which have been demonstrated feasible by several successful cases. The insights in this manuscript may provide a potential direction for rational drug design and accelerate the discovery of PI3K gamma selective inhibitors.