PI3Kδ inhibitors for the treatment of cancer: a patent review (2015-present)

Introduction: PI3Kδ is an important subtype of PI3K kinases, which is mainly expressed in leukocytes and plays an important role in the proliferation, differentiation, maturation and self-reaction of B cells. It is an effective target in the treatment of hematological malignancies and autoimmune diseases such as rheumatoid arthritis. Therefore, many pharmaceutical companies and research institutions have focused on the PI3Kδ subtype in an attempt to develop potent and selective PI3Kδ inhibitors. Areas covered: This review aims to provide an overview of the patented selective PI3Kδ inhibitors in treating cancer from 2015 to present. Expert opinion: Due to the importance of PI3Kδ, the development of selective PI3Kδ inhibitors for the treatment of hematoma and autoimmune diseases is expected. On 23 July 2014, the world’s first selective PI3Kδ inhibitor, idelalisib, was approved by the FDA for the treatment of CLL, FL and SLL. Moreover, there are still many small molecule selective PI3Kδ inhibitors at different stages of development. The future research effort for development of PI3Kδ inhibitors is to manage the toxicity and lower the side-effects.