Interleukin-1 receptor-associated kinase 4 (IRAK4) inhibitors: an updated patent review (2016-2018).

INTRODUCTION: Interleukin-1 receptor-associated kinase 4 (IRAK4) is the most upstream kinase in Toll/Interleukin-1 receptor (TIR) signaling. Human and rodent genetics support the role of IRAK4 in immune function and the involvement of IRAK4-dependent signaling in certain cancers is hypothesized. The accumulating evidence has motivated the discovery of IRAK4 inhibitors that could be used therapeutically. Areas covered: This review summarizes patents published in 2016-2018 claiming IRAK4 inhibitors. Representative analogues from each patent are presented with a focus on compounds that have been profiled in cellular and in vivo assays. Expert opinion: The last three years have seen an increased number of IRAK4 inhibitors with which to assess the therapeutic potential of the target. At least 5 companies are believed to have advanced to the clinic. Pfizer is in phase II for rheumatoid arthritis (RA). The outcomes of these studies should inform on the therapeutic potential in autoimmune disease and cancer.