Therapeutic compounds targeting interleukin-1 receptor-associated kinase 4 (IRAK4): an updated patent review (2019 to present).

Background: It is more than two decades since IRAK4, a promising target for therapies against various medical conditions, was first reported, but no compounds targeting this enzyme are active on the market or under late-stage clinical development. So it is necessary to continue exploring new and/or improved chemotypes for IRAK4-targeting compounds, to which updated patent reviews are supposed to be of considerable contribution.

Areas covered: PCT patents claiming IRAK4-targeting compounds and published through 2019 to present were retrieved, screened and reviewed for the title compounds disclosed therein, where chemotype-specific strategies were adopted for the said reviewing process. Included patents featuring non-Protac compounds were described in terms of generic formulas and variable-indicated moieties of the title compounds, as well as selected title compounds and relevant prior documents. Included patents featuring Protac-based compounds were described in terms of general examples of IRAK-binding moieties and ligase-binding moieties, as well as the presence of conventional linker types. Insights were finally extracted from the patent review.

Expert opinion: The last five years has seen a steady increase in the number of PCT patents claiming IRAK4-targeting therapeutic compounds, with some of them being based on new chemotypes and/or discovered by new organizations as potential new players.