Discovery of an ITK and TRK kinase inhibitor for the potential topical treatment of atopic dermatitis.

Interleukin-2-inducible T cell kinase is expressed by T cells and amplifies T cell receptor-dependent signals. Interleukin-2-inducible T cell kinase deletion or inhibition reduces production of interleukin-4 and interleukin-13, key drivers of atopic dermatitis. Nerve growth factor signals via the receptor tropomyosin-related kinase A and may promote pruritus in atopic dermatitis lesions. Here we describe PF-07245303, a compound which potently inhibits interleukin-2-inducible T cell kinase and tropomyosin-related kinase family kinases capable of inhibiting T cell receptor-mediated cytokine production from CD4 and CD8 T cells and suppressing nerve growth factor-induced human basophil activation. In human skin explants, PF-07245303 demonstrates inhibition of tropomyosin-related kinase A phosphorylation, suppresses cytokine expression from T cell receptor-activated resident T cells and reverses the expression of atopic dermatitis associated genes. Topical application of PF-07245303 reduces proinflammatory and epidermal changes in a dermatitis model using female mice. By inhibiting both pathogenic inflammatory mechanisms, PF-07245303 may have therapeutic value for patients with atopic dermatitis.