Discovery of 5-Chloro-N2-[(1S)-1-(5-Fluoropyrimidin-2-Yl) Ethyl]-N4-(5-Methyl-1H-Pyrazol-3-Yl)Pyrimidine-2,4-Diamine (Azd1480) as a Novel Inhibitor of the Jak/Stat Pathway

The myeloproliferative neoplasms, polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis are a heterogeneous but related group of hematological malignancies characterized by clonal expansion of one or more myeloid lineages. The discovery of the Jak2 V617F gain of function mutation highlighted Jak2 as a potential therapeutic target in the MPNs. Herein, we disclose the discovery of a series of pyrazol-3-yl pyrimidin-4-amines and the identification of 9e (AZD1480) as a potent Jak2 inhibitor. 9e inhibits signaling and proliferation of Jak2 V617F cell lines in vitro, demonstrates in vivo efficacy in a TEL-Jak2 model, has excellent physical properties and preclinical pharmacokinetics, and is currently being evaluated in Phase I clinical trials.