CEP-33779

CEP-33779 is a **highly selective, orally active, small-molecule inhibitor** of **Janus kinase 2 (JAK2)**. Developed by Cephalon, CEP-33779 demonstrates potent inhibitory activity against JAK2 (IC50 of 1.8 nM) and is not known to clinically inhibit other kinases at relevant concentrations[1][3][7]. Its mechanism of action involves the blockade of JAK2-dependent phosphorylation of STAT3 and STAT5, suppressing downstream gene transcription involved in inflammation and cellular proliferation. In **preclinical models**, CEP-33779 has shown therapeutic efficacy in **autoimmune diseases** (rheumatoid arthritis, lupus nephritis), **colorectal cancer**, and **systemic lupus erythematosus** by reducing cytokine production, joint inflammation, and tumor growth[1][3][5][7]. It also demonstrated attenuation of LPS-induced acute lung injury in mice[2]. The antitumor effect is associated with reduced activation of both STAT3 and NF-κB signaling, particularly in inflammation-driven tumorigenesis such as colitis-associated colorectal cancer[1][5]. CEP-33779 has not advanced to marketed status and remains a **preclinical compound**.