BGJ398 is primarily used in cancer research and treatment, particularly for targeting fibroblast growth factor receptors (FGFRs). It is an FGFR inhibitor that has shown promise in treating cancers with FGFR genetic alterations, such as bladder cancer, breast cancer, and cholangiocarcinoma. By blocking FGFR signaling pathways, BGJ398 helps to inhibit tumor growth and proliferation. It is also being studied in clinical trials to evaluate its efficacy and safety in patients with advanced solid tumors harboring FGFR abnormalities. Additionally, BGJ398 is utilized in preclinical studies to better understand the role of FGFRs in cancer biology and to develop combination therapies for improved treatment outcomes.