Bosutinib is an oral second-generation tyrosine kinase inhibitor (TKI) used primarily for the treatment of Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia (CML). Developed initially by Wyeth and later acquired by Pfizer, bosutinib selectively inhibits the abnormal BCR-ABL tyrosine kinase responsible for uncontrolled leukemic cell proliferation and has shown effectiveness in patients resistant or intolerant to earlier TKIs such as Imatinib. Its clinical efficacy and safety were established through major studies including the BELA and BFORE trials. Bosutinib received orphan drug designation from the European Commission on 26 March 2010 and was first approved by the U.S. FDA on 4 September 2012 for adults with previously treated Ph+ CML. Subsequently, the European Medicines Agency granted approval on 27 March 2013, followed by expanded FDA approval on 19 December 2017 for newly diagnosed chronic-phase Ph+ CML and on 29 September 2023 for pediatric patients aged one year and older. Marketed under the brand name Bosulif, bosutinib represents an important advancement in targeted therapy for CML due to its efficacy, oral administration, and role in overcoming resistance to earlier treatments.
