Abstract
On March 27, 2013, a conditional marketing authorization valid throughout the European Union was issued for bosutinib (Bosulif) for the treatment of adult patients with chronic-phase, accelerated-phase, and blast-phase Philadelphia chromosome positive (Ph⁺) chronic myelogenous leukemia (CML) previously treated with one tyrosine kinase inhibitor or more and for whom imatinib, nilotinib, and dasatinib are not considered appropriate treatment options. Bosutinib is a kinase inhibitor that targets the BCR-ABL kinase. The recommended dose is 500 mg of bosutinib once daily. The main evidence of efficacy for bosutinib was based on a CML subgroup analysis of study 3160A4-200, a phase I/II study of bosutinib in Ph⁺ leukemia in imatinib-resistant or intolerant CML. The subgroup was defined based on the presence of a BCR-ABL kinase domain mutation that would be expected to confer resistance to dasatinib (F317, E255) or nilotinib (E255, Y253, F359) and expected to have sensitivity to bosutinib or based on the presence of medical conditions or prior toxicities that may predispose the patient to unacceptable risk in the setting of nilotinib or dasatinib therapy. A conditional marketing authorization was granted because of the limited evidence of efficacy and safety currently supporting this last-line indication.