ASCO20: Long-Term Study Update on Bosutinib for Imatinib-Resistant CML
Posted: Monday, June 8, 2020
Bosutinib continues to provide durable efficacy in some patients with chronic myeloid leukemia (CML) whose disease is resistant to imatinib treatment with or without other tyrosine kinase inhibitors (TKIs), according to the 8-year update of a phase I/II study. Lead author Tim H. Brümmendorf, MD, of Universitätsklinikum RWTH Aachen, Germany, and colleagues, identified no new safety signals and reported manageable toxicity with bosutinib therapy. Their findings were presented during the ASCO20 Virtual Scientific Program (Abstract 7549).
The study enrolled patients with chronic phase CML who were resistant or intolerant to imatinib (n = 284) and resistant or intolerant to imatinib plus dasatinib and/or nilotinib (n = 119). In addition, 167 patients with accelerated/blast phase CML or Philadelphia chromosome–positive acute lymphoblastic leukemia who had received prior TKI therapy were also included. After 9 or more years of treatment, 54 patients (19%) who were resistant to imatinib were still receiving bosutinib, as were 7% of patients resistant to imatinib plus dasatinib and 3% of patients with accelerated/blast phase CML or ALL after 8 or more years.
The most common reason for treatment discontinuation was disease progression or lack of efficacy, including 27% of imatinib-resistant patients, 42% of patients resistant to imatinib plus dasatinib/nilotinib, and 50% of patients with blast phase CML or ALL. New treatment-emergent adverse events reported since the 5-year update in the imatinib-alone resistant group included pleural effusion (n = 13), arthralgia (n = 12), and increased blood creatinine (n = 11).
Disclosure: For full disclosures of the authors, visit coi.asco.org.