Minimum Effective Dose of Second-Line Bosutinib in Elderly Patients With CML
Posted: Thursday, January 23, 2020
A dose of 300 mg of bosutinib may be effective and better tolerated in elderly patients with chronic myeloid leukemia (CML) than the standard dose of 500 mg, according to a phase II study conducted by Fausto Castagnetti, MD, PhD, of the University of Bologna Institute of Hematology, Italy. Use of second-generation tyrosine kinase inhibitors such as bosutinib, dasatinib, and nilotinib may be complicated by pulmonary, infectious, cardiovascular, and metabolic events, particularly in elderly patients. These findings were presented at the 2019 American Society of Hematology (ASH) Annual Meeting & Exposition (Abstract 496).
The prospective phase II single-arm multicenter study included 63 patients (between the ages of 60 and 90) with chronic phase CML who experienced intolerance of or failure to respond to a first-line tyrosine kinase inhibitor. Patients’ median age was 73. Patients received 200 mg of bosutinib daily for 2 weeks. Four patients stayed on the 200-mg dose, and the rest received 300 mg daily for 3 months. Then, the 49 patients with no more than 1% transcript of the BCR-ABL mutation continued on 300 mg, whereas the 10 patients with more than 1% transcript received 400 mg daily.
The median follow-up was 9 months. At the study’s baseline, 13 patients (21%) were already in molecular response. After 1 year, 60% of patients had achieved a major molecular response. The investigators reported that 51 of 63 patients (81%) were still on bosutinib: 6 patients on 400 mg, 34 on 300 mg, and 11 on 200 mg.
Two deaths unrelated to treatment were reported. Adverse events caused seven patients to discontinue treatment: three patients had hypertransaminasemia, and one patient each had nephrotoxicity, diarrhea, skin rash, and myalgia/fatigue. Other adverse events included cardiac ischemia in two patients and pericardial effusion in two patients.
Disclosure: The study authors’ disclosure information may be found at ash.confex.com.