Bosutinib in the Real-Life Treatment of Chronic Phase Chronic Myeloid Leukemia (CML) Patients Aged > 65 Years Resistant/Intolerant to Frontline Tyrosine-Kynase Inhibitors

Background Bosutinib is a 2nd generation tyrosine-kinase inhibitor (TKI) active in Chronic Myeloid Leukemia (CML) patients resistant or intolerant to frontline imatinib, dasatinib or nilotinib; the favourable toxicity profile makes bosutinib potentially useful in elderly patients, but at present there are no data in unselected cohorts of these subjects. Aim To highlight this issue, a real-life cohort of 91 patients followed in 21 Italian Centers and treated with bosutinib when aged > 65 years was retrospectively evaluated. Patients The main clinical features of the whole cohort at diagnosis and at baseline of bosutinib treatment are reported in the Table; all patients were in CP when bosutinib was started. Median interval from diagnosis to bosutinib treatment was 49.7 months [interquartile range (IQR) 14.2 - 117.5]. Results Starting dose of bosutinib was 500 mg/day in 20 patients (22.0%), 400 mg/day in 7 patients (7.7%), 300 mg/day in 28 patients (30.8%), 200 mg/day in 34 patients (37.3%) and 100 mg/day in 2 patients (2.2%), respectively. After a median period of treatment of 18.1 months (IQR 9.4 - 27.7) all patients were evaluable for toxicity; on the whole, all grade hematological and extra-hematological toxicities were reported in 12/91 (13.1%) and 45/91 (49.4%) patients, respectively. A grade 3 - 4 hematological toxicity occurred in 5/91 patients (5.4%); a grade 3 - 4 extra-hematological toxicity occurred in 16/91 patients (17.5%). Overall, 46 patients (50.5%) never discontinued bosutinib: a temporary discontinuation 6 weeks in 2 patients (2.2%). A permanent bosutinib discontinuation was needed in the remaining 24 patients (26.4%): in particular, 11 patients (12.1%) permanently discontinued bosutinib due to toxicity (skin rash in 3 cases, gastro-intestinal toxicity in 3 cases, pleural effusion in 2 cases, transaminitis, QTc prolongation and myalgia in 1 case each), 6 patients (6.6%) due to resistance and 7 patients (7.7%) due to other reasons (unrelated death in 6 cases and patient decision in 1 case). As to response, 5 patients (5.5%) were considered too early for assessment ( Conclusions Our real-life data show that bosutinib is effective, even if initial doses in many cases were lower than recommended, with a favourable safety profile also in elderly patients with important comorbidities resistant/intolerant to previous TKI treatments,: as a consequence, it could play a significant role in the current clinical practise for these frail patients. Download : Download high-res image (99KB) Download : Download full-size image Disclosures Latagliata: Celgene: Honoraria; Janssen: Honoraria; Novartis: Honoraria; Pfizer: Honoraria. Trawinska: Novartis: Consultancy, Honoraria. Annunziata: Pfizer: Consultancy; Incyte: Consultancy; Novartis: Consultancy. Elena: Novartis: Consultancy; Pfizer: Consultancy. Crugnola: Incyte: Honoraria; Novartis: Honoraria. Bonifacio: Novartis: Honoraria; Amgen: Honoraria; Pfizer: Honoraria; Incyte: Honoraria; BMS: Honoraria. Sgherza: Incyte: Honoraria; Pfizer: Honoraria; BMS: Honoraria; Novartis: Honoraria. Iurlo: Pfizer: Other: Speaker Honoraria; Incyte: Other: Speaker Honoraria; Novartis: Other: Speaker Honoraria. Breccia: Celgene: Honoraria; Incyte: Honoraria; Novartis: Honoraria; BMS: Honoraria; Pfizer: Honoraria.