Dasatinib in the Treatment of CML Patients Aged > 60 Years Resistant/Intolerant to Imatinib

Dasatinib is a 2^nd generation tyrosine-kinase inhibitor active in CML patients resistant or intolerant to Imatinib; at present there is no data on its toxicity and efficacy in elderly patients. To highlight this issue, 37 patients treated with Dasatinib when aged > 60 years were retrospectively evaluated. There were 21 males and 16 females, median age at Dasatinb was 69.3 years (IR 64.9–73.0), Sokal Risk at diagnosis was low in 13 patients, intermediate in 14, high in 5 and not valuable in 5. Twenty-two patients (59.4%) were primary resistant, 4 (10.8%) intolerant and 11 (29.8%) secondary resistant to Imatinib; all but 2 patients were in CP when Dasatinib was started. Median time from diagnosis to Dasatinib treatment was 99.2 months (IR 56.8–124.5); 25/37 patients (67.5%) have been pretreated with IFN ± Ara-C before Imatinib, all patients received Imatinib at standard dose (400 mg/day) followed in 20/37 (54%) by Imatinib at increased dose (600–800 mg/day) with an overall median period of Imatinib treatment of 52.8 months (IR 26.2–60.9). In addition, 7/37 patients (18.9%) received other 2^nd line treatment (3 with Nilotinib, 2 with Imatinib + HU and 2 with other drugs) before Dasatinib. Starting dose of Dasatinib was 140 mg/day in 18 patients and 100 mg/day in 19 patients, respectively. After a median period of treatment of 9.4 months (IR 3.0–19.1) all patients were evaluable for toxicity; among 18 patients receiving 140 mg, grade 3–4 haematological and extra-haematological toxicities were reported in 14 (77.7%) and 6 (33.3%) patients, respectively; among 19 patients receiving 100 mg, grade 3–4 haematological and extra-haematological toxicities were reported in 4 (21.0%) and 1 (5.2%) patients, respectively. Pleuro-pericardial effusions occurred in 3 patients, all treated with 140 mg as starting dose. Overall, 3/37 patients (all treated with 140 mg) discontinued permanently Dasatinib due to early toxicity; a dose reduction was needed in 17/37 patients [16/18 (88.8%) treated with 140 mg and 1/19 (5.2%) with 100 mg]. As to response, 28 patients were considered evaluable (≥ 6 months of treatment) and 9 considered as too early; five patients (17.9%) did not have any response (including 3 patients with early Dasatinib discontinuation for toxicity) and 23 (82.1%) achieved Complete Haematological Response (CHR). Furthermore, 11/28 patients (39.2%) achieved a Cytogenetic Response (CyR) (Major CyR in 4 and Complete CyR in 7) and 4/28 patients (14.2%) achieved a molecular response. In conclusion, Dasatinib, when employed at the current recommended starting dose of 100 mg/day; seems effective and very well tolerated also in heavily pretreated elderly subjects; these results are encouraging also for a future use of this drug in early chronic phase elderly patients.