Imatinib In Very Elderly CML Patients: What Can We Achieve?

In the “real world” of clinical practice, many very elderly CML patients have been treated with imatinib (IM), but there are few data on the results and the best initial dosage in such patients. To highlight peculiar aspects of toxicity and efficacy of IM in this subset which accounts for at least 10-15% of all CML cases, we retrospectively revised 156 CML patients in chronic phase treated with IM when aged > 75 years from 23 haematological Institutions in Italy; there were 85 males and 71 females, median age at IM start was 78.4 years (IR 76.1 – 81.4), Sokal Risk at diagnosis was low in 2 patients, intermediate in 90, high in 50 and not evaluable in 14. One or more concomitant diseases requiring specific treatments were present in 144/156 patients (92.3%), with 94 patients (60.2%) assuming 3 or more concomitant drugs. Thirty patients (19.2%) were in late chronic phase (≥ 12 months from diagnosis) and pretreated (25 with HU and 5 with IFN) before starting IM; on the whole, median time from diagnosis to IM was 1.2 months (IR 0.5 – 3.6). Starting dose of IM was 400 mg/day in 117 patients (75.0%) and 300 mg/day or less in 39 patients (25.0%); overall, 59 patients (37.8%) (52/117 at 400 mg starting dose and 7/39 at ³ 300 mg starting dose) needed a dose reduction and 18 (11.5%) discontinued IM for toxicity (early toxicity in 13 and late toxicity in 5). Excluding the 13 patients who discontinued IM due to early toxicity, maximum tolerated daily dose during treatment was 400 mg in 63 patients, 300 mg in 51 patients and < 300 mg in 29 patients. According to CTC-AE, grade 3 – 4 hematological and extra-hematological toxicities were observed in 34 (21.7%) and 34 (21.7%) patients, respectively; 5 patients (3.2%) presented a pleural effusion during IM treatment. After a median treatment period of 29.4 months (IR 7.9 – 54.4), 8 patients (5.1%) are still too early (< 6 months of treatment), 13 (8.3%) discontinued IM due to early toxicity, 3 (1.9%) were resistant and 1 (0.7%) died from unrelated cause early after IM initiation: the remaining 131 patients (84.6%) achieved a complete haematological response (CHR). Among these 131 patients in CHR, 11 refused any other karyotipic or molecular evaluation (1 lost CHR and shifted to hydroxyurea, 4 are still alive in CHR, 6 died in CHR from unrelated causes), 17 achieved CHR only and 103 (66.0% of all 156 patients) achieved a cytogenetic response (CyR), which was major in 11 patients and complete (CCyR) in 92 (58.9% of all 156 patients). In addition, among the 92 patients in CCyR, 62 (39.7% of all 156 patients) achieved a molecular response (major molecular response in 40 patients and complete molecular response with an undetectable BCR/ABL hybrid gene at qualitative nested PCR in 22 patients). After a median follow-up of 34.0 months (IR 12.9 – 60.0), 36 patients have died (5 from disease progression and 31 from unrelated causes), 4 patients were lost to follow-up and 116 are still alive: 2-year and 4-year overall survival were 90.2% (CI95% 84.8 - 95.6) and 76.8% (CI95% 68.6 - 85.0), respectively. In conclusion, results from this large unselected cohort of patients show that should be definitely considered unethical to avoid IM therapy to any elderly patient; no upper age limit should be given but also very elderly (and with concomitant severe diseases) patients should have this chance of cure. The role of a reduced starting dose of IM warrants further studies