Elderly CML Patients On Early Applied High Dose Imatinib Achieve Molecular Remissions As Fast As Younger Patients In Contrast To Patients On Standard Dose Imatinib: A Subanalysis Of The German CML-Study IV

• Published in: Blood 2013-11, Vol.122 (21), p.96-96
• Main Authors: Proetel, Ulrike, Pletsch, Nadine, Lauseker, Michael, Kalmanti, Lida, Schreiber, Annette, Müller, Martin C., Hanfstein, Benjamin, Krause, Stefan W., Heim, Dominik, Baerlocher, Gabriela M., Hofmann, Wolf-Karsten, Lange, Elisabeth, Einsele, Hermann, Wernli, Martin, Kremers, Stephan, Schlag, Rudolf, Müller, Lothar, Hänel, Matthias, Link, Hartmut, Hertenstein, Bernd, Pfirrmann, Markus, Hochhaus, Andreas, Hasford, Joerg, Hehlmann, Rüdiger, Saussele, Susanne
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V122.21.96.96

The outcome of elderly patients with chronic myeloid leukemia (CML) treated with imatinib has been studied in several trials. However, there are no reports on the effects of different imatinib dosages in older vs. younger CML patients. To evaluate the efficacy of imatinib in the elderly, we analyzed data from the German CML-Study IV, a randomized 5-arm trial designed to optimize imatinib therapy alone or in combination. There was no upper age limit for inclusion. Patients with BCR-ABL positive CML in chronic phase randomized to imatinib 400 mg/d (IM400) or imatinib 800 mg/d (IM800) were compared, stratified according to median age at diagnosis in western populations ≥ 65 years vs. < 65 years, regarding effectively administered imatinib dose, time to hematologic, cytogenetic and molecular remissions, adverse events (AEs), rates of progression to accelerated phase (AP) and blast crisis (BC), survival, and causes of death. The full 800 mg dose was given after a 6 weeks run-in period with imatinib 400 mg/d to avoid excessive cytopenias. The dose could then be reduced according to tolerability for maximum patients' compliance. From July 2002 through March 2012, 1,551 patients were randomized, 828 of these to IM400 or IM800. Median age of these patients was 52 years (IM400: 53 years; IM800: 51 years). 784 patients were evaluable for follow-up (IM400: 382; IM800: 402). 193 patients were ≥ 65 years, 591 < 65 years. 110 patients (29%) on IM400 and 83 (21%) on IM800 were ≥ 65 years. Median observation time on IM400 was 63.0 months in the elderly and 67.6 months in the younger group, on IM800 50.9 months in the elderly and 50.1 months in the younger group. The median dose per day was lower for elderly patients on IM800 (421 mg/d for patients ≥ 65 years vs. 556 mg/d for patients < 65 years), with the highest median dose in the first year (466mg/d for patients ≥ 65 years vs. 630mg/d for patients < 65 years). The median dose for patients on IM400 was 400 mg/d for both age groups. There was no difference between age groups in achieving a complete hematologic remission or a complete cytogenetic remission, neither if IM400 and IM800 were combined, nor in an analysis according to treatment groups. Elderly patients on IM400 achieved major molecular remission (MMR) and deep molecular remission (MR4) significantly later than younger patients (18.1 vs. 15.9 months, p=0.013; 54.4 vs. 33.3 months, p=0.012, respectively) whereas no difference was detected for patients on IM800 (11