Comparison of Short-Term Outcomes Between CSTIBES02 and ALL Ph08 Trials for Young Patients with Philadephia Chromosome-Positive ALL (Ph+ALL) Differing In Imatinib Dose and Amount of Chemotherapy Before Stem Cell Transplantation

Abstract

2582 Background and objectives. Concurrent imatinib and chemotherapy followed by allogeneic stem cell transplantation (SCT) is the most used treatment for young patients with Ph+ALL. However, the amount of chemotherapy before SCT is not well established. The Spanish PETHEMA Group conducted two consecutive protocols (CSTIBES02 -Haematologica 2010; 95: 87–95- and ALL Ph08) differing in the imatinib dose (400 mg/d vs. 600 mg/d) and the amount of chemotherapy (two consolidation cycles vs. one consolidation cycle) before SCT. The short –term outcomes are herein compared. Patients and methods. CSTIBES02 trial included 30 patients with a median age of 44 yr and ALL Ph08 includes 26 patients (median age 37 yr). The main clinical and biological features of the two series of patients are comparable. The initial induction chemotherapy schedule included VCR, DNR and PDN at the same doses in the two protocols, but in the CSTIBES02 mitoxantrone and ARA-C were administered on day 15 if >5% blast cells were present in bone marrow smear, whereas no change in the chemotherapy schedule was prescribed in the ALL Ph08 trial according to the percentage of blast cells on day 15. The first consolidation cycle included HD MTX, ID ARA-C, MP and teniposide in both protocols. Patients in CR were then submitted to SCT in ALL Ph08 study, whereas those included in CSTIBES02 received a second consolidation cycle before SCT. Imatinib was administered concurrently with chemotherapy from diagnosis (400 mg/d in CSTIBES02 trial and 600 mg/d in ALL Ph08 study). Results. The main short-term outcomes are compared in the table Conclusion. Despite non-significant improvement has been observed in ALL Ph08 protocol regarding CR attainment, molecular response after induction and consolidation, 2-yr EFS has been improved after the increase of imatinib dose and the decrease of amount of chemotherapy. Both decrease in relapse before SCT and TRM observed in the ALL Ph08 protocol are responsible for the better EFS. Supported in part by grants RD06/0020/1056 from RTICC and P-EF-11 from FJC Disclosures: No relevant conflicts of interest to declare.