Outcome of HR-I patients in CoALL08-09 versus CoALL07-03
The 5-year pEFS of the whole cohort of HR-I patients in CoALL08-09 was 70.4 % with an overall survival of 86.2 % (intention-to-treat analysis, supplemental figures S1 and S2). The 5-year pEFS of the 77 HR-I AEP-treated patients was 72.9 % (SE 6.0) compared to 66.4 % (SE 7.3) pEFS under standard treatment in the HR-matched CoALL07-03 cohort (figure 3). This trend toward an improved event-free survival upon HR-I treatment reached significance in the comparative analysis of the overall survival of HR-I AEP treated patients (pOS 92.3 % (SE 3.4)) in CoALL08-09 vs. patients under standard HR-treatment (pOS 73.7 % (SE 6.8)) ( p= 0.0038) in CoALL07-03 (figure 4). In a subgroup analysis according to immunophenotype patients with T-ALL showed a significantly improved event-free as well as overall outcome after HR-I AEP treatment in CoALL08- 09 (pEFS 85.1 % and pOS 92.3 %) compared to standard HR-treatment in CoALL07-03 (pEFS 54.5 % and pOS 63.6 %). In line with the outcome analyses of the overall HR-I and HR-standard cohorts the overall survival of patients with pB-ALL was superior in HR-I AEP-treated patients (CoALL08-09) compared with patients in the CoALL07-03 HR-standard arm (pOS 92.2 % vs. 77.3 %), whereas the difference in pEFS did not reach significance between HR-I AEP and HR-standard treated patients (supplemental figures S3-S6).