Page 20 - Haematologica May 2022

G. Escherich et al.
incidence of hematopoietic stem cell transplantation (HSCT) in first complete remission due to persistent MRD was comparable between arms (n=11 vs. n=12 HSCT in clofarabine and HIDAC cohorts, respectively). T-ALL patients were similarly underrepresented in both random- ized arms compared to the whole study cohort (5.3% [n=8] in the clofarabine and 5.9% [n=9] in the HIDAC cohort vs. 14.2% [n=67] in the total cohort), mainly due to a greater proportion of T-ALL in the induction failure cohort (n=24/31 patients [77%]) and in the HR-reduced cohort (n=15/51 patients [29%]), both of which were
excluded from randomization according to the study pro- tocol (Table 2; Online Supplementary Appendix).
Minimal residual disease response
In the randomized treatment arms, we observed a rate of
44% MRD-positivity after high-dose cytarabine versus 33%
MRD-positivity after clofarabine in BCP-ALL (P 2=0.03; chi
left-sided Fisher test P=0.04). The overall reduction of MRD in BCP-ALL was significantly more profound after clofara- bine compared to cytarabine, with 93 clofarabine-treated patients versus 79 HIDAC-treated patients reaching MRD
A
B
Figure 1. Treatment overview. (A) Randomized treatment block clofarabine vs. high-dose cytarabine, each combined with pegylated asparaginase (PEG-ASP). (B) Schematic overview of the CoALL 08-09 protocol. ADR: doxorubicin; BCP: B-cell precursor; BMP: bone marrow puncture; CNS: central nervous system; d: day; Dex: dexamethasone; DNR: daunorubicin; EOI: end of induction; HIDAC: high-dose cytarabine; I: induction; MRD: minimal residual disease; R: randomization; VCR: vin- cristine; CoALL: Cooperative Acute Lymphoblastic Leukemia study group.
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