Efficacy of Reduced Induction Chemotherapy and Early Transplantation in ALL Patients
Authors: Ghavamzadeh Ardeshir , Pourkhani Amir Hooshang , Alimoghaddam Kamran , Ostadali Dehaghi Mohammadreza , Hamidieh Amir Ali , Mousavi Seied Asadollah , Derakhshandeh Roshanak , Jalali Arash , Jalili Mahdi , Jahani Mohamad 
Published: October 2019

Abstract
Abstract 4487
Eighty percent of acute lymphoblastic leukemia (ALL) patients achieve a complete remission (CR) but only 30–40% are long-term survivors. Hematopoietic stem cell transplantation (HSCT) is only curable treatment in ALL patients. However, the efficacy of induction, consolidation chemotherapy and early hematopoietic stem cell transplantation remain unclear.
Therefore, at our center, patients with newly diagnosed ALL, are randomly divided into 2 arms from 2008 to 2011. Patients in the study arm received reduced induction chemotherapy (Vincristine 1 mg/m2 every week for 4 weeks plus Dexamethasone 24mg/d for 28 days) and undergone early HSCT after disease stabilized within 15–30 days without intention of achieving complete remission (CR). The control arm received conventional chemotherapy (routine induction and then consolidation) followed by HSCT. Both arms received Busulfan (4mg/kg for 4 days) plus Cyclophosphamide (60mg/kg for 2 days) as a conditioning regimen. The GVHD prophylaxis consisted of Methotrexate plus Cyclosporine. Here, we compare the efficacy of these two kinds of treatment.
A total of 89 patients enrolled in the study. Seventeen patients allocated to the study arm and 72 others allocated to the control arm. The median age was 22 years (range: 16–33) in the study arm and 22 years (range: 3–49) in the control arm. All patients underwent Allogeneic HSCT with peripheral blood source. The median waiting time from diagnosis to HSCT was 708 days (range: 45–219) in the control arm. In the study arm, 13 patients (76%) were in CR1.The median follow-up time was 15.5 months (range: 1–30) in the study arm and 10.2 months (range: 1–34) in the control arm. Relapse occurred in 2 (11.7%) and 6 (8.3%) patients of the study and the control arms, respectively. Five patients (29.4%) of the study arm and 10 patients (13.5%) of the control arm were died. The causes of death were GVHD and sepsis in 4 (80%) patients and relapse in 1 (20%) patient in the study arm. The causes of death were GVHD in 6 (60%) patients and relapse in 4 (40%) patients in the control arm. One-year overall survival was 75% and 83.7% in study and control arms, respectively (Fig 1, P-value: 0.212). One-year disease-free survival was 75% and 81.1% in study and control group, respectively (Fig 2, P-value: 0.273).Figure 1.Overall Survival of ALL Patients in Study arm vs. Control armFigure 1. Overall Survival of ALL Patients in Study arm vs. Control armFigure 2.Disease-free Survival of ALL Patients in Study arm vs. Control armFigure 2. Disease-free Survival of ALL Patients in Study arm vs. Control arm
Reduced induction followed by early transplantation without consolidation reveals no significant statistical different outcome compared with routine treatment. This result might be due to small size of patients and short time of follow-up. A study with more cases and long time follow-up is recommended.

Disclosures:
No relevant conflicts of interest to declare.