Abstract
Background: Despite pronounced improvement in overall survival (OS) in pediatric leukemia, a proportion of patients continue to suffer from lack of response or relapse, and the management of such patients is exceedingly difficult. Immunotherapy and engineered chimeric an-tigen receptor (CAR) T-cell therapy have shown promising results in the course of relapsed or refractory acute lymphoblastic leukemia (ALL). However, conventional chemotherapy continues to be utilized for re-induction purposes whether independently or in combination with immunotherapy.Methods: Forty-three pediatric leukemia patients (age < 14 years at diagnosis) consecutively diagnosed at our institution and got treated with clofarabine based regimen at a single tertiary care hospital be-tween January 2005 and December 2019 were enrolled in this study. ALL comprised of 30 (69.8%) patients of the cohort while the re-maining 13 (30.2%) were with acute myeloid leukemia (AML).Results: Post-clofarabine bone marrow (BM) was negative in 18 (45.0%) cases. Overall clofarabine failure rate was 58.1% (n = 25) with 60.0% (n = 18) in ALL and 53.8% (n = 7) in AML (P = 0.747). Eighteen (41.9%) patients eventually underwent hematopoietic stem cell trans-plantation (HSCT); 11 (61.1%) were from ALL group and remaining seven (38.9%) were AML (P = 0.332). Three-and 5-year OS of our patients was 37.7 +/- 7.6% and 32.7 +/- 7.3%. There was a trend of better OS for ALL patients compared to AML (40.9 +/- 9.3% vs. 15.4 +/- 10.0%, P = 0.492). Cumulative probability of 5-year OS was significantly better in transplanted patients (48.1 +/- 12.1% vs. 21.4 +/- 8.4%, P = 0.024). Conclusions: Though almost 90% of our patients proceeded to HSCT with complete response post-clofarabine treatment, yet clofarabine-based regimens are associated with the significant burden of infec-tious complications and sepsis-related deaths.