Cancer Res Treat.  2021 Oct;53(4):1184-1194. 10.4143/crt.2020.289.

Effectiveness and Safety of Clofarabine Monotherapy or Combination Treatment in Relapsed/Refractory Childhood Acute Lymphoblastic Leukemia: A Pragmatic, Non-interventional Study in Korea

  • 1Department of Pediatrics, Seoul National University Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
  • 2Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea
  • 3Division of Pediatric Hematology/Oncology, Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea
  • 4Division of Pediatric Hematology and Oncology, Department of Pediatrics, Yonsei University Health System, Yonsei University College of Medicine, Seoul, Korea
  • 5Department of Pediatrics, Pusan National University Children’s Hospital, Pusan National University School of Medicine, Yangsan, Korea
  • 6Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
  • 7Department of Pediatrics, Chonnam National University Hwasun Hospital, Chonnam National University Medical School, Hwasun, Korea
  • 8Department of Pediatrics, Gachon University, Gil Medical Center, Incheon, Korea
  • 9Sanofi Aventis, Seoul, Korea


Effectiveness and safety of clofarabine (one of the treatment mainstays in pediatric patients with relapsed/refractory acute lymphoblastic leukemia [ALL]) was assessed in Korean pediatric patients with ALL to facilitate conditional coverage with evidence development.
Materials and Methods
In this multicenter, prospective, observational study, patients receiving clofarabine as mono/combination therapy were followed up every 4-6 weeks for 6 months or until hematopoietic stem cell transplantation (HSCT). Response rates, survival outcomes, and adverse events were assessed.
Sixty patients (2-26 years old; 65% B-cell ALL, received prior ≥ 2 regimen, 68.3% refractory to previous regimen) were enrolled and treated with at least one dose of clofarabine; of whom 26 (43.3%) completed 6 months of follow-up after the last dose of clofarabine. Fifty-eight patients (96.7%) received clofarabine combination therapy. Overall remission rate (complete remission [CR] or CR without platelet recovery [CRp]) was 45.0% (27/60; 95% confidence interval [CI], 32.4 to 57.6) and the overall response rate (CR, CRp, or partial remission [PR]) was 46.7% (28/60; 95% CI, 34.0 to 59.3), with 11 (18.3%), 16 (26.7%), and one (1.7%) patients achieving CR, CRp, and PR, respectively. The median time to remission was 5.1 weeks (95% CI, 4.7 to 6.1). Median duration of remission was 16.6 weeks (range, 2.0 to 167.6 weeks). Sixteen patients (26.7%) proceeded to HSCT. There were 24 deaths; 14 due to treatment-emergent adverse events.
Remission with clofarabine was observed in approximately half of the study patients who had overall expected safety profile; however, there was no favorable long-term survival outcome in this study.


Acute lymphoblastic leukemia; Clofarabine; Leukemia; Pediatric malignancy; Pediatric cancer


  • Fig. 1 Patient disposition. HSCT, hematopoietic stem cell transplantation.

  • Fig. 2 Survival status with clofarabine use. Overall survival (A) and survival by HSCT (B). CI, confidence interval; HR, hazard ratio; HSCT, hematopoietic stem cell transplantation.



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