for people ages up to 17 years (full criteria)
study started
estimated completion
Principal Investigator
by Janel Long-Boyle, PharmD, PhD (ucsf)
Photo of Janel Long-Boyle
Janel Long-Boyle



Fludarabine and clofarabine are chemotherapy drugs used extensively in bone marrow transplantation. The goal of this study is to determine what causes some children to have different drug concentrations of clofarabine and fludarabine in their bodies and if drug levels are related to whether or not a child experiences severe side-effects during their bone marrow transplant. The hypothesis is that clinical and individual factors cause changes in clofarabine and fludarabine drug levels in pediatric bone marrow transplant patients and that high levels may cause severe side-effects.

Official Title

Population Pharmacokinetics of the Nucleoside Analogues Clofarabine and Fludarabine in Pediatric Patients Undergoing Hematopoietic Cell Transplantation (alloHCT)


Fludarabine and clofarabine are nucleoside analogs with potent antitumor and immunosuppressive properties used in conditioning regimens of pediatric allogeneic hematopoietic cell transplantation (alloHCT) to promote stem cell engraftment. This is a single-center, prospective, non-interventional pharmacokinetic (PK) study investigating the clinical pharmacology of combination nucleoside analogue therapy in 24 children undergoing alloHCT at UCSF Benioff Children's Hospital. Patients would receive clofarabine and fludarabine regardless of whether or not they decide to consent to PK sampling. Clofarabine and fludarabine doses will not be adjusted based on PK data. The investigators will apply the combination of a limited sampling strategy and population PK methodologies to determine specific factors influencing clofarabine and fludarabine exposure in pediatric alloHCT recipients and identify exposure-response relationships. Subjects will undergo PK sampling of clofarabine and fludarabine drug concentrations over the duration of combination therapy (3 to 5 days). To evaluate sources of variability impacting clofarabine and fludarabine exposure clinical data will be obtained from the patient's medical chart on each day of PK sampling. To assess exposure-response relationships neutrophil engraftment, treatment-related toxicity, and survival data will be collected through day 100 post-transplant.


Hematologic Malignancies Nonmalignant Diseases Immunodeficiencies Hemoglobinopathies Genetic Inborn Errors of Metabolism Fanconi's Anemia Thalassemia Sickle Cell Disease fludarabine clofarabine pharmacokinetics pediatric allogeneic Hematologic Neoplasms Anemia, Sickle Cell Fanconi Anemia Metabolism, Inborn Errors


You can join if…

Open to people ages up to 17 years

  • Children 0-17 years of age
  • Undergoing alloHCT for the treatment of malignant or nonmalignant disorder
  • Receiving clofarabine and fludarabine-based preparative regimen

You CAN'T join if...

  • Any child 7-17 years of age unwilling to provide assent


  • University of California, San Francisco
    San Francisco California 94143 United States

Lead Scientist at University of California Health

  • Janel Long-Boyle, PharmD, PhD (ucsf)
    Dr. Boyle is a translational scientist with research interests that include pediatric cancer therapeutics, pharmacokinetics, pharmacodynamics, pharmacogenomics, and clinical trial design.


in progress, not accepting new patients
Start Date
Completion Date
University of California, San Francisco
Study Type
Last Updated