Integration of pharmacogenetics into the dosing method of busulfan in children intended to receive hematopoietic stem cell transplantation: a prospective, international, multicenter, and randomized clinical trial.
Summary description of the study
Busulfan (Bu) is used in myeloablative conditioning treatments prior to hematopoietic stem cell transplantation (HSCT) in pediatric patients. Bu has a narrow therapeutic window as low exposure is associated with higher rates of relapse and graft failure, while higher exposure is associated with treatment-related toxicities. Therefore, therapeutic drug monitoring is strongly indicated, particularly in children, who exhibit greater inter-subject variability in pharmacokinetic (PK) parameters of Bu than adults. Genetic variations in the promoter region of GSTA1, the gene encoding glutathione-S-transferase alpha 1 (the main enzyme involved in Bu metabolism), are associated with the PK of Bu. Our research group has developed the first pediatric population pharmacokinetic model (PopPK) that includes genetic variations in predicting Bu clearance and consequently Bu dosing. The present proposal aims to validate this new pharmacogenomic (PG) model in children and adolescents receiving Bu intravenously. To achieve this goal, we will collect DNA from all eligible children prior to HSCT. Patients will be centrally genotyped for GSTA1 variants and classified into 3 groups. Subjects will be randomized to receive the first doses of Bu calculated according to one of the most commonly used methods, as a control: 1) the McCune's model (Canadian method). In the experimental arm, subjects will receive personalized doses based on pharmacogenomics (GSTA1). The first doses will be centrally recommended for both treatment arms. The percentages of patients in the therapeutic target after the first dose will be compared between groups.
(BASEC)
Intervention under investigation
DNA samples will be collected from all included children via buccal swab, saliva, or blood (in case of blood sample collection for clinical reasons) prior to hematopoietic stem cell transplantation (HSCT) and will be sent for GSTA1 genotyping, in order to determine the haplotypes of patients based on single nucleotide variants occurring in the promoter region of the gene. Already extracted DNA, such as the remnants of HLA typing prior to transplantation, may also be used. Once the haplotypes of the GSTA1 alleles are defined, the resulting diplotypes (combinations of haplotypes) will be used to classify patients based on their Bu metabolization potential, i.e., rapid, normal, or slow metabolizers. After obtaining the genotype results, subjects will be randomized in a 1:1 ratio, stratified by groups based on GSTA1, to receive the first dose of busulfan calculated according to current practice (Canadian method) or personalized based on GSTA1 diplotypes using the pharmacogenomics-based model. The resulting doses of Bu will be administered intravenously by infusion over 2 hours every 6 hours (q6h) or by infusion over 3 hours every 12 (q12h) or 24 hours (q24h), regardless of the assigned arm.
(BASEC)
Disease under investigation
Recent research has identified a gene that may influence the pharmacokinetics of busulfan. The CANSEARCH research platform in pediatric oncology and hematology at the University of Geneva has demonstrated that genetic variations in the GSTA1 gene, which encodes the protein primarily involved in the elimination of busulfan, would partially explain the variability in the pharmacokinetics of busulfan. Until now, busulfan dosing was determined based on clinical parameters such as age, weight, and height. Our research project aims to study pharmacogenetics, namely the role of genetic factors in treatment response. The goal is to individualize treatment to make therapy more targeted and less toxic. Genotyping (genetic analysis) of the aforementioned gene would allow predicting the pharmacokinetics of busulfan. With this project, we could therefore predict the dose of busulfan to be administered to the participant, based on their genetics, for an optimal therapeutic outcome.
(BASEC)
- Patients must be aged 0 to 18 years at the time of entry into the study - The conditioning protocol must include IV formulations of Bu, Busulfex® (Otsuka Pharmaceutical) or Busilvex® (Pierre Fabre Pharma), regardless of the administration schedule (q6h, q12h, or q24h) - The expected duration between recruitment and the start of the conditioning regimen must be greater than 10 days. (BASEC)
Exclusion criteria
Use of any medication with a relevant drug interaction with busulfan 7 days prior to the first dose of Bu until 24 hours after the last dose. (BASEC)
Trial sites
Basel, Bern, Geneva
(BASEC)
Sponsor
Geneva University Hospitals Prof. Marc Ansari
(BASEC)
Contact
Contact Person Switzerland
Aurore BRITAN-WOOD
+41795536100
aurore.britan@clutterhug.chGeneva University Hospitals
(BASEC)
Scientific Information
(ICTRP)
Name of the authorising ethics committee (for multicentre studies, only the lead committee)
Ethics Committee Geneva
(BASEC)
Date of authorisation
20.04.2021
(BASEC)
ICTRP Trial ID
NCT04822532 (ICTRP)
Official title (approved by ethics committee)
Implementing pharmacogenetics in the busulfan dosing method for children undergoing hematopoietic stem-cell transplantation: a prospective, multicentric, randomized clinical trial. The BuGenes 01 Study. (BASEC)
Academic title
Implementing Pharmacogenetics in the Busulfan Dosing Method for Children Undergoing Hematopoietic Stem-cell Transplantation: a Prospective, Multicentric, Randomized Clinical Trial (ICTRP)
Public title
Precision Dosing of Busulfan in Children Undergoing HSCT (ICTRP)
Disease under investigation
Allogeneic Hematopoietic Stem Cell Transplantation
Autologous Hematopoietic Stem Cell Transplantation
Hematopoietic Stem Cell Transplantation
(ICTRP)
Intervention under investigation
Genetic: GSTA1 genotyping
(ICTRP)
Type of trial
Interventional (ICTRP)
Trial design
Allocation: Randomized. Intervention model: Parallel Assignment. Primary purpose: Treatment. Masking: Single (Participant). (ICTRP)
Inclusion/Exclusion criteria
Inclusion Criteria:
- Patients must be aged from 0-18 years old on entry to the study;
- Clinical indication of allogeneic or autologous hematopoietic stem cell
transplantation;
- The conditioning protocol must include IV Bu formulations, Busulfex® (Otsuka
Pharmaceutical), Busilvex® (Pierre Fabre Pharma) or other European Medicines Agency
(EMA) or Food and Drugs Administration (FDA) approved generic formulations regardless
of the administration schedule (q6h, q12h, or q24h)
- The expected length of time from recruitment to starting the conditioning regimen must
be superior to 10 days;
- Informed written consent to participate in the study signed by the participant/parent
Exclusion Criteria:
• At least one of the drugs listed below scheduled to be administered in the Bu
administration days up to 24h after the last dose of Bu, whenever a washout is not
possible:
- Metronidazol (required washout: 7 days)
- Nalidixic acid (required washout: 7 days)
- Phenytoin (required washout: 21 days)
- Itraconazole (required washout: 14 days)
- Ketoconazole (required washout: 7 days)
- Voriconazole (required washout: 7 days)
- Deferasirox (required washout: 7 days)
(ICTRP)
not available
Primary and secondary end points
Accuracy of the Bu Clearance prediction
Accuracy of the first-dose Bu area under the curve (AUC) prediction
Dose adjustment requirement
(ICTRP)
Event-free survival
Incidence and severity of acute graft-versus-host disease (aGVHD)
Incidence and severity of sinusoidal obstruction syndrome (SOS)
Incidence of primary and secondary graft failure
Incidence of treatment-related toxicities (TRTs)
Overall survival
Time to deliver the personalized dose
(ICTRP)
Registration date
12.03.2021 (ICTRP)
Incorporation of the first participant
15.06.2021 (ICTRP)
Secondary sponsors
not available
Additional contacts
Marc Ansari, MD Prof, research@cansearch.ch, +41795536100 (ICTRP)
Secondary trial IDs
BuGenes 01 (ICTRP)
Results-Individual Participant Data (IPD)
not available
Further information on the trial
https://trialsearch.who.int/Trial2.aspx?TrialID=NCT04822532 (ICTRP)
Results of the trial
Results summary
not available
Link to the results in the primary register
not available