Laurent Nguyen

Novel pharmacokinetic behavior of intravenous busulfan in children with thalassemia undergoing hematopoietic stem cell transplantation: a prospective evaluation of pharmacokinetic and pharmacodynamic profile with therapeutic drug monitoring

We prospectively studied the pharmacokinetics (PK) and clinical outcomes of intravenous busulfan (Bu) in 71 children with preexisting liver damage who underwent hematopoietic stem cell transplantation for thalassemia. Intravenous Bu was administered every 6 hours as part of a conditioning regimen with PK-based dose adjustment to target a conservative area under the concentration-versus-time curve (AUC) range (900-1350 microMol*min). The first-dose Bu clearance (CL) was significantly higher than the subsequent daily CL that remained unchanged in the ensuing days. One-third of patients required dose escalation based on dose 1 AUC, whereas dose reduction was needed in the subsequent days. At doses 5, 9, and 13, 78%, 81%, and 87% of patients, respectively, achieved the target range of AUC. A population PK analysis confirmed that the first-dose CL was 20% higher and that body weight was the most important covariate to explain PK variability. Patients with variant GSTA1*B had a 10% lower Bu CL than wild-type. These results suggest that the disease-specific behavior of intravenous Bu PK should be considered for PK-guided dose adjustment in patients with thalassemia, and the use of a conservative AUC range resulted in low toxicity, good engraftment, and good survival rate.

Weight-based strategy of dose administration in children using intravenous busulfan: clinical and pharmacokinetic results.

A prospective clinical trial was performed in order to validate the pharmacokinetic (PK) and clinical benefits of a new dosing schedule of intravenous busulfan (IV Bu) in children.

Phase I Clinical Pharmacology Study of F14512, a New Polyamine-Vectorized Anticancer Drug, in Naturally Occurring Canine Lymphoma

Purpose: F14512 is a new topoisomerase II inhibitor containing a spermine moiety that facilitates selective uptake by tumor cells and increases topoisomerase II poisoning. F14512 is currently in a phase I/II clinical trial in patients with acute myeloid leukemia. The aim of this study was to investigate F14512 potential in a new clinical indication. Because of the many similarities between human and dog lymphomas, we sought to determine the tolerance, efficacy, pharmacokinetic/pharmacodynamic (PK/PD) relationship of F14512 in this indication, and potential biomarkers that could be translated into human trials. Experimental Design: Twenty-three dogs with stage III–IV naturally occurring lymphomas were enrolled in the phase I dose-escalation trial, which consisted of three cycles of F14512 i.v. injections. Endpoints included safety and therapeutic efficacy. Serial blood samples and tumor biopsies were obtained for PK/PD and biomarker studies. Results: Five dose levels were evaluated to determine the recommended dose. F14512 was well tolerated, with the expected dose-dependent hematologic toxicity. F14512 induced an early decrease of tumoral lymph node cells, and a high response rate of 91% (21/23) with 10 complete responses, 11 partial responses, 1 stable disease, and 1 progressive disease. Phosphorylation of histone H2AX was studied as a potential PD biomarker of F14512. Conclusions: This trial demonstrated that F14512 can be safely administered to dogs with lymphoma resulting in strong therapeutic efficacy. Additional evaluation of F14512 is needed to compare its efficacy with standards of care in dogs, and to translate biomarker and efficacy findings into clinical trials in humans. Clin Cancer Res; 21(23); 5314–23. ©2015 AACR.

How to manage intravenous vinflunine in cancer patients with renal impairment: results of a pharmacokinetic and tolerability phase I study.

AIMS Vinflunine (VFL) ditartrate, a novel tubulin-targeted inhibitor, is registered for the treatment of patients with advanced or metastatic urothelial transitional cell carcinoma. This phase I study assessed the effect of renal impairment on the pharmacokinetics and tolerability of VFL. METHODS VFL was infused in patients with advanced/metastatic solid tumours once every 3 weeks with anticipated dose reduction on the first cycle stratified according to the creatinine clearance (CLcr ) values. Pharmacokinetic data were collected on the first two cycles in renally impaired patients (CLcr ≤ 60 ml min(-1) ) and were compared with a control cohort of patients (CLcr > 60 ml min(-1) ). RESULTS Thirty-three patients (46-86 years) were treated, 13 in group 1 (40 ml min(-1) ≤ CLcr ≤ 60 ml min(-1) ) and 20 in group 2 (20 ml min(-1) ≤ CLcr < 40 ml min(-1) ). The renal dysfunction induced a mean decrease in VFL clearance of 12% in group 1 and 28% in group 2, compared with the control group. The anticipated dose reduction given in renally impaired patients (i.e. 280 mg m(-2) and 250 mg m(-2) in groups 1 and 2, respectively) yielded similar drug exposure to control patients. The tolerance profile of VFL in patients with renal dysfunction was similar to that observed in patients with CLcr > 60 ml min(-1) . CONCLUSION In conclusion, the recommended doses of intravenous VFL administered once every 3 weeks in cancer patients with renal impairment are 280 mg m(-2) when CLcr is between 40 and 60 ml min(-1) and 250 mg m(-2) when CLcr is between 20 and <40 ml min(-1) .

New insights into the pharmacokinetics of intravenous busulfan in children with sickle cell anemia undergoing bone marrow transplantation

Busulfan (Bu) is an integral part of conditioning regimens for patients with sickle cell anemia (SCA) undergoing transplantation. Patients with SCA might predispose to transplant‐related neurological and pulmonary toxicities due to pre‐existing disease‐related cerebrovascular and lung injury. Bu therapy appears to be an important contributing factor in this context.

Population Pharmacokinetics of Busulfan in Children–Letter

Appropriate busulfan dosing in children is a highly sensitive issue in the context of high dose-conditioning regimens for bone marrow transplantation (BMT). Indeed, a therapeutic window of plasma exposure to busulfan [area under the curve (AUC) from 900–1,500 μmol/L min] has been defined both