Pharmacokinetics of extended dose intervals of micafungin in haematology patients: optimizing antifungal prophylaxis.

Background: Extended dosing intervals for micafungin could overcome the need for hospitalization for antifungal prophylaxis. Objectives: This multicentre, open-label, randomized trial compared the pharmacokinetics of 300 mg of micafungin given twice weekly with 100 mg once daily as antifungal prophylaxis in adult haematology patients at risk of developing invasive fungal disease. Secondary objectives were assessment of adequate exposure with an alternative dosing regimen of micafungin (700 mg once weekly) through Monte Carlo simulations and assessment of safety in this patient population. Patients and methods: Twenty adult patients were randomized to receive either 300 mg of micafungin twice weekly or 100 mg once daily for 8 days. Blood samples were drawn daily and pharmacokinetic curves were determined on days 4/5 and 8. Monte Carlo simulations were performed for both investigated regimens as well as a frequently proposed alternative regimen (700 mg once weekly). Results: The predicted median AUC0-168h (IQR) for a typical patient on the investigated regimens of 100 mg once daily and 300 mg twice weekly and the hypothetical regimen of 700 mg once weekly were 690 (583-829), 596 (485-717) and 704 (585-833) mg·h/L, respectively. Conclusions: We observed comparable exposure with 300 mg of micafungin twice weekly and 100 mg of micafungin once daily. We provide the pharmacokinetic proof for an extended dosing regimen, which now needs to be tested in a clinical trial with hard endpoints.

Evaluation of 'out-of-specification' CliniMACS CD34-selection procedures of hematopoietic progenitor cell-apheresis products.

BACKGROUND: Immunomagnetic selection of CD34(+) hematopoietic progenitor cells (HPC) using CliniMACS CD34 selection technology is widely used to provide high-purity HPC grafts. However, the number of nucleated cells and CD34+ cells recommended by the manufacturer for processing in a single procedure or with 1 vial of CD34 reagent is limited. METHODS: In this retrospective evaluation of 643 CliniMACS CD34-selection procedures, we validated the capacity of CliniMACS tubing sets and CD34 reagent. Endpoints of this study were the recovery and purity of CD34+ cells, T-cell depletion efficiency and recovery of colony-forming units-granulocyte-macrophage (CFU-GM). RESULTS: Overloading normal or large-scale tubing sets with excess numbers of total nucleated cells, without exceeding the maximum number of CD34+ cells, had no significant effect on the recovery and purity of CD34+ cells. In contrast, overloading normal or large-scale tubing sets with excess numbers of CD34+ cells resulted in a significantly lower recovery of CD34+ cells. Furthermore, the separation capacity of 1 vial of CD34 reagent could be increased safely from 600 x 10(6) CD34+ cells to 1000 x 10(6) CD34+ cells with similar recovery of CD34(+) cells. Finally, T-cell depletion efficiency and the fraction of CD34+ cells that formed CFU-GM colonies were not affected by out-of-specification procedures. DISCUSSION: Our validated increase of the capacity of CliniMACS tubing sets and CD34 reagent will reduce the number of selection procedures and thereby processing time for large HPC products. In addition, it results in a significant cost reduction for these procedures.