Optimal dosing regimen of biapenem based on population pharmacokinetic/pharmacodynamic modelling and Monte Carlo simulation in patients with febrile neutropenia and haematological malignancies

•A population pharmacokinetic model was established in Chinese febrile neutropenic (FN) patients with haematologic malignancies.•Creatinine clearance and concomitant posaconazole were considered to be significant covariates affecting the clearance of biapenem.•Biapenem 300 mg every 12 h (0.5 h and 3 h infusion) may not achieve satisfactory clinical results with minimum inhibitory concentration >1 g/L.•Other antibacterial agents were more suitable for treatment of Pseudomonas aeruginosa and Acinetobacter baumannii infection. In the current study, a population pharmacokinetic (PPK) model was developed for biapenem in patients with febrile neutropenia (FN) and haematological malignancies. Through Monte Carlo simulation, optimal administration regimens were suggested based on the developed PPK model. In a prospective, single-centre, open-label study, 174 plasma samples from 120 Chinese patients with FN and haematological malignancies were analysed by chromatography, and PK parameters were analysed by NONMEM. The drug clearance process was influenced by crucial covariates, namely creatinine clearance (CLCR) and concomitant posaconazole (POS). The ultimate PPK model was as follows: CL (L/h)=29.81 × (CLCR/121.38)0.806 × (1−POS × 0.297); volume of distribution (L)=114. For the target of ≥40% fT>minimum inhibitory concentration (MIC) (duration that the plasma level exceeds the MIC of the causative pathogen) and achieving the probability of target attainment ≥90%, the PK/pharmacodynamic breakpoint was 2 mg/L for the 2.4 g/day dosing regimen consisting of 600 mg q6h and 800 mg q8h. The breakpoint was 1 mg/L for the 1.2 g/day dosing regimen consisting of 300 mg q6h and 600 mg q12h. Empirical therapy would benefit from utilizing higher dosages and extended infusion durations. Therefore, it is suggested that patients with symptoms that are strongly suggestive of Pseudomonas aeruginosa or Acinetobacter baumannii infection may be suitable for combined treatment with other antibacterial drugs.