Ibrexafungerp (MK 3118) is an orally active β-1,3-glucan synthase inhibitor with antifungal activity, disrupting fungal cell wall integrity, used in fungal infection research.

Ibrexafungerp exhibited broad in vitro activity against a wide range of Candida spp. including Candida auriculata and Candida auriculata isolates with fks mutations, with minimum inhibitory concentrations (MIC50 and MIC90) of 0.5 μg/mL and 1.0 μg/mL, respectively, in more than 400 C. auris isolates.

Methods: Ibrexafungerp (3.125, 12.5, 50 and 200 mg/kg, oral) was administered to mice for single-dose pharmacokinetic (PK) evaluation: plasma was collected from 3 mice groups at each time point, and plasma drug concentrations were determined by liquid chromatography-tandem mass spectrometry; a non-compartmental model was used in the pharmacokinetic analysis, and the elimination half-life was calculated by nonlinear least squares technique; the area under the concentration-time curve (AUC) was calculated by the trapezoidal rule.
Results: The pharmacokinetics of Ibrexafungerp were relatively linear over the entire dose range, with an elimination half-life in plasma ranging from 5.9 h to 8.5 h; within the dose range, the maximum concentration (Cmax) of the drug in serum increased from 0.04 mg/L to 2.66 mg/L.[6]