Quantitative Prediction of Human Pharmacokinetics and Pharmacodynamics of CKD519, a Potent Inhibitor of Cholesteryl Ester Transfer Protein (CETP)

Prediction of first-in-human dose for new composition bee venom based on allometric scaling and pharmacokinetic modeling approach

Bee venom is a traditional remedy used to treat conditions related to the nervous and musculoskeletal systems, as well as autoimmune diseases. Recently, we developed a new composition bee venom (NCBV), a fortified content of bee venom phospholipase A2 (bvPLA2), which may be effective in the treatment of Alzheimer's disease. NCBV is currently preparing to conduct a phase 1 clinical trial, and this study aimed to predict the first-in-human (FIH) dose using a mechanistic approach. First, animal pharmacokinetic (PK) studies from three different species were explored and integrated to build a PK model using nonlinear mixed-effect modeling. The final models were described by two-compartment model with first order absorption and elimination, and were used to define the PK parameters for each species. To predict human PK parameters, simple, brain weight (BrW) or maximum lifespan potential (MLP) incorporated allometric scaling approaches were used, with the BrW method showing the highest correlation (R2 = 0.974). The initial FIH dose was back-calculated based on the area under the concentration-time curve of 0.397 μg·h/mL after the injection of an efficacious dose of 0.1 mg/kg in mice using the developed PK model. The predicted initial doses for a 70 kg human were 5.5, 1.3, and 3.5 mg, when using the simple, BrW, and MLP incorporated model, respectively. A subcutaneous FIH dose of 1.3 mg NCBV was ultimately recommended for a 70-kg human. Based on the no observed adverse effect level, the suggested FIH dose ranges for NCBV are 0.1 to 3 mg, which correspond with our proposed dose.

Marked Changes in Serum Amyloid A Distribution and High-Density Lipoprotein Structure during Acute Inflammation

High-density lipoprotein- (HDL-) cholesterol measurements are generally used in the diagnosis of cardiovascular diseases. However, HDL is a complicated heterogeneous lipoprotein, and furthermore, it can be converted into dysfunctional forms during pathological conditions including inflammation. Therefore, qualitative analysis of pathophysiologically diversified HDL forms is important. A recent study demonstrated that serum amyloid A (SAA) can remodel HDL and induce atherosclerosis not only over long periods of time, such as during chronic inflammation, but also over shorter periods. However, few studies have investigated rapid HDL remodeling. In this study, we analyzed HDL samples from patients undergoing orthopedic surgery inducing acute inflammation. We enrolled 13 otherwise healthy patients who underwent orthopedic surgery. Plasma samples were obtained on preoperative day and postoperative days (POD) 1-7. SAA, apolipoprotein A-I (apoA-I), and apolipoprotein A-II (apoA-II) levels in the isolated HDL were determined. HDL particle size, surface charge, and SAA and apoA-I distributions were also analyzed. In every patient, plasma SAA levels peaked on POD3. Consistently, the HDL apoA-I : apoA-II ratio markedly decreased at this timepoint. Native-polyacrylamide gel electrophoresis and high-performance liquid chromatography revealed the loss of small HDL particles during acute inflammation. Furthermore, HDL had a decreased negative surface charge on POD3 compared to the other timepoints. All changes observed were SAA-dependent. SAA-dependent rapid changes in HDL size and surface charge were observed after orthopedic surgery. These changes might affect the atheroprotective functions of HDL, and its analysis can be available for the qualitative HDL assessment.

A Population Pharmacokinetic and Pharmacodynamic Model of CKD-519

CKD-519 is a selective and potent cholesteryl ester transfer protein (CETP) inhibitor that is being developed for dyslipidemia. Even though CKD-519 has shown potent CETP inhibition, the exposure of CKD-519 was highly varied, depending on food and dose. For highly variable exposure drugs, it is crucial to use modeling and simulation to plan proper dose selection. This study aimed to develop population pharmacokinetic (PK) and pharmacodynamics (PD) models of CKD-519 and to predict the proper dose of CKD-519 to achieve target levels for HDL-C and LDL-C using results from multiple dosing study of CKD-519 with a standard meal for two weeks in healthy subjects. The results showed that a 3-compartment with Erlang’s distribution, followed by the first-order absorption, adequately described CKD-519 PK, and the bioavailability, which decreased by dose and time was incorporated into the model (NONMEM version 7.3). After the PK model development, the CETP activity and cholesterol (HDL-C and LDL-C) levels were sequentially modeled using the turnover model, including the placebo effect. According to PK-PD simulation results, 200 to 400 mg of CKD-519 showing a 40% change in HDL-C and LDL-C from baselines was recommended for proof of concept studies in patients with dyslipidemia.