Optimized Treatment of Refractory Hypercholesterolemia in Patients With Atherosclerotic Cardiovascular Disease or Heterozygous Familial Hypercholesterolemia With Alirocumab (OPTIMIZE).

Background: Low-density lipoprotein cholesterol (LDL-C) is a major risk factor for atherosclerotic cardiovascular disease (ASCVD). In confirmatory trials, proprotein convertase subtilisin/kexin type 9 inhibitor alirocumab substantially lowered LDL-C and reduced cardiovascular morbidity and mortality. However, the routine clinical use of alirocumab in Switzerland has not yet been studied. Methods: In this prospective nation-wide cohort study, we aimed to investigate the patient profile and routine clinical efficacy and safety of alirocumab in 207 patients with ASCVD or heterozygous familial hypercholesterolemia and increased LDL-C despite maximally tolerated statin therapy. LDL-C was measured at baseline and after 3-months follow-up. Results: Overall, mean age was 63 ± 11 years, 138 (67%) were men, and 168 (81%) had statin intolerance (SI). Patients with SI had a higher baseline LDL-C (4.3 ± 1.4 vs. 3.3 ± 1.4 mmol/l; p < 0.001) and less frequently ASCVD (71% vs. 95%; p = 0.002). After 3 months of treatment with alirocumab, LDL-C was reduced from 4.1 ± 1.5 to 2.0 ± 1.2 mmol/l (50.5%; p < 0.001). Mean absolute and relative reductions in LDL-C were similar in patients with vs. without SI (2.2 ± 1.2 vs. 1.9 ± 1.3 mmol/l; p = 0.24 and 49.0 vs. 56.6%; p = 0.11, respectively). In total, adverse events were recorded in 25 (12%) patients, with no new safety signals. Conclusions: In routine clinical practice, alirocumab was predominantly used in patients with SI suggesting that the great majority of patients with insufficient LDL-C control who would be candidates for alirocumab are not receiving this therapeutic option in Switzerland. LDL-C lowering was potent and similar in patients with and without SI, replicating the favorable efficacy-safety profile of alirocumab from randomized trials.

Biorelevant Two-Stage In Vitro Testing for rDCS Classification and in PBPK Modeling-Case Example Ritonavir.

Biorelevant two-stage in vitro testing is increasingly used as a tool for various applications in drug development. Three important applications of two-stage in vitro testing are the classification of weakly basic drug compounds as part of the refined Developability Classification System, the prediction of intraluminal drug concentrations in the gastrointestinal tract and the prediction of plasma concentration profiles using physiologically based pharmacokinetic modeling. For the weakly basic, antiretroviral drug ritonavir, two-stage testing is triggered as a customized investigation in the refined Developability Classification System classification process to assess whether the drug could supersaturate and precipitate when exposed to the steep change in pH that occurs during drug transfer from the stomach into the small intestine. It was shown that for 2 Norvir® formulations, a tablet and an oral powder formulation, the two-stage test yielded similar results to the more complex "transfer" model with regard to the supersaturation and precipitation behavior of these amorphous solid dispersion formulations. Furthermore, solubility and two-stage data were mechanistically modeled in the in vitro data Analysis Toolkit and the results used as input parameters for a physiologically based pharmacokinetic model built in the Simcyp Simulator.

Development, current applications and future roles of biorelevant two-stage in vitro testing in drug development.

OBJECTIVES: Various types of two stage in vitro testing have been used in a number of experimental settings. In addition to its application in quality control and for regulatory purposes, two-stage in vitro testing has also been shown to be a valuable technique to evaluate the supersaturation and precipitation behavior of poorly soluble drugs during drug development. KEY FINDINGS: The so-called 'transfer model', which is an example of two-stage testing, has provided valuable information about the in vivo performance of poorly soluble, weakly basic drugs by simulating the gastrointestinal drug transit from the stomach into the small intestine with a peristaltic pump. The evolution of the transfer model has resulted in various modifications of the experimental model set-up. Concomitantly, various research groups have developed simplified approaches to two-stage testing to investigate the supersaturation and precipitation behavior of weakly basic drugs without the necessity of using a transfer pump. SUMMARY: Given the diversity among the various two-stage test methods available today, a more harmonized approach needs to be taken to optimize the use of two stage testing at different stages of drug development.

Prediction of Ketoconazole absorption using an updated in vitro transfer model coupled to physiologically based pharmacokinetic modelling.

The aim of this study was to optimize the in vitro transfer model and to increase its biorelevance to more accurately mimic the in vivo supersaturation and precipitation behaviour of weak basic drugs. Therefore, disintegration of the formulation, volumes of the stomach and intestinal compartments, transfer rate, bile salt concentration, pH range and paddle speed were varied over a physiological relevant range. The supersaturation and precipitation data from these experiments for Ketoconazole (KTZ) were coupled to physiologically based pharmacokinetic (PBPK) model using Stella® software, which also incorporated the disposition kinetics of KTZ taken from the literature, in order to simulate the oral absorption and plasma profile in humans. As expected for a poorly soluble weak base, KTZ demonstrated supersaturation followed by precipitation under various in vitro conditions simulating the proximal small intestine with the results influenced by transfer rate, hydrodynamics, volume, bile salt concentration and pH values. When the in vitro data representing the "average" GI conditions was coupled to the PBPK model, the simulated profiles came closest to the observed mean plasma profiles for KTZ. In line with the high permeability of KTZ, the simulated profiles were highly influenced by supersaturation whilst precipitation was not predicted to occur in vivo. A physiological relevant in vitro "standard" transfer model setup to investigate supersaturation and precipitation was established. For translating the in vitro data to the in vivo setting, it is important that permeability is considered which can be achieved by coupling the in vitro data to PBPK modelling.