Drug development for the treatment of onchocerciasis: Population pharmacokinetic and adverse events modeling of emodepside

• Published in: PLoS neglected tropical diseases Vol. 16; no. 3; p. e0010219
• Main Authors: Assmus, Frauke, Hoglund, Richard M, Monnot, Frédéric, Specht, Sabine, Scandale, Ivan, Tarning, Joel
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.03.2022; Public Library of Science (PLoS)
• Subjects: Absorption; Adult; Adverse events; Allometry; Anthelmintics; Bioavailability; Biology and Life Sciences; Body Weight; Care and treatment; Chemical kinetics; Clinical trials; Depsipeptides - adverse effects; Diagnosis; Dosage; Drug Development; Drug discovery; Drug dosages; Drugs; Exposure; Health care; Heart rate; Humans; Medicine and Health Sciences; Methods; Modelling; Nematodes; Onchocerciasis; Onchocerciasis - drug therapy; Parasites; Pharmacodynamics; Pharmacokinetics; Pharmacology; Properties; Research and Analysis Methods; Risk factors; Testing; Tropical diseases; United Kingdom; United Kingdom > UK; Africa
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0010219

To accelerate the progress towards onchocerciasis elimination, a macrofilaricidal drug that kills the adult parasite is urgently needed. Emodepside has shown macrofilaricidal activity against a variety of nematodes and is currently under clinical development for the treatment of onchocerciasis. The aims of this study were i) to characterize the population pharmacokinetic properties of emodepside, ii) to link its exposure to adverse events in healthy volunteers, and iii) to propose an optimized dosing regimen for a planned phase II study in onchocerciasis patients. Plasma concentration-time profiles and adverse event data were obtained from 142 subjects enrolled in three phase I studies, including a single-dose, and a multiple-dose, dose-escalation study as well as a relative bioavailability study. Nonlinear mixed-effects modeling was used to evaluate the population pharmacokinetic properties of emodepside. Logistic regression modeling was used to link exposure to drug-related treatment-emergent adverse events (TEAEs). Emodepside pharmacokinetics were well described by a transit-absorption model, followed by a 3-compartment disposition model. Body weight was included as an allometric function and both food and formulation had a significant impact on absorption rate and relative bioavailability. All drug-related TEAEs were transient, and mild or moderate in severity. An increase in peak plasma concentration was associated with an increase in the odds of experiencing a drug-related TEAE of interest. Pharmacokinetic modeling and simulation was used to derive an optimized, body weight-based dosing regimen, which allows for achievement of extended emodepside exposures above target concentrations while maintaining acceptable tolerability margins.