Assessment of Pharmacokinetic, Pharmacodynamic Profile, and Tolerance of Gadopiclenol, A New High Relaxivity GBCA, in Healthy Subjects and Patients With Brain Lesions (Phase I/IIa Study)

Objectives The aim of this study was to evaluate the pharmacokinetics, safety profile, and pharmacodynamics of gadopiclenol, a new high relaxivity macrocyclic gadolinium-based contrast agent, in healthy subjects and patients with brain lesions. Materials and Methods This was a single ascending dose phase I/IIa study. Phase I was double-blind, randomized, placebo-controlled and included 54 healthy subjects. In each dose group (0.025, 0.05, 0.075, 0.1, 0.2, and 0.3 mmol/kg), 6 subjects received gadopiclenol and 3 received placebo (NaCl 0.9%) in intravenous injection. Phase IIa was open-label and included 12 patients with brain lesions, 3 per dose group (0.05, 0.075, 0.1, and 0.2 mmol/kg). Concentrations were measured in plasma samples collected before administration and over a 24-hour period postadministration and in urine specimens (phase I) collected until 7 days after administration. A noncompartmental approach was used for pharmacokinetic analysis. Pharmacodynamic assessments included a qualitative evaluation of the visualization of brain structures/lesions and quantitative measurements (signal-to-noise ratio, contrast-to-noise ratio) on magnetic resonance imaging. A clinical and biological safety follow-up was performed up to 7 days after administration for phase I and up to 1 day after administration for phase IIa. Results In healthy subjects (male, 50%; median age, 26.0 years), the pharmacokinetics of gadopiclenol is considered linear with mean maximum concentration C-max values ranging from 248.7 to 3916.4 mu g/mL. Gadopiclenol was excreted in an unchanged form via the kidneys, eliminated from plasma with a terminal elimination half-life (t(1/2)) of 1.5 to 2 hours. There was no difference in the pharmacokinetics between males and females. After administration of gadopiclenol, the contrast enhancement scores in brain structures were improved in all dose groups. Similar rates of related adverse events were observed with gadopiclenol (36.1%) and placebo (33.3%). No clinically significant modifications in biochemistry, hematology, urinalysis, electrocardiogram parameters, and vital signs were reported. In patients (male, 58%; median age, 53.0 years), a similar pharmacokinetic and safety profile was observed, and sufficient contrast enhancement was seen at all tested doses. Conclusions The pharmacokinetics of gadopiclenol is dose-independent in healthy subjects and patients with brain lesions. Its good safety profile is in line with that reported for other macrocyclic gadolinium-based contrast agents. Preliminary pharmacodynamic results in patients suggest that gadopiclenol is a promising macrocyclic contrast agent with the potential use of lower dose for clinical routine magnetic resonance imaging scans. The study is registered on under the trial registration number NCT03603106.