5.1. Q134R

Q134R was synthesized by Avidin Ltd. as described previously and used in cell culture conditions at similar concentrations (Hackler et al., 2019). The pharmacokinetic properties of Q134R were determined earlier during preclinical development using radioactive‐labeled Q134R (CLINICAL INVESTIGATOR'S BROCHURE, Q134R‐K, January 12, 2016). In male rats, organ/tissue concentrations of total radioactivity [μgE/g were measured (Dose: 10 mg/kg [14C]‐Q134R orally as potassium salt). The absorbed radioactivity showed relatively weak distribution properties. At 1‐hr post‐dose, tissue concentrations of Q134R (0.879 μgE/g) were markedly higher than the blood concentration. The brain levels of Q134R were similar to the blood level (0.963 μgE/g). The determined peak concentration in the brain was comparable to effective concentrations determined in vitro for NFAT inhibitory activity.