Plasma concentration–time curves (A), plasma AUC0–4h (B), brain concentration (C), brain-to-plasma ratio (D), testis concentration (E) and testis-to-plasma ratio (F) of selpercatinib in male wild-type and Abcb1a/1b;Abcg2-/- mice over 2 h after oral administration of 10 mg/kg selpercatinib with or without coadministration of elacridar. Data are given as mean ± S.D. (n = 6). *, p < 0.05; **, p < 0.01; ***, p < 0.001 compared to vehicle-treated wild-type mice; #, p < 0.05; ##, p < 0.01; ###, p < 0.001 compared to elacridar-treated wild-type mice. Statistical analysis was applied after log-transformation of linear data.