PK and Pharmacodynamics
SE
BLOOD
Blood samples from all 44 patients drawn on Cycle 1 Day 1 (C1D1) and from 39 patients drawn on C1D14 were used to assess pemigatinib PK. The geometric mean (CV%) peak plasma concentration (Plasma pemigatinib concentrations on (A) Cycle 1 Day 1 (C1D1), (B) Cycle 1 Day 14 (C1D14; steady state). Data are presented as mean ± SE. FGFR2, fibroblast growth factor receptor 2; ICThe geometric mean accumulation ratio for area under the plasma concentration‐time curve from 0 to 24 h (AUCA comparison of pemigatinib PK between the Japanese patients in this study and the predominantly white patients from the FIGHT‐101 study showed similar pemigatinib exposures. With pemigatinib 13.5 mg QD dosing, the steady‐state FGF23 concentrations at baseline and at Day 15 of treatment Cycle 1 were measured in plasma from 41 patients (9 mg, Ex vivo target inhibition as defined by ≥50% inhibition of pFGFR2α at any timepoint was observed for all patients. Mean inhibition of pFGFR2α at trough pemigatinib concentration (C1D15, 0 h) was 80% (Figure 