Dose-exposure relationship. Steady-state (day 28) idelalisib plasma exposures by idelalisib dosing regimen (N = 40). AUC_τ indicates area under the concentration-time curve over 12 (daily) or 24 hours (twice daily); BID, twice daily; C_τ, trough concentration; C_max, maximum concentration; QD, daily; SD, standard deviation.