Plasma concentration-time profile of zanubrutinib after initial doses of 40, 80, 160, and 320 mg once daily and 160 mg twice daily in part 1 and cohort 2a patients. Lines represent mean plasma concentration and error bars indicate standard deviation. *For the 160-mg twice-daily dose group, patients received only the morning dose (one-half of the daily dose) for the 24-hour pharmacokinetic evaluation on day 1 of week 1. BID, twice daily; QD, once daily.