In vivo efficacy of pirtobrutinib in BTK and BTK C481S mutant lymphoma xenograft models. Tumor-bearing mice were treated with pirtobrutinib with the indicated doses, for the indicated time. Means and standard error of the mean were plotted for each treatment group vs days of treatment (A) or days after randomization (B-D). For OCI-LY10 xenografts (A), tumor volumes were measured 3 times per week, and the tumor volumes were measured for an additional 35 days after the last dose. For TMD8 xenografts (B), tumor volumes were measured 3 times per week. The experiment was stopped on day 14 after randomization for the vehicle control group, and on day 18 after randomization for the other groups. For REC-1 xenografts (C), tumor volumes were measured biweekly. For TMD8 BTK C481S xenografts (D), tumor volumes were measured 2 or 3 times per week.