Anti-tumor activity of tirabrutinib in TMD8 and TMD8R xenograft models. SCID mice were injected with 1 × 107 of (a) TMD8 or (b) TMD8R cells in Matrigel, subcutaneously. After randomization, mice were administered with a vehicle or tirabrutinib via mixed diet for three weeks (TMD8) or two weeks (TMD8R), respectively. The tumor volumes measured for nine mice for TMD8 and ten mice for TMD8R at each measurement time point are presented as the mean ± standard error. The Dunnett-test was used to compare data on tumor volume in the 0.0037%, 0.012%, and 0.037% group, versus the vehicle. A p value of less than 5% was considered statistically significant. * p < 0.05. ** p < 0.01. *** p < 0.001.