Blockade of OX40 signaling attenuates bendamustine-induced T-cell depletion. (A) T-cell counts at baseline and 2 and 4 weeks after bendamustine administration in C57BL/6 mice pretreated with anti-OX40L Ab (n = 17) or isotype control Ab (n = 18). Statistical significance was assessed by Welch t test based on T-cell counts at 2 and 4 weeks. The results are indicated as: n.s., P > .05; ∗P < .05; ∗∗P < .01; ∗∗∗P < .001. (B) Changes in the volume of transplanted B-cell lymphoma (HM876) in C57BL/6 mice after bendamustine administration with anti-OX40L Ab (n = 10) or isotype control Ab (n = 10) pretreatment. The tumor reduction rates at day 8 were compared between the 2 groups using the Brunner-Munzel test, which does not require assumptions of normality and homoscedasticity. (C) T-cell counts at baseline and 2 and 4 weeks after cyclophosphamide administration in C57BL/6 mice pretreated with anti-OX40L Ab (n = 10) or isotype control Ab (n = 10). Statistical significance was assessed by Welch t test based on T-cell counts at 2 and 4 weeks. The results are indicated as: n.s., P > .05. Ab, antibody.