Triple combination manifests synergistically in vivo in xenograft mice-bearing ATL tumors. (A) The triple combination prolonged the survival of xenograft mice-bearing ATL43Tβ (-) tumors. Ten days after tumor inoculation, I-BET762 was given orally at a dose of 10 mg/kg, and copanlisib and bardoxolone methyl were administered via intraperitoneal injection at a dose of 5 mg/kg and 2.5 mg/kg, respectively, 3 times per week for 20 days. The vehicle group received a 15% solutol dissolved in water. Average tumor volumes during the therapeutic time course were measured twice weekly until the tumor volume reached 2000 mm³ (n = 7 to 10). (B) Kaplan-Meier curves illustrate the survival of mice that received single therapy or double or triple combinations. (C) Percentages of mouse body weight change from day 0 until day 20 after treatment. (D) Serum levels of human sIL-2Rα were measured on day 20 after treatment with an ELISA assay (n = 7 to 10 mice per group). Data were pooled from 2 independent experiments and expressed as mean ± SEM. One-way ANOVA and log-rank (Mantel-Cox) tests were performed to determine statistical differences. (E) Representative images of human-c-MYC with IHC staining of tumor isolated from the mice after treatment with vehicle or the triple combination for 5 days. Bar graphs depicted the percentages of c-MYC positive nuclei of tumor tissues (n = 4 mice per group), unpaired Student t test was used to determine statistical differences. (F) Diagram showing the interaction of the 3 drugs combination generated by the Chou-Talalay method: the heavy line is indicating a strong synergism between I-BET762 with copanlisib and copanlisib with bardoxolone methyl. The thin line indicates moderate synergism between I-BET762 and bardoxolone methyl. *P < .05, **P < .01, ***P < .001, ****P < .0001.