DHODH inhibition results in disease response in a PDX model of T-ALL. (A) Schematic outline of the experiment, with dosing and treatment time points. (B) Spleen weights measured in mice after the engraftment of the T-ALL PDX (MAAT-43298), which were either untreated or designated as brequinar. Each group included 3 animals. Measurements were recorded fter 2 or 4 doses of BRQ, with matched untreated controls. (C) Disease burden in the bone marrow as measured by the percentage of human CD45⁺ cells detected by flow cytometry following either 2 or 4 doses of BRQ. Each group included 3 animals. (D) Kaplan-Meier survival curve comparing mice after the engraftment of the T-ALL PDX (MAAT-43298), which were either untreated or designated as brequinar; n = 7 in the untreated group; n = 9 in the brequinar group; P < .0001. (E) Spleen weights measured in mice after the engraftment of the T-ALL PDX (MAAT-93235) that were either untreated or designated as brequinar. Each group included 3 animals. Measurements were recorded after 2 or 4 doses of BRQ, with matched untreated controls. (F) Disease burden in the bone marrow as measured by the percentage of human CD45⁺ cells detected by flow cytometry after either 2 or 4 doses of BRQ. Each group included 3 animals. (G) Kaplan-Meier survival curve comparing mice after the engraftment of the T-ALL PDX (MAAT-93235), which were either untreated or designated as brequinar. n = 10 in the untreated group; n =10 in the brequinar group; P < .0001. Created with BioRender.com.