Figure. Efficacy of telacebec against Mycobacterium leprae bacteria in axenic culture (A), in murine bone marrow–derived macrophages (B), and in athymic nude mouse foot pad model (C, D). M. leprae hsp18 (C) and esxA (D) expression levels were used as a surrogate measure of viability. For panels A and B, the assays were performed in triplicate for each condition. For panels C and D, each foot pad is taken as a data point, and the red dotted lines indicate ≈99% M. leprae kill. Significance was determined by 2-tailed unpaired Student t-test. 14C, carbon 14; CPM, counts per minute; Q203, telacebec; RMP, rifampin.