S2157, a N-alkylated tranylcypromine (TCP) derivative, is a potent lysine-specific demethylase 1 (LSD1) inhibitor. S2157 increases H3K9 methylation and reciprocal H3K27 deacetylation at super-enhancer regions. S2157 induces apoptosis in TCP-resistant T-cell acute lymphoblastic leukemia (T-ALL) cells by repressing transcription of the NOTCH3 and TAL1 genes. S2157 efficiently pass through the blood-brain barrier and can almost completely eradicate CNS leukemia in mice transplanted with T-ALL cells.