Optimization and Biological Evaluation of Novel 1H-Pyrrolo[2,3-c]pyridin Derivatives as Potent and Reversible Lysine Specific Demethylase 1 Inhibitors for the Treatment of Acute Myelogenous Leukemia

Lysine-specific demethylase 1 (LSD1) plays a vital role in the epigenetic regulation of various cancers, making it a promising therapeutic target for anticancer treatments. Herein, we designed and synthesized a novel series of 1H-pyrrolo[2,3-c]pyridin derivatives as potent LSD1 inhibitors. A detailed structure–activity relationship exploration was carried out to discover multiple derivatives with nanomolar enzymatic IC₅₀ values. Further biological evaluation demonstrated that these compounds acted as selective and reversible LSD1 inhibitors. The representative compounds exhibited highly potent antiproliferative activity against both AML (MV4–11 and Kasumi-1) and SCLC (NCI-H526) cell lines. Additionally, they effectively activated CD86 mRNA expression in MV4–11 cells and induced differentiation of AML cell lines. Notably, the most promising compound 23e showed a favorable oral PK profile and effectively suppressed the tumor growth in an AML xenograft model. Overall, our medicinal chemistry efforts provide compound 23e as a lead compound for developing LSD1 inhibitors for the treatment of AML and other advanced malignancies.