BI 9564

BI 9564 is a potent and highly selective small-molecule inhibitor of the **Bromodomain-containing protein 9 (BRD9)**. Developed by **Boehringer Ingelheim** in collaboration with the **Structural Genomics Consortium (SGC)**, it serves as a high-quality chemical probe for investigating the biological role of BRD9, a key component of the non-canonical BAF (ncBAF) chromatin remodeling complex. BI 9564 binds to the acetyl-lysine binding pocket of the BRD9 bromodomain with high affinity (K_d ~14 nM) and shows significant selectivity over the closely related BRD7 and other BET family members. In preclinical studies, BI 9564 has demonstrated the ability to inhibit cell proliferation in various cancer models, including acute myeloid leukemia (AML) and marginal zone lymphoma (MZL), by disrupting the epigenetic signaling required for oncogenic gene expression.