The future of BRD9 inhibitors: a patent perspective (2019-present).

[INTRODUCTION] Bromodomain-containing protein 9 (BRD9) is an epigenetic reader component of the non-canonical BAF (BRG1/BRM-Associated Factors) chromatin remodeling complex, involved in the regulation of transcription. The ncBAF complex differs from the other two complexes, the canonical BAF and PBAF, as it contains unique subunits encoded by genes including BRD9, GLTSCR1 (Glioma Tumor Suppressor Candidate Region 1), and GLTSCR1L (GLTSCR1-Like). In recent years, BRD9 has emerged as a promising therapeutic target in several diseases.

[AREAS COVERED] This review explores the most compelling patents released from 2019 to 2025 concerning compounds, classified as small molecules and protein degraders (PROTACs), interfering with BRD9 activity. Relevant patents were identified through searches in European Patent Office (EPO) and World Intellectual Property Organization WIPO databases.

[EXPERT OPINION] The patent landscape reflects a growing interest in BRD9 as an epigenetic target for its key role in various pathologies. The recent patent data show how selective BRD9 degraders represent a significant step forward in terms of efficacy and selectivity, with promising results in preclinical models of acute myeloid leukemia (AML), synovial sarcoma (SS), and Huntington's disease (HD). Despite several critical issues, the selective degradation of this epigenetic target shows great potential to be an innovative therapeutic strategy.