CIDD-97

CIDD-97 (also known as CIDD-0149897) is a potent and selective small molecule agonist of the estrogen receptor beta (ERβ), developed for the treatment of glioblastoma (GBM). It belongs to a chemical class of indanone and tetralone-oximes. CIDD-97 demonstrates approximately 40-fold selectivity for ERβ over the alpha isoform (ERα), which is critical for avoiding the proliferative and potentially oncogenic effects associated with ERα activation. In preclinical studies, the compound has shown high blood-brain barrier (BBB) permeability and significant anti-tumor activity in both cell-line-derived and patient-derived xenograft models of GBM. Its mechanism of action involves the activation of ERβ target genes, reduction of stemness markers in glioma stem cells, and induction of apoptosis. Additionally, CIDD-97 has been shown to sensitize GBM cells to the standard-of-care chemotherapy temozolomide (TMZ).