Definition

The hydrobromide salt form of nirogacestat, a selective gamma secretase (GS) inhibitor with antitumor activity. Upon administration, nirogacestat targets and binds to GS, thereby blocking the proteolytic activation of Notch receptors. This inhibits the Notch signaling pathway and results in the induction of apoptosis in tumor cells that overexpress Notch. The integral membrane protein GS is a multi-subunit protease complex that cleaves single-pass transmembrane proteins, such as Notch receptors, at residues within their transmembrane domains. Overexpression of the Notch signaling pathway has been correlated with increased tumor cell growth and survival.