S-PAC-1

**S-PAC-1** is a small-molecule derivative of PAC-1 designed to activate procaspase-3 into active caspase-3, thereby inducing apoptosis specifically in cancer cells while minimizing neurotoxicity associated with the parent compound. Developed by researchers at the University of Illinois Urbana-Champaign, it chelates zinc ions that inhibit procaspase-3, enabling its autoactivation and downstream executioner caspase activity. S-PAC-1 demonstrated antitumor activity and safety in a veterinary clinical trial in pet dogs with spontaneously occurring lymphoma, achieving partial responses or stable disease in several patients when administered as continuous IV infusions, positioning it as a proof-of-concept for direct procaspase activation as an anticancer strategy.