– SK-575 is a Highly Potent and Efficacious Proteolysis-Targeting Chimera Degrader of PARP1 for Treating Cancers. SK-575 potently inhibits the growth of cancer cells bearing BRCA1/2 mutations and induces potent and specific degradation of PARP1 in various human cancer cells even at low picomolar concentrations. SK-575 achieves durable tumor growth inhibition in mice when used as a single agent or in combination with cytotoxic agents, such as temozolomide and cisplatin.