HDM201 + LEE011

**HDM201 + LEE011** is an investigational combination therapy composed of two orally administered small molecules: HDM201 (siremadlin), an MDM2 inhibitor, and LEE011 (ribociclib), a selective CDK4/6 inhibitor. HDM201 is designed to block the interaction between MDM2 and p53, thus reactivating the tumor-suppressor function of p53 and inducing cell cycle arrest and apoptosis in p53 wild-type tumors. LEE011 inhibits CDK4/6 to maintain cell cycle arrest, targeting cancers reliant on dysregulated cyclin D-CDK4/6 activity. Developed and tested by Novartis, the combination was primarily evaluated for advanced liposarcoma that progressed despite prior therapy, with trials completed up to Phase 1. Both agents act via oral administration and are investigated for synergistic anti-tumor activity, especially in soft tissue sarcomas[1][3][4].

Other names

siremadlin + ribociclib