spartalizumab + HDM201

**Spartalizumab + HDM201** is an investigational combination therapy composed of two separate agents developed by Novartis: spartalizumab, a humanized IgG4 monoclonal antibody targeting the programmed death-1 (PD-1) receptor (a checkpoint inhibitor used in immunotherapy to block PD-1-mediated tumor immune evasion), and HDM201 (also called siremadlin), a small molecule MDM2 antagonist which reactivates the tumor suppressor protein p53 by inhibiting the interaction between MDM2 and p53. The combination is designed for cancer treatment, hypothesized to enhance antitumor immunity through both immune checkpoint inhibition (spartalizumab) and restoration of p53 tumor suppressor function (HDM201), potentially providing synergistic activity against tumor cells.