idasanutlin + cyclophosphamide + topotecan

This is a **combination regimen** containing three drugs: - **Idasanutlin** is a second-generation, orally administered small molecule inhibitor of MDM2, developed to restore and activate p53 function in cancer cells. By blocking the interaction between MDM2 and p53, it prevents p53 degradation, leading to increased tumor cell apoptosis, cell cycle arrest, and restoration of DNA damage responses[1][2][6][7][8]. - **Cyclophosphamide** is an alkylating agent that causes DNA crosslinking and damage, inhibiting replication and inducing apoptosis in rapidly dividing cells[3]. - **Topotecan** is a topoisomerase I inhibitor that prevents DNA unwinding and relegation, causing DNA damage and cell death, especially in cancer cells[3]. This combination is under investigation for relapsed or refractory sarcoma, solid tumors, neuroblastoma, and other advanced malignancies. It is not an approved regimen but has been used in trial settings and salvage therapies[1][3].