seclidemstat + topotecan + cyclophosphamide

This is a combination regimen of three drugs used in oncology clinical research: - **Seclidemstat** is a selective, reversible, oral **LSD1 inhibitor** (lysine-specific demethylase 1) developed for cancers characterized by oncogenic chromosomal translocations, such as Ewing sarcoma and other sarcomas. It inhibits both catalytic and scaffolding functions of LSD1, thereby blocking oncogenic transcriptional activity[4]. - **Topotecan** is a **topoisomerase I inhibitor**; it stabilizes the cleavable complex between topoisomerase I and DNA during replication, leading to double-strand DNA breaks and cell death. It is approved for ovarian cancer, small cell lung cancer, and cervical cancer. - **Cyclophosphamide** is an **alkylating agent** of the nitrogen mustard class. It is activated in the liver to form phosphoramide mustard, which crosslinks DNA strands, thereby inhibiting DNA and RNA synthesis and leading to cell death. It is widely used for lymphoid malignancies, sarcomas, and some solid tumors, and has immunosuppressive effects[3][6]. These three drugs together would represent a **multi-agent chemotherapeutic and targeted therapy regimen**, likely studied for relapsed/refractory sarcomas or other malignancies where synergy between an epigenetic modulator (seclidemstat), DNA-damaging alkylator (cyclophosphamide), and topoisomerase I inhibitor (topotecan) is hypothesized.