GDC-0575 + gemcitabine

GDC-0575 + gemcitabine is a **combination therapy** of two anticancer agents used in investigational clinical studies to treat refractory solid tumors, including soft tissue sarcomas and breast cancer. **GDC-0575** is a highly selective, oral, small-molecule inhibitor of checkpoint kinase 1 (CHK1), which is a protein involved in DNA damage response and cell cycle arrest; its inhibition leads to mitotic catastrophe and tumor cell death. **Gemcitabine** is a nucleoside analog (antimetabolite) used as standard chemotherapy, which causes cytotoxicity by inhibiting DNA synthesis. Combination therapy is designed to enhance cancer cell death by preventing repair of chemotherapy-induced DNA damage through CHK1 blockade. GDC-0575 has shown modest tolerability and preliminary antitumor activity when combined with gemcitabine in phase 1 clinical trials, with hematological toxicities such as neutropenia and anemia being common but manageable[1][3][5].