PT - JOURNAL ARTICLE AU - Qingxu Liu AU - Long Li AU - Wan Qin AU - Tengfei Chao TI - Repurposing drugs for solid tumor treatment: focus on immune checkpoint inhibitors AID - 10.20892/j.issn.2095-3941.2023.0281 DP - 2023 Nov 15 TA - Cancer Biology & Medicine PG - 856--868 VI - 20 IP - 11 4099 - http://www.cancerbiomed.org/content/20/11/856.short 4100 - http://www.cancerbiomed.org/content/20/11/856.full SO - Cancer Biology & Medicine2023 Nov 15; 20 AB - Cancer remains a significant global health challenge with limited treatment options beyond systemic therapies, such as chemotherapy, radiotherapy, and molecular targeted therapy. Immunotherapy has emerged as a promising therapeutic modality but the efficacy has plateaued, which therefore provides limited benefits to patients with cancer. Identification of more effective approaches to improve patient outcomes and extend survival are urgently needed. Drug repurposing has emerged as an attractive strategy for drug development and has recently garnered considerable interest. This review comprehensively analyses the efficacy of various repurposed drugs, such as transforming growth factor-beta (TGF-β) inhibitors, metformin, receptor activator of nuclear factor-κB ligand (RANKL) inhibitors, granulocyte macrophage colony-stimulating factor (GM-CSF), thymosin α1 (Tα1), aspirin, and bisphosphonate, in tumorigenesis with a specific focus on their impact on tumor immunology and immunotherapy. Additionally, we present a concise overview of the current preclinical and clinical studies investigating the potential therapeutic synergies achieved by combining these agents with immune checkpoint inhibitors.