Olaratumab is a fully human monoclonal antibody that targeted platelet-derived growth factor receptor alpha (PDGFRα), a receptor tyrosine kinase involved in cell proliferation, migration, and stromal support. By binding to PDGFRα, olaratumab blocked ligand (PDGF-AA, PDGF-BB, PDGF-CC) binding and receptor activation, thereby inhibiting downstream signaling pathways. It was granted accelerated approval in 2016 in combination with doxorubicin for the treatment of advanced soft tissue sarcoma (STS) in adults not amenable to curative treatment with radiotherapy or surgery, based on improved overall survival in a Phase II trial. However, subsequent Phase III trial (ANNOUNCE) failed to confirm survival benefit, leading to its voluntary withdrawal from the market in 2019.