Olaratumab: a platelet-derived growth factor receptor-α-blocking antibody for the treatment of soft tissue sarcoma

The outcome of patients with unresectable or metastatic soft tissue sarcoma (STS) remains poor with few treatment options. A number of randomized trials in the first-line setting have shown no difference in overall survival between combination anthracycline schedules and single-agent doxorubicin. A Phase Ib/randomized Phase II trial of doxorubicin with or without the platelet-derived growth factor receptor-α (PDGFRα)-blocking antibody, olaratumab, demonstrated a significant difference in median overall survival in favor of the olaratumab arm. The results of this trial led to the approval of olaratumab in combination with doxorubicin in adult anthracycline-naïve unresectable STS. In this review, we discuss the potential role of PDGFRα signaling, early clinical data with olaratumab in sarcomas, the Phase Ib/II trial and ongoing trials with olaratumab in sarcomas.