LAUSR

e22550 Background: Olaratumab is a humanized monoclonal anti platelet-derived growth factor receptor α antibody that has been approved in combination with doxorubicin for the treatment of patients with metastatic soft tissue sarcoma (STS). The purpose of this retrospective study was to assess the clinical efficacy in STS patients treated with olaratumab in a real-world setting in Austria. Methods: Retrospectively collected, longitudinal data from patients treated between November 2016 and September 2018 at 9 Austrian centers were obtained from respective medical charts. Eligible patients were all patients who received at least one dose of olaratumab. Parameters of most interest collected were response rates, progression-free survival (PFS) and overall survival (OS). Results: Altogether 55 patients were included into analysis. Median age was 58 years. In total, 65.5% (n = 36), 21.8% (n = 12) and 12.7% (n = 7) received olaratumab as first-, second- or ≥ third-line treatment, respectively. Olaratumab was administered either in combination with doxorubicin (81.8%, n = 45) or liposomal doxorubicin (16.4%, n = 9); 1 patient received olaratumab as upfront monotherapy. Median PFS and OS were 2.6 and 11.4 months. The objective response rate was 11.4 % and the disease control rate was 40.9 %. Conclusions: In this real-world analysis outcome was less pronounced compared to the results of the Phase Ib/II approval trial ( Tap WD et al. Lancet 2016). Thus, the results of the ongoing phase III trial (NCT02451943) are urgently needed to confirm the efficacy of the combination of olaratumab and doxorubicin in STS patients.