Additional Study Information: This study is for patients with metastatic or locally advanced soft tissue sarcoma (STS) who are not amenable to treatment with surgery or radiotherapy with curative intent. Patients will be treated with doxorubicin plus olaratumab versus doxorubicin plus placebo intravenously for 8 cycles. Patients without disease progression will be allowed to continue olaratumab or placebo monotherapy for more than 8 cycles.