Olaratumab for the Treatment of Patients (pts) with Advanced/metastatic Soft Tissue Sarcoma (STS): Treatment Patterns in the United States (US) During the First Year Post-Approval.

e23535 Background: Olaratumab (olara) is a fully human platelet-derived growth factor receptor alpha (PDGFR-α) receptor antagonist that received US Food and Drug Administration (FDA) accelerated approval in October 2016 for the treatment of adult patients with STS in combination with doxorubicin (dox) for whom an anthracycline-containing regimen is appropriate. This approval was based on a randomized Phase 2 study showing a statistically significant 11.8 months median overall survival benefit. This retrospective observational study was designed to understand the real-world treatment patterns of olara in the US during the first year following FDA approval. Methods: The Flatiron electronic medical records database includes HIPAA-compliant de-identified data from patients treated at 265 cancer clinics by > 2,500 oncologists. Data are refreshed every 30 days. Eligible patients were age 18+ who received olara after approval in Oct 2016 Descriptive analyses were conducted to summarize patient characteristics, duration of therapy, and treatment patterns as of Oct 2017 (data available at time of analysis). Results: There were 267 eligible patients in the Flatiron database [mean age 63.2 years (SD = 12.9); 52.8% female]. Consistent with the data source, 77.2% of patients were treated in community practices. Most patients were treated with olara-based therapy in the first- (n = 158, 59.2%) or second-line setting (n = 60, 22.5%). The majority (n = 238, 89.1%) received olara in combination with dox; 20 (7.5%) received olara monotherapy, 5 (1.9%) received olara with liposomal doxorubicin, and the remaining patients (n = 4, 1.5%) received olara with other agents. Of all patients, 41.2% had received olara-based therapy within 60 days of the end of the database. The recent FDA approval and proportion of patients who may not have completed therapy limit the ability to estimate duration of therapy at the time of analysis. Conclusions: These early data show that within the first year of approval, olara has been primarily used in combination with dox, consistent with the label. Future studies will evaluate the clinical outcomes of treatment as data mature.