Real-world utilization and outcomes of systemic therapy among patients with advanced or recurrent endometrial cancer in the United States

Objective: Evaluate systemic therapy utilization patterns and outcomes by line of therapy among patients with advanced/recurrent endometrial cancer (EC) treated in the United States. Methods: This retrospective observational study used the Optum Clinformatics Extended Data Mart Date of Death database (1 January 2004–31 December 2019) and included de-identified data from adult patients with advanced/recurrent EC who were treated with first-line (1L) platinum-based chemotherapy and initiated second-line (2L) anti-neoplastic therapy. The index date was the date of 1L therapy initiation. The number and sequence of treatments received and the proportion of patients who received each type of treatment for each line of therapy were evaluated. To account for new drug approvals, patients first treated in 2018 or 2019 were also assessed separately. Results: Among the 1317 patients who met all eligibility criteria, 520 (39.5%) and 235 (17.8%) patients received 3 or 4+ lines of treatment, respectively, during a median total follow-up time of 25.2 months (range, 2.5–173.3 months) following the index date. Chemotherapy, including platinum- and non-platinum-based regimens, was the most common treatment across all lines of therapy: 2L, 80.0%; 3L, 66.2%; 4L+, 80.4%. Overall, 2.5%, 2.3%, and 8.9% of 2L, 3L, and 4L + patients, respectively, received anti-program death 1 (anti-PD-1) immunotherapies. In patients first treated in 2018 and 2019 (n = 163), 9.8% of patients received anti-PD-1 immunotherapy in the 2L. In the overall population, median time to next treatment (TTNT) was 19.3, 10.5, and 8.1 months for patients undergoing 2L, 3L, and 4L treatment, respectively. Conclusions: Among patients with advanced/recurrent EC treated with 1L platinum-based therapy in clinical practice, chemotherapy was the most common treatment choice across all lines of therapy. Immunotherapy use was low overall but increased in patients who started treatment in 2018 or 2019. Overall, median TTNT decreased as lines of therapy increased.