Background The purpose of this study was to understand how the COVID-19 pandemic has affected health care patterns and outcomes for patients diagnosed with metastatic pancreatic ductal adenocarcinoma (mPDAC) in 2020 compared with those diagnosed with mPDAC in 2019. Patients and Methods We used the Flatiron Health database to identify adults diagnosed with mPDAC from March 1 to September 30, 2019 (pre-COVID-19 cohort) and March 1 to September 30, 2020 (post-COVID-19 cohort). Between-cohort comparisons included demographic and clinical characteristics and year-over-year data for diagnosis of mPDAC, newly treated patients, time to and types of first-line therapy, and adverse events (AEs) during first-line therapy. Overall survival (OS) and milestone survival rates were evaluated. Kaplan-Meier methods were used to assess OS. Results Pre-COVID-19 (n = 923) and post-COVID-19 (n = 796) cohorts had similar baseline demographic characteristics. A smaller proportion of patients in the pre-COVID-19 cohort were initially diagnosed with stage IV disease versus the post-COVID-19 cohort (62.2% vs 69.7%). Between 2019 and 2020, there was a 13.8% decrease in diagnosis of mPDAC and a 13.0% decrease in newly treated patients. Median (interquartile range) times to first-line treatment were similar (21 [13-40] and 19 [12-32] days). Median OS (months) was significantly longer in the pre-COVID-19 cohort (8·4 [95% CI: 7·5, 9·0]) versus the post-COVID-19 cohort (6·1 [95% CI: 5·4, 6·9]; P < .001). Survival rates were higher in the pre-COVID-19 versus post-COVID-19 cohorts. Conclusions During the pandemic, patients were initially diagnosed with PDAC at more advanced stages. While patients in both cohorts appeared to receive similar care, survival outcomes were adversely affected.

4137 Background: The coronavirus disease 2019 (COVID-19) pandemic has caused abrupt changes to the US health system and disruption in cancer care delivery. Little has been reported on the impact of COVID-19 on patients with mPDAC and the care delivery. Our study aimed to characterize the impact of COVID-19 on healthcare utilization and outcomes for patients with mPDAC in the US in the community oncology setting. Methods: We performed a retrospective cohort study of adult patients diagnosed with mPDAC between March – September 2019 and March – September 2020 using the nationwide Flatiron Health EHR database, comprising data from over 280 (largely community based) cancer clinics. Patients were stratified into two cohorts based on the year of diagnosis (2019 vs. 2020). Clinical characteristics were summarized including age at metastatic diagnosis, stage at initial diagnosis, and ECOG performance score (PS). Overall survival (OS) from metastatic diagnosis was estimated using Kaplan-Meier methods. A sensitivity analysis limiting the follow-up time to November of each year was conducted. Results: Overall, 1,719 patients were included in the study (2019: n = 923, 2020: n = 796); both cohorts had similar demographic compositions in terms of age and sex (2019: median age = 70 (IQR: 62 – 76), 52.2% male; 2020: median age = 70 [IQR: 62 – 76], 53.5% male). In 2020, the number of newly diagnosed mPDAC patients decreased by 13.8% compared to 2019. A slightly higher proportion of patients were initially diagnosed with stage IV disease in 2020 (69.7%) vs 2019 (62.3%). A similar proportion of patients with ECOG PS 0-1 was observed between the two cohorts (2019: 48.5%; 2020: 47.9%). The number of visits recorded within the first 90 days after metastatic diagnosis was similar between the two cohorts (2019: median 8 [IQR: 3 – 14]; 2020: median 9 [IQR: 4 – 14]). For both cohorts, the proportion of patients who received 1L treatment was similar (2019: 75.8%; 2020: 76.5%), and the most common 1L treatment regimen was gemcitabine plus nab-paclitaxel (2019: 37.6%; 2020: 40.9%). Of the 1L treated populations, 37.6% of patients diagnosed in 2019 received second line (2L) compared to 17.9% of the 2020 cohort; 16.9% of 1L treated patients in 2019 received 2L in the sensitivity analysis. Patients diagnosed in 2020 had a significantly lower median OS of 6.1 months (95% CI: 5.4 – 6.9) compared to patients diagnosed in 2019: 8.4 months (7.5 – 9.0) (p < 0.001). Conclusions: During the COVID-19 pandemic era, the diagnoses of de novo mPDAC appears to have been impacted, with a higher number of patients diagnosed with advanced stage at presentation. Our analysis suggests that while patients diagnosed in 2020 received a similar level of care as those in 2019, their survival outcomes were adversely affected. Further research is necessary to characterize the impact of the COVID-19 pandemic on cancer care and outcomes.