Ivermectin use in patients with cancer over the past decade at an academic cancer center.

e23175 Background: Patient interest in ivermectin has increased over time, initially as potential treatment for COVID-19 and currently for purported anti-cancer effects. Scarcity of evidence-based medicine has limited translation to clinical practice, however the growing public dialogue has led providers to anecdotally note increased patient off-label use. This study sought to characterize ivermectin use among patients seen at a large, academic cancer center. Methods: All patients seen at a tertiary referral center from 2016-2025 with an active medication reconciliation were included. Foundry (an AI-powered analytic platform by Palantir) was used to query the electronic health record to identify patients with oral ivermectin (brand name stromectol) documented on their medication list (topicals were excluded). Descriptive statistics categorized patient characteristics; time trends were assessed by linear regression. Results: A total of 2,187 unique patients were identified with documented ivermectin use (0.05% of the 416,042 patients seen in the past decade). The median age was 63 years (IQR 52-70); most were White (79.9%), and non-Hispanic or Latino (83.6%); slightly more than half were male (55.9%), most were nonsmokers (60.9%). Patients lived a median of 145 miles from the center (IQR 24-412). Documented ivermectin use increased over time, from 66 patients in 2016 to 475 in 2025 (p < 0.001)75.8% of documented use in the past 10 years has been since 2021. There was a notable rise in 2021 (n = 379) followed by a slight decline in 2022 and consistent rise since then. The most common cancer diagnoses were leukemia and lymphoma (27% of use), followed by breast (13%), prostate (8%), and lung (5.5%). This has changed over time with 2016-2020 use dominated by patients with hematologic malignancies (62% of use) and then a shift 2021-2025 to solid tumors (89% of use). Between 2016-2020, 35% of ivermectin use was associated with an Infectious Diseases (ID) sub-specialty provider; this decreased sharply to 4.6% by 2025, with the majority of use being patient self-reported during medication reconciliation. Conclusions: Documented ivermectin use has rapidly increased in the past decade in patients with cancer, highlighting the essential role of full and accurate medication reconciliation. Our study likely underestimates the true frequency, as it relies on patient report and accurate documentation. These results underscore the importance of understanding patient off-label use, given 7-fold increase despite no change in FDA recommended indications. Further research is needed to understand patient beliefs and to evaluate clinical recognition and management of ivermectin-related interactions and complications (and/or potential benefits) based on specifics of cancer treatment and clinical course.