1582P Real-world Management of Immune-Related Adverse Events in the Community Setting

Immune checkpoint inhibitors (ICIs) are integral to the treatment of many cancers, often leading to improved survival outcomes and durable response. Immune-related adverse events (irAEs) differ in presentation and management from adverse events associated with other cancer therapies. This study describes the characteristics and management of irAEs in the community setting. This retrospective cohort study used electronic health record data from 2 community health systems (30+ hospitals, 500+ sites) from the Syapse Learning Health Network. Patients (pts) first exposed to ICIs between 1/1/2015 and 2/28/2019 were included with data cutoff of 3/1/2020. Pts with irAEs were identified using a 2-step screening process with a target cohort of ∼400 pts. Step 1: Technology-enabled screening using medication names, ICD codes, ER/hospitalization records and abnormal clinical labs. Step 2: Chart review by certified tumor registrars to confirm and characterize irAEs (attribution, severity, management and outcomes), with adjudication by a medical oncologist. 1382 pts were reviewed from a pool of 2129 pts with suspected irAEs, resulting in a cohort of 403 pts with irAEs. Lung cancer (60%) and melanoma (16%) were the most common histologies. The median time to irAE onset was 77 days. 91 pts (23%) had an ER/hospitalization visit due to irAE, with 43% of visits due to gastrointestinal irAE. irAE-related deaths occurred in 7 pts (1.7% of irAE cases). Systemic steroid use was documented in 236 pts (59%; duration of use 31 days).) Pts treated with steroids ≤24 hours of irAE onset had a higher resolution proportion at 3 months (0.7; 95% CI 0.6-0.8) than pts treated >72 hours (0.5; 95% CI 0.5-0.6). Of 78 pts with irAE related treatment discontinuation who were retreated with ICIs, half developed irAE recurrence.Table: 1582PICI Monotherapy (N = 328)ICI + Chemotherapy (N = 29)ICI + ICI (N = 46)All (N = 403)ICI initiation to irAE onset, days, median (IQR)84 (41-170)99 (13-140)24 (11-60)77 (33-150)Most common irAEsEndocrine115 (35%)6 (21%)16 (35%)137 (34%)Dermatologic77 (23%)7 (24%)21 (46%)105 (26%)GI81 (25%)11 (38%)25 (54%)117 (29%)Pulmonary45 (14%)3 (10%)1 (2%)49 (12%)ER/hospitalization68 (21%)10 (34%)13 (28%)91 (23%)Most common irAEs (ER/hospitalization patients)GI27 (40%)4 (40%)8 (62%)39 (43%)Pulmonary23 (34%)2 (20%)0 (0%)25 (27%)Treated with steroids188 (57%)16 (55%)32 (70%)236 (59%)Retreated with ICI62 (19%)2 (7%)14 (30%)78 (19%)Death (among patients with irAE)6 (2%)0 (0%)1 (2%)7 (2%) Open table in a new tab Pts with prompt recognition and management of irAEs experienced superior irAE resolution in a community setting.