Introduction and Aims
Checkpoint Inhibitors (CPIs) form a key pillar of modern oncologic care. Immune-related adverse events (irAEs) present specific management issues. Multiple admissions or prolonged hospitalisation may occur due to irAEs. We aimed to describe this burden in routine clinical care.
A retrospective single centre study was performed including patients treated between 2015 and 2018. Patients who commenced CPIs in routine clinical care were identified from pharmacy records (clinical trial participants were excluded). Data were collected on irAEs requiring hospitalisation.
307 patients commenced CPIs- single agent PD-1 or PD-L1 inhibitor (n=241; 79%); PD-1 inhibitor plus CTLA-4 inhibitor (n=62; 20%) and single agent CTLA-4 inhibitor (n=4; 1%). 218 patients had melanoma (71%); 64 had NSCLC (21%); 23 other (8%).
70 patients (23%) required 124 hospitalisations for irAEs. 42 (60%) received single agent PD-1/PD-L1 inhibition, 25 (36%) received a PD-1 inhibitor plus a CTLA-4 inhibitor; and 3 received single agent CTLA-4 inhibition (4%). The median length of stay was 6 days (range 1-27 days). 8 patients required ICU admission. 6 patients (1.9%) died from irAEs.
Toxicities requiring admission included colitis (35%, n = 44), hepatitis (20%, n = 25), endocrinopathies (14%, n = 17), pneumonitis (10%, n = 12), dermatological (6%, n = 8), nephritis (5%, n = 6), musculoskeletal (4%, n = 5) and haematological (2%, n=2), with 5 admissions having >2 organ toxicities (4%). Corticosteroids were used in 96% of admissions. Additional immunosuppression was required in 26 admissions (21%). 40 patients (57%) were retreated with immunotherapy.
Admissions for CPI induced irAEs are common in routine care. Oncology services must account for these needs in planning services. Education, vigilance and prompt management of irAEs may reduce this burden. Predictive tools to assess which patients are at greatest risk for irAEs would help care planning and delivery.