PCN65 ESTIMATED COSTS OF TREATMENT-RELATED ADVERSE EVENTS (TRAES) FOR RECURRENT OR METASTATIC (R/M) SQUAMOUS CELL CARCINOMA OF THE HEAD AND NECK (SCCHN) IN THE CHECKMATE 141 TRIAL IN SPAIN

To assess the estimated costs of managing grade 3-4 TRAEs requiring treatment in CheckMate-141. Nivolumab, a programmed death-1 (PD-1) immune checkpoint inhibitor antibody, is approved in the European Union for treatment of SCCHN progressing on or after platinum-based chemotherapy. In the phase 3 CheckMate 141 trial, nivolumab significantly improved overall survival vs investigator’s choice (IC) of standard, single-agent systemic therapy (methotrexate, docetaxel, or cetuximab) in patients with R/M SCCHN. The frequency, grade, and attribution of TRAEs for which treatment was received were extracted from CheckMate 141 patient-level safety data. Grade 3-4 TRAE treatment costs were estimated mostly based on Spanish National Hospital Discharge Database (Conjunto mínimo básico de datos, CMBD) and some based on regional discharge database. Among the 347 patients in the safety population, 236 received nivolumab and 111 received IC. A total of 88 grade 3-4 TRAEs requiring treatment were observed: 28 among patients receiving nivolumab (11.8%) and 60 among patients receiving IC (54.0%). The mean cost of managing grade 3-4 TRAEs per treated patient was 4.15 times higher in the IC arm (1.967€) than in the nivolumab arm (473€) which corresponded to a total cost of managing grade 3-4 TRAE of 111.711,62€ receiving nivolumab and 218.284,66€ in the IC arm. Patients with platinum-refractory R/M SCCHN treated with nivolumab had fewer grade 3-4 TRAEs requiring treatment (11.8% vs 54.0%), lower estimated total costs of managing TRAEs (111.711,62€ vs 218.284,66€), and reduced TRAEs costs per treated patient compared with standard, single-agent systemic therapy (473€ vs 1.967€).