OBJECTIVES : Multiple immune checkpoint inhibitors are expensive therapies for metastatic lung cancer, which can be healthcare resource use (HRU) intensive. We aimed to analyze the HRU among patients with metastatic lung cancer on pembrolizumab, nivolumab, or atezolizumab, using real-world data.

METHODS : We conducted a retrospective cohort study in adult patients with metastatic lung cancer on pembrolizumab, nivolumab or atezolizumab identified from IBM MarketScan Commercial database from January 2014 to December 2018. Outcomes assessed were hospital admissions, length of stay, outpatient clinic visits, facility days, out-of-pocket cost (OOP) and non-out-of-pocket cost measured in per patient per month (PPPM). Adjusted group analysis was also conducted using propensity score matching with 1:1 ratio between pembrolizumab and nivolumab groups.

RESULTS : A total of 3,647 patients were identified (pembrolizumab=1,364, nivolumab=2,121, atezolizumab=162). Mean ages were around 57yo and about half of patients were females. Comorbidities were mostly balanced except for diabetes and chronic kidney disease. In the base case analysis, the number of hospital admissions were 0.42, 0.38 and 0.41 PPPM for pembrolizumab, nivolumab and atezolizumab, respectively. The pembrolizumab group had the longest length of stay (2.53 days PPPM, SE=0.1) and lowest number of outpatient clinic visits (5.69 visits PPPM, SE=0.09). Number of facility days were similar. Total non-OOP cost was the lowest for nivolumab ($31,228 PPPM, SE=620) and total OOP the lowest for pembrolizumab ($295 PPPM, SE=16). In the adjusted group analysis, all HRU outcomes were similar to the base-case analysis results except that inpatient admissions were significantly lower for pembrolizumab than nivolumab. Total non-OOP cost was significantly higher for pembrolizumab compared to nivolumab while the total OOP cost was the lowest for pembrolizumab.

CONCLUSIONS : The HRU outcomes are different among immune checkpoint inhibitors in the metastatic lung cancer population. Pembrolizumab-based therapy may be cheaper and lead to less clinic visits for metastatic lung cancer patients.