OBJECTIVES: ROS1+ NSCLC is rare but economically burdensome. This exploratory analysis examined unexpected healthcare resource utilization (HCRU) of ROS1+ NSCLC patients in the US from physician narratives of patient encounters.

METHODS: Natural language processing and manual abstractions were performed on electronic medical transcriptions of 29 million unique patients from over 150,000 providers, 2015 to Nov 2021. Study population was limited to NSCLC, ROS1+ patients, age >/= 18 years, and taking TKI (crizotinib, entrectinib, ceritinib or/and lorlatinib).

RESULTS: Study criteria identified 103 ROS1+ patients, of whom 25 received TKI. This treatment cohort was 52% female, 8% current smokers; 20% with history of cancer, with mean age of 62 years. Crizotinib was the most frequently used TKI (23/25). The majority of patients experienced treatment disruptions (holds, dose reductions, discontinuations or switches). The most common reason for disruption was tolerability/adverse effects (AE). Approximately 68% of TKI-treated patients experienced a major or minor unexpected HCRU event; 35% and 38% respectively. 45% of crizotinib (13 of 29), 67% of entrectinib (2 of 3), 25% of ceritinib (1 of 4), and 20% of lorlatinib (1 of 5) were associated with major or minor HCRU events. Most common major HCRU events were referrals to a specialist due to a tolerability/AE issue, unscheduled visit to an emergency room (ER) or clinic, or hospital admission. Specialist referrals included ophthalmology, cardiovascular, and gastroenterology. Most common minor HCRU events were for IV fluid or oxygen administration, new laboratory tests, and management of nausea/vomiting and/or edema.

CONCLUSIONS: 68% of all ROS1+ NSCLC patients experienced an unexpected HCRU event; 35% major and 38% minor. Most common major events were referrals to specialist, unscheduled visit to ER/clinic, and admittance to hospital. As ROS1+ NSCLC patients are routinely managed, unexpected HCRU events from their current TKIs may be common, and add to the overall economic burden of this condition.