OBJECTIVES: To estimate the costs of grade 3/4 adverse events (AEs) related to amivantamab or mobocertinib among patients with non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor exon 20 insertion mutation with disease progression despite prior platinum-based chemotherapy, from a Commercial or Medicare payer perspective.

METHODS: Grade 3/4 AEs including laboratory abnormalities (anemia, lymphopenia, thrombocytopenia, hypoalbuminemia, hypophosphatemia and hypokalemia) and clinical symptoms (diarrhea, fatigue, infusion-related reaction and nausea) occurring with either treatment were identified from prescribing information. A specialist visit cost was applied to nausea, fatigue, hypoalbuminemia, hypophosphatemia or hypokalemia; inpatient management costs were applied to other AEs. Specialist costs were identified from InHealth Physicians’ Fee and Coding Guide (Commercial patients) and the Centers for Medicare & Medicaid Services Physician Fee schedule (Medicare patients). Inpatient costs from the Healthcare Cost and Utilization Project 2018 data using diagnosis-related group codes were inflated to 2021 USD using the Consumer Price Index for Medical Care. AEs were assumed to occur once during treatment. The cost per event was multiplied with the rate of each event to derive the AE cost for each treatment.

RESULTS: Incidence of anemia (3.5%), lymphopenia (15%), thrombocytopenia (0.9%), diarrhea (22%), fatigue (3.5%) and nausea (4.4%) were more common with mobocertinib treatment, whereas hypoalbuminemia (8%), hypophosphatemia (8%), hypokalemia (6%), and infusion-related reactions (3.1%) were more common with amivantamab treatment. The estimated total AE management cost per patient treatment course was $1,712 for amivantamab and $4,158 for mobocertinib from the Commercial perspective, and $1,717 for amivantamab and $4,397 for mobocertinib from the Medicare perspective.

CONCLUSIONS: Costs of Grade 3/4 AE management were estimated to be lower for amivantamab than for mobocertinib. Higher costs associated with mobocertinib were due to higher inpatient management cost per each event of anemia, diarrhea, lymphopenia, and thrombocytopenia.