Objectives: Amivantamab and mobocertinib received accelerated approval by the US FDA in May and September 2021, respectively, for the treatment of locally advanced or metastatic non-small-cell lung cancer (mNSCLC) harboring epidermal growth factor receptor (EGFR) exon 20 insertion (ex20ins) mutations previously treated with platinum-based chemotherapy (PBC). Before May 2021, there were no approved targeted treatments for this underserved population. This study quantifies the budget impact (BI) of introducing mobocertinib in a US payer health plan.

Methods: A dynamic budget impact model based on a partitioned survival structure was developed to compare a reference scenario reflecting available options before the approval of mobocertinib including amivantamab and physician’s choice [PC] each with 50% market share vs. an alternative scenario with mobocertinib replacing PC. Treatment patterns and efficacy of PC were obtained from the US Flatiron database. The efficacy and safety of amivantamab were from the literature and for mobocertinib from the pooled patients with EGFR ex20ins mutations previously treated with PBC in study NCT02716116. Epidemiological and cost inputs were from public databases and the literature. The analysis was conducted over five years in a hypothetical health plan of 10 million members accounting for direct medical costs: drug acquisition and administration of initial and subsequent treatments, management of adverse events, routine monitoring, and terminal care.

Results: Over five years, an estimated 55 people in a health plan of 10 million members will suffer from mNSCLC harboring EGFR ex20ins mutations and would have been previously treated with PBC. Given the projected uptake of mobocertinib, the BI per member of the health plan per month (PMPM) was $0.05, at $0.01 each year. Across extensive scenario analyses the BI PMPM ranged from $0.01 to $0.06.

Conclusions: Mobocertinib treats a rare subset of patients with NSCLC and is associated with a minimal budget impact for US payers.