Efficacy of Mobocertinib and Amivantamab in Patients With Advanced Non–Small Cell Lung Cancer With EGFR Exon 20 Insertions Previously Treated With Platinum-Based Chemotherapy: An Indirect Treatment Comparison

Objectives Exon 20 insertions (ex20ins) mutations of the EGFR gene account for 1-2% of all non-small cell lung cancers (NSCLC). Targeted therapies have been developed to treat this cancer type but have not been studied in head-to-head trials. Our objective was to use a matching-adjusted indirect comparison (MAIC) to assess the efficacy of mobocertinib and amivantamab in patients with NSCLC EGFR ex20ins mutations who were previously treated with platinum-based chemotherapy. Materials and Methods An unanchored MAIC was conducted to estimate the treatment effects of mobocertinib and amivantamab using individual-level data from the mobocertinib phase I/II single-arm trial (NCT02716116) and published data from the amivantamab single-arm CHRYSALIS trial (NCT02609776). Confirmed overall response rate (cORR), progression-free survival (PFS), overall survival (OS), and duration of response (DoR) were assessed. Results Both trials were comparable in terms of study population, study design, and outcome definitions and included 114 patients who received mobocertinib and 114 patients who received amivantamab. After MAIC weighting, all reported baseline characteristics were balanced between mobocertinib and amivantamab. The weighted odds ratio (OR) [95% confidence interval (CI)] comparing mobocertinib to amivantamab was 0.56 (0.30-1.04) for Independent review committee (IRC)-assessed cORR and 0.98 (0.53-1.82) for investigator (INV)-assessed cORR. The weighted hazard ratio (HR) comparing mobocertinib to amivantamab was 0.74 (0.51-1.07) for IRC-assessed PFS, 0.92 (0.57-1.48) for OS HR (95% CI), and 0.59 (0.30-1.18) for INV-assessed DoR. Conclusions MAIC analysis showed that mobocertinib and amivantamab had similar efficacy in patients with NSCLC harboring EGFR ex20ins mutations whose disease progressed during or after platinum-based chemotherapy. These findings may benefit patients by supporting future treatment options.