Amivantamab Compared with Real-World Physician’s Choice after Platinum-Based Therapy from a Pan-European Chart Review of Patients with Lung Cancer and Activating EGFR Exon 20 Insertion Mutations

SIMPLE SUMMARY: Patients with advanced non-small cell lung cancer (NSCLC) with epidermal growth factor receptor gene (EGFR) Exon 20 insertion mutations (Exon20ins) used to have poor outcomes after the failure of platinum-based therapies. Amivantamab, a drug that targets two proteins involved in NSCLC (EGFR/MET), was developed and studied in the CHRYSALIS clinical trial. This paper summarizes an analysis comparing outcomes for amivantamab from CHRYSALIS to the outcomes for a mix of treatments that were used in real-world clinical practice (real-world physician’s choice [RWPC]). RWPC data were collected from hospitals across Europe in the CATERPILLAR real-world evidence (RWE) study. The outcomes of 114 patients from CHRYSALIS were compared to 55 lines of treatment (LOTs) from CATERPILLAR-RWE, accounting for differences in patient characteristics between the two populations. Overall, the results show that amivantamab was at least twice as good as RWPC for platinum pre-treated patients in terms of tumor response and survival rates. ABSTRACT: Patients with advanced non-small cell lung cancer (NSCLC) with epidermal growth factor receptor gene (EGFR) Exon 20 insertions (Exon20ins) at the second line and beyond (2L+) have an unmet need for new treatment. Amivantamab, a bispecific EGFR- and MET-targeted antibody, demonstrated efficacy in this setting in the phase 1b, open-label CHRYSALIS trial (NCT02609776). The primary objective was to compare the efficacy of amivantamab to the choices made by real-world physicians (RWPC) using an external control cohort from the real-world evidence (RWE) chart review study, CATERPILLAR-RWE. Adjustment was conducted to address differences in prognostic variables between cohorts using inverse probability weighting (IPW) and covariate adjustments based on multivariable regression. In total, 114 patients from CHRYSALIS were compared for 55 lines of therapy from CATERPILLAR-RWE. Baseline characteristics were comparable between the amivantamab and IPW-weighted RWPC cohorts. For amivantamab versus RWPC using IPW adjustment, the response rate ratio for the overall response was 2.14 (p = 0.0181), and the progression-free survival (PFS), time-to-next-treatment (TTNT) and overall survival (OS) hazard ratios (HRs) were 0.42 (p < 0.0001), 0.47 (p = 0.0063) and 0.48 (p = 0.0207), respectively. These analyses provide evidence of clinical and statistical benefits across multiple outcomes and adjustment methods, of amivantamab in platinum pre-treated patients with advanced NSCLC harboring EGFR Exon20ins. These results confirm earlier comparisons versus pooled national registry data.