Effectiveness of amivantamab compared with real-world therapies in patients with non-small cell lung cancer with EGFR exon 20 insertion mutations post platinum-based chemotherapy

BACKGROUND: Amivantamab showed durable response and manageable safety in the CHRYSALIS study patients with non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) exon 20 insertion mutations (ex20ins) who progressed on prior platinum-based chemotherapy. We compared the effectiveness of amivantamab with systemic anti-cancer therapy in the real-world setting in Taiwan. METHODS: The external control (EC) group was selected from the National Taiwan University Hospital NSCLC database using CHRYSALIS eligibility criteria. Baseline variables were adjusted using propensity score for the average treatment effect on the treated. Outcomes were compared using weighted generalized estimating equations for objective response rate (ORR), and weighted Cox proportional hazards regression for progression-free survival (PFS), time to next treatment (TTNT), and overall survival (OS). Real-world treatment patterns were also summarized. RESULTS: Overall, 114 CHRYSALIS and 44 EC patients were identified. Compared to the adjusted EC group, amivantamab-treated patients had significantly improved PFS (median 6.9 vs. 2.3 months, p < 0.0001), TTNT (median 12.2 vs. 3.5 months, p < 0.0001), ORR (36.8% vs. 3.0%, p < 0.00001), and OS (median 23.1 vs. 7.5 months, p = 0.0005). In the EC group, after platinum-based therapy, non-platinum chemotherapy was the most common treatment for each line followed by tyrosine kinase inhibitors. CONCLUSION: The worse prognoses and limited treatment options for patients with advanced NSCLC harboring EGFR ex20ins from the Taiwan real-world setting indicate an urgent need for effective treatment for this population. This study showed that amivantamab, when administrated in the CHRYSALIS trial setting, represents a promising treatment option for patients compared to current real-world therapies.