656P Real-world (RW) frontline (1L) treatments (Txs) in patients (Pts) with advanced non-small-cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EFGR) exon 20 insertions (exon20ins) and adjusted comparisons versus PAPILLON study

In this retrospective, observational study, routinely collected data from 2010 to 2023 were pooled from 4 databases (NCRAS England, ESME France, and COTA, Concert AI US). Pts aged ≥ 18 years with locally advanced/metastatic NSCLC, without prior systemic tx, with ECOG PS 0-1 (when available), and confirmed exon20ins were included. Objectives were to describe 1L tx patterns and outcomes, and compare time to next tx (TTNT; as a proxy for progression-free survival) and overall survival (OS) of amivantamab + CP (from PAPILLON) vs RW tx options (alternatives to platinum (P)-based chemotherapy) using inverse probability weighting of the average tx effect in the treated (IPW-ATT) adjustment for potential confounders.

A total of 232 RW pts were included in the analysis. Median follow-up was 50.5 months; 65.5% of pts were female, 57.8% were aged > 65 years, 40.5% reported a history of smoking, 40.1% had ≥ 3 metastasis locations, 21.6% had liver metastases (mets), and 30.2% had brain mets. Observed 1L txs were: P-based chemotherapies (31.5%), P + immunotherapy (IO) (24.1%), EGFR TKI alone (15.5%), IO alone (9.1%), or other txs (19.8%). Amivantamab + CP demonstrated better comparative effectiveness (TTNT and OS) vs RW txs other than P-based chemotherapy (Table).

In RW practice, P-based chemotherapies were the most commonly used 1L tx in NSCLC pts with EGFR exon20ins. 1L amivantamab + CP demonstrated superior effectiveness vs other commonly used RW txs