Amivantamab plus chemotherapy vs chemotherapy as first-line treatment among patients with EGFR exon 20 insertion–mutated advanced non-small cell lung cancer (NSCLC): PAPILLON Chinese subgroup analysis.

8606 Background: Amivantamab (Ami) is a bispecific antibody targeting EGFR and MET tyrosine kinase receptors with immune cell-directing activity. The phase 3 PAPILLON study (NCT04538664) investigated the combination of Ami and carboplatin/pemetrexed (ACP) vs. carboplatin/pemetrexed (CP) as first-line treatment in patients (pts) with advanced EGFR Exon20ins-mutated NSCLC. ACP improved progression free survival (PFS) in both the overall population and Asian subgroup. Methods: Pts were randomized 1:1 to ACP or CP. The primary endpoint was PFS by blinded independent central review (BICR) and key secondary endpoints included objective response rate (ORR), PFS after first subsequent therapy (PFS2), overall survival (OS), and safety. Crossover to Ami monotherapy was allowed for pts in CP arm following disease progression. Results: Among the 308 pts enrolled, 87 were Chinese, with 39 receiving ACP and 48 receiving CP. Median age was 57/57 years, 46%/63% were female, and 15%/25% history of brain metastases for pts in ACP/CP arms. Baseline characteristics were generally balanced between arms. After a median follow-up of 16.4 months (mo), median PFS was 12.3 mo (95% CI: 7.00, NE) in ACP arm compared with 6.7 mo (95% CI: 4.21, 8.57) in CP arm (hazard ratio HR, 0.47; 95% CI, 0.26-0.85; P = 0.011) (Table). ORR was 71.8% (95% CI, 55.1%-85.0%) for ACP, and 48.9% (95% CI, 34.1%–63.9%) for CP (odds ratio, 2.46; 95% CI, 1.01-5.98; P = 0.048). Median PFS2 was not estimable (NE) for ACP vs 18.8 mo for CP (HR, 0.32; 95% CI, 0.11-0.88; P = 0.021). Interim OS showed a favorable trend for ACP vs CP (HR, 0.58; 95% CI: 0.17-2.02; P = 0.387) despite crossover among CP-randomized pts (n = 24, 50%) who had progressed. Most common AEs (all grades) ( > 50%) in ACP arm were rash, paronychia, hypoalbuminemia, neutropenia, anemia, leukopenia and thrombocytopenia which were consistent with the known safety profile of the individual agents. Notably, no pts had discontinuation of Ami due to an AE. Conclusions: ACP demonstrated superior PFS compared to CP in Chinese pts. The safety profile was manageable and tolerable. These findings in Chinese subgroup were consistent with those of overall population and Asian subgroup. Clinical trial information: NCT04538664 . Table: see text