Abstract CT054: Amivantamab in wild-type advanced non-small cell lung cancer after disease progression on checkpoint inhibition and chemotherapy: Results from the phase 1b CHRYSALIS study

Abstract Background: Overexpression of EGFR and MET has been observed in wild-type (WT) adenocarcinoma and squamous non-small cell lung cancer (NSCLC; Huang L. J Thorac Oncol. 2014). Amivantamab (ami), an EGFR-MET bispecific antibody with immune cell-directing activity, demonstrated pre-clinical activity against WT tumors overexpressing EGFR and MET. We examined ami monotherapy activity in WT-NSCLC after disease progression on platinum-based chemotherapy and anti-PD-1 or PD-L1 therapy. Methods: The WT-Ad and WT-Sq cohorts of the CHRYSALIS study enrolled pateints (pts) with adenocarcinoma or squamous cell carcinoma histology, respectively, without evidence of EGFR, ALK, and MET Exon 14 skipping activating mutations. Pts received ami monotherapy at the approved dose (1050 mg; 1400 mg if ≥80 kg) weekly for the first 4 weeks and biweekly thereafter. Response was assessed by the investigator per RECIST v1.1. Plasma samples were collected pre-treatment, with ctDNA analyzed by Guardant Health (Redwood City, CA). Results: In the WT-Ad cohort, 41 pts received ami (30 with ≥1 post-baseline disease assessment; 11 discontinued due to adverse events [AEs], disease progression, or physician decision), with a median follow-up of 6.2 mo. The median age was 62 years, 63% were men, and 37% were Asian. The objective response rate (ORR) was 7% (3/41), the clinical benefit rate (CBR) was 29%, and the median duration of response (DoR) was 4.2 mo (95% CI, 4.1-not estimable [NE]). Among pts with detectable ctDNA (n=24), 9 pts had KRAS/HER2 mutations. The ORR for pts with and without KRAS/HER2 mutations was 0% (0/9) and 20% (3/15), respectively. The corresponding median PFS for pts with and without KRAS/HER2 mutations was 1.4 mo (95% CI, 1.4-NE) and 4.2 mo (95% CI, 1.6-NE), respectively. In the WT-Sq cohort, 14 pts received ami (12 with ≥1 post-baseline disease assessment; 2 discontinued), with a median follow-up of 6.3 mo. Median age in the WT-Sq cohort was 71 years, 57% were men, and 43% were Asian. ORR was 21% (3/14) with a median DoR that was NE and 2 pts with a DoR ≥6 mo. The overall CBR was 43% (6/14), median PFS was 4.0 mo (95% CI, 2.2-7.3), and median OS was NE. Most common treatment-emergent AEs in both cohorts were rash (grouped term; 66% for WT-Ad, 57% for WT-Sq) and infusion-related reactions (63% WT-Ad and 57% WT-Sq). Grade ≥3 treatment-related AEs (TRAEs) were reported in 17% of pts in the WT-Ad cohort and 21% the WT-Sq cohort. One (2%) pt in the WT-Ad cohort experienced grade 2 interstitial lung disease. Four pts in WT-Ad and 2 pts in WT-Sq cohort discontinued due to TRAEs. Conclusions: Ami demonstrated preliminary antitumor activity in pts with refractory WT squamous and adenocarcinoma NSCLC, particularly in those lacking KRAS/HER2 activating mutations. Safety profile was consistent with the previously reported monotherapy experience, and no new signals were identified. Citation Format: Byoung Chul Cho, Jonathan Goldman, Natasha Leighl, Filippo De Braud, Ki Hyeong Lee, François Ghiringhelli, Pilar Garrido, Julio Peguero, Benjamin Besse, Philippe Cassier, Nicolas Girard, Maria de Miguel, Rosa Alvarez, Alastair Greystroke, Yuichiro Ohe, Te-Chun Hsia, Joshua C. Curtin, Sanjib Chowdhury, Xuesong Lyu, Grace Gao, Siyang Qu, Patricia Lorenzini, Aastha Kapoor, Priya Kim, Mahadi Baig, Meena Thayu, Roland E. Knoblauch, Sandrine Hiret, Pascale Tomasini. Amivantamab in wild-type advanced non-small cell lung cancer after disease progression on checkpoint inhibition and chemotherapy: Results from the phase 1b CHRYSALIS study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT054.