Abstract 5651: JNJ-61186372, an Fc enhanced EGFR/cMet bispecific antibody, mediates EGFR and cMet downmodulation and therapeutic efficacy preclinically through monocyte / macrophage mediated trogocytosis

Small molecule inhibitors targeting EGFR are now standard of care in NSCLC patients harboring EGFR mutations, but acquired resistance invariably develops through secondary mutations within EGFR and/or through activation of compensatory pathways such as cMet. JNJ-61186372 (JNJ-372) is an anti-EGFR and cMet bispecific antibody with enhanced binding to immune cell Fcγ receptors, designed to target tumors with activated EGFR and cMet signaling through a distinct mechanism of action. Ongoing first-in-human study in patients with advanced, treatment refractory EGFR mutant NSCLC revealed JNJ-372 to have clinical activity in patients with diverse EGFR-mutated NSCLC, including Exon 20 mutations, TKI resistance mutations (T790M, C797S), and resistance due to MET amplification. However preclinically, despite potent anti-tumor activity in NSCLC xenograft models, only modest anti-proliferative effects were observed with JNJ-372 in cell lines in vitro. Interestingly, the addition of isolated human immune cells (PBMCs) to the in vitro assays enhanced JNJ-372-mediated EGFR and cMet downregulation, and dose-dependent tumor cell killing. Through depletion or enrichment of individual immune cell types, we demonstrated that monocytes and/or macrophages are necessary for JNJ-372 Fc interaction-mediated EGFR/cMet downmodulation. Depletion of macrophages in mice showed that they are required for JNJ-372 anti-tumor efficacy. Finally, we showed that the down-modulation of EGFR and cMet receptors occurs through monocyte or macrophage-mediated trogocytosis. Collectively, these results demonstrate a novel Fc-dependent mechanism of action for JNJ-372 and support its continued clinical development in patients with aberrant EGFR and cMet signaling. Citation Format: Smruthi Vijayaraghavan, Lorraine Lipfert, Barbara Bushey, Kristen Chevalier, Benjamin Henley, Ryan Lenhart, Marilda Beqiri, Hillary J. Millar, Kathryn Packman, Matthew V. Lorenzi, Sylvie Laquerre, Sheri Moores. JNJ-61186372, an Fc enhanced EGFR/cMet bispecific antibody, mediates EGFR and cMet downmodulation and therapeutic efficacy preclinically through monocyte / macrophage mediated trogocytosis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5651.