About InVivoMAb anti-human/mouse amphiregulin (AREG) The AR37 monoclonal antibody reacts with human and mouse amphiregulin (AREG), a member of the epidermal growth factor (EGF) family. AREG shows constitutive expression in many epithelial and mesenchymal cell types during developmental stages as well as homeostasis. AREG is also expressed by some leukocyte populations, such as mast cells, basophils, ILC2 cells, and a subset of tissue-resident CD4+ Tregs. After translation, the transmembrane AREG pro-protein is cleaved by TACE/ADAM17 protease to release the active, soluble form of AREG that acts as a ligand of the EGF receptor (EGFR). AREG's interaction with EGFR induces EGFR phosphorylation (stimulatory effects), and this AREG-EGFR signaling is involved in cell proliferation, migration, and differentiation. In preclinical studies, the anti-AREG antibodies, including AR37, are reported to offer prolonged survival and reduction in the growth of AREG-expressing ovarian, breast, and prostate cancer models. The AR37 antibody specifically targets the extracellular EGF domain and neutralizes AREG-mediated EGFR phosphorylation and downstream signaling. The AR37 antibody shows very weak binding affinity to human HB-EGF (~100-fold lower vs. human AREG), but it does not show any cross-reactivity with other EGF-like factors, including EGF, epiregulin (EREG), TGF alpha, epigen, and NRG1. InVivoMAb anti-human/mouse amphiregulin (AREG) Specifications IsotypeMouse IgG1, λ Recommended Isotype Control(s)InVivoMAb polyclonal mouse IgG Recommended Dilution BufferInVivoPure pH 7.0 Dilution Buffer ImmunogenHuman amphiregulin Reported Applicationsin vivo blocking of amphiregulin (AREG) in vitro blocking of amphiregulin (AREG) Immunofluorescence Western blot ELISA FormulationPBS, pH 7.0 Contains no stabilizers or preservatives Endotoxin<2EU/mg (<0.002EU/μg) Determined by LAL gel clotting assay Purity>95% Determined by SDS-PAGE Sterility0.2 μm filtered ProductionPurified from cell culture supernatant in an animal-free facility PurificationProtein G Molecular Weight150 kDa StorageThe antibody solution should be stored at the stock concentration at 4°C. Do not freeze. Application ReferencesInVivoMAb anti-human/mouse amphiregulin (AREG) (CLONE: AR37)Rivera-Soto R, Henley B, Pulgar MA, Lehman SL, Gupta H, Perez-Vale KZ, Weindorfer M, Vijayaraghavan S, Yao TS, Laquerre S, Moores SL (2024). "Amivantamab efficacy in wild-type EGFR NSCLC tumors correlates with levels of ligand expression" NPJ Precis Oncol 8(1):192. PubMedAmivantamab is an FDA-approved bispecific antibody targeting EGF and Met receptors, with clinical activity against EGFR mutant non-small cell lung cancer (NSCLC). Amivantamab efficacy has been demonstrated to be linked to three mechanisms of action (MOA): immune cell-mediated killing, receptor internalization and degradation, and inhibition of ligand binding to both EGFR and Met receptors. Among the EGFR ligands, we demonstrated that amphiregulin (AREG) is highly expressed in wild-type (WT) EGFR (EGFRWT) NSCLC primary tumors, with significantly higher circulating protein levels in NSCLC patients than in healthy volunteers. Treatment of AREG-stimulated EGFRWT cells/tumors with amivantamab or with an AREG-targeting antibody inhibited ligand-induced signaling and cell/tumor proliferation/growth. Across 11 EGFRWT NSCLC patient-derived xenograft models, amivantamab efficacy correlated with AREG RNA levels. Interestingly, in these models, amivantamab anti-tumor activity was independent of Fc engagement with immune cells, suggesting that, in this context, the ligand-blocking function is sufficient for amivantamab maximal efficacy. Finally, we demonstrated that in lung adenocarcinoma patients, high expression of AREG and EGFR mutations were mutually exclusive. In conclusion, these data 1) highlight EGFR ligand AREG as a driver of tumor growth in some EGFRWT NSCLC models, 2) illustrate the preclinical efficacy of amivantamab in ligand-driven EGFRWT NSCLC, and 3) identify AREG as a potential predictive biomarker for amivantamab activity in EGFRWT NSCLC.Lindzen M, Ghosh S, Noronha A, Drago D, Nataraj NB, Leitner O, Carvalho S, Zmora E, Sapoznik S, Shany KB, Levanon K, Aderka D, Ramírez BS, Dahlhoff M, McNeish I, Yarden Y (2021). "Targeting autocrine amphiregulin robustly and reproducibly inhibits ovarian cancer in a syngeneic model: roles for wildtype p53" Oncogene 40(21):3665-3679. PubMedOvarian cancer (OvCA) remains one of the most devastating malignancies, but treatment options are still limited. We report that amphiregulin (AREG) can serve as an effective and safe pharmacological target in a syngeneic murine model. AREG is highly abundant in abdominal fluids of patients with advanced OvCa. In immunocompetent animals, depletion or overexpression of AREG respectively prolonged or shortened animal survival. A new antibody we generated in AREG-knockout mice recognized murine AREG and reproducibly prolonged animal survival in the syngeneic model. The underlying mechanism likely involves binding of wildtype p53 to AREG's promoter and autocrine activation of the epidermal growth factor receptor (EGFR), a step blocked by the antibody. Accordingly, depletion of p53 downregulated AREG secretion and conferred tolerance, whereas blocking an adaptive process involving CXCL1, which transactivates EGFR, might increase therapeutic efficacy. Consistent with these observations, analysis of OvCa patients revealed that high AREG correlates with poor prognosis of patients expressing wildtype TP53. In conclusion, clinical tests of the novel antibody are warranted; high AREG, normal TP53, and reduced CXCL1 activity might identify patients with OvCa who may derive therapeutic benefit.
