Epidermal Growth Factor Receptor Inhibitors in Glioblastoma: Current Status and Future Possibilities

Victor Ramboiu^*
*Correspondence: Victor Ramboiu, Department of Molecular Medicine, University of Aarhus, Aarhus, Denmark, Email:

Introduction

Glioblastoma is a devastating brain tumor associated with poor prognosis despite aggressive treatment approaches, including surgery, radiation, and chemotherapy. The limited efficacy of conventional therapies underscores the urgent need for novel therapeutic strategies. Over the past few decades, targeted therapies have gained considerable attention in the management of GBM, with the Epidermal Growth Factor Receptor (EGFR) signaling pathway being one of the most extensively studied targets. The Epidermal Growth Factor Receptor (EGFR) signaling pathway has been a major focus of research in glioblastoma. EGFR is a cell surface receptor involved in regulating cell growth and division, and aberrant activation of EGFR signaling is common in glioblastoma. Mutations, amplifications, and overexpression of EGFR have been observed in a significant proportion of glioblastoma cases, making it an attractive target for therapy. Several approaches have been explored to target EGFR in glioblastoma, including small molecule inhibitors and monoclonal antibodies. Small molecule inhibitors, such as erlotinib and gefitinib, target the intracellular tyrosine kinase domain of EGFR, inhibiting its activity and downstream signaling pathways. Monoclonal antibodies, such as cetuximab and panitumumab, bind to the extracellular domain of EGFR, blocking ligand binding and receptor activation [1].

Description

EGFR is a transmembrane receptor tyrosine kinase that plays a critical role in regulating cell proliferation, survival, migration, and angiogenesis. Aberrant activation of EGFR signaling, often through gene amplification, mutation, or overexpression, is a common molecular alteration in GBM, contributing to tumor growth and therapy resistance. The most frequently observed EGFR alteration in GBM is the deletion of exons 2-7, resulting in the constitutively active EGFRvIII variant [2]. Several EGFR inhibitors have been developed for the treatment of GBM, including small molecule Tyrosine Kinase Inhibitors (TKIs) and Monoclonal Antibodies (mAbs). TKIs such as erlotinib, gefitinib, and lapatinib target the intracellular kinase domain of EGFR, blocking downstream signaling pathways. Monoclonal antibodies like cetuximab and nimotuzumab bind to the extracellular domain of EGFR, preventing ligand binding and receptor activation. Despite promising preclinical data, clinical trials evaluating EGFR inhibitors as monotherapy in GBM have shown limited efficacy. The heterogeneity of GBM, intrinsic and acquired resistance mechanisms, and the blood-brain barrier pose significant challenges to the success of EGFRtargeted therapies [3].

However, combination approaches incorporating EGFR inhibitors with other agents, such as chemotherapy, radiotherapy, and immunotherapy, have demonstrated improved outcomes in preclinical models and early-phase clinical trials. Overcoming resistance to EGFR inhibitors remains a major obstacle in GBM treatment. Strategies to enhance drug delivery across the c, identify predictive biomarkers of response, and circumvent compensatory signaling pathways are actively being investigated. Furthermore, novel EGFRtargeted agents, including antibody-drug conjugates, bispecific antibodies, and immune checkpoint inhibitors, hold promise for improving therapeutic efficacy and patient outcomes [4,5].