Abstract Glioblastoma multiforme (GBM) represents a significant challenge in adult brain tumor management, characterized by its aggressive nature and poor prognosis despite multimodal therapies. Current standard chemotherapy, Temozolomide (TMZ), offers limited survival benefits. In a recent breakthrough, the cyclic peptide cyclo-((2-Nal)-Leu-Ser-(2-Nal)-Arg) acetate (c2), initially developed for prostate cancer, demonstrates remarkable promise against GBM. By selectively inhibiting the inflammatory phospholipase enzyme sPLA2IIA, c2 significantly impedes GBM cell proliferation, surpassing TMZ efficacy in multiple resistant cell lines. Moreover, c2 exhibits potential to inhibit tumor growth and metastasis, confirmed in 3D tumoroid and wound healing assays. Mechanistic insights reveal modulation of crucial cellular pathways, including viral entry, cytoskeletal structure, and signaling cascades. Preclinical investigations demonstrate c2’s ability to penetrate the blood-brain barrier and attenuate tumor progression markers. At multiple levels, c2 is shown to target inhibition of ERBB2 and EGFR signalling and also have impacts on HIF1-NF-kB axis. This study proposes c2 as a potent anti-GBM candidate, warranting evaluations for its pharmacological profile, safety, and efficacy. With its potential to address the urgent need for effective GBM therapies, c2 holds promise as a significant advancement in GBM treatment, offering hope for improved patient outcomes.