PEP 44

PEP 44 is a therapeutic fusion peptide developed by Proteimax Biotechnology for the treatment of various cancers, including glioblastoma and breast cancer. It consists of a nonapeptide fragment derived from cyclin D2 (sequence: WELVVLGKL) covalently linked to a TAT-derived cell-penetrating peptide (sequence: YGRKKRRQRRR) to facilitate intracellular delivery. PEP 44 exerts its anti-tumor effects through a multi-targeted mechanism: it induces apoptosis by activating Caspase 3, Caspase 7, and Caspase 9; inhibits the phosphorylation and activity of RAC-beta serine/threonine-protein kinase (AKT2); activates p38 mitogen-activated protein kinases (specifically p38 alpha and p38 gamma); and inhibits proteasome activity. Preclinical studies have demonstrated its efficacy in reducing tumor volume in glioblastoma models and its activity against melanoma and thyroid cancer. Beyond oncology, the peptide has also shown broad-spectrum antimicrobial activity against bacteria, fungi, and parasites.