Science Magazine Feature (May 8): iRGD Tumor-Penetrating Peptide Could Reshape Cancer Drug Delivery if Safety and Efficacy Pan Out
A Science magazine feature published May 8 highlighted iRGD — a 9-amino-acid tumor-penetrating peptide originally identified by Erkki Ruoslahti's group at Sanford Burnham Prebys — as a candidate to improve delivery of cancer chemotherapy and immunotherapy into solid tumors. iRGD binds α-v integrins overexpressed on tumor vasculature, then is proteolytically processed to expose a cryptic CendR motif that engages neuropilin-1 and triggers a transient tumor-vascular permeability burst. Co-administered with chemotherapy, iRGD increases drug penetration into the tumor without covalent conjugation. Early clinical studies in pancreatic cancer combining iRGD with nab-paclitaxel and gemcitabine showed improved tumor response and progression-free survival; later-stage development continues through DrugCendR (the Ruoslahti lab spinout) and academic-industrial partnerships. The Science piece frames iRGD as a complementary technology to antibody-drug conjugates and peptide-drug conjugates — a co-administered delivery enhancer rather than a covalent payload carrier.