2-[(2S,5R,8S,11S)-5-benzyl-11-[3-(diaminomethylideneamino)propyl]-7-methyl-3,6,9,12,15-pentaoxo-8-propan-2-yl-1,4,7,10,13-pentazacyclopentadec-2-yl]acetic acid

Cilengitide (EMD 121974) is a molecule designed and synthesized at the Technical University Munich in collaboration with Merck KGaA in Darmstadt. It is based on the cyclic peptide cyclo(-RGDfV-), which is selective for αv integrins, which are important in angiogenesis (forming new blood vessels), and other aspects of tumor biology. Hence, it is under investigation for the treatment of glioblastoma, where it may act by inhibiting angiogenesis, and influencing tumor invasion and proliferation.
The European Medicines Agency has granted cilengitide orphan drug status.
Cilengitide seems to function by inhibiting the FAK/src/AKT pathway and inducing apoptosis in endothelial cells. Preclinical studies in mice of cilengitide were able to demonstrate efficacious tumor regression.
In a rat xenograft model, cilengitide was able to potentiate the cytotoxic effects of radiation when cilengitide was administered prior to radiation therapy. When combined with radiation, inhibition of integrin expression by cilengitide synergistically improves the cytotoxic effects of ionizing radiation for glioblastoma.