Duocarmycin SA is an orally active antitumor antibiotic with an IC50 of 10 pM[1]. Duocarmycin SA is an extremely potent cytotoxic agent capable of inducing a sequence-selective alkylation of duplex DNA. Duocarmycin SA demonstrates synergistic cytotoxicity against glioblastoma multiforme (GBM) cells treated with proton radiation in vitro[2].