Trabectedin D3 (Ecteinascidin 743 D3) is deuterium labeled Trabectedin. Trabectedin is a tetrahydroisoquinoline alkaloid with potent antitumor activity. Trabectedin binds to the minor groove of DNA, blocks transcription of stress-induced proteins, induces DNA backbone cleavage and cancer cells apoptosis, and increases the generation of ROS in MCF-7 and MDA-MB-453 cells. Trabectedin has tje potential for soft tissue sarcoma and ovarian cancer treatment[2].