Temozolamide – (Brand name Temodar, Temodal and Temcad) An agent that alkylates DNA, most often at the N-7 or O-6 positions of guanine residues. This leads ot terminal DNA damage in targeted cancer cells. Its injury can be repaired in some tumor cells that possess the enzyme O-6-methylguanine-DNA methyltransferase (MGMT) or O-6-alkylguanine-DNA alkyltransferase (AGT or AGAT). Increasingly tuors are being screened for these enzymes as their presence predicts non-response to temozolomide.