semustine

Semustine is a small molecule alkylating nitrosourea compound used as a chemotherapy agent. It is structurally similar to lomustine but distinguished by an additional methyl group[9][5]. Semustine acts as an alkylating agent that forms covalent linkages with nucleophilic centers in DNA, leading to depurination, base-pair miscoding, strand scission, and DNA-DNA cross-linking. This results in cytotoxicity and inhibition of DNA replication in rapidly dividing tumor cells[1][5][4]. Due to its lipophilicity, semustine can cross the blood-brain barrier and has been primarily used for the treatment of brain tumors (including gliomas), colorectal cancer (including colon and rectal cancer), lymphomas, stomach cancer (gastric carcinoma), and malignant melanoma[1][2][6][10]. It is typically administered orally once every 28 days at a dose of 150 mg/m²/day[1], though intravenous administration has also been reported. Semustine's use has declined due to concerns about delayed toxicities such as nephrotoxicity and rare cases of therapy-related acute leukemia[10][5].

Brand names

MeCCNU

Other names

methyl-CCNU1-(2-chloroethyl)-3-(trans-4-methylcyclohexyl)-1-nitrosourea