Semustine (MeCCNU, DB13647): A Comprehensive Pharmacological and Clinical Review

1. Introduction and Overview

1.1. Identification and Nomenclature

Semustine, an investigational antineoplastic agent, is widely recognized by its common abbreviation MeCCNU, which stands for Methyl-CCNU.[1] Its formal DrugBank accession number is DB13647.[3] The primary Chemical Abstracts Service (CAS) Registry Number assigned to Semustine is 13909-09-6.[3] Other CAS numbers, such as 33073-59-5 and 33185-87-4, have also been associated with the substance, potentially referring to different salt forms or isomers, though Semustine itself is typically handled as the free base.[3] It is classified pharmacologically as a small molecule drug [User Query]. Throughout its research and development, Semustine has been identified by various synonyms and codes, including Methyl-CCNU, Me-CCNU, and the National Cancer Institute (NCI) designation NSC 95441.[3]

1.2. Drug Class and Chemical Family

Semustine is a member of the nitrosourea class of alkylating agents.[1] This chemical family is characterized by its potent cytotoxic properties, primarily mediated through the alkylation of DNA, and a notable physicochemical property that allows many of its members, including Semustine, to penetrate the blood-brain barrier.[1] Chemically, Semustine is an organochlorine compound and is specifically categorized as an N-nitrosourea.[1] Its structure reveals it to be a 4-methyl derivative of lomustine (CCNU) and a methylated derivative of carmustine (BCNU), two other well-known nitrosourea anticancer drugs.[1]

1.3. Historical Context and Development