Pentostatin (deoxycoformycin)'s an anticancer chemotherapeutic drug. Mechanism It's classified as a purine analog, which's a type of antimetabolite. It mimics the nucleoside adenosine and thus inhibits the enzyme adenosine deaminase, interfering with the cell's ability to process DNA. Cancer cells generally divide more often than healthy cells; DNA's highly involved in cell division (mitosis) and drugs which target DNA-related processes are therefore more toxic to cancer cells than healthy cel… (More on Pentostatin)