Cladribine is a drug commonly used to treat hairy cell leukemia (leukemic reticuloendotheliosis). Its brand name is Leustatin, and it's commonly referred to as 2CDA. A purine analog, it's a synthetic antineoplastic agent with immunosuppressive effects. Chemically, it mimics the nucleoside adenosine and thus inhibits the enzyme adenosine deaminase, which interferes with the cell's ability to process DNA. It is easily destroyed by normal cells in the body except for blood cells, with the result t… (More on Cladribine)