Pentostatin (2′-Deoxycoformycin, Nipent ® ): A Structural Analogue of the Purine Adenosine Acting as Potent Adenosine Deaminase Inhibitor

Pentostatin, a structural analogue of the purine adenosine, is acting as a potent inhibitor of adenosine deaminase. It has been studied in the treatment of various lymphoproliferative disorders and proved to be very effective in the treatment of hairy-cell leukemia achieving complete remissions in up to 93%, complete or partial remissions in 63 to 100% of patients. Furthermore, pentostatin has shown activity in treating chronic lymphocytic leukemia, prolymphocytic leukemia, adult T cell leuke-mia/lymphoma and especially cutaneous T cell lymphoma refractory to conventional chemotherapy. Randomized clinical studies show that in the treatment of hairy-cell leukemia pentostatin achieves a faster response, significantly higher response rates and longer duration of remissions than interferon-α. Nevertheless it remains uncertain if patients with complete remission have finally been cured. Since pentostatin does produce a substantial response in a highly practicable therapy with low toxicity it should be applied as standard first-line treatment of hairy-cell leukemia.