Pentostatin. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in lymphoproliferative disorders.

Pentostatin, a potent inhibitor of adenosine deaminase, is an antineoplastic agent which has been studied in the treatment of a variety of lymphoproliferative disorders. It is particularly effective in the treatment of hairy cell leukaemia, achieving complete remissions in 33 to 92% of patients, and has useful activity in treating B cell chronic lymphocytic leukaemia, prolymphocytic leukaemia, adult T cell leukaemia/lymphoma and cutaneous T cell lymphoma refractory to conventional chemotherapy. Initial results suggest that in the treatment of hairy cell leukaemia pentostatin achieves a more rapid response and higher frequency of complete remission with longer duration than interferon-alpha 2a, although it is still not known if some patients experiencing complete remission have been cured. The drug has yet to be directly compared with other promising purine analogues such as cladribine and fludarabine, and results of such comparisons are required before the ultimate role of pentostatin in the treatment of hairy cell leukaemia can be clearly established. However, pentostatin does produce a substantial response in a difficult therapeutic area and should be considered for initial treatment of hairy cell leukaemia.