**6.2 Purine nucleoside analogous: (fludarabin, deoxycoformycin, 2-chlorodeoxy-adenosine)**

Are unique drugs that are effective in low grade lymphomas and chronic lymphatic leukemia.

Fludarabine is active and useful in patients resist to chlorambucil and in newly diagnosed CLL. The alternative use of CVP (Cyclophosphamide, Vincristine and Prednisone). In addition fludarabine and cladribine in treatment of CLL, the combination of rituximab against CD20 and alemtuzumab against CD52, has an acceptable safety profile, and has clinical activity with a short course in patients with refractory or relapsed to chemotherapy.
