2-CHLORODEOXYADENOSINE IN THE TREATMENT OF RELAPSED REFRACTORY CHRONIC LYMPHOPROLIFERATIVE DISORDERS/

2-Chlorodeoxyadenosine (2-CdA) is a purine analog with cytotoxic activ ity on both resting and cycling lymphocytes which has been used as sal vage therapy in advanced/resistant chronic lymphoproliferative disorde rs. In our study 39 patients (19 B-CLL, 5 B-PLL, 9 low-grade B-NHL, 5 CTCL and 1 high-grade T-NHL) who relapsed or became resistant after 1- 4 chemotherapy regimens were treated with 2-CdA 6 mg/m(2) per day by 2 h infusion for 5 d every 28 d. The overall clinical response rate, in cluding complete remission (CR) and partial remission (PR), was 66%. T wo of 19 (10%) B-CLL patients achieved a CR lasting 9 months, while 11 /19 B-CLL (58%) and 4/5 B-PLL (3 B-PLL/B-CLL and 1 B-PLL) (80%) achiev ed a PR. Interestingly, 5 of 6 patients who had been previously treate d with fludarabine obtained a clinical response (2 CR and 3 PR). One o f 9 (11%) low-grade B-NHL patients achieved a CR and relapsed after 26 months, and 5/9 (55%) achieved a PR. One of 5 (20%) CTCL achieved a C R lasting 32 months, while 2/5 (40%) achieved a PR. The overall mean d uration of PR was 7.4 months and no differences were observed among di fferent groups of patients. Toxicity was acceptable, as only a transie nt severe hematological impairment was observed in 20% of the patients while nonhematological toxicity was not documented. Two patients died because of bacterial pneumonia, 1 of meningitis due to Listeria and 9 from progression of the disease. In conclusion, treatment with 2-CdA in heavily pretreated patients with chronic lymphoproliferative disord ers is well tolerated and obtains high response rates, even in patient s relapsed after treatment with fludarabine.