High response rates with short infusional 2‐chlorodeoxyadenosine in de novo and relapsed low‐grade lymphoma

Thirty-five patients (eight de novo, 27 relapsed disease) with low-grade non-Hodgkin's lymphoma (diffuse small lymphocytic, follicular small cleaved cell, follicular mixed cell, and lymphoplasmacytoid) were treated with 2-chlorodeoxyadenosine (2CdA) at a daily dose of 0.14 mg/kg for 5d (2 h infusion) for an average of three cycles. Minor treatment delays, generally due to haematological toxicities, occurred in nine of 105 cycles. Major toxicities were lymphopenia, neutropenia and thrombocytopenia. Opportunistic infections occurred in seven patients. Overall response rate was 69% (five complete, 19 partial) reaching 88% for de novo patients (two complete, five partial). Elevated beta 2-microglobulin level was negatively predictive of response (P = 0.0014). Eight of 24 responders relapsed, with a median follow-up of 13 months. 2CdA administered as an intermittent infusion shows considerable single-agent activity in low-grade lymphomas achieving high response rates of prolonged duration. Consideration of schedules where 2CdA is alternatively administered with combination chemotherapy appears warranted.