Five day intermittent vs seven day continuous 2-chlorodeoxyadenosine infusion for the treatment of hairy cell...

The new purine-analogue 2-chlorodeoxyadenosine (2-CdA) has proved to induce an high CR rate and a long lasting disease free survival. In this study we compare the efficacy and toxicity of 2-CdA employed in two different schedules (A and B). Forty-one patients have been enrolled from 1994: 22 p. (group A) were treated with a single cycle of 2-CdA given as two hour i.v. infusion on 5 consecutive days (0.15 mg/kg/die); while 19 p. (group B) with continuous i.v. infusion for 7 consecutive days (0.10 mg/kg/die). Response criteria were those proposed by NCI. The Hairy Cell Index (HCI) was calculated using DBA44 MoAb. At three months, the responses in group A (19/22) were: 5 CR (26.3%), 6 GPR (31.5%), 5 PR and 3 NR.; in group B (17/19): 6 CR (35.3%), 3 GPR (17.6%), 4 PR and 4 NR. Overall response at six months was respectively 84.2% and 76.5%. At six months the responses were: in group A (18/22): 9 CR (50%), 4 GPR (22.2%), 3 PR, 2 NR; in group B (16/19): 4 CR (25%), 6 GPR (37.5%), 3 PR, 3 NR. Overall response at 6 months was respectively 88.8% (group A) and 81.2% (group B). The 5 day intermittent schedule appears efficient, well tolerated and suitable for out-patient treatment. DBA44 MoAb appears useful to better define the HCI and to distinguish CR from GPR.