Randomized Comparison of Weekly Administration and Daily Courses of Cladribine in Patients with Hairy Cell Leukemia - Updated Results.

Cladribine is the drug of choice in the treatment of hairy cell leukemia (HCL). However, its optimal method of administration is still unknown. There are suggestions that weekly administration is less toxic than daily schedule. We, therefore, compared these two methods of 2-CdA administration in a prospective randomized study. One group was treated with 2-CdA 0.12 mg/kg/d in 2 h i.v. infusion for 5 consecutive days and the second group received the same doses once a week for six weeks. Inclusion and response criteria were those recommended by Grever et al (J. Clin. Oncol 1995, 13, 974). From January 1998 to December 2003 118 patients with previously untreated symptomatic HCL were included into the study.

Both complete response (CR) and overall response (OR) rates are similar in compared groups. Response duration has not reached median yet. There is no statistically significant difference in toxicity between groups except for thrombocytopenia. It seems, however, that daily administration of 2-CdA may more frequently induce neutropenia and lead to more frequent infections.

In conclusion, the updated results of our study suggest that weekly administration of cladribine in HCL may be equally effective but less toxic than daily courses.