DEOXYCOFORMYCIN INDUCES LONG-LASTING REMISSIONS IN HAIRY-CELL LEUKEMIA - CLINICAL AND BIOLOGICAL RESULTS OF 2 DIFFERENT REGIMENS

The use of alpha interferon (alpha IFN) and, more recently, of the purine analogues deoxycoformycin (dCF) and 2-chlorodeoxyadenosine (2-CdA) has dramatically improved the prognosis of patients affected by hairy cell leukemia (HCL). DCF has been shown to induce an higher and more durable response rate than IFN, with only moderate myelosuppression and relatively few side effects. In this paper, we report our experience with dCF in a series of 38 HCL patients who had progression of their disease after IFN therapy. Serum interleukin-1 beta (IL-I beta), soluble interleukin-2 receptors (sIl-2R) and Tumor Necrosis Factor alpha (TNF alpha) levels were also evaluated before, both during and after treatment in order to monitor clinical response. Two schedules of treatment were employed: 23 patients were treated with the EORTC protocol and the following 15 with the NCI regimen. The overall response rate was 94.7%; no significant differences in response rates were observed between the two schedules. In respect to toxicity, we recorded nausea and in two cases a cutaneous rash. Four patients experienced localized herpes tester and one had a fungal pneumonia. Median overall survival after therapy is 38.5 months, 55 percent of patients enrolled in the EORTC schedule and 77% of those who received the NCI program are currently in CCR at 3 years. Serum IL-1 beta and sIL-2R levels significantly decreased after treatment, while no significant changes in serum TNF alpha levels were observed. In our study, dCF was confirmed as an effective agent in KCL, inducing an high response rate with only moderate side effects. Evaluation of serum cytokines such as Il-1b and sIl-2R may be useful to evaluate tumour burden.