Long term results with 2'deoxycoformycin in hairy cell leukemia.

We have treated 159 patients with hairy cell leukemia (HCL) with 2'deoxycoformycin (DCF) in a phase II study that started in 1986. 151 patients had typical HCL and 8 HCL-variant. Ages ranged from 30 to 81 years. Most patients had previously received interferon-alpha, splenectomy or both and 23 had DCF as first line; all had active disease. In the first 40 patients DCF was given at 4 mg/m2 weekly for 4 weeks and every 2 weeks thereafter and in the remainder every 2 weeks until maximal response. Three patients died early on and were non-evaluable for response. The response rates in 148 patients with typical HCL were: CR 74.3%, PR 22.3% and NR 3.4%. None of the HCL-variants achieved CR; 4 had PR and 4 NR. The median number of DCF injections to CR was 9. Lymphopenia and neutropenia were seen in 52% and 34%, respectively, but 72% of patients started treatment with low leucocyte counts. 27% had infectious complications of which 6% were life threatening. The disease free interval of the first 105 remitters (CR + PR) was 84% at 4 years with no significant difference between CR (86%) and PR (77%). There have been 12 relapses at a median time of 22 months (range 6-60 months) since stopping DCF, of these, 5 had massive abdominal lymphadenopathy, a features seen also in 4 of the 5 primary non-responders. There were 13 deaths but 7 were unrelated to HCL. The 5-year survival from starting DCF in 110 patients with typical HCL was 88% and 97% if we exclude non-HCL deaths.(ABSTRACT TRUNCATED AT 250 WORDS)