An update: 12-year follow-up of patients with hairy cell leukemia following treatment with 2-chlorodeoxyadenosine

Abstract

Long-term results of both pretreated and previously untreated patients (pts) with hairy cell leukemia (HCL) using uniformly a single 7-day course of 2-chlorodeoxyadenosine (2-CdA) by continuous infusion are reported. In addition, the probability of obtaining another response with this drug in pts who relapsed after 2-CdA treatment will be addressed. A total of 44 consecutive pts (34 males, 10 females) with a median age of 57 years (range 33-77) at the time of initiation of 2-CdA treatment were analyzed. In all, 11 pts were pretreated with either splenectomy (n ¼ 6), interferon a (n ¼ 9) or deoxycoformycin (dCF) (n ¼ 3) or all procedures in sequence. Two pts treated with dCF did not respond to dCF, but only 2-CdA. The median time to the start of 2-CdA treatment of the 11 pretreated pts was 47 months (mo) (10-160). Out of 44, 43 (98%) achieved complete response (CR) (13 pts with residual disease-RD), one pt reached a good partial response with a single cycle of 2-CdA. Out of 44 pts, 13 had no nonhematologic toxicities at all. Toxicities (WHO grade I-IV) were mainly of grade I and II, in one pt grade IV infectious complication. Bone marrow biopsies were performed at the time of recovery of hematopoiesis, thereafter at 2-3 mo intervals, thereafter at 6 mo, and finally annually in 35 pts. The median follow-up is 8.5 years (0.1-12.2). Disease-free survival from the start of 2-CdA treatment is 36% at 12 years (median 8.4 years), 17/44 pts relapsed. Nine of these pts were treated with 2-CdA again, eight achieved a second CR (median 2.5 yrs), one pt did not respond. Eight of our cohort had a second malignancy before receiving 2-CdA. Six pts died in CR due to the second malignancy. The overall survival at 12 years after the start of 2-CdA treatment is 79%. 2-CdA is a safe and effective treatment of HCL inducing complete remissions in the majority of pts with only a single cycle of 2-CdA, and a paucity of toxicities. Responses are durable and long-lasting. Pts who relapsed following treatment with 2-CdA responded to subsequent retreatment with 2-CdA.

My Treatment Approach to Hairy Cell Leukemia

“…At the University of Munich, extended results were reported by Jehn et al 16 in 44 patients with a median follow-up of 8.5 years. All except 1 individual (98%) achieved a CR, defined as normalized peripheral blood cell counts, no morphologic evidence of HCL in the bone marrow, and lack of measurable disease.…”

Clinical characteristics and long-term outcome of young hairy cell leukemia patients treated with cladribine: a single-institution series

“…[14][15][16][17] Northwestern University has reported similar outcomes, with an OS rate of 87% at 12 years in HCL patients receiving a single course of cladribine. 17 In this report, 88 HCL patients were #40 years of age at diagnosis, with a median age of 36 years.…”

Hairy cell leukemia

“…8,[11][12][13][14]16,[18][19][20] After relapse, treatment with an additional course of purine analogues is recommended. It is acceptable to repeat the same treatment that was given initially, although changing to a different purine analogue will yield the same results.…”

“…5,6 Treatment with 2-chlorodeoxyadenosine or 2 0 -deoxycoformycin resulted in 80% to 90% CR, with a relapse rate of 25% to 30% at 3-to 5-year follow-up. 7 In past years, several reports [8][9][10][11][12][13][14] of long-term follow-up studies with a single purine analogue have confirmed that the overall CR rates are very similar, ranging from 76% to 98%, and the relapse rates are equally comparable, showing that about 30% to 40% of patients would relapse after 5 to 10 years of follow-up. These reports indicate that both purine analogues are highly effective and lead to excellent overall survival; however, it appears that neither purine analogue is likely curative, because molecular studies suggest that all patients have evidence of minimal residual disease while in CR.…”