Cord blood transplantation with a reduced-intensity conditioning regimen using fludarabine and melphalan for adult T-cell leukemia/lymphoma.

Adult T-cell leukemia/lymphoma (ATLL) is a peripheral T-cell lymphoma with a poor prognosis when treated with chemotherapy alone; therefore, allogeneic stem cell transplantation is a consideration. We attempted cord blood transplantation (CBT) using a reduced-intensity conditioning regimen without total body irradiation (non-TBI-RIC) to allow for the best possible timing of transplantation and improve survival outcomes, particularly in older patients. Forty-eight patients (27 male, 21 female) underwent CBT using fludarabine (Flu) 125 mg/m2 and melphalan (Mel) 140 mg/m2 as pre-transplant conditioning. The median age was 32 years (range 44-72), and 21 patients were in complete remission (CR) at the time of CBT. The median duration to neutrophil engraftment (NE) was 19.5 days (range 15-50), with a cumulative incidence of NE of 86.7% at day 50 after CBT. The 1- and 3-year overall survival (OS) rates were 40.4% and 37.7%, respectively. The 3-year OS rate in CR patients was 60.8%, compared with 18.8% in non-CR patients. In ATLL patients, CBT with non-TBI-RIC using Flu/Mel is a promising treatment strategy.

Aggressive NK cell leukaemia after splenectomy: association with CD95-resistant memory T-cell proliferation and recalcitrant clinical course of haemophagocytic syndrome.

We describe a 44-yr-old Japanese woman with persistent polyclonal T-cell proliferation and recalcitrant clinical course of haemophagocytic syndrome (HPS). T cells bearing alphabeta T-cell receptors (TCR) expressed increased amounts of CD95 and of CD45RO, which are phenotypically memory T cells. The TCR repertoire was broad and diverse. Regardless of CD95 expression, these cells were resistant to CD95-mediated apoptosis. Aggressive natural killer cell leukaemia (ANKL) without an association with Epstein-Barr virus was detected 1 month after therapeutic splenectomy that followed 3 yr of immunosuppressive therapy against HPS. The immunophenotype of these leukaemia cells was CD56, CD16(dim), CD7, CD45RA and they expressed some CD2, CD8 and HLA-DR. Moreover, hyperdiploid clones with complex chromosomal abnormalities were also detected. Latent NK-cell malignancy seemed to cause the CD95-resistant memory T-cell proliferation and splenectomy resulted in overt ANKL progression. There should be careful consideration of the risks versus benefits of splenectomy in HPS, in light of the possibility of fatal leukaemia/lymphoma progression.

Phase II study of cladribine (2-chlorodeoxyadenosine) in relapsed or refractory adult T-cell leukemia-lymphoma.

Adult T-cell leukemia-lymphoma (ATL) is a retrovirus-associated T-cell malignancy with an extremely poor prognosis; the median survival time of ATL patients with the acute or lymphoma type is less than 1 year with various combination chemotherapies. Cladribine (2-chlorodeoxyadenosine; 2-CdA), a purine analog resistant to degradation by adenosine deaminase, has shown definitive clinical activity against various lymphoid malignancies, including hairy cell leukemia, indolent lymphoma, and cutaneous T-cell lymphoma. An in vitro study showed the sensitivity of T-lymphoblastoid cell lines to cladribine, and a preceding Japanese phase I study of cladribine showed that 1 refractory patient with ATL achieved an objective response. To evaluate the therapeutic efficacy of cladribine in treating ATL, we conducted a multicenter phase II study. The plan was to administer cladribine to 30 ATL patients as 0.09 mg/kg per day by 7-day continuous intravenous infusion every 4 weeks for up to 3 courses. Before the planned interim analysis, 16 patients with relapsed or refractory ATL were enrolled, 15 of whom were eligible. Only 1 of the 15 eligible patients showed an objective response (overall response rate, 7%; 90% confidence interval, 0% to 28%), and 11 patients (73%) showed progressive disease, mostly during the first course of treatment. Because the upper limit of the 90% confidence interval of the overall response rate did not reach 30% in the interim analysis, the Independent Monitoring Committee advised us to discontinue patient enrollment. In conclusion, cladribine is not worthy of further investigation for the treatment of ATL.