Long-term outcome of patients with newly diagnosed chronic myeloid leukemia: a randomized comparison of stem cell transplantation with drug treatment.

Tyrosine kinase inhibitors represent today's treatment of choice in chronic myeloid leukemia (CML). Allogeneic hematopoietic stem cell transplantation (HSCT) is regarded as salvage therapy. This prospective randomized CML-study IIIA recruited 669 patients with newly diagnosed CML between July 1997 and January 2004 from 143 centers. Of these, 427 patients were considered eligible for HSCT and were randomized by availability of a matched family donor between primary HSCT (group A; N=166 patients) and best available drug treatment (group B; N=261). Primary end point was long-term survival. Survival probabilities were not different between groups A and B (10-year survival: 0.76 (95% confidence interval (CI): 0.69-0.82) vs 0.69 (95% CI: 0.61-0.76)), but influenced by disease and transplant risk. Patients with a low transplant risk showed superior survival compared with patients with high- (P<0.001) and non-high-risk disease (P=0.047) in group B; after entering blast crisis, survival was not different with or without HSCT. Significantly more patients in group A were in molecular remission (56% vs 39%; P=0.005) and free of drug treatment (56% vs 6%; P<0.001). Differences in symptoms and Karnofsky score were not significant. In the era of tyrosine kinase inhibitors, HSCT remains a valid option when both disease and transplant risk are considered.

A prospective, randomised, phase II study of horse antithymocyte globulin vs rabbit antithymocyte globulin as immune-modulating therapy in patients with low-risk myelodysplastic syndromes.

Immunosuppression has recently been proposed for low-risk myelodysplastic syndromes (MDS) to reverse bone marrow failure by inhibiting intramedullary secretion of proapoptotic cytokines. We treated 35 MDS patients (24 refractory anaemia (RA), 10 RA with excess blasts and one chronic myelomonocytic leukaemia) with either horse antithymocyte globulin 15 mg/kg/day or rabbit antithymocyte globulin 3.75 mg/kg/day, each for 5 days. Median age was 63 years (range: 41-75). After 1 to 34+ months of follow-up (mean: 15+), four patients experienced complete haematological responses (CR), six good responses (GR) and two minor responses. All CRs and GRs occurred in patients with RA, in whom both horse and rabbit ATG yielded five responses out of 12 (42%). Time to response varied between 1 and 10 (mean: 3) months. The median duration of response was 9+ (1-17+) months; five patients are in continuing response. In all, 23 patients suffered side effects > degrees II WHO (the degree of toxicity encountered according to the internationally accepted WHO toxicity grading); one patient died 2 weeks after rabbit ATG from rhinocerebral mucormycosis. Parameters that correlated with response were duration of disease and RA subgroup. In our experience, immune-modulating therapy with either horse or rabbit ATG is feasible in patients with RA and short duration of disease.

Randomized comparison of interferon alpha and hydroxyurea with hydroxyurea monotherapy in chronic myeloid leukemia (CML-study II): prolongation of survival by the combination of interferon alpha and hydroxyurea.

The optimum treatment conditions of interferon (IFN) alpha therapy in chronic myeloid leukemia (CML) are still controversial. To evaluate the role of hydroxyurea (HU) for the outcome of IFN therapy, we conducted a randomized trial to compare the combination of IFN and HU vs HU monotherapy (CML-study II). From February 1991 to December 1994, 376 patients with newly diagnosed CML in chronic phase were randomized. In all, 340 patients were Ph/BCR-ABL positive and evaluable. Randomization was unbalanced 1:2 in favor of the combination therapy, since study conditions were identical to the previous CML-study I and it had been planned in advance to add the HU patients of study I (n=194) to the HU control group. Therefore, a total of 534 patients were evaluable (226 patients with IFN/HU and 308 patients with HU). Analyses were according to intention-to-treat. Median observation time of nontransplanted living patients was 7.6 years (7.9 years for IFN/HU and 7.3 years for HU). The risk profile (new CML score) was available for 532 patients: 200 patients (38%) were low, 239 patients (45%) intermediate, and 93 patients (17%) high risk. Complete hematologic response rates were higher in IFN/HU-treated patients (59 vs 32%). Of 169 evaluable IFN/HU-treated patients (75%), 104 patients (62%) achieved a cytogenetic response that was complete in 12% (n=21), major in 14% (n=24), and at least minimal in 35% (n=59). Of the 534 patients, 105 (20%) underwent allogeneic stem cell transplantation in first chronic phase. In the low-risk group, 65 of 200 patients were transplanted (33%), 30 (13%) in the intermediate-risk group, and nine (10%) in the high-risk group. Duration of chronic phase was 55 months for IFN/HU and 41 months for HU (P<0.0001). Median survival was 64 months for IFN/HU and 53 months for HU-treated patients (P=0.0063). We conclude that IFN in combination with HU achieves a significant long-term survival advantage over HU monotherapy. In view of the data of CML-study I, these results suggest that IFN/HU is also superior to IFN alone. HU should be combined with IFN in IFN-based therapies and for comparisons with new therapies.

Autologous stem cell transplantation for follicular lymphoma: no benefit for early transplant?

Autologous stem cell transplantation (SCT) is widely used as salvage treatment for patients with relapsed follicular lymphoma (FL). Although SCT can induce prolonged remissions, it does not appear to be curative in the vast majority of patients. The purpose of this study was to investigate if incorporation of SCT into first-line therapy can improve its efficacy. Fifty-five patients underwent sequential high-dose therapy as up-front (n=33) or salvage treatment (n=22) for advanced stage FL at our institution. Treatment consisted of intensive chemotherapy with dexamethasone, carmustine (BCNU), etoposide, cytarabine, and melphalan (Dexa-BEAM) for mobilization of peripheral stem cells and reduction of tumor load, followed by one of three different myeloablative regimens and SCT. With a median follow-up of 4 years, projected event-free survival (EFS) and overall survival (OS) at 4 years post transplant was 59% and 84%, respectively, with no evidence of plateau in the survival curves. By univariate and multivariate analysis weighing age, sex, stage, BM and extranodal involvement, timing of transplant, ex vivo purging, and conditioning regimen [total body irradiation (TBI) vs non-TBI], the only significant factor predicting for superior EFS and OS was up-front vs salvage transplant (4-year EFS 76% vs 38%, p=0.02; 4-year OS 92% vs 73%, p=0.033). However, when calculated from diagnosis, EFS and OS of the up-front and salvage groups were virtually identical, implying that the longer survival post SCT in the up-front group was completely compensated by the longer interval between diagnosis and transplant in the salvage group. Median OS from diagnosis was 13.5 years. Except for one case of anaplastic large cell lymphoma, secondary neoplasms have not occurred to date. In conclusion, our data indicate that SCT might improve the prognosis of patients with disseminated FL, although it is probably not curative even if applied early during the course of the disease. The optimum timing of SCT remains to be determined by the ongoing randomized multicenter trial of the German Low-grade Lymphoma Study Group. The impact of radiotherapy on the success of SCT does not seem to be as essential as originally believed.

Fludarabine plus cyclophosphamide is an efficient treatment for advanced chronic lymphocytic leukaemia (CLL): results of a phase II study of the German CLL Study Group.

The efficacy and toxicity of a combination of fludarabine and cyclophosphamide (FC) was evaluated in patients with B-cell chronic lymphocytic leukaemia (CLL). Between April 1997 and July 1998, 36 patients with CLL (median age 59 years) received a regimen that consisted of fludarabine 30 mg/m(2) in a 30-min IV infusion, d 1-3, and cyclophosphamide 250 mg/m(2) in a 30-min IV infusion on d 1-3. Cycles were repeated every 28 d. Twenty-one patients had received between one and three different treatment regimens prior to the study, while 15 patients had received no prior therapy. The median Eastern Cooperative Oncology Group performance score was 1. One patient was at Binet stage A, 18 were stage B and 17 patients were stage C. Objective responses, assessed according to the revised guidelines of the National Cancer Institute-sponsored Working Group, were recorded in 29 out of 32 assessable patients (90.6%). Twenty-four partial remissions and five complete remissions were observed. Two patients showed no change and one patient showed disease progression. At February 2000, three of the responders had relapsed. Severe neutropenia, anaemia and thrombocytopenia (Common Toxicity Criteria grade 3 and 4) were observed in 25, six and six patients (69.4%, 16.7% and 16.7%) respectively. Other side-effects were uncommon. No treatment-related deaths and no grade 3 or 4 infections occurred. We conclude that the combination of fludarabine and cyclophosphamide showed significant activity in patients with CLL. Myelosuppression was the major side-effect. These results warrant further study on the FC combination in randomized trials.

Rituximab therapy of patients with B-cell chronic lymphocytic leukemia.

Rituximab (IDEC-C2B8) is a chimeric antibody that binds to the B-cell surface antigen CD20. Rituximab has significant activity in follicular non-Hodgkin lymphomas. Much less is known about the effects in chronic lymphocytic leukemia (CLL). We have initiated a phase II trial to evaluate the efficacy and safety of rituximab in patients with CD20+ pretreated CLL. To avoid the rituximab-associated toxicity, we restricted the tumor cell load, as measured by the number of circulating lymphocytes and the spleen size, in the first 2 cohorts of patients included in the study. Patients received 4 intravenous infusions of 375 mg/m2 once a week over a period of 1 month. Of the 28 patients evaluable for response, 7 patients showed a partial remission (National Cancer Institute criteria) lasting for a median of 20 weeks, with 1 patient still in remission after 71 weeks. Based on lymphocyte counts only, we found at least a 50% reduction of lymphocyte counts lasting for at least 4 weeks in 13 (45%) of 29 patients. Fifteen patients from 3 institutions were monitored for the immunophenotype profile of lymphocyte subsets. The number of CD5+CD20+ cells decreased significantly and remained low until day 28 after therapy. T-cell counts were not affected. With the exception of one rituximab-related death, adverse events in the remaining patients were mild. The results suggest that rituximab has clinical activity in pretreated patients with B-CLL. Toxicity is tolerable. Response duration after withdrawal of rituximab is rather short. Therefore, other modes of application and the combination with other agents need to be tested.

Which factors render cost-covering lump-sum charging difficult for the treatment of patients with acute leukemias?

BACKGROUND: Growing budget limitations and the planned charging subject to Diagnosis-Related Groups (DRG) points raise the question as to what costs are incurred by the induction therapy and early consolidation treatment of patients with acute myeloid leukemias (AML) and whether these can be compensated in a cost-covering manner by a system based on DRG points. PATIENTS AND METHODS: For 100 patients recruited within the framework of the "Kooperative AML-Studie 96" of the Süddeutsche Hämoblastosegruppe a process cost analysis was made between 1996 and 1999. All manpower and material costs incurred in the department itself and in the secondary services departments as well as the basic cost shares were recorded taking into due account the length of stay. The cost breakdown was effected based on a double induction therapy and one early consolidation treatment. RESULTS: It turns out that substantial differences exist between lower und upper limits of the length of stay and costs. For all three therapy blocks for patients up to 60 years the cost spread varies between 63 and 204 kDM with a median of 105 kDM, and for older patients between 55.6 and 146.6 kDM with a median of 87.6 kDM. On average, the costs subject to length of stay were roughly 70%. CONCLUSIONS: As the costs per case are subject to a spread and, for this relatively small group of patients, are extremely high, the fixing of a case-related lump sum is problematic, the more so as age of patient, comorbidity, type of therapy, ist outcome, and therapy-induced complications represent decisive influencing factors.

Donor lymphocyte infusion enhances remission status in patients with persistent disease after allografting for multiple myeloma.

Two patients with persistent disease after allografting for multiple myeloma received donor T-cell lymphocyte infusion (DLI) (1.5 x 10(8) and 7 x 10(7)) to induce a graft-vs.-myeloma effect for further tumour regression after withdrawal of immunosuppression. The interval between stem cell transplantation and DLI was 8 and 14 months respectively. Both patients converted from partial to complete remission, lasting 12+ and 28+ months. Immunofixation became negative after 3 and 4 months. The main toxicity was grade II and III acute graft-vs.-host disease (GvHD) and limited or extensive chronic GvHD in each patient. We conclude that DLI induced further tumour reduction in patients with persistent disease after allografting for multiple myeloma.

Role of angiogenesis inhibitors in acute myeloid leukemia.

Neovascularization is increasingly recognized as an important factor in the pathogenesis of hematologic malignancies as well as solid tumors. The complex interactions between several cell types and numerous cytokine mediators suggest the involvement of autocrine and paracrine signaling mechanisms. Vascular endothelial growth factor (VEGF) in particular is critical to both stimulation of leukemic growth and proliferation of endothelial cells. Tyrosine kinase receptors specific for certain growth factors represent attractive target molecules for anticancer therapy. SU5416 is a competitive inhibitor of VEGF receptor subtypes VEGFR-1 and VEGFR-2 and stem cell factor receptor c-kit. Preclinical evidence shows that SU5416 effectively inhibits VEGF-induced endothelial cell proliferation and slows growth of subcutaneous solid tumor xenografts. This agent is in late-stage clinical trials in patients with solid tumors, and a Phase 2 study was recently initiated to evaluate its utility in the treatment of acute myeloid leukemia. In this Phase 2 study, investigators are seeking to determine the response rate to the antiangiogenic agent SU5416. Translational research in this study is intended to aid our understanding of the precise mechanisms by which SU5416 affects acute myeloid leukemia cells and the bone marrow microenvironment.

Dose-dependent effect of etoposide in combination with busulfan plus cyclophosphamide as conditioning for stem cell transplantation in patients with acute myeloid leukemia.

To evaluate the efficacy and toxicity of two different etoposide (VP-16) dosages (30 or 45 mg/kg) in combination with busulfan/cyclophosphamide as conditioning therapy followed by stem cell transplantation in acute myeloid leukemia (AML), 90 patients with AML received either 30 mg/kg (n = 60) or 45 mg/kg (n = 30) etoposide in combination with busulfan (16 mg/kg) and cyclophosphamide (120 mg/kg). The stem cell source was allogeneic related bone marrow (BM) (n = 53), allogeneic unrelated BM (n = 5), allogeneic unrelated peripheral blood (PBSC) (n = 2), syngeneic BM (n = 2), autologous BM purged (n = 9) or unpurged (n = 9), autologous PBSC (n = 10). Fifty-six patients (62%) were in first CR, 26 (29%) were > first CR, and eight (9%) were transplanted in relapse. Principal toxicities in both groups were mucositis and hepatotoxicity. Forty-five mg/kg etoposide resulted in greater hepatic toxicity (P = 0.03), and a higher incidence of VOD (23 vs 12%, P = 0.04) and acute GVHD grade III/IV (13 vs 5%, NS). The treatment-related mortality was 17% in the 30 mg/kg group and 33% in the 45 mg/kg group, mainly due to infections, intestinal pneumonia and GVHD. Hematological recovery of leukocytes 1/nl was comparable in both groups (17 vs 16 days). After a median follow-up of 16 months 19% in the 30 mg/kg group and 23% in the 45 mg/kg group relapsed. In patients who had undergone allogeneic related bone marrow transplantation in first CR no relapses occurred after a median follow-up of 3 years. For all patients the 3-year estimated disease-free survival was 62% in the 30 mg/kg group and 40% in the 45 mg/kg group (P = 0.03). For patients in first CR who underwent allogeneic related stem cell transplantation the 3 year disease-free survivals were 80% and 66%, respectively (P = 0.4). We conclude that etoposide 30 mg/kg or 45 mg/kg in combination with busulfan/cyclophosphamide is a highly active regimen for bone marrow transplantation of patients with AML with a low relapse rate. However, conditioning with 30 mg/kg rather than 45 mg/kg etoposide resulted in less toxicity and a better overall survival due to a lower transplant-related mortality. Bone Marrow Transplantation (2000) 26, 711-716.

Multicenter phase II study of oral idarubicin in treated and untreated patients with B-chronic lymphocytic leukemia.

Idarubicin is the first anthracycline that can be administered orally facilitating antineoplastic chemotherapy at an improved quality of life. In different studies idarubicin has proved clinical effectiveness in patients with advanced low grade non Hodgkin's lymphoma. We performed a phase II study in 19 patients with untreated and pretreated B-CLL of Binet stage A-C. Idarubucin was administered orally at a dose of 15 mg/m2 over 3 days every 4 weeks. Of 19 evaluable patients (m:f, 16:3, median age 64 years, range 41-80 years) 7 were previously untreated while 12 patients had received prior therapy with fludarabine, chlorambucil or similar non-anthracycline containing regimens. 12 pts had Binet stage C, 5 Binet stage B and 2 Binet stage A. Five patients achieved a partial remission (26%), 5 patients had stable disease (26%) and 9 patients showed progressive disease (47%), resulting in an overall response of 26% (5/19). There was no correlation of response rate with Binet stages or previous treatment regimens. Treatment associated side effects consisted predominantly of mild nausea and vomiting (26%) as well as minor infections (21%) and diarrhoea (16%). These data demonstrate that oral idarubicin as a single agent is well tolerated but of limited effectiveness in B-CLL. Further studies are needed to assess different doses and schedules of oral idarubucin and to test it in combination with other chemotherapeutic agents.

Efficacy of further attempts to mobilize CD34+ peripheral stem cells with alternative procedures after primary failure.

19 patients who failed the target collection of at least 2.5 x 10(6) CD34+ cells/kg underwent further mobilization procedures either with granulocyte-colony-stimulating factor (G-CSF) alone after failure to chemotherapy plus G-CSF (group 1), or with chemotherapy plus G-CSF (group 2), or with high-dose G-CSF (24 microg/kg) alone (group 3) after failure to respond to standard dose of G-CSF (10 microg/kg) alone. In all groups, an increase in median CD34+ cell yield could be observed following alternative procedures (1.1- to 1.9 x 10(6) kg; p = 0.02). The highest increase in CD34+ cell harvest was achieved in group 1 (0.85 to 2.2 x 10(6) kg), followed by group 2 (1. 2 to 1.7) and group 3 (1.0 to 1.4), but without statistically significant difference between the mobilization technologies. All patients with more than 1.0 x 10(6) CD34+ cells/kg in the first apheresis procedure reached the overall target of 2.5 x 10(6) CD34+ cells/kg after a second or subsequent mobilization procedure. In contrast, only 3 of 8 patients (37%) with less than 1.0 x 10(6) CD34+ cells in the first harvest could reach the target of 2.5 x 10(6) CD34+ cells after further mobilization attempts.

The impact of autologous stem cell transplantation on the prognosis of mantle cell lymphoma: a joint analysis of two prospective studies with 46 patients.

INTRODUCTION: The purpose of this analysis was to investigate if early sequential high-dose therapy with autologous stem cell transplantation (ASCT) can improve the poor prognosis of patients with disseminated mantle cell lymphoma (MCL). PATIENTS AND METHODS: A joint analysis of two parallel single center studies was performed. Both were characterized by a sequential high-dose therapy consisting of an intensive chemotherapy ('HAM' or 'Dexa-BEAM') for mobilization of peripheral blood stem cells and induction of minimal disease followed by a total body irradiation-containing myeloablative regimen and ASCT. Forty-six patients with reference panel-confirmed stage III/IV MCL were included. Thirty-four patients were accrued to the protocol immediately after diagnosis ('upfront ASCT' group). These 34 patients received a standard first-line regimen prior to mobilization. The remaining 12 patients were put on the protocol later during the course of their disease ('delayed ASCT' group). RESULTS: All patients were in remission after mobilization chemotherapy and proceeded to ASCT; there were no exclusions due to poor response, poor mobilization, or patient refusal. With a follow-up of 24 (2-73) months post transplant, the event-free and overall survival probabilities at 2 years were 77 and 100% for the upfront ASCT group compared to 30% (P=0.0007) and 54% (P=0.0016) for the delayed ASCT group. Event-free and overall survival tended to be longer in the upfront ASCT group than in the delayed ASCT group also if calculated from initial diagnosis (76 and 93% vs 42 and 63%, respectively, at 4 years after diagnosis; median follow-up 35 months), although this was not statistically significant. Besides timing of ASCT, only spleen size was identified as an independent predictor of survival by univariate and multivariate analysis. CONCLUSION: ASCT is not curative but may improve the prognosis of patients with MCL if performed as part of an intensive first-line treatment strategy. In contrast, the benefits of this approach for salvaging individuals with relapsed disease appear to be limited.

Origin of stroma cells in long-term bone marrow cultures from patients with acute myeloid leukemia.

Bone marrow stroma cells from patients with acute myeloid leukemia (AML) display a variety of functional abnormalities. In order to determine whether this is related to an imbalance in the proportion of different stroma cell types or to integration of leukemic progeny into the regulatory cell network, stroma layers were established in mycophenolic acid-treated long-term marrow cultures from 16 patients with AML and 42 controls and analyzed by means of simultaneous membrane immunofluorescence and interphase cytogenetics. Macrophages were identified by CD14 expression, fibroblasts by staining with the AS02 antibody, and malignant cells by leukemia-specific numerical chromosome aberrations, including monosomy 7 and trisomy 8. Compared with normal controls, there was a slight decrease in the proportion of stroma fibroblasts (52+/-27% versus 77+/-5%) in 10-week-old cultures from patients with AML. Two of five AML patients with trisomy 8 and both patients with monosomy 7 had evidence of leukemic stroma cells. Most malignant cells were CD14+ macrophages (3.8-98.1% of all CD14+ cells), but some were AS02+ (2.8-5.2%). AML stroma layers showed a reduced capacity to support the growth of normal hematopoietic cells in standard two-stage long-term cultures, but this was unrelated to the presence or absence of leukemic stroma elements. In conclusion, AML populations vary with respect to their ability to produce a malignant microenvironment. Functional defects in the hematopoietic microenvironment, however, are not limited to AML patients with cytogenetically abnormal stroma cells, but extend to cases without evidence of malignant stroma cells.

Myeloablative radiochemotherapy followed by reinfusion of purged autologous stem cells for Waldenström's macroglobulinaemia.

Waldenström's macroglobulinaemia (WM) is an incurable lymphoproliferative disorder. The purpose of this study was to investigate the role of autologous peripheral blood stem cell transplantation (ASCT) for the treatment of WM. Seven patients (untreated or after first-line therapy) with symptomatic WM underwent two or three cycles of Dexa-BEAM chemotherapy + G-CSF with stem cell harvesting and proceeded to total body irradiation and high-dose cyclophosphamide followed by reinfusion of ex-vivo B-cell-depleted stem cells. Engraftment was prompt, and procedure-related deaths did not occur. A strong reduction or normalization of BM infiltration and serum IgM levels occurred in all evaluable patients, but immunofixation electrophoresis revealed persistent paraproteinaemia in five of them. With 3-30 months of follow-up, all patients are alive without clinical or serological signs of disease progression. This pilot trial shows for the first time that high-dose radiochemotherapy with purged stem cells is effective and may improve the course of patients with WM. In the majority of cases, however, complete eradication of the disease does not appear to be possible with ASCT alone.

Jumping translocation of 1q as the sole aberration in a case of follicular lymphoma.

Cytogenetic and fluorescence in situ hybridization (FISH) studies in a case of follicular lymphoma grade III showed a "jumping translocation" of chromosome 1q21-qter to chromosomes Xq28 and 18q23, which resulted in a partial trisomy 1q as the only chromosome aberration. This case represents, to the best of our knowledge, the first report of a jumping translocation in a malignant lymphoma occurring as the sole aberration.

Granulocyte colony-stimulating factor shortens duration of critical neutropenia and prolongs disease-free survival after sequential high-dose cytosine arabinoside and mitoxantrone (S-HAM) salvage therapy for refractory and relapsed acute myeloid leukemia. German AML Cooperative Group.

Patients with primary refractory or relapsed acute myeloid leukemia (AML) who undergo intensive salvage chemotherapy carry a high risk of treatment failure due to infectious complications and early relapses. The study presented here assessed the effect of granulocyte colony-stimulating factor (G-CSF) on the duration of post-treatment neutropenia, the incidence of infection-related deaths, and the disease-free and overall survival. Sixty-eight evaluable patients with relapsed and refractory AML received G-CSF 5 microg/kg per day subcutaneously starting 2 days after the completion of salvage treatment with the S-HAM regimen, consisting of high-dose cytosine arabinoside twice daily on days 1, 2, 8, and 9 and mitoxantrone on days 3, 4, 10, and 11. Ninety-one patients who were treated with the identical S-HAM regimen but without G-CSF support during a preceding study served as controls. The application of G-CSF resulted in a significant shortening of critical neutropenia of less than 500 microl (36 vs. 40 days; p = 0.008), which translated into a trend towards a lower early death rate (21% vs. 30%) and an increase of complete remissions (56% vs. 47%, p=0.11). In patients younger than 60 years a significant prolongation of time to treatment failure (159 vs. 93 days, p=0.038) and of duration of disease-free survival (203 vs. 97 days, p=0.003) was observed. These results indicate a beneficial effect of G-CSF on early mortality as well as on long-term outcome when administered after S-HAM salvage therapy for advanced AML.

Early stem cell transplantation for chronic lymphocytic leukaemia: a chance for cure?

B-cell chronic lymphocytic leukaemia (CLL) cannot be cured by conventional therapy. To improve the prognosis of patients with CLL, we have designed a sequential treatment strategy that comprises intensive chemotherapy for mobilization of peripheral blood progenitor cells (PBPCs) and induction of minimal disease, followed by high-dose radiochemotherapy with stem cell reinfusion and post-transplant molecular monitoring by polymerase chain reaction (PCR) amplification of the complementary determining region III (CDRIII) gene. In a prospective study, we have evaluated this protocol in 18 patients with CLL, also including early stages of the disease. The median age was 49 (29-61) years; Binet stages were A, six; B, nine; and C, three. Adverse prognostic factors [high lymphocyte count and/or diffuse bone marrow (BM) infiltration] were present in 16 out of 18 patients. All patients showed a clone-specific molecular marker as demonstrated by PCR amplification of CDRIII rearrangements. For stem cell mobilization and reduction of tumour load, one to two cycles of Dexa-BEAM chemotherapy were administered, resulting in minimal disease (circulating lymphoma cells <1 x 10(9) l(-1); BM infiltration <20%; lymphomas <2 cm) in 16 out of 18 patients, including four patients who already had minimal disease before Dexa-BEAM. Stem cell harvesting was successful in 14 patients. All grafts [three BM, 11 peripheral blood (PB)] were purged from leukaemic cells using immunomagnetic methods. Thirteen patients having achieved minimal disease were reinfused with purged autologous stem cells (ASC) after preparation with total body irradiation and cyclophosphamide. Engraftment was delayed in patients receiving BM (n = 3) but prompt [neutrophils >0.5 x 10(9) l(-1) after 10 (9-13) days, platelets >20 x 10(9) l(-1) after 11 (9-214) days] in patients restored with PBPCs (n = 10). Procedure-related deaths did not occur. Although the results of CDRIII PCR suggest persistence or recurrence of the leukaemic clone in at least three cases, to date only one patient has relapsed, whereas all others survive without clinical evidence of disease with a maximum follow-up of 48 months. We conclude that sequential high-dose therapy using Dexa-BEAM and autologous stem cell transplantation is a safe and highly effective treatment for patients with CLL. However, a longer follow-up is needed to assess whether definite cures can be achieved using this strategy.