Herbert G. Sayer

Evidence of a Graft-Versus-Leukemia Effect in Chronic Lymphocytic Leukemia After Reduced-Intensity Conditioning and Allogeneic Stem-Cell Transplantation: The Cooperative German Transplant Study Group

PURPOSE To study whether hematopoietic stem-cell transplantation (HSCT) after reduced-intensity conditioning is effective and tolerable in patients with advanced chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS Thirty patients with advanced B-cell CLL were included into the study. After reduced-intensity conditioning with fludarabine, busulfan, and antithymocyte globulin, patients received a transplant from related (n = 15) or unrelated donors (n = 15). Minimal residual disease (MRD) was monitored with a clone-specific polymerase chain reaction. RESULTS After a median follow-up of 2 years, 23 patients are alive (to date). Neutrophil and platelet engraftment occurred after a median of 17.5 and 15 days, respectively. Acute graft-versus-host disease (GVHD) grade 2 to 4 was observed in 17 patients (56%), and chronic GVHD was observed in 21 patients (75%). Twelve patients (40%) achieved a complete remission (CR), and 16 patients (53%) achieved a partial remission. Late CR occurred up to 2 years after transplantation. MRD was monitored in eight patients with CR. All patients achieved a molecular CR. At last follow-up, six patients were in ongoing molecular CR. Causes of death were treatment-related complications in four patients and progressive disease in three patients. The probability of overall survival, progression-free survival, and nonrelapse mortality at 2 years was 72% (95% confidence interval [CI], 54% to 90%), 67% (95% CI, 49% to 85%), and 15% (95% CI, 1% to 29%), respectively. CONCLUSION Treatment-related mortality after reduced-intensity conditioning followed by allogeneic HSCT was low. The procedure induced molecular remissions in patients with advanced CLL. The observation of late remissions provided evidence of a graft-versus-leukemia effect.

Reduced intensity conditioning for allogeneic hematopoietic stem cell transplantation in patients with acute myeloid leukemia: disease status by marrow blasts is the strongest prognostic factor.

Summary:We analyzed predictive factors for the outcome of 113 acute myeloid leukemia patients receiving reduced-intensity conditioning prior to allogeneic hematopoietic stem cell transplantation (HSCT). Patients were ineligible for conventional-intensity HSCT. Conditioning consisted of fludarabine and 50% of the conventional dose of busulfan (n=93) or total body irradiation (n=20). The source of stem cells was blood in 102 patients, marrow in 10, and both in one. In total, 50 (44.2%) donors were HLA-matched siblings, 50 (44.2%) unrelated fully matched and 13 (11.5%) partially mismatched family (n=1) or unrelated (n=12) donors. In all, 107 (94.6%) patients showed neutrophil and platelet engraftment after a median time of 13.5 and 13 days. The probabilities of event-free survival (EFS) (median follow-up: 12 months) were 49% for patients with less than 5% blasts in the marrow, 24% for patients with 5–20% blasts (P=0.002) and 14% with >20% blasts (P⩽0.001). Death occurred because of relapse in 29 patients (25.6%), infection in 12 patients (10.6%), acute graft-versus-host disease in eight patients (7.0%) and organ toxicity in nine patients (7.9%). In multivariate analysis, higher number of blasts in the marrow, alternative donors and low Karnofsky performance score were independent adverse prognostic factors for EFS.

Dynamics of BCR-ABL mRNA expression in first-line therapy of chronic myelogenous leukemia patients with imatinib or interferon α/ara-C

We sought to determine dynamics of BCR-ABL mRNA expression levels in 139 patients with chronic myelogenous leukemia (CML) in early chronic phase, randomized to receive imatinib (n=69) or interferon (IFN)/Ara-C (n=70). The response was sequentially monitored by cytogenetics from bone marrow metaphases (n=803) and qualitative and quantitative RT-PCR from peripheral blood samples (n=1117). Complete cytogenetic response (CCR) was achieved in 60 (imatinib, 87%) vs 10 patients (IFN/Ara-C, 14%) after a median observation time of 24 months. Within the first year after CCR, best median ratio BCR-ABL/ABL was 0.087%, (imatinib, n=48) vs 0.27% (IFN/Ara-C, n=9, P=0.025). BCR-ABL was undetectable in 25 cases by real-time PCR, but in only four patients by nested PCR. Median best response in patients with relapse after CCR was 0.24% (n=3) as compared to 0.029% in patients with continuous remission (n=52, P=0.029). We conclude that (i) treatment with imatinib in newly diagnosed CML patients is associated with a rapid decrease of BCR-ABL transcript levels; (ii) nested PCR may reveal residual BCR-ABL transcripts in samples that are negative by real-time PCR; (iii) BCR-ABL transcript levels parallel cytogenetic response, and (iv) imatinib is superior to IFN/Ara-C in terms of the speed and degree of molecular responses, but residual disease is rarely eliminated.

Nonmyeloablative stem cell transplantation in adults with high-risk ALL may be effective in early but not in advanced disease.

The feasibility of nonmyeloablative stem cell transplantation (NST) was evaluated in 22 adults with high-risk ALL. 16/22 patients had advanced disease and 11/22 had Ph+ ALL. Eleven patients received NST as first stem cell transplantation (SCT). Eleven patients had relapses after allogeneic or autologous SCT and underwent a salvage NST. 18/22 patients (82%) engrafted after NST. 13/16 patients (81%) with active disease reached complete remission (CR). 11 of 13 patients developed GVHD. After first NST 10/11 patients (91%) engrafted. Six of seven patients with active disease reached CR. Three of five relapsing patients reached subsequent CR after donor lymphocyte infusions, termination of immunosuppression or imatinib. Three of 11 patients (27%) are alive in CR 5 to 30 months after NST. Eight of 11 patients have died, 3/8 from leukemia and 5/8 from transplant-related causes. After salvage NST, 8/11 patients (73%) engrafted. Seven of nine patients with active disease reached CR. Only one of 11 patients transplanted, who was in CR before undergoing salvage NST is alive 19 months after NST. Five of 11 have died from leukemia, one of 11 after graft failure and four of 11 from transplant-related causes. Four of 22 patients (18%) are alive in CR 5, 14, 19 and 30 months after NST. NST is feasible in adults with high risk ALL. However, transplant-related mortality remains high and only patients transplanted in CR seem to have long-term disease-free survival.

Comparison between antithymocyte globulin and alemtuzumab and the possible impact of KIR-ligand mismatch after dose-reduced conditioning and unrelated stem cell transplantation in patients with multiple myeloma.

We compared antithymocyte globulin (ATG) with alemtuzumab in 73 patients with multiple myeloma, who underwent reduced conditioning with melphalan/fludarabine, followed by allogeneic stem cell transplantation from human leucocyte antigen‐matched or ‐mismatched unrelated donors. The ATG group had more prior high‐dose chemotherapies (P < 0·001), while bone marrow was used more as the stem cell source in the alemtuzumab group (P < 0·001). Alemtuzumab resulted in faster engraftment of leucocytes (P = 0·03) and platelets (P = 0·02) and in a lower incidence of acute graft versus host disease (GvHD) grades II–IV (24% vs. 47%, P = 0·06). More cytomegalovirus (CMV) seropositive patients in the alemtuzumab group experienced CMV reactivation (100% vs. 47%, P = 0·001). The cumulative incidence of treatment‐related mortality at 2 years was 26% [95% confidence interval (CI) = 12–37%] for ATG vs. 28% (95% CI = 15–55%) for alemtuzumab, P = 0·7. There was no significant difference in the estimated 2‐year overall and progression‐free survival between ATG and alemtuzumab: 54% (95% CI: 39–75%) vs. 45% (95% CI: 28–73%) and 30% (95% CI: 16–55%) vs. 36% (95% CI: 20–62%) respectively. In multivariate analysis, treatment with alemtuzumab had a higher risk for relapse (hazard ratio: 2·37; P = 0·05) while killer immunoglobulin‐like receptor (KIR)‐ligand mismatch was protective for relapse (P < 0·0001). We conclude that alemtuzumab produced less acute GvHD, but higher probability of relapse. The data implicated a major role of KIR‐ligand mismatched transplantation in multiple myeloma.

Early related or unrelated haematopoietic cell transplantation results in higher overall survival and leukaemia-free survival compared with conventional chemotherapy in high-risk acute myeloid leukaemia patients in first complete remission

Between 1996 and 2004, a total of 708 patients were enrolled in the acute myeloid leukaemia (AML) ‘96 and ‘02 studies of the East German Study Group (OSHO). Of these, 138 patients (19.5%) had unfavourable cytogenetics defined as complex karyotype, del (5q)/-5, del (7q)/-7, abn (3q26) and abn (11q23). In all, 77 (56%) achieved complete remission 1 (CR1) after induction chemotherapy and were eligible for haematopoietic cell transplantation (HCT). HCT was performed after a median of two cycles of consolidation chemotherapy (CT) in the AML ‘96 and one cycle in the AML ‘02 study (P=0.03). After a median follow-up of 19 months, overall survival (OS) at two years was significantly better in the donor group (52±9%) versus the no-donor group (24±8%; P=0.005). Differences in outcomes were mainly because of a lower relapse incidence in patients after HCT (39±11%) compared with a higher relapse incidence in patients undergoing CT (77±10%; P=0.0005). Treatment-related mortality was low and not statistically significantly different between the two treatment groups (15±7 and 5±5% for HCT and chemotherapy, respectively; P=0.49).We conclude that early HCT from related or unrelated donors led to significantly better OS and leukaemia-free survival compared with chemotherapy in patients with unfavourable karyotype.

Dose-reduced conditioning for allografting in 44 patients with chronic myeloid leukaemia: a retrospective analysis

This retrospective study describes the outcome of patients with chronic myeloid leukaemia after allografting using dose‐reduced conditioning with fludarabine and busulphan. Forty‐four Philadelphia chromosome (Ph)‐positive patients were transplanted in nine German centres; 26 patients were in chronic phase, 11 in accelerated phase and seven in blast crisis. Thirty‐four patients achieved complete remission, with 18 alive and disease‐free at a median follow‐up of 562 d (range 244–922 d). Grade II–IV acute graft‐versus‐host disease (GVHD) incidence was 43%. Twenty patients died, 15 of causes unrelated to relapse. Risk factors predisposing to graft failure by univariate analysis were an unrelated donor (8/23 compared with a related donor 2/21, P = 0·07) and interferon therapy within 90 d of transplant (4/6 versus 3/17, P = 0·025). At the last follow‐up, of 31 patients for whom molecular or cytogenetic data were available, 16 (52%) were polymerase chain reaction‐negative, and seven (23%) were Ph‐negative by fluorescent in situ hybridization. These findings demonstrate that dose‐reduced conditioning with fludarabine and busulphan provides durable engraftment and a low rate of relapse. However, in this population, many of whom were not eligible for high‐dose conditioning due to age, reduced performance status, previous complications or extensive pre‐treatment, these data highlight the need for effective anti‐infectious and GVHD prophylaxis. In addition, this study supports the discontinuation of interferon therapy at least 90 d before transplant

Efficacy and toxicity of low-dose escalating donor lymphocyte infusion given after reduced intensity conditioning allograft for multiple myeloma.

Efficacy and toxicity of low-dose escalating donor lymphocyte infusion given after reduced intensity conditioning allograft for multiple myeloma

Allogeneic haematopoietic cell transplantation for chronic myelogenous leukaemia in the era of imatinib: a retrospective multicentre study

Abstract:  Objective: To analyse the results of allogeneic haematopoietic cell transplantation (HCT) in patients with advanced stages of Philadelphia chromosome‐positive chronic myelogenous leukaemia (CML) who had previously been treated with imatinib mesylate (IM). Methods: We analysed the outcome of 61 patients with CML who had received allogeneic HCT from sibling (n = 18) or unrelated (n = 43) donors after having been treated with IM. Forty‐one patients had received IM because of accelerated or blast phase CML. Conditioning therapy contained standard doses of busulfan (n = 25) or total‐body irradiation (n = 20) in conjunction with cyclophosphamide in the majority of cases. Sixteen patients received dose‐reduced conditioning with fludarabine‐based regimens. Results: The incidence of grades II–IV and III–IV graft‐versus‐host disease was 66% and 38% respectively. The probability of overall survival (OS), disease‐free survival (DFS) and relapse at 18 months for the whole patient cohort were 37%, 33% and 24% respectively. The probability of non‐relapse mortality (NRM) at 100 d and 12 months was 30% and 46% respectively. Univariate analysis showed that fludarabine‐based conditioning therapy, age ≥40 yr and >12 months interval between diagnosis and transplantation were associated with a significantly lower OS and DFS and a higher NRM. Conclusion: These data suggest that although pretreatment with IM is not an independent negative prognostic factor, it cannot improve the dismal prognosis of CML patients at high risk for transplant‐related mortality.

German consensus on immunogenetic donor search for transplantation of allogeneic bone marrow and peripheral blood stem cells

In Germany allotransplantation of bone marrow or peripheral blood stem cells is presently performed by 34 different teams operating more or less independently. Thus, strategies of immunogenetic donor search, use of the various tissue typing techniques and policy on acceptable HLA mismatches in related and unrelated settings may vary considerably from one transplant centre to another. This paper summarises the results of the first German consensus meeting on immunogenetic donor search for bone marrow/peripheral blood stem cell grafting. The main goal of the participating transplant physicians and immunogeneticists was to define national standards for the above issues.