Long-term outcomes in patients with high-risk myeloid malignancies following matched related donor hematopoietic cell transplantation with myeloablative conditioning of BU, etoposide and CY

Efficacy and safety of cladribine in combination with busulfan and cyclophosphamide as an intensive conditioning regimen preceding allogeneic hematopoietic stem cell transplantation in relapsed or refractory acute myeloid leukemia

BACKGROUND

Cladribine, an analogue of deoxyadenosine, is used for therapy of hematological malignancies. Cladribine-containing regimen has been recommended as a rescue therapy for relapsed or refractory (R/R) acute myeloid leukemia (AML). Its combination with busulfan plus cyclophosphamide (BuCy), as an intensive conditioning regimen prior to allogeneic hematopoietic stem cell transplantation (allo-HSCT), requires more clinical evidence. This study aimed to explore the efficacy and safety of cladribine plus BuCy administered as an intensive conditioning regimen before allo-HSCT in R/R AML patients.

METHODS

Twenty-three R/R AML patients, who underwent cladribine plus BuCy intensive conditioning regimen before allo-HSCT, were retrospectively analyzed. The median (range) follow-up duration time of observation was 0.73 (0.08-2.69) years.

RESULTS

The median (range) returned levels of mononuclear cells were 11.5 (6.1-18.5) x 108/kg and CD34+ cells were 5.5 (3.5-9.3) x 106/kg. The median (range) time of platelet reconstitution was 13.0 (9.0-21.0) days and neutrophil reconstitution was 14.0 (11.0-26.0) days. The incidence of conditioning regimen related toxicity (CRRT) affected 69.6% of patients; all CRRT-affected patients had grade I-II symptoms, including gastrointestinal tract (39.1%), oral cavity (26.1%), liver (8.7%), and kidney (4.3%) CRRTs. The incidence of acute graft-versus-host disease (GVDH) included 30.4% among all patients with 4.3% of grade III-IV acute GVHD, and 34.8% of chronic GVHD. During the follow-up period, 4 (17.4%) patients relapsed, and 6 (26.1%) patients died (cause of death: disease relapse, n = 3; infection, n = 2; GVHD, n = 1). The 1-year and 2-year accumulating event-free survival rates were 66.3% and 53.1%, respectively. The 1-year accumulating overall survival rate was 74.7% and 2-year survival rate was 64.0%.

CONCLUSION

Cladribine plus BuCy intensive conditioning regimen before allo-HSCT exhibits favorable treatment efficacy with acceptable toxicity in R/R AML patients.

Idarubicin-intensified BUCY2 conditioning regimen improved survival in high-risk acute myeloid, but not lymphocytic leukemia patients undergoing allogeneic hematopoietic stem cell transplantation: A retrospective comparative study

The intensity of conditioning regimen is highly correlated with outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT). We have previously reported that idarubicin (IDA) intensified BUCY2 regimen could reduce relapse and improve survival for high-risk hematological malignancies undergoing allo-HSCT. However, there is no published study comparing the efficacy of IDA-BUCY2 regimen for high-risk acute myeloid leukemia (AML) versus acute lymphocytic leukemia (ALL). We further retrospectively compared therapeutic outcomes of intensified conditioning regimen on 140 high-risk AML and ALL patients in the data analyses. IDA 15mg/m(2)/d was administered by continuous infusion from day -11 to -9, followed by intravenous injection of busulfan (BU) (3.2mg/kg/d) from day -6 to -4, and intravenous injection of cyclophosphamide (CY) (1.8g/m(2)/d) from day -3 to -2 in IDA-BUCY2 regimen. For high-risk AML, cumulative probabilities of 3-year relapse rates in IDA-BUCY2 and traditional BUCY2 regimens were 16.9%, 43.3% (P=0.016). Cumulative probabilities of 3-year overall survival (OS) and disease-free survival (DFS) were 69.2% vs 44.0% (P=0.024), and 66.9% vs 38.2% (P=0.01). However, two regimens showed no significant differences for high-risk ALL. Multivariate analysis also indicated that IDA intensified BUCY2 conditioning was the favorable variable to reduce relapse and elevate survival for high-risk AML patients. In conclusion, IDA-BUCY2 regimen reduces relapse and improves survival for high-risk AML undergoing allo-HSCT, but not presenting uniform therapeutic effects for high-risk ALL.

Pretransplantation use of the second-generation tyrosine kinase inhibitors has no negative impact on the HCT outcome

Introduction

Allogeneic hematopoietic cell transplantation (HCT) was a standard therapy in chronic phase (CP) chronic myeloid leukemia (CML). As a result of the effective therapy with tyrosine kinase inhibitors (TKI), HCT was shifted to defined clinical situations. We present the results of observational prospective analysis of 28 CML patients undergoing HCT after exposure to, at least, two lines of TKI (including dasatinib and/or nilotinib), with respect to response, overall survival (OS), treatment toxicity, graft versus host disease (GVHD), and progression/relapse incidence.

Results

All the patients but one engrafted with median time 19 days. OS for patients in CP1 and CP2/accelerated phase (AcP) were 92.9 and 85.7 %, respectively. Six patients allotransplanted in blast crisis (BC) CML died early after HCT.

Eighteen patients achieved deep molecular remission (MR^4.5 or MR^4.0). Relapse incidence was 29.6 %. Median time to progression (TTP) differs significantly depending on the CML phase prior to HCT, the best response achieved after HCT and development of chronic GvHD.

NRM yielded the values 7.1, 12.5, and 50 % in CP1, CP2/AcP, and BC, respectively. Fatal outcome, due to veno-occlusive disease (VOD), was observed in two (7 %) patients. In five (17.9 %) patients, mild or moderate VOD was observed with no negative impact of preceding therapy with TKI2. Acute GvHD was diagnosed in 25.9 % of patients, while chronic GvHD developed in 42.9 % of individuals.

Conclusion

Pretransplantation therapy with TKI2 in CP CML is safe and reasonable. In BC, the optimal approach before HCT is to reduce the leukemic burden and achieve subsequent CP.

Allo-SCT using BU, CY and melphalan for children with AML in second CR

Based on the results from the AML-BFM 98 trial, hematopoietic SCT (HSCT) is recommended for children with AML in second CR only. Here, we retrospectively analyze interphase data of children who underwent HSCT after myeloablative conditioning with BU, CY, and melphalan (BuCyMel) for AML in second remission (CR2) between 1998 and 2009. Out of 152 children, transplant data were available on 109 individuals. Sixty out of 109 children (55%) received BuCyMel. Median age at HSCT was 12.2 years (range 3.0; 18.3). GVHD prophylaxis mostly consisted of CsA and short term MTX with or without antithymocyte globulin. Matched-sibling donors were used for 6/60 analyzed recipients, the remainder either received grafts from matched unrelated (30/60) or mismatched donors. OS after 5 years was 62% (s.e. 6%), relapse incidence 35% (18/60 children) and treatment-related mortality accounted for 12% (7/60) of fatal events. In conclusion, even taking into account possible selection bias in this retrospective analysis, HSCT in CR2 using BuCyMel resulted in a respectable OS. Based on this data the prospective, controlled and centrally monitored AML SCT-BFM 2007 trial has started to recruit patients in January 2010 aiming to generate valid outcome data for further strategy decisions.

Donor compatibility and performance status affect outcome of allogeneic haematopoietic stem cell transplant in patients with relapsed or refractory acute myeloid leukaemia

We retrospectively analysed 78 patients with relapsed (n = 38), primary refractory (n = 34) or untreated (n = 6) acute myeloid leukaemia (AML) who underwent allogeneic HSCT at our Institution between 2002 and 2011, to verify outcome and to identify factors that can affect long-term outcome. Myeloablative conditioning regimens were used in 48 patients (24 siblings, 24 matched unrelated donor (MUD)), while 30 patients (18 siblings, 12 MUD) received reduced-intensity conditioning. Acute graft versus host disease (GVHD) developed in 37 (47 %) patients, while chronic GVHD occurred in 19 of the 65 evaluable patients (29 %). With a median follow-up time of 5 years, 13 of 78 patients (17 %) are alive and in complete remission (CR), while 64 have died. Cause of death was disease recurrence in 37 patients (58 %), infection in ten patients (16 %) and GVHD in six (9 %). One-year non-relapse mortality was 35 %. In multivariate analysis, performance status ≥80 % WHO and a full-matched donor were associated with a better outcome: these two variables allowed for risk stratification, identifying three groups with significantly different survival after transplant (P = 0.0001). Considering post-transplant variables, only CR at recovery and development of cGVHD were correlated with a longer survival. Our data confirm the capacity of allogeneic transplant to prolong survival in a significant proportion of extremely high-risk AML patients.

Busulphan-cyclophosphamide cause endothelial injury, remodeling of resistance arteries and enhanced expression of endothelial nitric oxide synthase

Stem cell transplantation (SCT) is a curative treatment for malignant and non malignant diseases. However, transplantation-related complications including cardiovascular disease deteriorate the clinical outcome and quality of life. We have investigated the acute effects of conditioning regimen on the pharmacology, physiology and structure of large elastic arteries and small resistance-sized arteries in a SCT mouse model. Mesenteric resistance arteries and aorta were dissected from Balb/c mice conditioned with busulphan (Bu) and cyclophosphamide (Cy). In vitro isometric force development and pharmacology, in combination with RT-PCR, Western blotting and electron microscopy were used to study vascular properties. Compared with controls, mesenteric resistance arteries from the Bu-Cy group had larger internal circumference, showed enhanced endothelium mediated relaxation and increased expression of endothelial nitric oxide synthase (eNOS). Bu-Cy treated animals had lower mean blood pressure and signs of endothelial injury. Aortas of treated animals had a higher reactivity to noradrenaline. We conclude that short-term consequences of Bu-Cy treatment divergently affect large and small arteries of the cardiovascular system. The increased noradrenaline reactivity of large elastic arteries was not associated with increased blood pressure at rest. Instead, Bu-Cy treatment lowered blood pressure via augmented microvascular endothelial dependent relaxation, increased expression of vascular eNOS and remodeling toward a larger lumen. The changes in the properties of resistance arteries can be associated with direct effects of the compounds on vascular wall or possibly indirectly induced via altered translational activity associated with the reduced hematocrit and shear stress. This study contributes to understanding the mechanisms that underlie the early effects of conditioning regimen on resistance arteries and may help in designing further investigations to understand the late effects on vascular system.

Sirolimus and mycophenolate mofetil as GVHD prophylaxis in myeloablative, matched-related donor hematopoietic cell transplantation

We investigated sirolimus and mycophenolate mofetil (MMF) as graft-versus-host disease (GVHD) prophylaxis in patients with advanced hematologic malignancies receiving myeloablative hematopoietic cell transplantation (HCT) from HLA-identical sibling donors. Based on pre-study stopping rules, the trial was closed to accrual after enrollment of 11 adult patients. Seven of the 11 patients received busulfan-containing preparative regimens. Sirolimus was discontinued in 3 patients due to toxicity-related events of severe sinusoidal obstructive syndrome, portal vein thrombosis, altered mental status and in 1 patient due to risk of poor wound healing. Six of the 11 patients developed grade II-IV acute GVHD (AGVHD) a median of 15.5 days post-HCT. Two of 3 patients with grade IV AGVHD had sirolimus discontinued by 9 days post-HCT. All patients responded to AGVHD therapy without GVHD-related deaths. There were 2 nonrelapse- and 2 relapse-related deaths. At a median follow-up of 38 months (2–47 months), 7 of 11 patients were alive without disease. MMF and sirolimus GVHD prophylaxis did not reduce the risk of acute GVHD, however, there were no GVHD-related deaths. The severe toxicities in the patients receiving the busulfan-containing preparative regimens limited the continued use of sirolimus and MMF for the prevention of AGVHD.