Post‐transplantation cyclophosphamide versus conventional graft‐versus‐host disease prophylaxis in mismatched unrelated donor haematopoietic cell transplantation

Post‐transplantation cyclophosphamide (PTCy) is an effective strategy to prevent graft‐versus‐host disease (GVHD) after haploidentical haematopoietic cell transplantation (HCT). We determined the efficacy of PTCy‐based GVHD prophylaxis in human leucocyte antigen (HLA)‐mismatched unrelated donor (MMUD) HCT. We analysed 113 adult patients with high‐risk haematological malignancies who underwent one‐antigen MMUD transplantation between 2009 and 2013. Of these, 41 patients received PTCy, tacrolimus and mycophenolate mofetil (MMF) for GVHD prophylaxis; 72 patients received conventional prophylaxis with anti‐thymocyte globulin, tacrolimus and methotrexate. Graft source was primarily bone marrow (83% PTCy vs. 63% conventional group). Incidence of grade II–IV (37% vs. 36%, P = 0·8) and grade III–IV (17% vs. 12%, P = 0·5) acute GVHD was similar at day 100. However, the incidence of grade II‐IV acute GVHD by day 30 was significantly lower in the PTCy group (0% vs. 15%, P = 0·01). Median time to neutrophil (18 days vs. 12 days, P < 0·001) and platelet (25·5 days vs. 18 days, P = 0·05) engraftment was prolonged in PTCy group. Rates of graft failure, chronic GVHD, 2‐year non‐relapse mortality, relapse, progression‐free survival or overall survival were similar. Our results demonstrate that PTCy, tacrolimus and MMF for GVHD prophylaxis is safe and produced similar results as conventional prophylaxis in patients with one antigen HLA‐MMUD HCT.     

Improved outcome with hematopoietic stem cell transplantation in a poor prognostic subgroup of patients with mixed‐lineage‐leukemia‐rearranged acute leukemia: Results from a prospective,multi‐center study

The purpose of this study is to define the role for allogeneic hematopoietic stem cell transplantation (allo‐HSCT) in mixed‐lineage‐leukemia (MLL)‐rearranged acute leukemia, which is now poorly understood. A prospective, multi‐center cohort study to determine whether allo‐HSCT could decrease relapse rates and improve long‐term survival of MLL+ leukemia patients was performed. Fifty‐six consecutive patients diagnosed with MLL–rearranged acute leukemia undergoing allo‐HSCT from two transplant centers in China were enrolled between October 2007 and October 2012. The trial was registered at www.chictr.org as # ChiCTR‐ONC‐12002739. The incidences of grades II to IV acute graft versus host disease (aGVHD) and of grades III and IV aGVHD were 28.8% (CI, 16.87–40.8%), and 14.2% (CI, 5.4–23.0%), respectively. The cumulative incidences for chronic GVHD (cGVHD) at 2 years after HSCT were 35.2% (CI, 21.2–49.2%). Up to April 30, 2013, 12 patients had relapsed and 11 died from relapse, and 37 patients were still alive without disease recurrence. The relapse and NRM rates at 3 years were 25.3% (CI, 12.7–37.9%) and 18.0% (CI, 2.6–33.4%), respectively. The probalities of overall survival and leukemia free survival were 61.8% (CI, 46.0–77.6%) and 56.3% (CI, 38.1–74.5%) at 3 years, respectively. Patients transplanted during their hematological first complete remission (CR1) had a lower relapse rate (17.9% vs. 48.1%, P = 0.03) compared with patients transplanted beyond CR1. The median overall survival for the 29 patients not receiving allo‐HSCT during the study period was 145 days from diagnosis. This study showed that allo‐HSCT could be a valuable treatment choice for MLL+ acute leukemia. Am. J. Hematol. 89:130–136, 2014. © 2013 Wiley Periodicals, Inc.     

Comparable long‐term outcomes after reduced‐intensity conditioning versus myeloablative conditioning allogeneic stem cell transplantation for adult high‐risk acute lymphoblastic leukemia in complete remission

The role of reduced‐intensity conditioning (RIC) in adult acute lymphoblastic leukemia (ALL) remains unclear because of the small sample size, short follow‐up duration, various regimens for conditioning and graft‐versus‐host disease (GVHD) prophylaxis, and the heterogeneity of selection criteria for transplantation. We compared long‐term outcomes of 60 consecutive RIC transplants (fludarabine plus melphalan) with 120 myeloablative conditioning (MAC) transplants (total body irradiation plus cyclophosphamide) for adult high‐risk ALL in first or second complete remission. All transplants received a uniform strategy of pretransplant chemotherapy and GVHD prophylaxis. Compared to MAC transplants, RIC transplants had older age (46 years vs. 33 years, P < 0.001) and higher proportions of transplantation using peripheral blood (93.3% vs. 13.3%; P < 0.001) but otherwise showed similar characteristics. After a median follow‐up of 67 months, RIC transplants showed comparable nonrelapse mortality (21.2% vs. 24.3%) and disease‐free survival (50.8% vs. 54.9%) to MAC transplants, although relapse risk was higher (34.2% vs. 26.4%; HR, 2.07; P = 0.019) in multivariate analysis. Other independent factors associated with better outcomes were the presence of chronic GVHD and transplantation in first complete remission. Interestingly, the negative impact of RIC on relapse risk was seen only for Philadelphia‐positive ALL transplants (32.7% vs. 19.6%; HR, 3.46; P = 0.020), while no difference was found between RIC and MAC for Philadelphia‐negative ALL transplants (35.0% vs. 32.1%; HR, 1.39; P = 0.429). RIC can be considered as a reasonable choice for providing a sufficient long‐term graft‐versus‐leukemia effect for adult high‐risk ALL patients ineligible for MAC. Am. J. Hematol. 88:634–641, 2013. © 2013 Wiley Periodicals, Inc.     

Sirolimus and tacrolimus as immune prophylaxis compared to cyclosporine with or without methotrexate in patients undergoing allogeneic haematopoietic stem cell transplantation for non-malignant disorders

For prevention of graft‐versus‐host disease (GVHD), treatment of 24 haematopoietic stem cell transplantation (HSCT) patients with sirolimus and tacrolimus was compared to treatment of matched controls with cyclosporine‐based regimens. The patients mainly had non‐malignant disorders. Two‐thirds of the donors were unrelated, and bone marrow was the most common source of stem cells. Rejection occurred in four patients in the sirolimus group and three in the control group. Donor chimerism for CD3, CD19 and CD33 was similar in the two groups. The cumulative incidence of grade II acute GVHD was 22% in the sirolimus patients and 17% in the controls (P = 0.78). No patients developed acute GVHD of grades III–IV. The cumulative incidence of chronic GVHD was 25% and 37% in the two groups, respectively (P = 0.40). Two patients in the sirolimus group developed Epstein–Barr virus lymphoma, and none in the controls. Side effects and toxicity were similar in the two groups. There was no transplant‐related mortality at 5 yr in the sirolimus group, as opposed to 8% in the controls (P = 0.47). Survival at 5 yr was 95% and 92%. Thus, sirolimus combined with tacrolimus is a promising immunosuppressive regimen in HSCT, also for non‐malignancies, and its efficacy should be confirmed in prospective clinical trials.     

GVHD prophylaxis using low‐dose cyclosporine improves survival in leukaemic recipients of HLA‐identical sibling transplants

Graft‐versus‐host disease (GVHD) prophylaxis of short duration (6 months) with low‐dose cyclosporine A (CsA) starting at 1 mg/kg per day i.v. and four doses of methotrexate (MTX) were given to 171 consecutive leukaemic recipients of HLA‐identical sibling transplants. In contrast, apart from MTX, retrospective controls received high‐dose CsA, starting at 5–7.5 mg/kg per day i.v. and discontinued 1 yr post‐transplant. In the low‐dose CsA group, the probability of acute GVHD grades I–II (70% vs. 53%, P < 0.01), and chronic GVHD were increased (58% vs. 25%, P < 0.01), whereas the incidences of acute GVHD grades III–IV (9% vs. 5%, P = 0.62), and non‐relapse mortality (20% vs. 22%, P = 0.58) were similar. Moreover, the probability of relapse was decreased (31% vs. 54%, P < 0.01), and both relapse‐free (56% vs. 38%, P = 0.04) and overall survival (61% vs. 40%, P = 0.04) were markedly improved using the low‐dose CsA regimen. In multivariate analyses, low‐dose CsA was strongly associated with chronic GVHD [relative hazard (RH) 2.56, P < 0.01], which decreased the risk of relapse (RH 0.46, P < 0.01) and improved the probability of survival (RH 1.84, P < 0.01). In conclusion, a low‐dose CsA regimen in leukaemic recipients of HLA‐identical sibling transplants increases the rate of chronic GVHD, which seems to attenuate the risk of relapse, thereby improving patient survival owing to enhanced graft‐versus‐leukaemia effect.     

Haploidentical vs matched unrelated donor transplantation for acute myeloid leukemia in remission: A prospective comparative study

Despite comparable outcomes of haploidentical transplants (Haplo‐HSCT) with HLA‐matched unrelated transplants (MUD‐HSCT) in retrospective comparisons, few studies have prospectively compared Haplo‐HSCT with MUD‐HSCT in AML. Here, we prospectively compared the outcomes of Haplo‐HSCT with MUD‐HSCT for AML in remission (n = 110) to prove non‐inferiority of overall survival in Haplo‐HSCT. Both groups were well balanced in factors related to biological features of AML and measurable residual disease (MRD) status by Wilms' tumor gene 1 (WT1) assay. A unique, reduced‐toxicity preparative regimen was used for Haplo‐HSCT, whereas mostly‐myeloablative regimen was for MUD‐HSCT. Both groups showed similar patterns of neutrophil and platelet recovery, whereas delayed T‐cell reconstitution in Haplo‐HSCT was found compared with MUD‐HSCT. No significant differences were found in acute or chronic graft‐vs‐host‐disease (GVHD) and post‐transplant infectious events with an exception of EBV or CMV infection, which occurred more frequently in Haplo‐HSCT. After a median follow‐up of 47 months, no significant differences in overall survival (65% vs 54%, P = .146), disease‐free survival (67% vs 53%, P = .142), relapse (20% vs 21%, P = .858), non‐relapse mortality (14% vs 26%, P = .103), or GVHD‐free/relapse‐free survival (54% vs 41%, P = .138) were observed for Haplo‐HSCT vs MUD‐HSCT. In multivariate analysis, WT1 expression before transplantation independently predicted relapse, resulting in inferior survival. Separate analysis of unenrolled patients (n = 110) who were excluded or refused to participate in this study showed consistent results with enrolled patients. This prospective study demonstrated the non‐inferiority of Haplo‐HSCT to MUD‐HSCT for AML in remission, and validated the role of WT1 quantification as an MRD marker (ClinicalTrial.gov identifier: NCT01751997).     

The use of ATG abrogates the antileukemic effect of cytomegalovirus reactivation in patients with acute myeloid leukemia receiving grafts from unrelated donors

Several studies provided evidence of a consistent antileukemic effect induced by cytomegalovirus (CMV) replication in acute myeloid leukemia (AML) patients receiving allogeneic hematopoietic stem cell transplantation (HSCT), however the use of antithymocyte globulin (ATG) as graft‐versus‐host disease prophylaxis, may potentially abrogate the protective effect of CMV infection. To address this issue, we retrospectively analyzed the risk of relapse in a cohort of 101 patients with AML who received grafts from an unrelated donor after a conditioning regimen including ATG. The cumulative incidence of CMV reactivation, evaluated by RT qPCR, was 59% at 12 months, and 93% of CMV reactivations occurred within the first 100 days post HSCT. The 5‐year cumulative incidence of relapse in patients with CMV reactivation was 29% compared with 37% for patients without CMV reactivation, and the only factor associated with a reduced 5‐year cumulative incidence of relapse was the disease status at HSCT (P < 0.001). In the multivariable model adverse cytogenetics (HR 2.42, 95% CI 1.02‐5.72; P = 0.044) and acute GVHD (HR 3.36, 95% CI 1.32‐8.54; P = 0.011) were independent risk factors for reducing overall survival (OS), while the presence of chronic GVHD was associated with a better OS (HR 0.37, 95% CI 0.15‐0.89; P = 0.027). CMV replication was not an independent risk factor for OS (HR 1.06, 95% CI 0.07‐15.75; P = 0.965). In Conclusion, the results of present study suggest that relapse prevention in patients with AML receiving T‐cell depleted HSCT using ATG do not benefit from CMV reactivation. Am. J. Hematol. 90:E117–E121, 2015. © 2015 Wiley Periodicals, Inc.     

Sequential chemotherapy followed by reduced‐intensity conditioning and allogeneic haematopoietic stem cell transplantation in adult patients with relapse or refractory acute myeloid leukaemia: a survey from the Acute Leukaemia Working Party of EBMT

This study analysed the outcome of 267 patients with relapse/refractory acute myeloid leukaemia (AML ) who received sequential chemotherapy including fludarabine, cytarabine and amsacrine followed by reduced‐intensity conditioning (RIC ) and allogeneic haematopoietic stem cell transplantation (HSCT ). The transplants in 77 patients were from matched sibling donors (MSD s) and those in 190 patients were from matched unrelated donors. Most patients (94·3%) were given anti‐T‐cell antibodies. The incidence of acute graft‐versus‐host disease (GVHD ) of grades II ‒IV was 32·1% and that of chronic GVHD was 30·2%. The 3‐year probability of non‐relapse mortality (NRM ) was 25·9%, that of relapse was 48·5%, that of GVHD ‐free and relapse‐free survival (GRFS ) was 17·8% and that of leukaemia‐free survival (LFS ) was 25·6%. In multivariate analysis, unrelated donor recipients more frequently had acute GVHD of grades II ‒IV [hazard ratio (HR ) = 1·98, P  = 0·017] and suffered less relapses (HR  = 0·62, P  = 0·01) than MSD recipients. Treatment with anti‐T‐cell antibodies reduced NRM (HR  = 0·35, P  = 0·01) and improved survival (HR  = 0·49, P  = 0·01), GRFS (HR  = 0·37, P  = 0·0004) and LFS (HR  = 0·46, P  = 0·005). Thus, sequential chemotherapy followed by RIC HSCT and use of anti‐T‐cell antibodies seems promising in patients with refractory AML .     

Long-term outcomes of corticosteroid graft versus host disease prophylaxis in peripheral blood allogeneic haemopoietic stem cell transplant: a comparative cohort analysis

Background

Corticosteroids (CSs) have previously been incorporated into graft versus host disease (GVHD) prophylaxis regimens for bone marrow (BM) and haemopoietic stem cell transplant (HSCT).

Aims

To assess the impact of prophylactic CS in HSCT using peripheral blood (PB) stem cells.

Methods

Patients were identified from three HSCT centres receiving a first PB-HSCT between January 2011 and December 2015 from a fully human leukocyte antigen (HLA)-matched sibling or unrelated donor for acute myeloid leukaemia or acute lymphoblastic leukaemia. To enable meaningful comparison, patients were divided into two cohorts.

Results

Cohort 1 included only myeloablative-matched sibling HSCT, where the only variation in GVHD prophylaxis was the addition of CS. In these 48 patients, there were no differences in GVHD, relapse, non-relapse mortality, overall survival or GVHD-relapse-free-survival (GRFS) at 4 years after transplant. Cohort 2 included the remaining HSCT recipients, where one group received CS-prophylaxis and the non-CS group received an antimetabolite, ciclosporin and anti-T-lymphocyte globulin. In these 147 patients, those receiving CS-prophylaxis experienced higher rates of chronic GVHD (71% vs 18.1%, P < 0.001) and lower rates of relapse (14.9% vs 33.9%, P = 0.02). Those receiving CS-prophylaxis had a lower 4-year GRFS (15.7% vs 40.3%, P = 0.002).

Conclusions

There does not appear to be a role for adding CS to standard GVHD prophylaxis regimens in PB-HSCT.     

Allogeneic bone marrow vs. peripheral blood stem cell transplantation: a long-term retrospective single-center analysis in 329 patients

Objectives: Granulocyte colony‐stimulating factor‐mobilized peripheral blood hematopoietic stem cell transplantation (HSCT) provides a valuable and increasingly used alternative to bone marrow transplantation (BMT). This retrospective study aimed at determining whether the stem cell source is predictive for outcome, relapse incidence, non‐relapse mortality, and severity and incidence of both, acute and chronic graft‐versus‐host disease (GVHD) in patients undergoing allogeneic HSCT. Patients and methods: Between 1983 and 2007, 329 adult patients (median age 40, range 18–76) received a first allogeneic HSCT from either sibling (n = 203) or volunteer unrelated donors (n = 126) at our institution. The source of stem cells was bone marrow in 177 (54%) and peripheral blood in the remaining 152 (46%) patients. Results: Overall survival was 37% (31–43%, 95% confidence interval, CI), the relapse incidence was 30% (25–36%, 95% CI), and the non‐relapse mortality was 43% (38–49%, 95% CI) for the entire cohort with no significant differences between peripheral blood stem cell or BMT. In patients receiving myeloablative conditioning, peripheral blood stem cell transplantation (PBSCT) was associated with a significantly lower non‐relapse mortality (32% vs. 46%, P = 0.05), which, however, was restricted to standard‐risk disease (23% vs. 42%, P = 0.02). The overall cumulative incidences of acute GVHD II–IV were 51% and 54% following bone marrow and PBSCT, respectively. Severe acute GVHD III–IV was significantly more frequent after BMT (24% vs. 14%, P = 0.04), whereas chronic GVHD was significantly more frequent following PBSCT (48% vs. 24%, P = 0.0001). By multivariate analysis, PBSCT was only predictive for chronic GVHD (RR 2.29, P = 0.02). Conclusion: Although we failed to demonstrate any advantage of PBSCT over conventional BMT with regard to overall survival, relapse incidence and non‐relapse mortality PBSCT were associated with a significantly higher incidence of chronic graft‐versus‐host disease. Therefore, and by virtue of observations, that some patient groups might benefit from either stem cell source, there is still need for prospective randomized trials with special emphasize on quality of life in long‐term survivors.     

Next‐generation sequencing‐based detection of circulating tumour DNA After allogeneic stem cell transplantation for lymphoma

Next‐generation sequencing (NGS)‐based circulating tumour DNA (ctDNA) detection is a promising monitoring tool for lymphoid malignancies. We evaluated whether the presence of ctDNA was associated with outcome after allogeneic haematopoietic stem cell transplantation (HSCT) in lymphoma patients. We studied 88 patients drawn from a phase 3 clinical trial of reduced‐intensity conditioning HSCT in lymphoma. Conventional restaging and collection of peripheral blood samples occurred at pre‐specified time points before and after HSCT and were assayed for ctDNA by sequencing of the immunoglobulin or T‐cell receptor genes. Tumour clonotypes were identified in 87% of patients with adequate tumour samples. Sixteen of 19 (84%) patients with disease progression after HSCT had detectable ctDNA prior to progression at a median of 3·7 months prior to relapse/progression. Patients with detectable ctDNA 3 months after HSCT had inferior progression‐free survival (PFS) (2‐year PFS 58% vs. 84% in ctDNA‐negative patients, P = 0·033). In multivariate models, detectable ctDNA was associated with increased risk of progression/death (Hazard ratio 3·9, P = 0·003) and increased risk of relapse/progression (Hazard ratio 10·8, P = 0·0006). Detectable ctDNA is associated with an increased risk of relapse/progression, but further validation studies are necessary to confirm these findings and determine the clinical utility of NGS‐based minimal residual disease monitoring in lymphoma patients after HSCT.     

Reduced-intensity conditioning regimen with low-dose ATG-F for unrelated bone marrow transplant is associated with lower non-relapse mortality than a regimen with low-dose TBI: a single-center retrospective analysis of 103 cases

Although anti-T lymphocyte globulin-Fresenius (ATG-F) is commonly used as prophylaxis for graft-versus-host disease (GVHD), the appropriate dosage of ATG-F in the setting of a reduced-intensity conditioning (RIC) regimen has not been determined. In the present study, we retrospectively analyzed the clinical outcomes of 103 patients after unrelated bone marrow transplant (uBMT) with RIC regimens. RIC regimens consisted of purine analogue plus busulfan with low-dose TBI or ATG-F (5–10 mg/kg in total). Median age was 57 years (range 20–68). The incidence of grade II–IV acute GVHD and chronic GVHD with ATG-F was significantly lower than that with TBI 2 Gy (15 vs. 61 %, P < 0.05; 33 vs. 57 %, P < 0.05). The incidence of 2-year NRM with ATG-F was significantly lower than that with TBI 2 Gy (6 vs. 28 %, P < 0.05). There was no statistically significant difference in the cumulative incidence of 2-year relapse between the ATG-F and TBI 2 Gy groups (37 vs. 20 %, P = 0.13). In conclusion, the addition of low-dose ATG-F to GVHD prophylaxis in patients who received uBMT resulted in decreased incidence of acute and chronic GVHD, which led to a significantly reduced risk of NRM without compromising overall survival. The beneficial effect of low-dose ATG-F should be assessed in a prospective clinical trial.     

Primary treatment of leukemia relapses after allogeneic hematopoietic stem cell transplantation with reduced‐intensity conditioning second transplantation from the original donor

Acute leukemia relapsing after allogeneic hematopoietic stem cell transplantation (HSCT) has dismal outcome. Consecutive consenting patients (acute myeloid leukemia: N = 71; acute lymphoblastic leukemia: N = 37), at a median age of 37 (16–57) years, who had relapsed 7.9 (1.3–132) months post‐HSCT, were treated with three cytarabine‐based intensive regimens as reduced‐intensity conditioning (RIC), followed by infusion of mobilized HSC from the original donors. There were four treatment‐related mortalities (TRMs). Of 104 evaluable cases, 72 patients (67%) achieved complete remission (CR)/CR with incomplete hematologic recovery (CRi). The median overall survival (OS) of the entire cohort was 11.6 months. The OS of patients achieving CR/CRi after the first RIC/HSCT was 18.8 months, as compared with 3.9 months for those not (P < 0.01). For 32 patients with nonremission, 11 received a repeat RIC‐HSCT, leading to CR/CRi in three cases. Therefore, 75/108 (69%) of patients achieved CR/CRi after one or two courses of RIC‐HSCT. Among CR/CRi patients, 48 cases relapsed again after 6.1 (1.0–64.4) months. Thirty cases received a repeat RIC‐HSCT, leading to CR/CRi in 22 patients. Multivariate analyses showed a significant impact of remission duration after initial HSCT (P = 0.026) and the presence of acute graft‐versus‐host disease after RIC‐HSCT (P = 0.011) on CR/CRi. RIC‐HSCT as primary treatment for acute leukemic relapses post‐HSCT induced a high CR rate with low TRM. Optimal postremission treatment remains to be defined. Am. J. Hematol. 88:485–491, 2013. © 2013 Wiley Periodicals, Inc.     

Salvage chemotherapy followed by granulocyte colony‐stimulating factor‐primed donor leukocyte infusion with graft‐vs.‐host disease control for minimal residual disease in acute leukemia/myelodysplastic syndrome after allogeneic hematopoietic stem cell transplantation: prognostic factors and clinical outcomes

This study investigated the prognostic factors and clinical outcomes of preemptive chemotherapy followed by granulocyte colony‐stimulating factor‐primed donor leukocyte infusion (Chemo‐DLI) according to minimal residual disease (MRD) status in patients with acute leukemia and myelodysplastic syndromes who received allogeneic hematopoietic stem cell transplantation (HSCT) (n = 101). Patients received immunosuppressive drugs to prevent graft‐vs.‐host disease (GVHD) after Chemo‐DLI. The 3‐yr cumulative incidences of relapse, non‐relapse mortality, and disease‐free survival (DFS) after HSCT were 39.5%, 9.6%, and 51.7%, respectively. The cumulative incidences of relapse and DFS were significantly poorer in patients who exhibited early‐onset MRD. Forty‐four patients turned MRD negative 1 month after Chemo‐DLI; their cumulative incidences of relapse and DFS were significantly better than those with persistent MRD 1 month after preemptive Chemo‐DLI (relapse: 19.8% vs. 46.8%, P = 0.001; DFS: 69.6% vs. 46.4%, P = 0.004). The cumulative incidences of relapse and DFS after HSCT were significantly better in patients with chronic GVHD (cGVHD) than those without cGVHD (relapse: 19.6% vs. 63.7%, P < 0.001; DFS: 74.4% vs. 23.8%, P < 0.001). Early‐onset MRD, persistent MRD after Chemo‐DLI, and non‐cGVHD after Chemo‐DLI, which were associated with increased relapse and impaired DFS, suggest unsatisfactory response to preemptive Chemo‐DLI.     

Haematopoietic stem cell transplantation for refractory Langerhans cell histiocytosis: outcome by intensity of conditioning

Patients with Langerhans cell histiocytosis (LCH) refractory to conventional chemotherapy have a poor outcome. There are currently two promising treatment strategies for high‐risk patients: the first involves the combination of 2‐chlorodeoxyadenosine and cytarabine; the other approach is allogeneic haematopoietic stem cell transplantation (HSCT). Here we evaluated 87 patients with high‐risk LCH who were transplanted between 1990 and 2013. Prior to the year 2000, most patients underwent HSCT following myeloablative conditioning (MAC): only 5 of 20 patients (25%) survived with a high rate (55%) of transplant‐related mortality (TRM). After the year 2000 an increasing number of patients underwent HSCT with reduced intensity conditioning (RIC): 49/67 (73%) patients survived, however, the improved survival was not overtly achieved by the introduction of RIC regimens with similar 3‐year probability of survival after MAC (77%) and RIC transplantation (71%). There was no significant difference in TRM by conditioning regimen intensity but relapse rates were higher after RIC compared to MAC regimens (28% vs. 8%, P = 0·02), although most patients relapsing after RIC transplantation could be salvaged with further chemotherapy. HSCT may be a curative approach in 3 out of 4 patients with high risk LCH refractory to chemotherapy: the optimal choice of HSCT conditioning remains uncertain.     

Tacrolimus instead of cyclosporine used for prophylaxis against graft-versus-host disease improves outcome after hematopoietic stem cell transplantation from unrelated donors, but not from HLA-identical sibling donors: a nationwide survey conducted in Japan

Despite recent advances, graft-versus-host disease (GVHD) remains the main cause of treatment failure for patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Tacrolimus (FK506) has been increasingly used in place of cyclosporine (CSP), and several studies have shown that FK506 reduces the incidence of acute GVHD more effectively than does CSP. However, no survival benefits have been demonstrated, and no established consensus exists on the choice of these immunosuppressive agents. To compare a CSP-based and an FK506-based regimen, we performed a large-scale retrospective study by using the data of 1935 patients who underwent HSCT from HLA-identical sibling donors (SIB-HSCT) and 777 patients who underwent HSCT from unrelated donors (UD-HSCT). For patients undergoing UD-HSCT, FK506 significantly reduced the risk of acute GVHD and treatment-related mortality (TRM) without an increase in relapse, thus improving overall survival (OS) (hazard ratio (HR): 2.20, 95% confidence interval (CI): 1.60-3.04, P<0.0001 for grade II-IV acute GVHD; HR: 1.81, 95% CI: 1.32-2.48, P=0.0003 for TRM; HR: 1.62, 95% CI: 1.23-2.14, P=0.0007 for OS). This superiority of FK506 was not observed in SIB-HSCT cases. These findings indicate that the use of FK506 instead of CSP for GVHD prophylaxis is beneficial for patients undergoing UD-HSCT.     

Treatment with mesenchymal stromal cells is a risk factor for pneumonia-related death after allogeneic hematopoietic stem cell transplantation

We performed a retrospective cohort study to find out whether the use of reduced‐intensity conditioning (RIC) might reduce the risk of early death from pneumonia. Pneumonia‐associated deaths were evaluated in 691 hematopoietic stem cell transplantation (HSCT) patients. The majority had a hematological malignancy (n = 504) and an HLA‐matched donor (n = 584). RIC was given to 336 patients and myeloablative conditioning (MAC) to 355. Data concerning radiology, culture and autopsy results were evaluated together with risk factors for death related to pneumonia within or after 100 d after HSCT (early and overall pneumonia). In 60 patients, pneumonia contributed to death (early n = 17). The cumulative incidence of early pneumonia‐related death was 2.8% and 2.1% in MAC and RIC patients, respectively. The cumulative incidence of overall pneumonia‐related death was 8.2% and 10.5%, respectively. In 40 patients, (67%) an etiology could be established, with 19 patients having proven or probable mold infection. In the multivariate analyses, acute graft‐versus‐host disease (GVHD) grades II–IV, cytomegalovirus (CMV) infection and having received mesenchymal stromal cells (MSCs) were factors associated with overall pneumonia‐related death. Bacteremia and a previous HSCT were associated with early pneumonia‐related death. RIC did not reduce the incidence of early death associated with pneumonia. Acute GVHD II–IV, CMV infection and MSC treatment were factors associated with pneumonia‐related death. Mold infection was the most common contributor to pneumonia‐related death in HSCT patients.     

RB but not R‐HCVAD is a feasible induction regimen prior to auto‐HCT in frontline MCL: results of SWOG Study S1106

Aggressive induction chemotherapy followed by autologous haematopoietic stem cell transplant (auto‐HCT ) is effective for younger patients with mantle cell lymphoma (MCL ). However, the optimal induction regimen is widely debated. The Southwestern Oncology Group S1106 trial was designed to assess rituximab plus hyperCVAD /MTX /ARAC (hyperfractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone, alternating with high dose cytarabine and methotrexate) (RH ) versus rituximab plus bendamustine (RB ) in a randomized phase II trial to select a pre‐transplant induction regimen for future development. Patients had previously untreated stage III , IV , or bulky stage II MCL and received either 4 cycles of RH or 6 cycles of RB , followed by auto‐HCT . Fifty‐three of a planned 160 patients were accrued; an unacceptably high mobilization failure rate (29%) on the RH arm prompted premature study closure. The estimated 2‐year progression‐free survival (PFS ) was 81% vs. 82% and overall survival (OS ) was 87% vs. 88% for RB and RH , respectively. RH is not an ideal platform for future multi‐centre transplant trials in MCL . RB achieved a 2‐year PFS of 81% and a 78% MRD negative rate. Premature closure of the study limited the sample size and the precision of PFS estimates and MRD rates. However, RB can achieve a deep remission and could be a platform for future trials in MCL .     

Pre‐transplant cytomegalovirus (CMV) serostatus remains the most important determinant of CMV reactivation after allogeneic hematopoietic stem cell transplantation in the era of surveillance and preemptive therapy

B. George, N. Pati, N. Gilroy, M. Ratnamohan, G. Huang, I. Kerridge, M. Hertzberg, D. Gottlieb, K. Bradstock. Pre‐transplant cytomegalovirus (CMV) serostatus remains the most important determinant of CMV reactivation after allogeneic hematopoietic stem cell transplantation in the era of surveillance and preemptive therapy.
Transpl Infect Dis 2010: 12: 322–329. All rights reserved Abstract: Between January 2001 and June 2008, 315 adult patients (median age 43 years, range 16–65) including 203 males and 112 females undergoing hematopoietic stem cell transplantation (HSCT) had serial monitoring for cytomegalovirus (CMV) followed by initiation of preemptive therapy. The majority (62.1%) had a conventional myeloablative transplant with 116 (36.9%) having a reduced‐intensity conditioning (RIC) transplant, using either matched sibling/family (63.3%) or unrelated donors (36.7%). Graft source was peripheral blood stem cells in 257 (81.5%), bone marrow in 41 (13.1%), and cord blood in 16 (5.4%). T‐cell depletion with anti‐thymocyte globulin or alemtuzumab was used in 35%. Based upon CMV serostatus, patients were classified into low risk (donor [D]?/recipient [R]?), intermediate risk (D+/R?), or high risk (D?/R+ or D+/R+). Serial weekly monitoring for CMV viremia was performed using a qualitative polymerase chain reaction (PCR) and when positive, quantification was done using either pp65 antigen or a quantitative PCR. CMV reactivation was seen in 123 patients (39.1%) at a median of 50 days post HSCT (range 22–1978). CMV serostatus was the most important risk factor with incidence of 53% in the high‐risk group (53.3%) compared with 10.2% in the intermediate risk and 0% in the low‐risk group (P<0.0001). Other significant risk factors identified included use of alemtuzumab during conditioning (P=0.03), RIC transplants (P=0.06), and the presence of acute graft‐versus‐host disease (GVHD) (P<0.0001). On a multivariate analysis, CMV serostatus, RIC transplants, and acute GVHD remained independent predictors of CMV reactivation. All were treated with antiviral therapy with responses seen in 109 (88.6%). Sixteen patients (13%) developed CMV disease at a median of 59 days post HSCT (range 26 days–46 months), 8 of whom died. At a median follow up of 43 months (range 6–93), 166 patients (52.6%) are alive with a significantly higher survival among patients without CMV reactivation (57.2%) as compared with patients with CMV reactivation (45.5%; P=0.049). CMV reactivation and disease remains a major problem in high‐risk patients undergoing allogeneic HSCT. Novel prophylactic measures such as immunotherapy and drug prophylaxis need to be considered in this specific group of patients.     

Reduced intensity conditioning in unrelated donor transplantation for refractory cytopenia in childhood

Myelodysplastic syndromes (MDS) are a heterogenous group of acquired hematopoietic stem cell disorders. Refractory cytopenia (RC) is the most common subtype of childhood MDS and hematopoietic stem cell transplantation (HSCT) is the only curative treatment. HSCT following a myeloablative preparative regimen is associated with a low probability of relapse and considerable transplant-related mortality. In the present European Working Groups of MDS pilot study, we investigated whether a reduced intensity conditioning regimen (RIC) is able to offer reduced toxicity without increased rates of graft failure or relapse. Nineteen children with RC were transplanted from an unrelated donor following RIC consisting of fludarabine, thiotepa and anti-thymocyte globulin. Three patients experienced graft failure. Neutrophil and platelet engraftment occurred at a median time of 23 and 30 days, respectively. Cumulative incidence of grade II-IV and grade III and IV acute graft-versus-host disease (GVHD) was 0.48 and 0.13, respectively; three patients developed extensive chronic GVHD. Although infections were the predominant complications, only one patient with extensive chronic GVHD died from infectious complications. Overall and event-free survival at 3 years were 0.84 and 0.74, respectively. In conclusion, our results were comparable to those of patients treated with myeloablative HSCT. Long-term follow-up is needed to demonstrate the expected reduction in long-term sequelae.