Nonlocal Spin Dynamics in the Crossover from Diffusive to Ballistic Transport.

Improved fabrication techniques have enabled the possibility of ballistic transport and unprecedented spin manipulation in ultraclean graphene devices. Spin transport in graphene is typically probed in a nonlocal spin valve and is analyzed using spin diffusion theory, but this theory is not necessarily applicable when charge transport becomes ballistic or when the spin diffusion length is exceptionally long. Here, we study these regimes by performing quantum simulations of graphene nonlocal spin valves. We find that conventional spin diffusion theory fails to capture the crossover to the ballistic regime as well as the limit of long spin diffusion length. We show that the latter can be described by an extension of the current theoretical framework. Finally, by covering the whole range of spin dynamics, our study opens a new perspective to predict and scrutinize spin transport in graphene and other two-dimensional material-based ultraclean devices.

Phase I/II Trial of a Combination of Anti-CD3/CD7 Immunotoxins for Steroid-Refractory Acute Graft-versus-Host Disease.

Effective therapies for treating patients with steroid-refractory acute graft-versus-host-disease (SR-aGVHD), particularly strategies that reduce the duration of immunosuppression following remission, are urgently needed. The investigated immunotoxin combination consists of a mixture of anti-CD3 and anti-CD7 antibodies separately conjugated to recombinant ricin A (CD3/CD7-IT), which induces in vivo depletion of T cells and natural killer (NK) cells and suppresses T cell receptor activation. We conducted a phase I/II trial to examine the safety and efficacy of CD3/CD7-IT in 20 patients with SR-aGVHD; 17 of these patients (85%) had severe SR-aGVHD, and all 20 patients had visceral organ involvement, including 18 (90%) with gastrointestinal (GI) involvement and 5 (25%) with liver involvement. A validated 2-biomarker algorithm classified the majority of patients (11 of 20) as high risk. On day 28 after the start of CD3/CD7-IT therapy, the overall response rate was 60% (12 of 20), with 10 patients (50%) achieving a complete response. The 6-month overall survival rate was 60% (12 of 20), including 64% (7 of 11) classified as high risk by biomarkers. The 1-week course of treatment with CD3/CD7-IT caused profound but transient depletion of T cells and NK cells, followed by rapid recovery of the immune system with a diverse TCR Vß repertoire, and preservation of Epstein-Barr virus- and cytomegalovirus-specific T cell clones. Furthermore, our results indicate that CD3/CD7-IT appeared to be safe and well tolerated, with a relatively low prevalence of manageable and reversible adverse events, primarily worsening of hypoalbuminemia, microangiopathy, and thrombocytopenia. These encouraging results suggest that CD3/CD7-IT may improve patient outcomes in patients with SR-aGVHD.

Measurable residual disease-guided treatment with azacitidine to prevent haematological relapse in patients with myelodysplastic syndrome and acute myeloid leukaemia (RELAZA2): an open-label, multicentre, phase 2 trial.

BACKGROUND: Monitoring of measurable residual disease (MRD) in patients with advanced myelodysplastic syndromes (MDS) or acute myeloid leukaemia (AML) who achieve a morphological complete remission can predict haematological relapse. In this prospective study, we aimed to determine whether MRD-guided pre-emptive treatment with azacitidine could prevent relapse in these patients. METHODS: The relapse prevention with azacitidine (RELAZA2) study is an open-label, multicentre, phase 2 trial done at nine university health centres in Germany. Patients aged 18 years or older with advanced MDS or AML, who had achieved a complete remission after conventional chemotherapy or allogeneic haemopoietic stem-cell transplantation, were prospectively screened for MRD during 24 months from baseline by either quantitative PCR for mutant NPM1, leukaemia-specific fusion genes (DEK-NUP214, RUNX1-RUNX1T1, CBFb-MYH11), or analysis of donor-chimaerism in flow cytometry-sorted CD34-positive cells in patients who received allogeneic haemopoietic stem-cell transplantation. MRD-positive patients in confirmed complete remission received azacitidine 75 mg/m2 per day subcutaneously on days 1-7 of a 29-day cycle for 24 cycles. After six cycles, MRD status was reassessed and patients with major responses (MRD negativity) were eligible for a treatment de-escalation. The primary endpoint was the proportion of patients who were relapse-free and alive 6 months after the start of pre-emptive treatment. Analyses were done per protocol. This trial is registered with ClincialTrials.gov, number NCT01462578, and finished recruitment on Aug 21, 2018. FINDINGS: Between Oct 10, 2011, and Aug 20, 2015, we screened 198 patients with advanced MDS (n=26) or AML (n=172), of whom 60 (30%) developed MRD during the 24-month screening period and 53 (88%) were eligible to start study treatment. 6 months after initiation of azacitidine, 31 (58%, 95% CI 44-72) of 53 patients were relapse-free and alive (p<0·0001; one-sided binomial test for null hypothesis pexp≤0·3). With a median follow-up of 13 months (IQR 8·5-22·8) after the start of MRD-guided treatment, relapse-free survival at 12 months was 46% (95% CI 32-59) in the 53 patients who were MRD-positive and received azacitidine. In MRD-negative patients, 12-month relapse-free survival was 88% (95% CI 82-94; hazard ratio 6·6 [95% CI 3·7-11·8], p<0·0001). The most common (grade 3-4) adverse event was neutropenia, occurring in 45 (85%) of 53 patients. One patient with neutropenia died because of an infection considered possibly related to study treatment. INTERPRETATION: Pre-emptive therapy with azacitidine can prevent or substantially delay haematological relapse in MRD-positive patients with MDS or AML who are at high risk of relapse. Our study also suggests that continuous MRD negativity during regular MRD monitoring might be prognostic for patient outcomes. FUNDING: Celgene Pharma, José Carreras Leukaemia Foundation, National Center for Tumor Diseases (NCT), and German Cancer Consortium (DKTK) Foundation.

Relative Impact of HLA Matching and Non-HLA Donor Characteristics on Outcomes of Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia and Myelodysplastic Syndrome.

Increasing donor-recipient HLA disparity is associated with negative outcomes of allogeneic hematopoietic stem cell transplantation (HSCT), but its comparative relevance amid non-HLA donor characteristics is not well established. We addressed this question in 3215 HSCTs performed between 2005 and 2013 in Germany for acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Donors were HLA-matched related (MRD; n = 872) or unrelated (10/10 MUD, n = 1553) or HLA-mismatched unrelated (<10/10 MMUD, n = 790). Overall survival (OS) was similar after MRD compared with 10/10 MUD HSCT, reflecting opposing hazards of relapse (hazard ratio [HR], 1.32; P < .002) and nonrelapse mortality (HR, .63; P < .001). After UD HSCT, increasing HLA disparity was associated with inferior OS (HR, 1.21 [P < .02] and HR, 1.57 [P < .001] for 9/10 and ≤8/10 MMUD, respectively, compared with 10/10 MUD). Among non-HLA donor characteristics, age, sex mismatching (male recipient-female donor), and cytomegalovirus (CMV) mismatching (positive recipient-negative donor) impacted OS. Multivariate subgroup analysis showed that OS was similar after HSCT from the youngest 9/10 MMUD (<30 years) compared with the oldest 10/10 MUD (>40 years) (HR, 1.18; P = .25) and also in male patients transplanted from female 10/10 MUD compared with male 9/10 MMUD (HR, .89; P = .46). In contrast, OS of CMV-positive patients tended to be better with CMV-negative 10/10 MUDs compared with CMV-positive 9/10 MMUDs (HR, 1.31; P = .04). Because of low patient numbers in subgroups, definite conclusions and establishment of a hierarchy among HLA matching and non-HLA donor characteristics could not be made. Our data suggest that the impact of donor age and sex mismatch but not CMV mismatch on outcome of allogeneic HSCT may be comparable with that of single HLA disparity.

High-dose melphalan-based sequential conditioning chemotherapy followed by allogeneic haematopoietic stem cell transplantation in adult patients with relapsed or refractory acute myeloid leukaemia.

Considering the unsatisfactory results of salvage therapies for patients with relapsed/refractory acute myeloid leukaemia (R/R-AML), their value before allogeneic haematopoietic stem cell transplantation (HSCT) remains questionable. However, direct allogeneic HSCT following established conditioning regimens applied in patients with R/R-AML during active disease has been equally disappointing. In this retrospective observational study, high-dose melphalan, as part of a sequential preparative regimen, followed by a total body irradiation (4 × 2 Gy)-based or a treosulfan-based dose-adapted conditioning therapy for allogeneic HSCT was administered to 292 adult patients (median age 56 years, range 17-74) with primary refractory (144 patients), secondary refractory (97 patients) or relapsed AML (51 patients). Overall survival rates at 3 years were 34%, 29% and 41%, respectively. Risk factors associated with an inferior survival were higher age, transplantation from a human leucocyte antigen-mismatched donor and high disease burden. Patients transplanted with blast infiltration <20% showed a notable survival rate of 51% at 3 years. In particular, patients with primary refractory AML showed a more favourable outcome when transplanted early during their disease course. Thus, high-dose melphalan-based sequential conditioning chemotherapy followed by an allogeneic HSCT is feasible and enables long-term remission to be achieved in a substantial proportion of patients with active R/R-AML.

Control of Multidrug-Resistant Pseudomonas aeruginosa in Allogeneic Hematopoietic Stem Cell Transplant Recipients by a Novel Bundle Including Remodeling of Sanitary and Water Supply Systems.

Background: Infections by multidrug-resistant Pseudomonas aeruginosa (MDRPa) are an important cause of morbidity and mortality in patients after allogeneic hematopoietic stem cell transplantation (HSCT). Humid environments can serve as a reservoir and source of infection by this pathogen. To minimize the risk of infection from these reservoirs, we performed extensive remodeling of sanitation and water installations as the focus of our hygiene bundle. Methods: During the reconstruction of our transplantation unit (April 2011-April 2014) we implemented several technical modifications to reduce environmental contamination by and subsequent spreading of MDRPa, including a newly designed shower drain, disinfecting siphons underneath the sinks, and rimless toilets. During a 3-year study period (2012-2014), we tracked the number of patients affected by MDRPa (colonized and/or infected) and the outcome of infected patients, and monitored the environmental occurrence of this pathogen. We further performed whole-genome sequencing of nosocomial MDRPa strains to evaluate genotypic relationships between isolates. Results: Whereas 31 (9.2%; 18 colonized, 13 infected) patients were affected in 2012 and 2013, the number decreased to 3 in 2014 (17%; 3 colonized, 0 infected). Lethality by MDRPa similarly decreased from 3.6% to 0%. Environmental detection of MDRPa decreased in toilets from 18.9% in 2012-2013 to 6.1% in the following year and from 8.1% to 3.0%, respectively, in shower outlets. Whole-genome sequencing showed close relationships between environmental and patient-derived isolates. Conclusions: Hospital construction measures aimed at controlling environmental contamination by and spread of MDRPa are effective at minimizing the risk of highly lethal MDRPa infections.

Letermovir for cytomegalovirus prophylaxis in hematopoietic-cell transplantation.

BACKGROUND: Cytomegalovirus (CMV) infection is a leading cause of illness and death in patients who have undergone allogeneic hematopoietic-cell transplantation. Available treatments are restricted by clinically significant toxic effects and drug resistance. METHODS: In this phase 2 study, we evaluated the effect of letermovir (also known as AIC246), a new anti-CMV drug with a novel mechanism of action, on the incidence and time to onset of prophylaxis failure in CMV-seropositive recipients of allogeneic hematopoietic-cell transplants from matched related or unrelated donors. From March 2010 through October 2011, we randomly assigned 131 transplant recipients in a 3:1 ratio to three sequential study cohorts according to a double-blind design. Patients received oral letermovir (at a dose of 60, 120, or 240 mg per day, or matching placebo) for 12 weeks after engraftment. The primary end point was all-cause prophylaxis failure, defined as discontinuation of the study drug because of CMV antigen or DNA detection, end-organ disease, or any other cause. Patients underwent weekly surveillance for CMV infection. RESULTS: The reduction in the incidence of all-cause prophylaxis failure was dose-dependent. The incidence of prophylaxis failure with letermovir, as compared with placebo, was 48% versus 64% at a daily letermovir dose of 60 mg (P=0.32), 32% at a dose of 120 mg (P=0.01), and 29% at a dose of 240 mg (P=0.007). Kaplan-Meier time-to-onset profiles for prophylaxis failure showed a significant difference in the comparison of letermovir at a dose of 240 mg per day with placebo (P=0.002). The safety profile of letermovir was similar to placebo, with no indication of hematologic toxicity or nephrotoxicity. CONCLUSIONS: Letermovir, as compared with placebo, was effective in reducing the incidence of CMV infection in recipients of allogeneic hematopoietic-cell transplants. The highest dose (240 mg per day) had the greatest anti-CMV activity, with an acceptable safety profile. (Funded by AiCuris; ClinicalTrials.gov number, NCT01063829.).

Control of the Oscillatory Interlayer Exchange Interaction with Terahertz Radiation.

The oscillatory interlayer exchange interaction between two magnetic layers separated by a metallic spacer is one of the few coherent quantum phenomena that persists at room temperature. Here, we show that this interaction can be controlled dynamically by illuminating the sample (e.g., a spin valve) with radiation in the 10-100 THz range. We predict that the exchange interaction can be changed from ferromagnetic to antiferromagnetic (and vice versa) by tuning the amplitude and/or the frequency of the radiation. Our chief theoretical result is an expression that relates the dynamical exchange interaction to the static one that has already been extensively measured.

Blinatumomab or Inotuzumab Ozogamicin as Bridge to Allogeneic Stem Cell Transplantation for Relapsed or Refractory B-lineage Acute Lymphoblastic Leukemia: A Retrospective Single-Center Analysis.

BACKGROUND: Blinatumomab and inotuzumab ozogamicin are now widely used to treat relapsed or refractory B-cell acute lymphoblastic leukemia (r/r B-ALL). PATIENTS AND METHODS: We have reported the clinical course of 34 adult patients with r/r B-ALL receiving blinatumomab or inotuzumab ozogamicin at our institution from 2009 to 2019. RESULTS: Blinatumomab-based salvage therapy was applied for overt r/r B-ALL (n = 13) or minimal residual disease (MRD) positivity (n = 5). Of the 13 patients with r/r B-ALL, 9 (69%; 95% confidence interval [CI], 39%-91%) achieved complete remission (CR), with 78% of CR patients (95% CI, 40%-97%) reaching MRD negativity. MRD negativity was also achieved in all 5 patients treated for MRD positivity. The 1-year overall survival of patients receiving blinatumomab for r/r B-ALL and MRD positivity was 54% (n = 13; 95% CI, 26%-81%) and 80% (n = 5; 95% CI, 44-100), respectively. In the inotuzumab ozogamicin group, all 16 patients were treated for overt r/r B-ALL. The rate of CR was 94% (95% CI, 70%-100%), with 67% (95% CI, 38%-88%) of CR patients reaching MRD negativity. The 1-year OS after the first application of inotuzumab ozogamicin was 46% (95% CI, 18%-74%). Of those patients receiving blinatumomab and inotuzumab ozogamicin as a bridge-to-transplant strategy, 79% and 80%, respectively, proceeded to allogeneic stem cell transplantation. The most frequent drug-specific adverse events were similar to those previously reported, including cytokine release syndrome, capillary leak syndrome, and neurotoxicity for blinatumomab and transplant-associated veno-occlusive disease of the liver for inotuzumab ozogamicin. CONCLUSION: Together with previous observations from phase III clinical trials, these data suggest that blinatumomab and inotuzumab ozogamicin are highly effective salvage regimens in r/r B-ALL.

Monitoring minimal residual/relapsing disease after allogeneic haematopoietic stem cell transplantation in adult patients with acute lymphoblastic leukaemia.

Relapse after allogeneic haematopoietic stem cell transplantation (SCT) is a major cause of death in patients with acute lymphoblastic leukaemia (ALL). Here, we retrospectively analysed the contributions of lineage-sorted donor cell chimerism (sDCC) and quantitative PCR (qPCR) targeting disease-specific genetic rearrangements to detect minimal residual/relapsing disease (MRD) and predict impending relapse in 94 adult ALL patients after SCT. With a median follow-up of surviving patients (n = 61) of 3.3 years, qPCR and/or sDCC measurements turned positive in 38 patients (40%). Of these, 22 patients relapsed and 16 remained in complete remission. At 3 years, qPCR and/or sDCC positive patients showed an increased incidence of relapse (50% vs. 4%, p < 0.0001), decreased relapse-free survival (RFS, 40% vs. 85%, p < 0.0001), and decreased overall survival (OS, 47% vs. 87%, p 0.004). Both, qPCR and sDCC pre-detected 11 of 21 relapses occurring within the first two years after SCT and, overall, complemented for each other method in four of the relapsing and four of the non-relapsing cases. Patients receiving pre-emptive MRD-driven interventions (n = 11) or not (n = 10) showed comparable median times until relapse, RFS, and OS. In our single centre cohort, qPCR and sDCC were similarly effective and complementary helpful to indicate haematological relapse of ALL after SCT.

Treosulfan or busulfan plus fludarabine as conditioning treatment before allogeneic haemopoietic stem cell transplantation for older patients with acute myeloid leukaemia or myelodysplastic syndrome (MC-FludT.14/L): a randomised, non-inferiority, phase 3 trial.

BACKGROUND: Further improvement of preparative regimens before allogeneic haemopoietic stem cell transplantation (HSCT) is an unmet medical need for the growing number of older or comorbid patients with acute myeloid leukaemia or myelodysplastic syndrome. We aimed to evaluate the efficacy and safety of conditioning with treosulfan plus fludarabine compared with reduced-intensity busulfan plus fludarabine in this population. METHODS: We did an open-label, randomised, non-inferiority, phase 3 trial in 31 transplantation centres in France, Germany, Hungary, Italy, and Poland. Eligible patients were 18-70 years, had acute myeloid leukaemia in first or consecutive complete haematological remission (blast counts <5% in bone marrow) or myelodysplastic syndrome (blast counts <20% in bone marrow), Karnofsky index of 60% or higher, and were indicated for allogeneic HSCT but considered at an increased risk for standard myeloablative preparative regimens based on age (≥50 years), an HSCT-specific comorbidity index of more than 2, or both. Patients were randomly assigned (1:1) to receive either intravenous 10 g/m2 treosulfan daily applied as a 2-h infusion for 3 days (days -4 to -2) or 0·8 mg/kg busulfan applied as a 2-h infusion at 6-h intervals on days -4 and -3. Both groups received 30 mg/m2 intravenous fludarabine daily for 5 days (days -6 to -2). The primary outcome was event-free survival 2 years after HSCT. The non-inferiority margin was a hazard ratio (HR) of 1·3. Efficacy was assessed in all patients who received treatment and completed transplantation, and safety in all patients who received treatment. The study is registered with EudraCT (2008-002356-18) and ClinicalTrials.gov (NCT00822393). FINDINGS: Between June 13, 2013, and May 3, 2016, 476 patients were enrolled (240 in the busulfan group received treatment and transplantation, and in the treosulfan group 221 received treatment and 220 transplanation). At the second preplanned interim analysis (Nov 9, 2016), the primary endpoint was met and trial was stopped. Here we present the final confirmatory analysis (data cutoff May 31, 2017). Median follow-up was 15·4 months (IQR 8·8-23·6) for patients treated with treosulfan and 17·4 months (6·3-23·4) for those treated with busulfan. 2-year event-free survival was 64·0% (95% CI 56·0-70·9) in the treosulfan group and 50·4% (42·8-57·5) in the busulfan group (HR 0·65 [95% CI 0·47-0·90]; p<0·0001 for non-inferiority, p=0·0051 for superiority). The most frequently reported grade 3 or higher adverse events were abnormal blood chemistry results (33 [15%] of 221 patients in the treosulfan group vs 35 [15%] of 240 patients in the busulfan group) and gastrointestinal disorders (24 [11%] patients vs 39 [16%] patients). Serious adverse events were reported for 18 (8%) patients in the treosulfan group and 17 (7%) patients in the busulfan group. Causes of deaths were generally transplantation-related. INTERPRETATION: Treosulfan was non-inferior to busulfan when used in combination with fludarabine as a conditioning regimen for allogeneic HSCT for older or comorbid patients with acute myeloid leukaemia or myelodysplastic syndrome. The improved outcomes in patients treated with the treosulfan-fludarabine regimen suggest its potential to become a standard preparative regimen in this population. FUNDING: medac GmbH.

Severe deficiency of switched memory B cells (CD27(+)IgM(-)IgD(-)) in subgroups of patients with common variable immunodeficiency: a new approach to classify a heterogeneous disease.

Hypogammaglobulinemia is the hallmark of common variable immunodeficiency (CVID) syndrome, a heterogeneous disorder predisposing patients to recurrent bacterial infections. In this study, we investigated the peripheral B-cell compartment of 30 well-characterized CVID patients in comparison to 22 healthy controls. Flow cytometric analysis of peripheral blood lymphocytes revealed a reduction of class-switched CD27(+)IgM(-)IgD(-) memory B cells below 0.4% in 77% of our patients (group I), while this B-cell subpopulation exceeded 0.5% in all healthy donors and in 23% of CVID patients (group II). These results correlate well with the capacity of peripheral blood lymphocytes to produce immunoglobulins in vitro upon stimulation with Staphylococcus aureus Cowan I (SAC) plus interleukin-2 because the production of immunoglobulin G in vitro is entirely dependent on the presence of switched memory B cells. The subdivision of group I into patients with an increased proportion of CD21(-) peripheral B cells (> 20%; group Ia) and patients with normal percentages of CD21(-) B cells (< 20%; group Ib) revealed a significant clustering of patients with splenomegaly and autoimmune cytopenias in group Ia. Based on these observations, we propose a fast and reliable new classification for CVID patients by flow cytometric quantification of class-switched memory and immature B cells in the peripheral blood of patients. Our results point toward defects at various stages of B-cell differentiation in CVID subgroups and support the value of a B-cell-oriented classification principle. A consensus on this new classification system will hopefully provide a tool for rapidly defining homogeneous subgroups of CVID for functional studies and genetic linkage analysis.