Factors Associated With Successful Discontinuation of Immune Suppression After Allogeneic Hematopoietic Cell Transplantation

Comparative Analysis of mRNA, microRNA of Transcriptome, and Proteomics on CIK Cells Responses to GCRV and Aeromonas hydrophila

Grass Carp Reovirus (GCRV) and Aeromonas hydrophila (Ah) are the causative agents of haemorrhagic disease in grass carp. This study aimed to investigate the molecular mechanisms and immune responses at the miRNA, mRNA, and protein levels in grass carp kidney cells (CIK) infected by Grass Carp Reovirus (GCRV, NV) and Aeromonas hydrophilus (Bacteria, NB) to gain insight into their pathogenesis. Within 48 h of infection with Grass Carp Reovirus (GCRV), 99 differentially expressed microRNA (DEMs), 2132 differentially expressed genes (DEGs), and 627 differentially expressed proteins (DEPs) were identified by sequencing; a total of 92 DEMs, 3162 DEGs, and 712 DEPs were identified within 48 h of infection with Aeromonas hydrophila. It is worth noting that most of the DEGs in the NV group were primarily involved in cellular processes, while most of the DEGs in the NB group were associated with metabolic pathways based on KEGG enrichment analysis. This study revealed that the mechanism of a grass carp haemorrhage caused by GCRV infection differs from that caused by the Aeromonas hydrophila infection. An important miRNA-mRNA-protein regulatory network was established based on comprehensive transcriptome and proteome analysis. Furthermore, 14 DEGs and 6 DEMs were randomly selected for the verification of RNA/small RNA-seq data by RT-qPCR. Our study not only contributes to the understanding of the pathogenesis of grass carp CIK cells infected with GCRV and Aeromonas hydrophila, but also serves as a significant reference value for other aquatic animal haemorrhagic diseases.

Feasibility and safety of the discontinuation of systemic immunosuppressive treatment after single-unit cord blood transplantation in adults

We retrospectively evaluated the incidence, factors, and clinical outcomes of the discontinuation of immunosuppressive treatment (IST) after single-unit unrelated cord blood transplantation (CBT) in adults receiving cyclosporine-based graft-versus-host disease (GVHD) prophylaxis at our institute. Among the 309 patients who achieved engraftment, 247 were able to discontinue IST with a median follow-up of 121 months for survivors. The cumulative incidence of the discontinuation of IST was 46.2% at 180 days, 72.8% at 2 years, and 79.3% at 5 years post-CBT. In the multivariate analysis, discontinuation of IST after CBT was significantly associated with the requirement for steroid therapy (hazard ratio [HR]: 0.46; P < 0.001) and the recent calendar year of CBT (HR: 1.79; P < 0.001). In the conditional landmark analysis at 180 days, discontinuation of IST was not associated with the development of extensive chronic GVHD (HR: 1.00; P = 0.989), non-relapse mortality (HR: 0.49; P = 0.122), relapse (HR: 1.46; P = 0.388), or overall survival (HR: 1.91; P = 0.065). Our data showed that successful discontinuation of IST is common after single-unit CBT in adults. Discontinuation of IST did not affect subsequent outcomes, suggesting that discontinuation of IST is both feasible and safe in adults undergoing single-unit CBT.

GVHD relapse-free survival after peripheral blood hematopoietic cell transplantation for hematologic malignancies

The preferred choice for hematopoietic cell transplantation (HCT) donors in India is a matched related donor (MRD) followed by a haploidentical (haplo) donor for patients with hematological malignancies. International data in the haplo-HCT setting is mainly using bone marrow as a source. Almost all HCTs in India use peripheral blood stem cells (PBSC), which increases the risk of graft-versus-host disease (GVHD). In this single-center prospective study from 2017 to 2021, we sought to compare these outcomes prospectively in adult patients with hematological malignancies. Patient, disease, donor, and HCT details were prospectively recorded. GVHD prophylaxis included cyclosporine + methotrexate in MRD-HCT and post-transplant cyclophosphamide (PTCy) based in haplo-HCT. The primary endpoint GVHD relapse-free survival (GRFS) was defined as the time post-HCT without any of the following events: grade III-IV acute GVHD, chronic GVHD requiring systemic immunosuppressive treatment, disease relapse, or death from any cause. A total of 41 MRD and 33 haplo-HCT recipients were included in the study. Both cohorts were matched for age, sex, diagnosis, disease risk index, donor age, sex and CMV mismatches, and CD34 counts. A lower proportion of MRD-HCT recipients than haplo-HCT received myeloablative conditioning (39% vs. 76%, p = 0.002). There was no difference in the cumulative incidence of grade III-IV acute GVHD (16% vs. 27%, p = 0.2) or moderate-to-severe chronic GVHD (58% vs. 71%, p = 0.5). The one-year GRFS was not significantly different (53% vs. 38%, p = 0.2), with median GRFS of 420 and 274 days. The relapse incidence (22% vs. 19%, p = 0.6) and non-relapse mortality (25% vs. 35%, p = 0.4) did not differ. There was no difference in overall survival at one year (60% vs. 52%, p = 0.3). Despite a higher proportion of myeloablative conditioning in the haplo-HCT cohort, all outcomes, including GRFS, were comparable to those of the MRD-HCT cohort. This should encourage patients without an MRD to undergo haplo-HCT.

Feasibility, safety, and efficacy of early prophylactic donor lymphocyte infusion after T cell-depleted allogeneic stem cell transplantation in acute leukemia patients

Prophylactic donor lymphocyte infusion (DLI) starting at 6 months after T cell-depleted allogeneic stem cell transplantation (TCD-alloSCT) can introduce a graft-versus-leukemia (GvL) effects with low risk of severe graft-versus-host-disease (GvHD). We established a policy to apply low-dose early DLI at 3 months after alloSCT to prevent early relapse. This study analyzes this strategy retrospectively. Of 220 consecutive acute leukemia patients undergoing TCD-alloSCT, 83 were prospectively classified to have a high relapse risk and 43 were scheduled for early DLI. 95% of these patients received freshly harvested DLI within 2 weeks of the planned date. In patients transplanted with reduced intensity conditioning and an unrelated donor, we found an increased cumulative incidence of GvHD between 3 and 6 months after TCD-alloSCT for patients receiving DLI at 3 months compared to patients who did not receive this DLI (0.42 (95%Confidence Interval (95% CI): 0.14-0.70) vs 0). Treatment success was defined as being alive without relapse or need for systemic immunosuppressive GvHD treatment. The five-year treatment success in patients with acute lymphatic leukemia was comparable between high- and non-high-risk disease (0.55 (95% CI: 0.42-0.74) and 0.59 (95% CI: 0.42-0.84)). It remained lower in high-risk acute myeloid leukemia (AML) (0.29 (95% CI: 0.18-0.46)) than in non-high-risk AML (0.47 (95% CI: 0.42-0.84)) due to an increased relapse rate despite early DLI.

Operational tolerance after hematopoietic stem cell transplantation is characterized by distinct transcriptional, phenotypic, and metabolic signatures

The mechanisms underlying operational tolerance after hematopoietic stem cell transplantation in humans are poorly understood. We studied two independent cohorts of patients who underwent allogeneic hematopoietic stem cell transplantation from human leukocyte antigen-identical siblings. Primary tolerance was associated with long-lasting reshaping of the recipients' immune system compared to their healthy donors with an increased proportion of regulatory T cell subsets and decreased T cell activation, proliferation, and migration. Transcriptomics profiles also identified a role for nicotinamide adenine dinucleotide biosynthesis in the regulation of immune cell functions. We then compared individuals with operational tolerance and nontolerant recipients at the phenotypic, transcriptomic, and metabolomic level. We observed alterations centered on CD38⁺-activated T and B cells in nontolerant patients. In tolerant patients, cell subsets with regulatory functions were prominent. RNA sequencing analyses highlighted modifications in the tolerant patients' transcriptomic profiles, particularly with overexpression of the ectoenzyme NT5E (encoding CD73), which could counterbalance CD38 enzymatic functions by producing adenosine. Further, metabolomic analyses suggested a central role of androgens in establishing operational tolerance. These data were confirmed using an integrative approach to evaluating the immune landscape associated with operational tolerance. Thus, balance between a CD38-activated immune state and CD73-related production of adenosine may be a key regulator of operational tolerance.

Impact of local recurrence on cause-specific death after stereotactic body radiotherapy for early-stage non-small cell lung cancer: dynamic prediction using landmark model

PURPOSE

The purpose of this study was to assess the impact of local recurrence (LR) on cause-specific death (CSD) in patients with non-small cell lung cancer (NSCLC) treated with stereotactic body radiotherapy (SBRT). A dynamic prediction model that incorporated LR as a time-dependent covariate was used.

METHODS AND MATERIALS

This study included 535 stage I (cT1-T2aN0M0) NSCLC patients treated with SBRT from two institutions. We developed a landmark dynamic prediction model to estimate the probability of a CSD. This model determined the probability of surviving for an additional 3 years at different prediction time points during follow-up, given the history of recurrence status. The baseline covariates included in the model were age, sex, T stage, and histology, while the time-dependent covariates were LR and regional and/or distant recurrence (RDR) status.

RESULTS

Overall, 137 patients (25.6%) died of lung cancer within a median follow-up of 4.1 years. Of the 195 patients who developed recurrence, 28, 125, and 42 patients had LR only, RDR only, and both, respectively. The landmark model showed that older age, advanced T stage, LR, and RDR were significantly associated with an increased risk of subsequent CSD. Among these covariates, LR (odds ratio [OR], 8.5; 95% confidence interval [CI], 6.0-12.0; P < .001) and RDR (OR, 11.6; 95% CI, 9.1-14.9; P < .001) demonstrated strong effects on CSD within 3 years after the prediction time points. The dynamic prediction provided information on the probability of future CSD according to individual recurrence status during follow-up.

CONCLUSIONS

Dynamic prediction using the landmark model showed that LR had a substantial impact on subsequent CSD, which was comparable to that of RDR. This result supports the notion that strategies to improve local control are reasonable.

Initial therapy for chronic graft-versus-host disease: analysis of practice variation and failure-free survival

Variation in initial systemic therapy for chronic graft-versus-host disease includes varied prednisone dose and use of nonsteroid agents.

Prospective trials are needed to verify efficacy of reduced-dose prednisone or prednisone-free initial therapy approaches.

Prior clinical trials largely considered prednisone 1 mg/kg per day with or without calcineurin inhibitor as standard initial therapy for chronic graft-versus-host disease (cGVHD), but uncertainty remains regarding the extent of practice variation and whether this affects subsequent outcomes. We assembled a cohort of 745 patients with cGVHD treated with initial systemic immune suppressive (IS) therapy from 3 prior cGVHD Consortium observational studies. Initial therapy was defined as first IS therapy started for cGVHD or prednisone increased to ≥0.4 mg/kg per day from lower doses within 30 days before cGVHD diagnosis to any time afterward. Initial therapies were nonprednisone IS therapies (n = 137, 18%), prednisone alone (n = 411, 55%), or prednisone plus other IS therapy (n = 197, 26%). In multivariate analysis, initial therapy group was not associated with failure-free survival (FFS; a composite of death, relapse, and new IS therapy), overall survival (OS), or nonrelapse mortality (NRM). Among the prednisone-based approaches, steroid dose was <0.25 (9%), 0.25 to 0.74 (36%), 0.75 to 1.25 (42%), or >1.25 mg/kg per day (13%). Prednisone dose within the patients treated with steroids was not significantly associated with FFS, OS, or NRM. No significant interactions were detected between overall cGVHD severity and either initial therapy group or prednisone dose for the outcomes of FFS, OS, or NRM. These observational data document heterogeneity in more contemporary cGVHD initial treatment practices, including prednisone dose and use of nonsteroid approaches. This variation was not associated with FFS, OS, or NRM. Prospective trials are needed to verify efficacy of reduced-dose prednisone or prednisone-free initial therapy approaches.

Phase 2 multicenter trial of ofatumumab and prednisone as initial therapy of chronic graft-vs-host disease

Ofatumumab with glucocorticoid therapy for cGVHD resulted in 62.5% ORR at 6 months and 53% FFS at 12 months.

Safety was observed with ofatumumab plus glucocorticoid for initial therapy.

Standard initial therapy of chronic graft vs. host disease (cGVHD) with glucocorticoids results in suboptimal response. Safety and feasibility of therapy with ofatumumab (1000 mg IV on days 0 and 14) and prednisone (1 mg/kg/day) was previously established in our phase I trial (n = 12). We now report the mature results of the phase II expansion of the trial (n = 38). The overall NIH severity of cGVHD was moderate (63%) or severe (37%) with 74% of all patients affected by the overlap subtype of cGVHD and 82% by prior acute cGVHD. The observed 6 month clinician-reported and 2014 NIH-defined overall response rates (ORR = complete + partial response [CR/PR]) of 62.5% (1-sided lower 90% confidence interval=51.5%) were not superior to pre-specified historic benchmark of 60%. Post-hoc comparison of 6 month NIH response suggested benefit compared to more contemporaneous NIH-based benchmark of 48.6% with frontline sirolimus/prednisone (CTN 0801 trial). Baseline cGVHD features (organ involvement, severity, initial immune suppression agents) were not significantly associated with 6-month ORR. The median time to initiation of second-line therapy was 5.4 months (range 0.9-15.1 months). Failure-free survival (FFS) was 64.2% (95% CI 46.5-77.4%) at 6 months and 53.1% (95% CI 35.8-67.7%) at 12 months, whereas FFS with CR/PR at 12 months of 33.5% exceeded a benchmark of 15% in post-hoc analysis, and was associated with greater success in steroid discontinuation by 24 months (odds ratio 8 (95% CI 1.21-52.7). This single-arm phase II trial demonstrated acceptable safety and potential efficacy of the upfront use of ofatumumab in combination with prednisone in cGVHD.  This trial was registered at www.clinicaltrials.gov as #NCT01680965.

National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host Disease: III. The 2020 Treatment of Chronic GVHD Report

Positive results from recent clinical trials have significantly expanded current therapeutic options for patients with chronic graft-versus-host disease (GVHD). However, new insights into the associations between clinical characteristics of chronic GVHD, pathophysiologic mechanisms of disease, and the clinical and biological effects of novel therapeutic agents are required to allow for a more individualized approach to treatment. The current report is focused on setting research priorities and direction in the treatment of chronic GVHD. Detailed correlative scientific studies should be conducted in the context of clinical trials to evaluate associations between clinical outcomes and the biological effect of systemic therapeutics. For patients who require systemic therapy but not urgent initiation of glucocorticoids, clinical trials for initial systemic treatment of chronic GVHD should investigate novel agents as monotherapy without concurrently starting glucocorticoids, to avoid confounding biological, pathological, and clinical assessments. Clinical trials for treatment-refractory disease should specifically target patients with incomplete or suboptimal responses to most recent therapy who are early in their disease course. Close collaboration between academic medical centers, medical societies, and industry is needed to support an individualized, biology-based strategic approach to chronic GVHD therapy.

Post-Transplant Cyclophosphamide and Tacrolimus-Mycophenolate Mofetil Combination Governs GVHD and Immunosuppression Need, Reducing Late Toxicities in Allogeneic Peripheral Blood Hematopoietic Cell Transplantation from HLA-Matched Donors

Combined direct antineoplastic activity and the long-lasting immunological effects of allogeneic hematopoietic cell transplant (HCT) can cure many hematological malignancies, but broad adoption requires non-relapse mortality (NRM) rates and graft-versus-host disease (GVHD) control. Recently, posttransplant cyclophosphamide (PTCy) given after a bone marrow transplant significantly reduced GVHD-incidence, while PTCy given with tacrolimus/mofetil mycophenolate (T/MMF) showed activity following allogeneic peripheral blood stem cell transplantation (alloPBSCT). Here, we report the experience of a larger cohort (85 consecutive patients) and expanded follow-up period (03/2011-12/2019) with high-risk hematological malignancies who received alloPBSCT from Human-Leukocyte-Antigens HLA-matched unrelated/related donors. GVHD-prophylaxis was PTCy 50 mg/kg (days+3 and +4) combined with T/MMF (day+5 forward). All patients stopped MMF on day+28 with day+110 = median tacrolimus discontinuation. Cumulative incidences were 12% for acute and 7% for chronic GVHD- and no GVHD-attributed deaths. For surviving patients, the 12, 24, and 36-month probabilities of being off immunosuppression were 92, 96, and 96%, respectively. After a 36-month median follow-up, NRM was 4%; median event-free survival (EFS) and overall survival (OS) had yet to occur. One- and two-year chronic GVHD-EFS results were 57% (95% CI, 46-68%) and 53% (95% CI, 45-61%), respectively, with limited late infections and long-term organ toxicities. Disease relapse caused the most treatment failures (38% at 2 years), but low transplant toxicity allowed many patients (14/37, 38%) to receive donor lymphocyte infusions as a post-relapse strategy. We confirmed that PTCy+T/MMF treatment effectively prevented acute and chronic GVHD and limited NRM to unprecedented low rates without loss of disease control efficacy in an expanded patient cohort. This trial is registered at U.S. National Library of Medicine as #NCT02300571.

Maintenance therapy for FLT3-ITD-mutated acute myeloid leukemia

FLT3-ITD is a constitutively activated variant of the FLT3 tyrosine kinase receptor. Its expression in acute myeloid leukemia (AML) is associated with a poor prognosis. Due to this, the development of tyrosine kinase inhibitors (TKI) blocking FLT3-ITD became a rational therapeutic concept. This review describes key milestones in the clinical development of different FLT3-specific TKI with a particular focus on FLT3-TKI maintenance therapy in remission after allogeneic hematopoietic stem cell transplantation (HCT). Recent evidence from randomized trials using sorafenib in FLT3-ITD mutated AML provided a proof of concept that targeted post-HCT maintenance therapy could become a new treatment paradigm in AML.

Tolerance to Bone Marrow Transplantation: Do Mesenchymal Stromal Cells Still Have a Future for Acute or Chronic GvHD?

Mesenchymal Stromal Cells (MSCs) are fibroblast-like cells of mesodermal origin present in many tissues and which have the potential to differentiate to osteoblasts, adipocytes and chondroblasts. They also have a clear immunosuppressive and tissue regeneration potential. Indeed, the initial classification of MSCs as pluripotent stem cells, has turned into their identification as stromal progenitors. Due to the relatively simple procedures available to expand in vitro large numbers of GMP grade MSCs from a variety of different tissues, many clinical trials have tested their therapeutic potential in vivo. One pathological condition where MSCs have been quite extensively tested is steroid resistant (SR) graft versus host disease (GvHD), a devastating condition that may occur in acute or chronic form following allogeneic hematopoietic stem cell transplantation. The clinical and experimental results obtained have outlined a possible efficacy of MSCs, but unfortunately statistical significance in clinical studies has only rarely been reached and effects have been relatively limited in most cases. Nonetheless, the extremely complex pathogenetic mechanisms at the basis of GvHD, the fact that studies have been conducted often in patients who had been previously treated with multiple lines of therapy, the variable MSC doses and schedules administered in different trials, the lack of validated potency assays and clear biomarkers, the difference in MSC sources and production methods may have been major factors for this lack of clear efficacy in vivo. The heterogeneity of MSCs and their different stromal differentiation potential and biological activity may be better understood through more refined single cell sequencing and proteomic studies, where either an “anti-inflammatory” or a more “immunosuppressive” profile can be identified. We summarize the pathogenic mechanisms of acute and chronic GvHD and the role for MSCs. We suggest that systematic controlled clinical trials still need to be conducted in the most promising clinical settings, using better characterized cells and measuring efficacy with specific biomarkers, before strong conclusions can be drawn about the therapeutic potential of these cells in this context. The same analysis should be applied to other inflammatory, immune or degenerative diseases where MSCs may have a therapeutic potential.

Long-term outcomes and risk factor analysis of steroid-refractory graft versus host disease after hematopoietic stem cell transplantation

Steroid-refractory graft versus host disease (GVHD) represents a fearsome complication after allogeneic hematopoietic stem cell transplantation (HSCT). We conducted a retrospective study on outcomes and risk factors associated with acute and chronic steroid-refractory GVHD in a large cohort of 1207 patients receiving HSCT in Saint Louis Hospital between 2007 and 2017. Among patients who developed an acute and/or a chronic GVHD, the cumulative incidences of acute and chronic steroid-refractory disease were 31% and 48%, respectively, at day +100 and 1-year post-HSCT. Through a multivariable analysis we selected several risk factors associated with the development of a steroid-refractory disease. For acute GVHD steroid refractoriness, we identified (1) a very high disease risk index, (2) an unrelated donor, (3) the absence of in vivo T-depletion as GVHD prophylaxis, and (4) a reduced intensity conditioning regimen. For chronic GVHD, (1) the use of peripheral blood stem cells, (2) unrelated donors, and (3) absence of in vivo T-depletion were more likely associated with a steroid-refractory disease. After the construction of a multistate dynamic model, we found that the probability of being alive without relapse after the resolution of all GVHD episodes was about 36% in the long term.

Randomized multicenter trial of sirolimus vs prednisone as initial therapy for standard-risk acute GVHD: the BMT CTN 1501 trial

Clinical- and biomarker-based tools may identify a lower-risk acute graft-versus-host disease (GVHD) population amenable to novel, reduced-intensity treatments. Previous data suggest sirolimus may rival standard of care prednisone. We conducted a National Heart, Lung, and Blood Institute/National Cancer Institute-funded Blood and Marrow Transplant Clinical Trials Network multicenter, open-label, randomized phase 2 trial to estimate the difference in day 28 complete response (CR)/partial response (PR) rates for sirolimus vs prednisone as initial treatment of patients with standard risk (SR) acute GVHD as defined by the Minnesota (MN) GVHD Risk Score and Ann Arbor (AA1/2) biomarker status. A total of 127 MN-SR patients were randomized (1:1), and 122 were AA1/2 (sirolimus, n = 58; prednisone, n = 64). Others were AA3 (n = 4), or AA status missing (n = 1). The day 28 CR/PR rates were similar for sirolimus 64.8% (90% confidence interval [CI], 54.1%-75.5%) vs 73% (90% CI, 63.8%-82.2%) for prednisone. The day 28 rate of CR/PR with prednisone ≤0.25 mg/kg/day was significantly higher for sirolimus than prednisone (66.7% vs 31.7%; P < .001). No differences were detected in steroid-refractory acute GVHD, disease-free survival, relapse, nonrelapse mortality, or overall survival. Sirolimus was associated with reduced steroid exposure and hyperglycemia, reduced grade 2 to 3 infections, improvement in immune suppression discontinuation and patient-reported quality of life, and increased risk for thrombotic microangiopathy. For patients with clinical- and biomarker-based SR acute GVHD, sirolimus demonstrates similar overall initial treatment efficacy as prednisone. In addition, sirolimus therapy spares steroid exposure and allied toxicity, does not compromise long-term survival outcomes, and is associated with improved patient-reported quality of life. This trial was registered at www.clinicaltrials.gov as #NCT02806947.