Ruxolitinib in corticosteroid-refractory graft-versus-host disease after allogeneic stem cell transplantation: a multicenter survey

Ruxolitinib in steroid-refractory acute graft-vs-host disease: Japanese subgroup analysis of the randomized REACH2 trial

Acute graft-versus-host disease (aGvHD) is a major complication after allogeneic hematopoietic stem cell transplantation in Japan and other countries. Nearly one-third of patients do not respond to standard systemic steroid therapy and no standard second-line treatment has been established in Japan. We report efficacy and safety findings of ruxolitinib versus best available therapy (BAT) from a subgroup analysis of the international, phase 3 REACH2 study in Japanese patients with steroid-refractory aGvHD. The primary endpoint was overall response rate (ORR) at day 28. Overall, 9 patients received ruxolitinib and 21 received BAT. The ORR at day 28 (88.9% vs 52.4%) and durable ORR at day 56 (66.7% vs 28.6%) were higher with ruxolitinib versus BAT. The estimated cumulative incidence of loss of response at 6 months was 12.5% with ruxolitinib and 18.2% with BAT. The median failure-free survival was longer with ruxolitinib versus BAT (2.73 vs 1.25 months). The most common adverse events up to day 28 in the ruxolitinib and BAT groups were anemia (55.6% vs 19.0%) and thrombocytopenia (44.4% vs 4.8%, respectively). Ruxolitinib showed better efficacy outcomes and a consistent safety profile compared with BAT in the Japanese subgroup, and the findings were consistent with overall study results.

The impact of regulatory T cells on the graft-versus-leukemia effect

Allogeneic Hematopoietic Stem Cell Transplantation (allo-HSCT) is the only curative therapy for many hematologic malignancies, whereby the Graft-versus-Leukemia (GVL) effect plays a pivotal role in controlling relapse. However, the success of GVL is hindered by Graft-versus-Host Disease (GVHD), where donor T cells attack healthy tissues in the recipient. The ability of natural regulatory T cells (Treg) to suppress immune responses has been exploited as a therapeutical option against GVHD. Still, it is crucial to evaluate if the ability of Treg to suppress GVHD does not compromise the benefits of GVL. Initial studies in animal models suggest that Treg can attenuate GVHD while preserving GVL, but results vary according to tumor type. Human trials using Treg as GVHD prophylaxis or treatment show promising results, emphasizing the importance of infusion timing and Treg/Tcon ratios. In this review, we discuss strategies that can be used aiming to enhance GVL post-Treg infusion and the proposed mechanisms for the maintenance of the GVL effect upon the adoptive Treg transfer. In order to optimize the therapeutic outcomes of Treg administration in allo-HSCT, future efforts should focus on refining Treg sources for infusion and evaluating their specificity for antigens mediating GVHD while preserving GVL responses.

A placebo-controlled, crossover trial to investigate the efficacy of tiotropium bromide or placebo added to usual care in stable symptomatic post-hematopoietic stem cell transplantation (HSCT) bronchiolitis obliterans syndrome (BOS)

BACKGROUND

Despite the fundamental progress in hematopoietic stem cell transplant, this treatment is also associated with complications. Graft-versus-host disease is a possible complication of HSCT. Bronchiolitis obliterans syndrome (BOS) is the pulmonary form of this syndrome. Due to the high morbidity and mortality rate of BOS, various studies have been conducted in the field of drug therapy for this syndrome, although no standard treatment has yet been proposed. According to the hypotheses about the similarities between BOS and chronic obstructive pulmonary disease, the idea of using tiotropium bromide as a bronchodilator has been proposed.

METHOD/DESIGN

A randomized, double-blind, placebo-controlled, and crossover clinical trial is being conducted to evaluate the efficacy of tiotropium in patients with BOS. A total of 20 patients with BOS were randomly assigned (1:1) to receive a once-daily inhaled capsule of either tiotropium bromide (KP-Tiova Rotacaps 18 mcg, Cipla, India) or placebo for 1 month. Patients will receive tiotropium bromide or placebo Revolizer added to usual standard care. Measurements will include spirometry and a 6-min walking test.

ETHICS/DISSEMINATION

This study was approved by the Research Ethics Committees of Imam Khomeini Hospital Complex, Tehran University of Medical Science. Recruitment started in September 2022, with 20 patients randomized. The treatment follow-up of participants with tiotropium is currently ongoing and is due to finish in April 2024. The authors will disseminate the findings in peer-reviewed publications, conferences, and seminar presentations.

TRIAL REGISTRATION

Iranian Registry of Clinical Trial (IRCT) IRCT20200415047080N3. Registered on 2022-07-12, 1401/04/21.

Addition of ruxolitinib to standard graft-versus-host disease prophylaxis for allogeneic stem cell transplantation in aplastic anemia patients

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) offers rapid hematopoietic and immune reconstitution for aplastic anemia (AA). As a non-malignant disorder, attenuation of GVHD remains a clinical priority in AA patients. Our study sought to investigate the safety and efficacy of the prophylactic use of ruxolitinib in allogeneic HSCT. A total of 35 AA patients were retrospectively consecutively treated with allo-HSCT whereby ruxolitinib was added to the standard GVHD prophylaxis regimen (rux group). The addition of peri-transplant ruxolitinib did not impact the engraftment and graft function, while better recovery of CD4+ Tregs in the rux group was observed. Interestingly, the rux group demonstrated significantly lower incidence of bacterial/fungal infections (17.14% vs 45.71%). Compared to the control group, the rux group exhibited significantly lower incidence of moderate to severe aGVHD (17.1% vs 48.6%) with a trend toward lower severe aGVHD (8.6% vs 20%) and cGVHD (26.2 vs 38.3). The rux group also demonstrated a trend toward higher GVHD and failure-free survival (GFFS: 85.7% vs 68.6%) and lower TRM (2.9% vs 14.3%). Addition of ruxolitinib to standard GVHD prophylaxis regimen, thus, represents a safe and highly efficient method for the attenuation of GVHD with better outcome of allo-HSCT.

Efficacy and Safety in Early application of Ruxolinitib for high-risk: Acute lymphoblastic leukemia to prevent GVHD and recurrence after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been identified as the potentially curative treatment for high-risk acute lymphoblastic leukemia (ALL) in adult patients. However, relapse of the disease and/or development of graft-versus-host disease (GVHD) remain to be the most common barriers for successful allo-HSCT. Preclinical studies showed that ruxolitinib, a Janus tyrosine kinase (Jak)1 and Jak2 inhibitor, has a selective anti-GVHD effects while preserving a potent graft-versus-leukemia (GVL) effect. Our study aimed to investigate the efficacy and safety in early application of ruxolitinib for the high-risk ALL patients to prevent GVHD.

METHODS

There were eight patients undergoing allo-HSCT at the Bone Marrow Transplantation Center of the Third Xiangya Hospital of Central South University between April 2020 and April 2021. Ruxolitinib (5-10 mg twice daily) was administered early (median time: 45 days) after stem cell infusion.

RESULTS

After a median follow-up of 14 months (range from 8 to 18 months), the ALL disease relapse occurred in two cases. Among all eight patients, two of them developed grade I/II acute (a) GVHD, while no patient developed grade III/IV aGVHD, and one patient developed chronic (c) GVHD. As for the virus activation, no patient developed EBV activation or EBV related lymphoproliferative disease, and three patients developed CMV activation. Our results suggest that the early application of ruxolitinib could safely and effectively prevent the occurrence of GVHD after allo-HSCT for the high-risk ALL patients. However, it may have a limited effect on preventing the recurrence of high-risk ALL and thus may require additional therapy with other anti-relapse drugs.

CONCLUSIONS

Our preliminary observations suggest that an early application of ruxolitinib can safely and effectively prevent the occurrence of GVHD after allo-HSCT for the high-risk ALL patients. However, ruxolitinib may have a limited effect on preventing the ALL recurrence of high-risk patients.

Recent insights into extracorporeal photopheresis for graft-versus-host disease

INTRODUCTION

Extracorporeal Photopheresis (ECP) may be considered the unique large-scale cell therapy currently available. It is currently employed mainly as second-line treatment, especially in steroid-resistant or steroid-dependent Graft versus Host Disease (GvHD) with good results and very few limitations.

AREAS COVERED

Many points need to be clarified regarding the ECP mechanism of action, that conditions the lack of uniqueness among the different centers, essentially cycle frequency, treatment duration, and the number of cells to be treated to obtain a response, according to the organs involved. Moreover, reliable biomarkers for prediction of response are lacking, as well as the best pharmacological combination. We will focus on the recent advances concerning ECP for GvHD treatment. We performed a systematic literature research in Pubmed and Embase as of September 2023.

EXPERT OPINION

The recent studies on ECP mechanism of action along with the promising biomarkers of response, and the synergistic benefit of ECP in association with the new drugs render this therapy an important weapon for GvHD resistant to conventional treatment and can be proposed as a valid first-line therapy option with promising results. We believe that it should be used early in all categories of patients, considering its high safety profile.

Cell Therapy Transplant Canada (CTTC) Consensus-Based Guideline 2024 for Management and Treatment of Chronic Graft-Versus-Host Disease and Future Directions for Development

This is a consensus-based Canadian guideline whose primary purpose is to standardize and facilitate the management of chronic graft-versus-host disease (cGvHD) across the country. Creating uniform healthcare guidance in Canada is a challenge for a number of reasons including the differences in healthcare authority structure, funding and access to healthcare resources between provinces and territories, as well as the geographic size. These differences can lead to variable and unequal access to effective therapies for GvHD. This document will provide comprehensive and practical guidance that can be applied across Canada by healthcare professionals caring for patients with cGvHD. Hopefully, this guideline, based on input from GvHD treaters across the country, will aid in standardizing cGvHD care and facilitate access to much-needed novel therapies. This consensus paper aims to discuss the optimal approach to the initial assessment of cGvHD, review the severity scoring and global grading system, discuss systemic and topical treatments, as well as supportive therapies, and propose a therapeutic algorithm for frontline and subsequent lines of cGvHD treatment in adults and pediatric patients. Finally, we will make suggestions about the future direction of cGvHD treatment development such as (1) a mode-of-action-based cGvHD drug selection, according to the pathogenesis of cGvHD, (2) a combination strategy with the introduction of newer targeted drugs, (3) a steroid-free regimen, particularly for front line therapy for cGvHD treatment, and (4) a pre-emptive approach which can prevent the progression of cGvHD in high-risk patients destined to develop severe and highly morbid forms of cGvHD.

Ruxolitinib for the treatment of acute and chronic graft-versus-host disease in children: a systematic review and individual patient data meta-analysis

Steroid-refractory graft-versus-host disease (SR-GvHD) represents a major complication of pediatric allogenic hematopoietic stem cell transplantation. Ruxolitinib, a selective JAK 1-2 inhibitor, showed promising results in the treatment of SR-GvHD in adult trial, including patients >12 years old. This systematic review aims to evaluate ruxolitinib use for SR-GvHD in the pediatric population. Among the 12 studies included, ruxolitinib administration presented slight differences. Overall response rate (ORR) ranged from 45% to 100% in both acute and chronic GvHD. Complete response rates (CR) varied from 9% to 67% and from 0% to 28% in aGvHD and cGvHD, respectively. Individual-patient meta-analysis from 108 children under 12 years showed an ORR and CR for aGvHD of 74% and 56%, respectively, while in cGvHD ORR was 78% but with only 11% achieving CR. Treatment-related toxicities were observed in 20% of patients, including cytopenia, liver toxicity, and infections. Age, weight, graft source, previous lines of therapy, and dose did not significantly predict response, while a higher rate of toxicities was observed in aGvHD patients. In conclusion, ruxolitinib shows promising results in the treatment of SR-GvHD in children, including those under 12 years. Specific pediatric perspective trials are currently ongoing to definitely assess its efficacy and safety.

Real-world experience with ruxolitinib therapy for steroid-refractory acute graft versus host disease

Acute graft versus host disease (aGVHD) is a complication of allogeneic hematopoietic stem cell transplant (HCT) and is associated with significant morbidity and mortality. Steroid refractory aGVHD (SR-aGVHD) carries a particularly grim prognosis. Ruxolitinib has shown promise for treatment of SR-aGVHD in a phase 3 trial; however, safety and efficacy data outside of the clinical trial setting is lacking. We performed a multicenter retrospective study to examine the response to ruxolitinib and its efficacy in patients with SR-aGVHD. We included 59 patients treated with ruxolitinib for SR-aGVHD between 2015 and 2022. Of these 59 patients, 36 patients (61.0%) achieved a complete (CR) or partial response (PR) at 28 days, while 31 patients (52.5%) obtained a CR/PR at day 56. Patients that achieved a CR or PR at day 28 had a higher rate of overall survival (OS; 69.2%), compared with patients that did not (31.6%; p = 0.037). OS at 12 months was 41.5%, with a median OS duration of 5.3 months. Failure free survival (FFS) at 12 months was 29.1%, with a median FFS of 2.6 months. Overall, this real-world experience data support ruxolitinib as the standard of care for SR-aGVHD in a non-controlled trial population.

Janus kinase inhibition in the treatment and prevention of graft-versus-host disease

Graft-versus-host disease (GVHD) is a significant cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). For many years, corticosteroids have been the mainstay treatment for GVHD, but cases of steroid-refractory GVHD and the severe adverse effects of high-dose corticosteroids have increased the need for preventative and therapeutic strategies for GVHD. Due to the nature of alloreactive T cells, GVHD is inherently linked to the graft-versus-leukemia (GVL) effect, the therapeutic driving force behind stem cell transplantation. A considerable clinical challenge is to preserve GVL while suppressing GVHD. The field of GVHD research has greatly expanded over the past decades, including advancements in T cell modulation and depletion, antibody therapies, chemotherapeutics, cellular therapies, and Janus kinase inhibition. In this review, we discuss current approaches and advances in the prophylaxis and treatment of GVHD with a focus on new emerging advancements in Janus kinase inhibitor therapy.

Improvement of survival after hematopoietic stem cell transplantation and trends at a pediatric transplantation center; a three-decade journey

BACKGROUND

Advances in stem cell transplantation have resulted in improved outcomes.

METHODS

This is a retrospective study aimed to analyze changes in patient profile, transplantation, graft characteristics, and outcome among 241 pediatric patients who received stem cell transplantation in a single center between 1993 and 2019.

RESULTS

In the 2010-2019, compared with the 1993-2009 period, a significantly higher 5-year overall survival (60% vs. 44%, p = .022) and an event-free survival (53% vs. 34%, p = .025) were observed. Cumulative incidence of deaths due to relapse or progression between the 1993-2009 and 2010-2019 periods were 33% and 26% respectively (p = .66). Cumulative incidence of non-relapse mortality was significantly higher during the 1993-2009 period compared with the 2010-2019 period for malignant diseases (57.7% vs. 28.3%, p = .007). The overall survival from acute graft-versus-host disease between 1993 and 2009 was 11% versus 46% between 2010 and 2019 (p = .0001). The overall survival from infection in both eras did not show any difference (p = .41).

CONCLUSIONS

Development in transplantation technology has led to a decrease in non-relapse mortality and better control of graft-versus-host disease. However, relapse and infection remained as major causes of death. Studies evaluating institutional trends in patients undergoing HSCT and analyzing their mortality profile, can improve the management of patients, leading to a reduction in transplant-related problems.

Corticosteroid-resistant immune-related adverse events: a systematic review

Immune checkpoint inhibitor (ICI) treatment has become an important therapeutic option for various cancer types. Although the treatment is effective, ICI can overstimulate the patient's immune system, leading to potentially severe immune-related adverse events (irAEs), including hepatitis, colitis, pneumonitis and myocarditis. The initial mainstay of treatments includes the administration of corticosteroids. There is little evidence how to treat steroid-resistant (sr) irAEs. It is mainly based on small case series or single case reports. This systematic review summarizes available evidence about sr-irAEs. We conducted a systematic literature search in PubMed. Additionally, we included European Society for Medical Oncology, Society for Immunotherapy of Cancer, National Comprehensive Cancer Network and American Society of Clinical Oncology Guidelines for irAEs in our assessment. The study population of all selected publications had to include patients with cancer who developed hepatitis, colitis, pneumonitis or myocarditis during or after an immunotherapy treatment and for whom corticosteroid therapy was not sufficient. Our literature search was not restricted to any specific cancer diagnosis. Case reports were also included. There is limited data regarding life-threatening sr-irAEs of colon/liver/lung/heart and the majority of publications are single case reports. Most publications investigated sr colitis (n=26), followed by hepatitis (n=21), pneumonitis (n=17) and myocarditis (n=15). There is most data for mycophenolate mofetil (MMF) to treat sr hepatitis and for infliximab, followed by vedolizumab, to treat sr colitis. Regarding sr pneumonitis there is most data for MMF and intravenous immunoglobulins (IVIG) while data regarding infliximab are conflicting. In sr myocarditis, most evidence is available for the use of abatacept or anti-thymocyte globulin (ATG) (both with or without MMF) or ruxolitinib with abatacept. This review highlights the need for prompt recognition and treatment of sr hepatitis, colitis, pneumonitis and myocarditis. Guideline recommendations for sr situations are not defined precisely. Based on our search, we recommend-as first line treatment-(1) MMF for sr hepatitis, (2) infliximab for sr colitis, followed by vedolizumab, (3) MMF and IVIG for sr pneumonitis and (4) abatacept or ATG (both with or without MMF) or ruxolitinib with abatacept for sr myocarditis. These additional immunosuppressive agents should be initiated promptly if there is no sufficient response to corticosteroids within 3 days.

ROCK1/2 signaling contributes to corticosteroid-refractory acute graft-versus-host disease

Patients with corticosteroid-refractory acute graft-versus-host disease (aGVHD) have a low one-year survival rate. Identification and validation of novel targetable kinases in patients who experience corticosteroid-refractory-aGVHD may help improve outcomes. Kinase-specific proteomics of leukocytes from patients with corticosteroid-refractory-GVHD identified rho kinase type 1 (ROCK1) as the most significantly upregulated kinase. ROCK1/2 inhibition improved survival and histological GVHD severity in mice and was synergistic with JAK1/2 inhibition, without compromising graft-versus-leukemia-effects. ROCK1/2-inhibition in macrophages or dendritic cells prior to transfer reduced GVHD severity. Mechanistically, ROCK1/2 inhibition or ROCK1 knockdown interfered with CD80, CD86, MHC-II expression and IL-6, IL-1β, iNOS and TNF production in myeloid cells. This was accompanied by impaired T cell activation by dendritic cells and inhibition of cytoskeletal rearrangements, thereby reducing macrophage and DC migration. NF-κB signaling was reduced in myeloid cells following ROCK1/2 inhibition. In conclusion, ROCK1/2 inhibition interferes with immune activation at multiple levels and reduces acute GVHD while maintaining GVL-effects, including in corticosteroid-refractory settings.

Glucocorticoids, their uses, sexual dimorphisms, and diseases: new concepts, mechanisms, and discoveries

The normal stress response in humans is governed by the hypothalamic-pituitary-adrenal (HPA) axis through heightened mechanisms during stress, raising blood levels of the glucocorticoid hormone cortisol. Glucocorticoids are quintessential compounds that balance the proper functioning of numerous systems in the mammalian body. They are also generated synthetically and are the preeminent therapy for inflammatory diseases. They act by binding to the nuclear receptor transcription factor glucocorticoid receptor (GR), which has two main isoforms (GRα and GRβ). Our classical understanding of glucocorticoid signaling is from the GRα isoform, which binds the hormone, whereas GRβ has no known ligands. With glucocorticoids being involved in many physiological and cellular processes, even small disruptions in their release via the HPA axis, or changes in GR isoform expression, can have dire ramifications on health. Long-term chronic glucocorticoid therapy can lead to a glucocorticoid-resistant state, and we deliberate how this impacts disease treatment. Chronic glucocorticoid treatment can lead to noticeable side effects such as weight gain, adiposity, diabetes, and others that we discuss in detail. There are sexually dimorphic responses to glucocorticoids, and women tend to have a more hyperresponsive HPA axis than men. This review summarizes our understanding of glucocorticoids and critically analyzes the GR isoforms and their beneficial and deleterious mechanisms and the sexual differences that cause a dichotomy in responses. We also discuss the future of glucocorticoid therapy and propose a new concept of dual GR isoform agonist and postulate why activating both isoforms may prevent glucocorticoid resistance.

When is the best time and grade to start ruxolitinib in corticosteroid-refractory acute graft-versus-host-disease: A multi-center research

OBJECTIVE

Ruxolitinib was recently approved to treat corticosteroid-resistant acute graft-versus-host disease (GvHD). However, it is unknown as to whether starting ruxolitinib at a lower versus higher acute GvHD grade or earlier versus later affected outcomes. This study identified the impact of starting acute GvHD grade and start time after declaring corticosteroid resistance and the effect on complete and overall response rates to ruxolitinib therapy.

METHODS

Retrospective, observational multi-center study. We divided cohorts into starting ruxolitinib ≤ 7 days (N = 45) versus at > 7 days after declaring corticosteroid resistance (N = 24).

RESULTS

In ≤ 7 days cohort complete response (CR) rates at day 28 were 69% (54, 81%) versus 25% (11, 47%; p = .001) in > 7 days cohort, and overall response (OR) rates were 91% (78, 96%) versus 80% (48, 92%; p = .25).

CONCLUSIONS

Our data suggest that starting ruxolitinib in ≤ 7 days of declaring corticosteroid failure regardless of G vHD grade improves complete response rate but not OR rates. Starting ruxolitinib at grade I and within 7 days may get a more significant response.

Soluble Urokinase-Type Plasminogen Activator Receptor (suPAR) and Growth Differentiation Factor-15 (GDF-15) Levels Are Significantly Associated with Endothelial Injury Indices in Adult Allogeneic Hematopoietic Cell Transplantation Recipients

Hematopoietic stem cell transplantation-associated thrombotic microangiopathy (HSCT-TMA) and graft-versus-host disease (GvHD) represent life-threatening syndromes after allogeneic hematopoietic stem cell transplantation (allo-HSCT). In both conditions, endothelial dysfunction is a common denominator, and development of relevant biomarkers is of high importance for both diagnosis and prognosis. Despite the fact that soluble urokinase plasminogen activator receptor (suPAR) and growth differentiation factor-15 (GDF-15) have been determined as endothelial injury indices in various clinical settings, their role in HSCT-related complications remains unexplored. In this context, we used immunoenzymatic methods to measure suPAR and GDF-15 levels in HSCT-TMA, acute and/or chronic GVHD, control HSCT recipients, and apparently healthy individuals of similar age and gender. We found considerably greater SuPAR and GDF-15 levels in HSCT-TMA and GVHD patients compared to allo-HSCT and healthy patients. Both GDF-15 and suPAR concentrations were linked to EASIX at day 100 and last follow-up. SuPAR was associated with creatinine and platelets at day 100 and last follow-up, while GDF-15 was associated only with platelets, suggesting that laboratory values do not drive EASIX. SuPAR, but not GDF-15, was related to soluble C5b-9 levels, a sign of increased HSCT-TMA risk. Our study shows for the first time that suPAR and GDF-15 indicate endothelial damage in allo-HSCT recipients. Rigorous validation of these biomarkers in many cohorts may provide utility for their usefulness in identifying and stratifying allo-HSCT recipients with endothelial cell impairment.

Chronic GVHD: review advances in prevention, novel endpoints, and targeted strategies

Allogeneic hematopoietic cell transplantation (allo-HCT) is a curative therapy for many malignant and non-malignant hematologic disorders. Chronic graft-versus-host (cGVHD) disease remains a significant hurdle for long-term survival in patients post allo-HCT, and it remains the leading cause of late non-relapse mortality. The risk factors for development of cGVHD include degree of human leukocyte antigen (HLA) disparity, increasing recipient age, use of peripheral blood stem cells as a source, myeloablative conditioning regimens, prior acute GVHD (aGVHD), and female donor to male recipient. Our biological understanding of cGVHD is mostly derived from transplantation mouse models and patient data. There are three distinct phases in the development of cGVHD. Approaches to prevent GVHD include pharmacologic strategies such as calcineurin inhibitors (cyclosporine, tacrolimus) combined with methotrexate or mTOR inhibitors (sirolimus), and IMP dehydrogenase inhibitors (mycophenolate mofetil). Increasingly, posttransplant cyclophosphamide is emerging as a promising strategy for GVCHD prevention especially in a setting of reduced intensity conditioning. Other approaches include serotherapy (ATG, Campath) and graft manipulation strategies. A significant obstacle to evaluating the response of novel GVHD-directed therapies has been standardized response assessments. This has functioned as a barrier to designing and interpreting clinical trials that are structured around the treatment of cGVHD. Novel endpoints including failure-free survival, Graft-versus-host disease-free, relapse-free survival (GRFS), and current GVHD-free, relapse-free survival (CGRFS) may create a clearer picture for post-HCT outcomes. Targeted therapies including Bruton's tyrosine kinase inhibition, JAK1/2 inhibition, and ROCK2 inhibitors have improved cGVHD therapy, especially in the steroid refractory setting. Continued improvement in prophylactic strategies for cGVHD, identification of accurate cGVHD treatment endpoints, and access to novel therapeutic agents are expected to improve cGVHD outcomes.

Ruxolitinib attenuates acute rejection and can serve as an immune induction therapy in heart transplantation

The benefits of IL2RA antagonists in heart transplant patients are controversial. We aimed to elucidate the effects of IL2RA antagonists and identify targets that could be better than IL2RA antagonists. By using single-cell RNA sequencing of immune cells at different time points in patients receiving IL2RA antagonists, we identified nineteen types of cells. We revealed higher IL2RA expression in regulatory T cells (Tregs), suggesting that IL2RA antagonists attenuated IL-2-induced Treg activation. CD4_C04_IFNGR1 and CD8_C05_IFITM2 which had more cytotoxic effects, remained elevated at later time points. IFNGR1 was upregulated in these two subtypes, but was not expressed in Treg. Ruxolitinib targeted the pathways of IFNGR1 (JAK1/2) while not affecting the pathway of IL-2-induced Tregs activation (JAK3). Ruxolitinib showed prolonged survival compared to IL2RA mAb-treated mice. Our study provided dynamic changes of immune cells after IL2RA antagonists treatment at single-cell resolution. Ruxolitinib has potential as a new immunoinduction therapy without affecting Treg.

Targeting Hedgehog Signaling with Glasdegib in Patients with Refractory Sclerotic Chronic GVHD: A Report of Two Phase I/II Trials

PURPOSE

Sclerotic chronic GVHD (scGVHD) is characterized by progressive skin fibrosis and frequent refractoriness to available therapies. Aberrant activation of Hedgehog signaling in dermal fibroblasts has been implicated in scGVHD. Here, we report the results of two phase I/II studies (NCT03415867, GETH-TC; NCT04111497, FHD) that evaluated glasdegib, a smoothened antagonist, as a novel therapeutic agent in refractory scGVHD.

PATIENTS AND METHODS

Adult patients with active scGVHD after ≥1 (FHD) or ≥2 (GETH-TC) lines of therapy were enrolled. Primary endpoints were dose-limiting toxicity (DLT) and MTD in the GETH-TC trial, and safety and tolerability measures in the FHD trial. Glasdegib was administered once daily in 28-day cycles. Responses were scored per 2014 NIH cGVHD criteria. Correlative studies were performed to evaluate the role of fibroblast-independent immune mechanisms on clinical activity.

RESULTS

Twenty (GETH-TC) and 15 (FHD) patients were recruited. Treatment-emergent grade (G) ≥2 adverse events (AE) in the GETH-TC trial included muscle cramps (85%), alopecia (50%), and dysgeusia (35%). Two patients experienced a DLT (G3 muscle cramps), and the MTD was established at 50 mg. G3 muscle cramps were the most frequently reported AE (33%) in the FHD trial. At 12-months, the skin/joint scGVHD overall response rate was 65% (all partial responses) in the GETH-TC trial and 47% (6 partial responses, 1 complete response) in the FHD cohort. No immune correlates of response were identified.

CONCLUSIONS

Glasdegib demonstrated promising responses in patients with refractory scGVHD, but tolerability was limited by muscle cramping.

Ruxolitinib versus basiliximab for steroid-refractory acute graft-versus-host disease: a retrospective study

Acute graft-versus-host disease (aGVHD) remains a major limitation of allogeneic hematopoietic stem cell transplantation; not all patients respond to standard glucocorticoids treatment. This study retrospectively evaluated the effects of ruxolitinib compared with basiliximab for steroid-refractory aGVHD (SR-aGVHD). One hundred and twenty-nine patients were enrolled, 81 in ruxolitinib and 48 in basiliximab group. The overall response (OR) at day 28 was higher in ruxolitinib group (72.8% vs. 54.2%, P = 0.031), as with complete response (CR) (58.0% vs. 35.4%, P = 0.013). Ruxolitinib led to significantly lower 1-year cumulative incidence of chronic GVHD (cGVHD) (29.6% vs. 43.8%, P = 0.021). Besides, ruxolitinib showed higher 1-year overall survival (OS) and 1-year cumulative incidence of failure-free survival (FFS) (OS: 72.8% vs. 50.0%, P = 0.008; FFS: 58.9% vs. 39.6%, P = 0.014). The 1-year cumulative incidence of non-relapse mortality (NRM) was lower in ruxolitinib group (16.1% vs. 37.5%, P = 0.005), and the 1-year relapse was not different. The 1-year cumulative incidence of cytomegalovirus (CMV) viremia, CMV-associated diseases and Epstein-Barr virus (EBV)-associated diseases was similar between the two groups, but EBV viremia was significantly lower in ruxolitinib group (6.2% vs. 29.2%, P < 0.001). Subgroup analyses revealed that OR and survival were similar in ruxolitinib 5 mg twice daily (bid) and 10 mg bid groups. However, ruxolitinib 10 mg bid treatment markedly reduced 1-year cumulative incidence of cGVHD compared with 5 mg bid (21.1% vs. 50.0%, P = 0.016). Our study demonstrated that ruxolitinib was superior to basiliximab in SR-aGVHD treatment and cGVHD prophylaxis, therefore should be recommended.

Updates in chronic graft-versus-host disease management

Chronic graft-versus-host disease (cGvHD) remains the most important long-term complication of allogeneic hematopoietic cell transplantation (allo-HCT), but the field has seen significant changes in the last decade. Remarkable advances in the understanding of the biological pathways of cGvHD, lead to the development of targeted therapy with novel drugs thereby minimizing the exposure to harmful corticosteroids, preserving function and mobility, preventing disability, and improving quality of life (QoL) and overall survival (OS). Steroid-refractory cGvHD management has recently experienced significant improvement since ibrutinib and ruxolitinib were approved for patients that failed at least one line of treatment and belumosudil for patients that failed two lines. These recently approved drugs will be discussed in this review, along with perspectives regarding cGVHD management and additional promising drug in development.

Chronic GvHD NIH Consensus Project Biology Task Force: evolving path to personalized treatment of chronic GvHD

Chronic graft-versus-host disease (cGvHD) remains a prominent barrier to allogeneic hematopoietic stem cell transplantion as the leading cause of nonrelapse mortality and significant morbidity. Tremendous progress has been achieved in both the understanding of pathophysiology and the development of new therapies for cGvHD. Although our field has historically approached treatment from an empiric position, research performed at the bedside and bench has elucidated some of the complex pathophysiology of cGvHD. From the clinical perspective, there is significant variability of disease manifestations between individual patients, pointing to diverse biological underpinnings. Capitalizing on progress made to date, the field is now focused on establishing personalized approaches to treatment. The intent of this article is to concisely review recent knowledge gained and formulate a path toward patient-specific cGvHD therapy.

The JAK1/2 inhibitor ruxolitinib in patients with COVID-19 triggered hyperinflammation: the RuxCoFlam trial

Dysregulated hyperinflammatory response is key in the pathogenesis in patients with severe COVID-19 leading to acute respiratory distress syndrome and multiorgan failure. Whilst immunosuppression has been proven to be effective, potential biological targets and optimal timing of treatment are still conflicting. We sought to evaluate efficacy and safety of the Janus Kinase 1/2 inhibitor ruxolitinib, employing the previously developed COVID-19 Inflammation Score (CIS) in a prospective multicenter open label phase II trial (NCT04338958). Primary objective was reversal of hyperinflammation (CIS reduction of ≥25% at day 7 in ≥20% of patients). In 184 patients with a CIS of ≥10 (median 12) ruxolitinib was commenced at an initial dose of 10 mg twice daily and applied over a median of 14 days (range, 2-31). On day 7, median CIS declined to 6 (range, 1-13); 71% of patients (CI 64-77%) achieved a ≥25% CIS reduction accompanied by a reduction of markers of inflammation. Median cumulative dose was 272.5 mg/d. Treatment was well tolerated without any grade 3-5 adverse events related to ruxolitinib. Forty-four patients (23.9%) died, all without reported association to study drug. In conclusion, ruxolitinib proved to be safe and effective in a cohort of COVID-19 patients with defined hyperinflammation.

Ruxolitinib Treatment of Steroid-Refractory Graft-versus-Host Disease in Children: A Case Series and Review of the Literature

BACKGROUND

Ruxolitinib has been increasingly used in the treatment of steroid-refractory graft-versus-host disease (SR-GVHD) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) patients. However, there are limited data on the use of ruxolitinib in children.

OBJECTIVE

This study aimed to assess the efficacy and toxicity of ruxolitinib in the treatment of SR-GVHD in children.

PATIENTS AND METHODS

Data of patients who suffered from SR-GVHD after allo-HSCT and received ruxolitinib treatment between June 2018 and December 2020 at our center were analyzed retrospectively. The characteristics of patients, the dosage of ruxolitinib, the response, toxicity, and the survival data were collected.

RESULTS

A total of 14 pediatric patients were diagnosed with SR-GVHD after allo-HSCT and received ruxolitinib. The age of the patients ranged from 3 months to 12 years old. The dosage of ruxolitinib ranged from 2.5 mg twice daily to 7.5 mg twice daily, mainly according to patient weight. The total overall response rate (ORR) was 64.3% (9/14), with 63.6% (7/11) in aGVHD and 67% (2/3) in cGVHD. Of the 14 patients, adverse effects were observed in 9 patients (64.3%), including cytopenia, infection, and elevated alanine aminotransferase. In addition, seven reports on the treatment of SR-GVHD in children with ruxolitinib were included for systematic analysis, with the ORR ranging from 45 to 87% in aGVHD and 70-91% in cGVHD.

CONCLUSION

Given its effectiveness and safety, ruxolitinib could be used to treat SR-GVHD in children after HSCT.

IFNγ Causes Keratinocyte Necroptosis in Acute Graft-Versus-Host Disease

Epidermal keratinocytes form the first-line cellular barrier of the skin for protection against external injuries and maintenance of local tissue homeostasis. Expression of ZBP1 was shown to cause necroptotic keratinocyte cell death and skin inflammation in mice. We sought to characterize the relevance of ZBP1 and necroptosis in human keratinocytes and type 1-driven cutaneous acute graft-versus-host disease. in this study, we identify ZBP1 expression, necroptosis, and interface dermatitis as being the hallmarks of acute graft-versus-host disease. ZBP1 expression was dependent on leukocyte-derived IFNγ, and interference with IFNγ signaling by Jak inhibition prevented cell death. In predominantly IL-17-driven psoriasis, both ZBP1 expression and necroptosis could not be detected. Of note, in contrast to the signaling in mice, ZBP1 signaling in human keratinocytes was not affected by RIPK1's presence. These findings show that ZBP1 drives inflammation in IFNγ-dominant type 1 immune responses in human skin and may further point to a general role of ZBP1-mediated necroptosis.

Graphical Learning and Causal Inference for Drug Repurposing

Gene expression profiles that connect drug perturbations, disease gene expression signatures, and clinical data are important for discovering potential drug repurposing indications. However, the current approach to gene expression reversal has several limitations. First, most methods focus on validating the reversal expression of individual genes. Second, there is a lack of causal approaches for identifying drug repurposing candidates. Third, few methods for passing and summarizing information on a graph have been used for drug repurposing analysis, with classical network propagation and gene set enrichment analysis being the most common. Fourth, there is a lack of graph-valued association analysis, with current approaches using real-valued association analysis one gene at a time to reverse abnormal gene expressions to normal gene expressions. To overcome these limitations, we propose a novel causal inference and graph neural network (GNN)-based framework for identifying drug repurposing candidates. We formulated a causal network as a continuous constrained optimization problem and developed a new algorithm for reconstructing large-scale causal networks of up to 1,000 nodes. We conducted large-scale simulations that demonstrated good false positive and false negative rates. To aggregate and summarize information on both nodes and structure from the spatial domain of the causal network, we used directed acyclic graph neural networks (DAGNN). We also developed a new method for graph regression in which both dependent and independent variables are graphs. We used graph regression to measure the degree to which drugs reverse altered gene expressions of disease to normal levels and to select potential drug repurposing candidates. To illustrate the application of our proposed methods for drug repurposing, we applied them to phase I and II L1000 connectivity map perturbational profiles from the Broad Institute LINCS, which consist of gene-expression profiles for thousands of perturbagens at a variety of time points, doses, and cell lines, as well as disease gene expression data under-expressed and over-expressed in response to SARS-CoV-2.

Ruxolitinib as the first post-steroid treatment for acute and chronic graft-versus-host disease

INTRODUCTION

Acute and chronic graft-versus-host disease (GvHD) are potentially life-threatening complications occurring after allogeneic stem cell transplantation (allo-HSCT). Although steroids represent the first-line treatment for both conditions, in those patients who do not adequately benefit from steroid therapy, standardized treatment algorithms are lacking. In recent years, ruxolitinib has emerged as the most promising agent for the second-line therapy of steroid-refractory (SR)-GvHD.

AREAS COVERED

This review will summarize the biological properties and the mechanistic aspects that justify the therapeutic role of ruxolitinib in GvHD. In addition, current treatment options for SR-GvHD will be briefly discussed. Finally, results of the most relevant clinical trials on the use of ruxolitinib for SR-GvHD will be analyzed, with a particular focus on two phase-III randomized trials in which ruxolitinib demonstrated its superiority in comparison with the best available therapy.

EXPERT OPINION

Ruxolitinib has considerably improved the outcome of patients with SR-acute/chronic-GvHD and should be regarded as the standard-of-care option when corticosteroids fail or cannot be tapered. Nevertheless, a number of questions still remain unanswered and significant room for improvement exists. Additional observations derived from a longer follow-up will certainly increase our expertise in the management of this powerful therapy.

The delicate balance of graft versus leukemia and graft versus host disease after allogeneic hematopoietic stem cell transplantation

INTRODUCTION

The curative basis of allogeneic hematopoietic stem cell transplantation (HSCT) relies in part upon the graft versus leukemia (GvL) effect, whereby donor immune cells recognize and eliminate recipient malignant cells. However, alloreactivity of donor cells against recipient tissues may also be deleterious. Chronic graft versus host disease (cGvHD) is an immunologic phenomenon wherein alloreactive donor T cells aberrantly react against host tissues, leading to damaging inflammatory symptoms.

AREAS COVERED

Here, we discuss biological insights into GvL and cGvHD and strategies to balance the prevention of GvHD with maintenance of GvL in modern HSCT.

EXPERT OPINION/COMMENTARY

Relapse remains the leading cause of mortality after HSCT with rates as high as 40% for some diseases. GvHD is a major cause of morbidity after HSCT, occurring in up to half of patients and responsible for 15-20% of deaths after HSCT. Intriguingly, the development of chronic GvHD may be linked to lower relapse rates after HSCT, suggesting that GvL and GvHD may be complementary sides of the immunologic foundation of HSCT. The ability to fine tune the balance of GvL and GvHD will lead to improvements in survival, relapse rates, and quality of life for patients undergoing HSCT.

Second-line therapy for patients with steroid-refractory aGVHD: systematic review and meta-analysis of randomized controlled trials

Objective

Steroids-refractory (SR) acute graft-versus-host disease (aGVHD) is a life-threatening condition in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT), but the optimal second-line therapy still has not been established. We aimed to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) to compare the efficacy and safety of different second-line therapy regimens.

Methods

Literature search in MEDLINE, Embase, Cochrane Library and China Biology Medicine databases were performed to retrieve RCTs comparing the efficacy and safety of different therapy regimens for patients with SR aGVHD. Meta-analysis was conducted with Review Manager version 5.3. The primary outcome is the overall response rate (ORR) at day 28. Pooled relative risk (RR) and 95% confidence interval (CI) were calculated with the Mantel-Haenszel method.

Results

Eight eligible RCTs were included, involving 1127 patients with SR aGVHD and a broad range of second-line therapy regimens. Meta-analysis of 3 trials investigating the effects of adding mesenchymal stroma cells (MSCs) to other second-line therapy regimens suggested that the addition of MSCs is associated with significantly improvement in ORR at day 28 (RR = 1.15, 95% CI = 1.01-1.32, P = 0.04), especially in patients with severe (grade III-IV or grade C-D) aGVHD (RR = 1.26, 95% CI = 1.04-1.52, P = 0.02) and patients with multiorgan involved (RR = 1.27, 95% CI = 1.05-1.55, P = 0.01). No significant difference was observed betwwen the MSCs group and control group in consideration of overall survival and serious adverse events. Treatment outcomes of the other trials were comprehensively reviewed, ruxolitinib showed significantly higher ORR and complete response rate at day 28, higher durable overall response at day 56 and longer failure-free survival in comparison with other regimens; inolimomab shows similar 1-year therapy success rate but superior long-term overall survial in comparison with anti-thymocyte globulin, other comparisons did not show significant differences in efficacy.

Conclusions

Adding MSCs to other second-line therapy regimens is associated with significantly improved ORR, ruxolitinib showed significantly better efficacy outcomes in comparison with other regimens in patients with SR aGVHD. Further well-designed RCTs and integrated studies are required to determine the optimal treatment.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022342487.

Acute graft-versus-host disease

Acute graft-versus-host disease (GVHD) is a common immune complication that can occur after allogeneic haematopoietic cell transplantation (alloHCT). Acute GVHD is a major health problem in these patients, and is associated with high morbidity and mortality. Acute GVHD is caused by the recognition and the destruction of the recipient tissues and organs by the donor immune effector cells. This condition usually occurs within the first 3 months after alloHCT, but later onset is possible. Targeted organs include the skin, the lower and upper gastrointestinal tract and the liver. Diagnosis is mainly based on clinical examination, and complementary examinations are performed to exclude differential diagnoses. Preventive treatment for acute GVHD is administered to all patients who receive alloHCT, although it is not always effective. Steroids are used for first-line treatment, and the Janus kinase 2 (JAK2) inhibitor ruxolitinib is second-line treatment. No validated treatments are available for acute GVHD that is refractory to steroids and ruxolitinib, and therefore it remains an unmet medical need.

Prognostic value of blood biomarkers in steroid-refractory or steroid-dependent acute graft-versus-host disease: a REACH2 analysis

Systemic steroids are the standard first-line treatment for acute graft-versus-host disease (aGVHD), but ∼50% of patients become steroid-refractory or dependent (SR/D). Ruxolitinib is the only Food and Drug Administration- and European Medicines Agency-approved therapy for patients with SR/D aGVHD. In the phase 3 REACH2 trial (NCT02913261), ruxolitinib demonstrated superior efficacy in SR/D aGVHD, with a significantly higher overall response rate (ORR) on day 28, durable ORR on day 56, and longer median overall survival compared with the best available therapy (BAT). Identifying biomarkers and clinical characteristics associated with increased probability of response can guide treatment decisions. In this exploratory analysis of the REACH2 study (first biomarker study), we developed baseline (pretreatment) and day 14 models to identify patient characteristics and biomarkers (12 aGVHD-associated cytokines/chemokines, 6 immune cell types, and 3 inflammatory proteins) before and during treatment, which affected the probability of response at day 28. Treatment with ruxolitinib, conditioning, skin involvement, and age were strongly associated with an increased likelihood of response in the ≥1 model. Lower levels of most aGVHD and immune cell markers at baseline were associated with an increased probability of response. In the day 14 model, levels of aGVHD markers at day 14, rather than changes from baseline, affected the probability of response. For both models, the bias-corrected area under the receiver operating characteristic values (baseline, 0.73; day 14, 0.80) indicated a high level of correspondence between the fitted and actual outcomes. Our results suggest potential prognostic value of selected biomarkers and patient characteristics.

Dermatologic complications in transplantation and cellular therapy for acute leukemia

Adoptive cellular immunotherapy, mainly hematopoietic stem cell transplant and CAR-T cell therapy have revolutionized treatment of patients with acute leukemia. Indications and inclusion criteria for these treatments have expanded in recent years. While these therapies are associated with significant improvements in disease response and overall survival, patients may experience adverse events from associated chemotherapy conditioning, engraftment, cytokine storm, supportive medications, and post-transplant maintenance targeted therapies. Supportive oncodermatology is a growing specialty to manage cutaneous toxicities resulting from the anti-cancer therapies. In this review, we summarize diagnosis and management of the common cutaneous adverse events including drug eruptions, graft-versus-host disease, neoplastic and paraneoplastic complications in patients undergoing cellular therapies.

Acute Graft-versus-Host Disease: An Update on New Treatment Options

Acute graft-versus-host disease (GVHD) occurs in approximately 50% of patients and remains a primary driver of non-relapse and transplant-related mortality. The best treatment remains prevention with either in vivo or ex vivo T-cell depletion, with multiple strategies used worldwide based on factors such as institution preference, ability to perform graft manipulation, and ongoing clinical trials. Predicting patients at high risk for developing severe acute GVHD based on clinical and biomarker-based criteria allows for escalation or potential de-escalation of therapy. Modern therapies for treatment of the disease include JAK/STAT pathway inhibitors, which are standard of care in the second-line setting and are being investigated for upfront management of non-severe risk based on biomarkers. Salvage therapies beyond the second-line remain suboptimal. In this review, we will focus on the most clinically used GVHD prevention and treatment strategies, including the accumulating data on JAK inhibitors in both settings.

Serum proteomics hint at an early T-cell response and modulation of SARS-CoV-2-related pathogenic pathways in COVID-19-ARDS treated with Ruxolitinib

Background

Acute respiratory distress syndrome (ARDS) in corona virus disease 19 (COVID-19) is triggered by hyperinflammation, thus providing a rationale for immunosuppressive treatments. The Janus kinase inhibitor Ruxolitinib (Ruxo) has shown efficacy in severe and critical COVID-19. In this study, we hypothesized that Ruxo's mode of action in this condition is reflected by changes in the peripheral blood proteome.

Methods

This study included 11 COVID-19 patients, who were treated at our center's Intensive Care Unit (ICU). All patients received standard-of-care treatment and n = 8 patients with ARDS received Ruxo in addition. Blood samples were collected before (day 0) and on days 1, 6, and 10 of Ruxo treatment or, respectively, ICU admission. Serum proteomes were analyzed by mass spectrometry (MS) and cytometric bead array.

Results

Linear modeling of MS data yielded 27 significantly differentially regulated proteins on day 1, 69 on day 6 and 72 on day 10. Only five factors (IGLV10-54, PSMB1, PGLYRP1, APOA5, WARS1) were regulated both concordantly and significantly over time. Overrepresentation analysis revealed biological processes involving T-cells only on day 1, while a humoral immune response and complement activation were detected at day 6 and day 10. Pathway enrichment analysis identified the NRF2-pathway early under Ruxo treatment and Network map of SARS-CoV-2 signaling and Statin inhibition of cholesterol production at later time points.

Conclusion

Our results indicate that the mechanism of action of Ruxo in COVID-19-ARDS can be related to both known effects of this drug as a modulator of T-cells and the SARS-CoV-2-infection.

The Development of New Agents for Post-Hematopoietic Stem Cell Transplantation Non-Infectious Complications in Children

Hematopoietic stem cell transplantation (HSCT) is often the only curative treatment option for patients suffering from various types of malignant diseases and some non-cancerous conditions. Nevertheless, it is associated with a high risk of complications leading to transplant-related mortality and long-term morbidity. An increasing number of therapeutic and prevention strategies have been developed over the last few years to tackle the complications arising in patients receiving an HSCT. These strategies have been mainly carried out in adults and some are now being translated into children. In this manuscript, we review the recent advancements in the development and implementation of treatment options for post-HSCT non-infectious complications in pediatric patients with leukemia and other non-malignant conditions, with a special attention on the new agents available within clinical trials. We focused on the following conditions: graft failure, prevention of relapse and early interventions after detection of minimal residual disease positivity following HSCT in acute lymphoblastic and myeloid leukemia, chronic graft versus host disease, non-infectious pulmonary complications, and complications of endothelial origin.

JAK1/2 inhibitor ruxolitinib promotes the expansion and suppressive action of polymorphonuclear myeloid-derived suppressor cells via the JAK/STAT and ROS-MAPK/NF-κB signalling pathways in acute graft-versus-host disease

Objectives

Ruxolitinib, a Janus kinase (JAK) 1/2 inhibitor, demonstrates efficacy for treating steroid-resistant acute graft-versus-host disease (SR-aGVHD) following allogeneic stem cell transplantation (allo-HSCT). Myeloid-derived suppressor cells (MDSCs) have a protective effect on aGVHD via suppressing T cell function. However, the precise features and mechanism of JAK inhibitor-mediated immune modulation on MDSCs subsets remain poorly understood.

Methods

A total of 74 SR-aGVHD patients treated with allo-HSCT and ruxolitinib were enrolled in the present study. The alterations of MDSC and regulatory T cell (Treg) populations were monitored during ruxolitinib treatment in responders and nonresponders. A mouse model of aGVHD was used to evaluate the immunosuppressive activity of MDSCs and related signalling pathways in response to ruxolitinib administration in vivo and in vitro.

Results

Patients with SR-aGVHD who received ruxolitinib treatment achieved satisfactory outcomes. Elevation proportions of MDSCs before treatment, especially polymorphonuclear-MDSCs (PMN-MDSCs) were better to reflect the response to ruxolitinib than those in Tregs. In the mouse model of aGVHD, the administration of ruxolitinib resulted in the expansion and functional enhancement of PMN-MDSCs and the effects could be partially reversed by an anti-Gr-1 antibody in vivo. Ruxolitinib treatment significantly elevated the suppressive function of PMN-MDSCs through reactive oxygen species (ROS) production by Nox2 upregulation as well as bypassing the activated MAPK/NF-κB signalling pathway. Additionally, ex vivo experiments demonstrated that ruxolitinib prevented the differentiation of mature myeloid cells and promoted the accumulation of MDSCs by inhibiting STAT5.

Conclusions

Ruxolitinib enhances PMN-MDSCs functions through JAK/STAT and ROS-MAPK/NF-κB signalling pathways. Monitoring frequencies and functions of MDSCs can help evaluate treatment responses to ruxolitinib.

Novel Approaches to the Treatment of Chronic Graft-Versus-Host Disease

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.Chronic graft-versus-host disease (cGVHD) is an immune-mediated disease that ensues after allogeneic hematopoietic cell transplantation often affecting multiple organs, decreases quality of life, and necessitates immunosuppressive therapy. The current standard first-line cGVHD therapy is glucocorticoids (GCs) which have major side effects. So far, all attempts to improve response to first-line GC therapy of cGVHD by adding other agents, such as mycophenolate mofetil, or cyclosporine A have not improved response. The data reported in the trial by Miklos et al indicate that ibrutinib should not be added to GC in first-line cGVHD therapy. The findings instruct future studies that aim at the identification of patients with cGVHD who may benefit from a GC-ibrutinib combination using biomarkers or clinical parameters. Currently, ibrutinib, ruxolitinib, and belumosudil are the only drugs that are approved by the Food and Drug Administration for steroid-refractory cGVHD. In light of the current standard management of cGVHD, the trial results indicate that ibrutinib will remain reserved for second-line therapy, which may be due to its mechanisms of action. The recommendation on the basis of this trial is that GC monotherapy remains the standard therapy for cGVHD.

Ruxolitinib-induced reactivation of cytomegalovirus and Epstein-Barr virus in graft-versus-host disease

OBJECTIVES

Steroid-refractory graft-versus-host disease (SR-GVHD) is a challenging complication of allogeneic hematopoietic stem cell transplantation, and leads to high morbidity and mortality rates. The orally administered, selective Janus-associated kinase 1/2 inhibitor ruxolitinib gives overall response rates (ORR) of more than 70 % in acute and chronic SR-GVHD. However, several studies have highlighted an elevated risk of cytomegalovirus (CMV) reactivation in patients with ruxolitinib-treated SR-GVHD.

METHODS

We therefore analyzed risk of CMV and Epstein-Barr virus (EBV) primary infection or reactivation in 57 patients with ruxolitinib-treated GVHD, while taking account of the competing risk (CR) of death prior to the first reactivation.

RESULTS

Initiation of ruxolitinib treatment was a significant adverse prognostic factor for the CR of first CMV reactivation (hazard ratio (HR)= 1.747, 95 % confidence interval (CI): 1.33-2.92, p < 0.0001) and first EBV reactivation (HR=2.657, 95 % CI: 1.82-3.87, p < 0.0001) during GVHD. In our cohort of ruxolitinib-treated patients, the ORR (48 % and 58 % for acute and chronic GVHD, respectively) and the toxicity profile (haematological adverse events in 29.8 % of the patients) were similar to the literature values.

CONCLUSION

Given ruxolitinib's efficacy in SR-GVHD, use of this drug should not be limited by the fear of viral reactivation; however, our present results emphasize the importance of monitoring the viral load.

Noninfectious Pulmonary Complications after Hematopoietic Stem Cell Transplantation

Pulmonary complications after hematopoietic stem cell transplantation (HSCT) are important sources of morbidity and mortality. Improvements in infection-related complications have made noninfectious pulmonary complications an increasingly significant driver of transplantation-related mortality. Broadly, these complications can be characterized as either early or late complications, with idiopathic pneumonia syndrome and bronchiolitis obliterans syndrome the most prevalent early and late complications, respectively. Outcomes with historical treatment consisting mainly of corticosteroids are often poor, highlighting the need for a deeper understanding of these complications' underlying disease biology to guide the adoption of novel therapies that are being increasingly used in the modern era.

Significance of Omitting Day 11 Mini-Dose Methotrexate for GVHD Prophylaxis After Unrelated Bone Marrow Transplantation

The combination of calcineurin inhibitors and short-term methotrexate has been used as a standard graft-versus-host-disease (GVHD) prophylaxis in allogeneic hematopoietic stem cell transplantation. Mini-dose methotrexate (mini-MTX), consisting of 5 mg/m²/d on days 1, 3, 6, and 11, is occasionally selected as an alternative considering toxicity. The significance of day 11 administration remains unclear. We performed a retrospective study of 135 cases of unrelated bone marrow transplantation at our institute between 2006 and 2019 and compared the outcomes between day 11 MTX dose omitted (n = 72) and full-doses of mini-MTX (n = 63). In total cohort, the 4-year overall survival (OS) was 58.7 %, and the omitted group showed poor GVHD/relapse-free-survival (P = .01) with comparable OS (P = .11) and relapse-free survival (P = .11). Human leukocyte antigen (HLA) mismatch is a major risk factor for severe GVHD. We analyzed the impact of omitting day 11 MTX in 2 cohorts from HLA matched or mismatched donors. In both cohorts, the omitted group had a higher risk of severe acute and chronic GVHD. In conclusion, the omission of day 11 MTX was associated with a higher risk of severe GVHD. Therefore the omission of the day 11 dose is not recommended.

Extracorporeal photopheresis (ECP) improves overall survival in the treatment of steroid refractory acute graft-versus-host disease (SR aGvHD)

Steroid refractory acute graft-versus-host disease (SR aGvHD) is a major limitation of successful allogeneic hematopoietic stem cell transplantation (HSCT). Extracorporeal photopheresis (ECP) has been used to treat SR aGvHD effectively and with low treatment related toxicity. In this study, we retrospectively analyzed the outcomes of 103 Steroid Refractory aGvHD (SR aGvHD) patients to identify factors associated with improved outcomes including the use of ECP. A total of 79 patients received ECP as part of their SR aGVHD treatment compared to 24 patients who did not. Both groups had similar aGVHD grade and maximum organ stage at onset of aGVHD and treatment initiation. Patients in the group that received ECP had better OS (p = 0.01), DFS (p = 0.008), lower relapse (p = 0.05) and similar NRM compared to the group that did not receive ECP. Patients that received ECP treatment also had shorter hospital stays in the first 180 days after onset of SR aGvHD (20 vs. 38 days, p = 0.03). Multivariable analysis for OS indicated patient CMV status (CMV+ versus CMV-, HR 2.34, CI 1.16-4.69), regimen intensity (Myelo vs. non-Myeloablative, HR 0.39, CI 0.20-0.75), and the use of ECP (ECP vs. no ECP, HR 0.39, CI 0.20-0.75) were associated with OS. In summary, the use of ECP in the treatment of SR aGvHD results in improved overall survival secondary to lower relapse rates compared to other therapeutic modalities that do not incorporate ECP.

Hepatobiliary disease after bone marrow transplant

INTRODUCTION

Bone marrow transplantation (BMT) is the standard treatment for several hematologic pathologies. Post-BMT patients may develop hepatobiliary complications that impact morbidity and mortality. The differential diagnosis may include drug-induced liver injury (DILI), sepsis-associated liver injury (SALI), sinusoidal obstruction syndrome (SOS), graft-versus-host disease (GVHD), viral hepatitis, ischemic and fulminant hepatitis, among others.

AREA COVERED

Defining the etiology of hepatobiliary injury is challenging due to the overlapping symptoms. Thus, it is necessary to be aware of and understand the clinical characteristics of these hepatobiliary complications and provide adequate management with possible better outcomes. We reviewed the scientific literature focused on early hepatobiliary complications associated with BMT. We searched the PubMed database using the following descriptors: hepatic complications, drug-induced liver disease, graft-versus-host disease, cholestasis, sepsis, sinusoidal obstruction syndrome, cytomegalovirus, viral hepatitis, bone marrow transplantation, and hematopoietic stem cell transplantation.

EXPERT OPINION

Post-BMT hepatobiliary complications comprise several differential diagnoses and are challenges for the hepatologist's clinical practice. When evaluating these patients, it is necessary to consider the temporality between the use of certain medications, the increase in liver enzymes, and the presence of infection, in addition to applying diagnostic criteria and complementary tests for a specific diagnosis.

Ruxolitinib on acute graft-versus-host disease prophylaxis after modified donor lymphocyte infusion

OBJECTIVE

To evaluate the effectiveness of ruxolitinib on acute graft-versus-host disease (aGVHD) prophylaxis and its impact on graft-versus-leukemia (GVL) effect in patients after modified donor lymphocyte infusion (mDLI).

METHODS

We retrospectively included patients with relapsed leukemia after allogeneic hematopoietic stem cell transplantation (allo-HSCT) who received ruxolitinib prophylaxis between October 2018 and April 2020. The incidence of aGVHD, disease-free survival (DFS), overall survival (OS), and treatment safety were evaluated.

RESULTS

Seventeen patients were followed up for a median time of 8 months (range: 1-26 months). The incidence of aGVHD on Day 30 after mDLI was 41.2% and ranged from Grade 1 to 4; ten of 17 patients (58.8%) achieved a complete response (CR), and two (11.8%) had a partial response (PR). Cytomegalovirus (CMV) reactivation rate was 23.5%, and the median time from mDLI to CMV reactivation was 48.5 days. The mean DFS and OS after mDLI were 1.0 (95% CI 0.0-3.5) and 9.0 (95% CI 1.2-16.8) months, respectively. The causes of death for 10 patients were leukemia relapse (n = 5), aGVHD and septic shock (n = 3), intracranial lesion (n = 1), and COVID-19 (n = 1).

CONCLUSIONS

We reported encouraging results of ruxolitinib monotherapy in the prevention of aGVHD and maintenance of GVL for post-transplantation relapsed patients, even though being at high risk with poor initial prognosis.

Ruxolitinib does not completely abrogate the functional capabilities of TLR4/9 ligand-activated NK cells

Introduction

Natural killer (NK) cells are lymphocytes from the innate immune system part of the first defense barrier against infected and transformed cells, representing 5%-15% of peripheral blood lymphocytes. The cytotoxic capacity of NK cells is controlled by a balance between inhibitory and activating NK receptors expressed on their surface, which recognize and interact with the ligands on stressed cells. The cytokines involved in NK cell activation, proliferation, survival, and cytotoxicity are signaled mainly through the Janus kinase and signal transducer and activator of transcription proteins (JAK/STAT) pathway. NK cells are also activated in response to pathogens through Toll-like receptors (TLRs) expressed on their surface. Ruxolitinib is a specific JAK1/2 inhibitor approved for treating myelofibrosis and for steroid-refractory acute and chronic graft-versus-host disease (SR-GvHD).

Methods

Purified NK cells from healthy donors were stimulated with two TOLL-like receptor ligands, LPS and CpG, in the presence of different concentrations of Ruxolitinib.

Results

This study showed the effects of ruxolitinib on TLR4 and TLR9 ligand-activated NK cells from healthy donors. Ruxolitinib did not completely inhibit STAT3 phosphorylation and had a moderate effect on NK cell cytokine activation via the TLR pathway. Only the highest doses of ruxolitinib led to a decrease in the pro-inflammatory cytokines tumor necrosis factor α, interferon-γ, interleukin-6, and interleukin-1β. The cytotoxic capacity of stimulated NK cells versus K562, SEM, and MV-4-11 cell lines was reduced by increasing doses of ruxolitinib, but it was not completely abolished and we observed no major changes in degranulation capacity. Phenotypic changes were observed in activated NK cells in the presence of ruxolitinib. In a small cohort of pediatric patients treated with ruxolitinib for SR-GvHD, we observed no decrease in NK cell counts; however, further prospective studies with larger cohorts are necessary to confirm this finding.

Discussion

In summary, our results showed that the functional capabilities and phenotype of NK cells activated through TLR4/9 agonists were not completely abolished by the inhibition of the JAK-STAT pathway by ruxolitinib.

Inhibition of JAK1,2 Prevents Fibrotic Remodeling of Pulmonary Vascular Bed and Improves Outcomes in the Rat Model of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism with poor clinical outcomes. Therapeutic approaches to prevention of fibrotic remodeling of the pulmonary vascular bed in CTEPH are limited. In this work, we tested the hypothesis that Janus kinase 1/2 (JAK1/2) inhibition with ruxolitinib might prevent and attenuate CTEPH in a rat model. CTEPH was induced by repeated embolization of the pulmonary artery with partially biodegradable 180 ± 30 μm alginate microspheres. Two weeks after the last injection of microspheres, ruxolitinib was administered orally at doses of 0.86, 2.58, and 4.28 mg/kg per day for 4 weeks. Prednisolone (1.475 mg/kg, i.m.) was used as a reference drug. Ruxolitinib in all doses as well as prednisolone reduced pulmonary vascular wall hypertrophy. Ruxolitinib at a dose of 2.58 mg/kg and prednisolone reduced vascular wall fibrosis. Prednisolone treatment resulted in decreased right ventricular systolic pressure. Pulmonary vascular resistance was lower in the prednisolone and ruxolitinib (4.28 mg/kg) groups in comparison with the placebo group. The plasma level of brain natriuretic peptide was lower in groups receiving ruxolitinib at doses of 2.58 and 4.28 mg/kg versus placebo. This study demonstrated that JAK1/2 inhibitor ruxolitinib dose-dependently reduced pulmonary vascular remodeling, thereby preventing CTEPH formation in rats.

Immune Ablation and Stem Cell Rescue in Two Pediatric Patients with Progressive Severe Chronic Graft-Versus-Host Disease

Transplantation of allogeneic hematopoietic stem cells represents an established treatment for children with high-risk leukemia. However, steroid-refractory chronic graft-versus-host disease (SR-cGvHD) represents a severe life-threatening complication, for which there is no standard therapy. After failing several lines of immunosuppressive and biological treatment, we applied an immunoablative therapy with re-transplantation of purified CD34⁺ donor stem cells to reset the aberrant immune system. Two pediatric patients, who had been transplanted for high-risk acute lymphoblastic leukemia, underwent the procedure. Interestingly, enough stem cells could be mobilized, harvested, and purified to be used as grafts more than one year after allogeneic transplantation under intensive immunosuppressive therapy and ongoing SR-cGvHD. With a follow-up of 8 and 22 months, respectively, both patients are without immunosuppressive therapy and do not show signs of active disease. Regeneration of skin manifestations started promptly, other damaged organs did not progress and continue to show recovery from severe fibrotic transformation. Bone marrow function is robust and T cell receptor repertoires showed polyclonal immune reconstitution. In conclusion, stem cell harvest and re-transplantation of human CD34⁺-selected allogeneic stem cells is possible and represents a new therapeutic option in SR-cGvHD by resetting a profoundly disturbed immune network.

[Effect of ruxolitinib combined with glucocorticoid on cytomegalovirus activation in acute graft-versus-host disease]

Objective: To observe the effect of ruxolitinib combined with glucocorticoid on cytomegalovirus (CMV) activation in patients with acute graft-versus-host disease (aGVHD) . Methods: The clinical data of 195 patients who underwent allogeneic hematopoietic stem cell transplantation in the Department of Hematology of the First Medical Center of the People's Liberation Army General Hospital from August 2018 to September 2020 were retrospectively analyzed. According to the severity of aGVHD, the patients were divided into the non-GVHD group, aGVHD grade Ⅰ group, aGVHD grade Ⅱ-Ⅳ group, and aGVHD grade Ⅲ/Ⅳ group. In addition, they were classified into two subgroups according to the first-line treatment regimen for aGVHD: combined regimen group (ruxolitinib combined with glucocorticoid) and classical regimen group (glucocorticoid alone) . The cumulative incidence of CMV activation, the duration of CMV activation, and the duration of CMV negativity in each subgroup at 90 and 180 days after transplantation were analyzed. The overall survival and disease-free survival rates of patients in both regimens were compared. Results: Sixty-four (32.8%) patients in the group did not develop aGVHD. The numbers of patients with grade Ⅰ, Ⅱ-Ⅳ, and Ⅲ/Ⅳ aGVHD were 30 (15.4%) , 101 (51.8%) , and 14 (7.2%) , respectively. Compared with patients in the classical regimen, no significant difference was observed in the cumulative incidence of CMV activation, duration of CMV activation, and duration of CMV negativity in patients with grade Ⅰ-Ⅳ aGVHD in the combined regimen at 90 and 180 days after transplantation (P>0.05) . Further analysis of patients with grade Ⅱ-Ⅳ and Ⅲ/Ⅳ aGVHD showed that the cumulative incidence of CMV activation, duration of CMV activation, and duration of CMV negativity did not show significant difference between the two treatment regimens (P>0.05) . In addition, there was no significant difference in the overall survival and disease-free survival rates of patients in both regimens (P>0.05) . Conclusion: Ruxolitinib combined with glucocorticoid as the first-line therapy for aGVHD did not increase the risk of CMV activation.

Herpesvirus Screening in Childhood Hematopoietic Transplant Reveals High Systemic Inflammation in Episodes of Multiple Viral Detection and an EBV Association with Elevated IL-1β, IL-8 and Graft-Versus-Host Disease

Infections remain a major cause of morbidity and mortality among hematopoietic stem cell transplant (HSCT) recipients. Unlike Epstein–Barr Virus (EBV) and Human Cytomegalovirus (HCMV), Human Herpesvirus (HHV) 6, HHV7 and HHV8 are not routinely monitored in many centers, especially in the pediatric population of low–medium income countries. We screened EBV, HCMV, HHV6, HHV7 and HHV8 in 412 leukocytes-plasma paired samples from 40 pediatric patients assisted in a tertiary hospital in Mexico. Thirty-two underwent allo-HSCT, whereas eight received auto-HSCT. Overall viral detection frequencies in allo- and auto-HSCT were: EBV = 43.7% and 30.0%, HCMV = 5.0% and 6.7%, HHV6 = 7.9% and 20.0% and HHV7 = 9.7% and 23.3%. HHV8 was not detected in any sample. Interestingly, HHV6 and HHV7 were more frequent in auto-HSCT, and HHV6 was observed in all episodes of multiple detection in auto-HSCT patients. We found EBV DNA in plasma samples, whereas HCMV, HHV6 and HHV7 DNA were predominantly observed in leukocytes, indicative of their expansion in cellular compartments. We also found that IL-1β, IL-2, IL-6 and IL-8 were significantly increased in episodes in which multiple viruses were simultaneously detected, and samples positive for EBV DNA and graft-versus-host disease had a further increase of IL-1β and IL-8. In conclusion, the EBV, HCMV, HHV6 and HHV7 burdens were frequently detected in allo- and auto-HSCT, and their presence associated with systemic inflammation.