Long-term follow-up of patients treated with daclizumab for steroid-refractory acute graft-vs-host disease

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.

Basiliximab Treatment for Patients With Steroid-Refractory Acute Graft-Versus-Host Disease Following Matched Sibling Donor Hematopoietic Stem Cell Transplantation

Basiliximab is an important treatment for steroid-refractory acute graft-versus-host disease (SR-aGVHD). We performed this retrospective study to evaluate the efficacy and safety of basiliximab treatment in SR-aGVHD patients following matched sibling donor hematopoietic stem cell transplantation (MSD-HSCT) (n = 63). Overall response rate (ORR) was 63.5% and 54% at any time and at day 28 after basiliximab treatment. Grade III-IV aGVHD before basiliximab treatment predicted a poor ORR after basiliximab treatment. The rates of virus, bacteria, and fungi infections were 54%, 23.8%, and 3.1%, respectively. With a median follow-up of 730 (range, 67-3,042) days, the 1-year probability of overall survival and disease-free survival after basiliximab treatment were 58.6% (95% confidence interval [CI] = 47.6%-72.2%) and 55.4% (95% CI = 44.3%-69.2%), respectively. The 3-year cumulative incidence of relapse and non-relapse mortality after basiliximab treatment were 18.9% (95% CI = 8.3%-29.5%) and 33.8% (95% CI = 21.8%-45.7%), respectively. Comorbidities burden before allo-HSCT, severity of aGVHD and liver aGVHD before basiliximab treatment showed negative influences on survival. Thus, basiliximab was safe and effective treatment for SR-aGVHD following MSD-HSCT.

Basiliximab for steroid-refractory acute graft-versus-host disease: A real-world analysis

Steroid-refractory (SR) acute graft-versus-host disease (aGVHD) is one of the leading causes of early mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We investigated the efficacy, safety, prognostic factors, and optimal therapeutic protocol for SR-aGVHD patients treated with basiliximab in a real-world setting. Nine hundred and forty SR-aGVHD patients were recruited from 36 hospitals in China, and 3683 doses of basiliximab were administered. Basiliximab was used as monotherapy (n = 642) or in combination with other second-line treatments (n = 298). The cumulative incidence of overall response rate (ORR) at day 28 after basiliximab treatment was 79.4% (95% confidence interval [CI] 76.5%-82.3%). The probabilities of nonrelapse mortality and overall survival at 3 years after basiliximab treatment were 26.8% (95% CI 24.0%-29.6%) and 64.3% (95% CI 61.2%-67.4%), respectively. A 1:1 propensity score matching was performed to compare the efficacy and safety between the monotherapy and combined therapy groups. Combined therapy did not increase the ORR; conversely, it increased the infection rates compared with monotherapy. The multivariate analysis showed that combined therapy, grade III-IV aGVHD, and high-risk refined Minnesota aGVHD risk score before basiliximab treatment were independently associated with the therapeutic response. Hence, we created a prognostic scoring system that could predict the risk of having a decreased likelihood of response after basiliximab treatment. Machine learning was used to develop a protocol that maximized the efficacy of basiliximab while maintaining acceptable levels of infection risk. Thus, real-world data suggest that basiliximab is safe and effective for treating SR-aGVHD.

Meta-Analysis of Interleukin-2 Receptor Antagonists as the Treatment for Steroid-Refractory Acute Graft-Versus-Host Disease

Acute graft-versus-host disease (aGVHD) is a major complication after allogeneic hematopoietic stem cell transplantation (HSCT). Corticosteroid is the first-line treatment for aGVHD, but its response rate is only approximately 50%. At present, no uniformly accepted treatment for steroid-refractory aGVHD (SR-aGVHD) is available. Blocking interleukin-2 receptors (IL-2Rs) on donor T cells using pharmaceutical antagonists alleviates SR-aGVHD. This meta-analysis aimed to compare the efficacy and safety of four commercially available IL-2R antagonists (IL-2RAs) in SR-aGVHD treatment. A total of 31 studies met the following inclusion criteria (1): patients of any race, any sex, and all ages (2); those diagnosed with SR-aGVHD after HSCT; and (3) those using IL-2RA-based therapy as the treatment for SR-aGVHD. The overall response rate (ORR) at any time after treatment with basiliximab and daclizumab was 0.81 [95% confidence interval (CI): 0.74-0.87)] and 0.71 (95% CI: 0.56-0.82), respectively, which was better than that of inolimomab 0.54 (95% CI: 0.39-0.68) and denileukin diftitox 0.56 (95% CI: 0.35-0.76). The complete response rate (CRR) at any time after treatment with basiliximab and daclizumab was 0.55 (95% CI: 0.42-0.68) and 0.42 (95%CI: 0.29-0.56), respectively, which was better than that of inolimomab 0.30 (95% CI: 0.16-0.51) and denileukin diftitox 0.37 (95% CI: 0.24-0.52). The ORR and CRR were better after 1-month treatment with basiliximab and daclizumab than after treatment with inolimomab and denileukin diftitox. The incidence of the infection was higher after inolimomab treatment than after treatment with the other IL-2RAs. In conclusion, the efficacy and safety of different IL-2RAs varied. The response rate of basiliximab was the highest, followed by that of daclizumab. Prospective, randomized controlled trials are needed to compare the efficacy and safety of different IL-2RAs.

The risk of tuberculosis infection in 410 Saudipatients receiving adalimumab therapy

BACKGROUND

Adalimumab is a fully humanized monoclonal antibody inhibitor of tumor necrosis factor-a used to treat various autoimmune disorders. Adalimumab poses a risk for tuberculosis (TB) infection, especially in countries where TB is endemic.

OBJECTIVE

Determine the rate of TB infection after adalimumab therapy in Saudi Arabia.

DESIGN

Medical record review.

SETTINGS

Tertiary care center in Riyadh.

PATIENTS AND METHODS

Demographic and clinical data were retrieved from the electronic healthcare records of all patients who received adalimumab treatment from 2015 to 2019.

MAIN OUTCOME MEASURES

Occurrence of TB after adalimumab therapy.

SAMPLE SIZE

410 patients (median ([QR] age, 37 [28], range 4-81 years), 40% males RESULTS: Rheumatoid arthritis was the most frequent indication (n=153, 37%). The patients were followed for a mean of 36 (8.9) months. No case of TB infection or reactivation was observed. An inter-feron-gamma release assay (IGRA) was requested in 353/391 (90.3%) patients, prior to initiating therapy. The IGRA was positive in 26 cases (6.6%). The IGRA-positive patients received isoniazid prophylactically. Bacterial infectious complications of adalimumab therapy occurred in 12 (2.9%) patients. Urinary tract infection was the most frequent complication (culture requested in 48 patients, positive in 8).

CONCLUSION

Adalimumab treatment was not associated with a risk of TB disease or TB reactivation in our cohort over the follow-up observation period. No TB reactivation occurred with adalimumab therapy when TB prophylaxis was used. The positive IGRA rate in patients on adalimumab treatment was low (7%).

LIMITATIONS

Single center and one geographical area in Saudi Arabia.

CONFLICT OF INTEREST

None.

Immunopathology and biology-based treatment of steroid-refractory graft-versus-host disease

Acute graft-versus-host disease (GVHD) is 1 of the major life-threating complications after allogeneic cell transplantation. Although steroids remain first-line treatment, roughly one-half of patients will develop steroid-refractory GVHD (SR-GVHD), which portends an extremely poor prognosis. Many agents that have shown encouraging response rates in early phase 1/2 trials for prevention and treatment have been unsuccessful in demonstrating a survival advantage when applied in the setting of SR-GVHD. The discovery of novel treatments has been further complicated by the absence of clinically informative animal models that address what may reflect a distinct pathophysiology. Nonetheless, the combined knowledge of established bone marrow transplantation models and recent human trials in SR-GVHD patients are beginning to illuminate novel mechanisms for inhibiting T-cell signaling and promoting tissue tolerance that provide an increased understanding of the underlying biology of SR-GVHD. Here, we discuss recent findings of newly appreciated cellular and molecular mechanisms and provide novel translational opportunities for advancing the effectiveness of treatment in SR-GVHD.

Current Prophylaxis and Treatment Approaches for Acute Graft-Versus-Host Disease in Haematopoietic Stem Cell Transplantation for Children With Acute Lymphoblastic Leukaemia

Acute graft-versus-host disease (aGvHD) continues to be a leading cause of morbidity and mortality following allogeneic haematopoietic stem cell transplantation (HSCT). However, higher event-free survival (EFS) was observed in patients with acute lymphoblastic leukaemia (ALL) and grade II aGvHD vs. patients with no or grade I GvHD in the randomised, controlled, open-label, international, multicentre Phase III For Omitting Radiation Under Majority age (FORUM) trial. This finding suggests that moderate-severity aGvHD is associated with a graft-versus-leukaemia effect which protects against leukaemia recurrence. In order to optimise the benefits of HSCT for leukaemia patients, reduction of non-relapse mortality-which is predominantly caused by severe GvHD-is of utmost importance. Herein, we review contemporary prophylaxis and treatment options for aGvHD in children with ALL and the key challenges of aGvHD management, focusing on maintaining the graft-versus-leukaemia effect without increasing the severity of GvHD.

Prognostic factors and long-term follow-up of basiliximab for steroid-refractory acute graft-versus-host disease: Updated experience from a large-scale study

Acute graft-vs-host disease (aGVHD) is one of the most important causes of early mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT), particularly for those with steroid-refractory (SR)-aGVHD. We aimed to identify the prognostic factors and long-term clinical outcomes of basiliximab treatment for SR-aGVHD. Basiliximab was administered on days 1, 3, and 8, and repeated weekly until aGVHD was less than grade II, or patients showed no response after four doses. Out of 1498 patients receiving allo-HSCT, 230 patients with SR-aGVHD were enrolled. Grade III to IV aGVHD before basiliximab treatment significantly and independently predicted a poorer response to basiliximab in multivariate analysis. And, the cumulative incidence of overall response at 14 days, 28 days, and 56 days after treatment was 41.4% vs 23.1% (P = .023), 70.2% vs 43.6% (P = .002), and 80.1% vs 66.7% (P = .013), respectively. This was for those with grade II and grade III to IV aGVHD. Patients receiving more than four doses of basiliximab had higher rates of infections. The 4-year cumulative incidence of total and severe chronic GVHD after basiliximab treatment was 44.8% (95% CI 38.3%-51.3%) and 2.2% (95% CI 0.3%-4.1%), respectively. The 4-year cumulative incidence of relapse, non-relapse mortality, disease-free survival, and overall survival after basiliximab treatment was 11.3% (95% CI 7.2%-15.4%), 30.0% (95% CI 24.1%-35.9%), 58.7% (95% CI 52.3%-65.1%), and 61.7% (95% CI 55.4%-68.0%), respectively. Comorbidities before allo-HSCT and refined Minnesota aGVHD risk score at diagnosis had significant influences on long-term survival. Thus, basiliximab was a safe and effective treatment for patients with SR-aGVHD.

Treatment and unmet needs in steroid-refractory acute graft-versus-host disease

Acute graft-versus-host disease (aGVHD) is a common complication of allogeneic hematopoietic stem cell transplantation (alloHCT) and is a major cause of morbidity and mortality. Systemic steroid therapy is the first-line treatment for aGVHD, although about half of patients will become refractory to treatment. As the number of patients undergoing alloHCT increases, developing safe and effective treatments for aGVHD will become increasingly important, especially for those whose disease becomes refractory to systemic steroid therapy. This paper reviews current treatment options for patients with steroid-refractory aGVHD and discusses data from recently published clinical studies to outline emerging therapeutic strategies.

Fungal Infections Potentiated by Biologics

Biologic therapies including monoclonal antibodies, tyrosine kinase inhibitors, and other agents represent a notable expansion in the pharmacotherapy armamentarium in treatment of a variety of diseases. Many of these therapies possess direct or indirect immunosuppressive and immunomodulatory effects, which have been associated with bacterial, viral, and fungal opportunistic infections. Careful screening of baseline risk factors before initiation, targeted preventive measures, and vigilant monitoring while on active biologic therapy mitigate these risks as use of biologics becomes more commonplace. This review compiles reported evidence of fungal infections associated with these agents with a focus on the tumor necrosis factor-α inhibitor class.

Fungal infections following treatment with monoclonal antibodies and other immunomodulatory therapies

Tumor necrosis factor (TNF) is a proinflammatory cytokine involved in a wide range of important physiologic processes and has a pathologic role in some diseases. TNF antagonists (infliximab, adalimumab, etanercept) are effective in treating inflammatory conditions. Antilymphocyte biological agents (rituximab, alemtuzumab), integrin antagonists (natalizumab, etrolizumab and vedolizumab), interleukin (IL)-17A blockers (secukinumab, ixekizumab) and IL-2 antagonists (daclizumab, basiliximab) are widely used after transplantation and for gastroenterological, rheumatological, dermatological, neurological and hematological disorders. Given the putative role of these host defense elements against bacterial, viral and fungal agents, the risk of infection during a treatment with these antagonists is a concern. Fungal infections, both opportunistic and endemic, have been associated with these biological therapies, but the causative relationship is unclear, especially among patients with poor control of their underlying disease or who are undergoing steroid therapy. Potential recipients of these drugs should be screened for latent endemic fungal infections. Cotrimoxazole prophylaxis could be useful for preventing Pneumocystis jirovecii infection in patients over 65 years of age who are taking TNF antagonists, antilymphocyte biological agents or who have lymphopenia and are undergoing concomitant steroid therapy. As with other immunosuppressant drugs, TNF antagonists and antilymphocyte antibodies should be discontinued for patients with active infectious disease.

Retrospective single center analysis of outcome, risk factors and therapy in steroid refractory graft-versus-host disease after allogeneic hematopoietic cell transplantation

Acute and chronic graft-vs.-host disease (aGvHD and cGvHD) are major complications after allogeneic hematopoietic cell transplantation (HCT) leading to substantial morbidity and mortality. This retrospective single-center study analyzes incidence, therapy, and outcome of GvHD in n = 721 patients ≥18 years having received allogeneic HCT 2004-2013 with a special focus on steroid refractory GvHD. Acute (n = 355/49.2%) and chronic (n = 269/37.3%) GvHD were mainly treated by steroids in first-line therapy. The proportion of steroid refractory aGvHD and cGvHD was 35.7% and 31.4%, respectively. As there is no standard therapy for steroid refractory GvHD, a range of different agents was used. In aGvHD, the overall response rate (ORR) of steroid refractory GvHD to second-line treatment was 27.4%. Mycophenolate mofetil (MMF) and mTOR inhibitors led to superior response rates (ORR 50.0% and 53.3%, respectively). In steroid refractory cGvHD therapy, ORR was 44.4%. Use of calcineurin inhibitors (CNI; n = 11/45.5%), MMF (n = 18/50.0%), mTOR inhibitors (n = 10/60.0%), and extracorporeal photophoresis (ECP; n = 16/56.3%) showed ORR above average. Targeted therapies lead to responses in 7.7% (n = 13). This data may help to improve the design of future prospective clinical studies in GvHD.

Non-Coding RNA Mediated Regulation of Allogeneic T Cell Responses After Hematopoietic Transplantation

Allogeneic bone marrow transplantation (BMT) is an effective therapy for several malignant and non-malignant disorders. The precise control of allogeneic T cells is critical for successful outcomes after BMT. The mechanisms governing desirable (graft-versus-leukemia) versus undesirable (graft-versus-host disease) allogeneic responses remain incompletely understood. Non-coding RNAs (ncRNA) are controllers of gene expression that fine-tune cellular responses. Multiple microRNAs (miRNAs), a type of ncRNA, have recently been shown to influence allogeneic T cell responses in both murine models and clinically. Here, we review the role of various miRNAs that regulate T cell responses, either positively or negatively, to allo-stimulation and highlight their potential relevance as biomarkers and as therapeutic targets for improving outcomes after allogeneic BMT.

α1-Antitrypsin infusion for treatment of steroid-resistant acute graft-versus-host disease

Corticosteroid resistance after acute graft-versus-host disease (SR-aGVHD) results in high morbidity and mortality after allogeneic hematopoietic cell transplantation. Current immunosuppressive therapies for SR-aGVHD provide marginal effectiveness because of poor response or excessive toxicity, primarily from infection. α₁-Antitrypsin (AAT), a naturally abundant serine protease inhibitor, is capable of suppressing experimental GVHD by downmodulating inflammation and increasing ratios of regulatory (T_reg) to effector T cells (T_effs). In this prospective multicenter clinical study, we sought to determine the safety and response rate of AAT administration in SR-aGVHD. Forty patients with a median age of 59 years received intravenous AAT twice weekly for 4 weeks as first-line treatment of SR-aGVHD. The primary end point was overall response rate (ORR), the proportion of patients with SR-aGVHD in complete (CR) or partial response by day 28 without addition of further immunosuppression. Treatment was well tolerated without drug-related adverse events. A significant increase in serum levels of AAT was observed after treatment. The ORR and CR rates by day 28 were 65% and 35%, respectively, and included responses in all aGVHD target organs. At day 60, responses were sustained in 73% of patients without intervening immunosuppression. Infectious mortality was 10% at 6 months and 2.5% within 30 days of last AAT infusion. Consistent with preclinical data, correlative samples showed an increase in ratio of activated T_regs to T_effs after AAT treatment. These data suggest that AAT is safe and may be potentially efficacious in treating SR-aGVHD. This trial was registered at www.clinicaltrials.gov as #NCT01700036.

Pentostatin therapy for steroid-refractory acute graft versus host disease: identifying those who may benefit

We report outcomes of 60 patients with steroid-refractory (SR)-aGVHD treated with pentostatin. Almost half (47%) of patients had grade 4 GVHD-22% had stage 3-4 liver GVHD and 51% had stage 3-4 lower gastrointestinal tract (LGI) GVHD. Patients received a median of 3 courses (range, 1-9) of pentostatin. Day 28 overall response rate (ORR) was 33% (n = 20) (complete response 18% (n = 11), partial response 15% (n = 9)). Non-relapse mortality was 72% (95% confidence interval (CI) 61-84%) and overall survival (OS) was 21% (95% CI 12-32%) at 18 months. On univariate analysis, age >60 years (HR 1.9, 95% CI 1.01-3.7, p = 0.045) and presence of liver GVHD (HR 1.9, 95% CI 1.9, 95% CI 1.5-3.3, p = 0.03) were significant predictors of poor OS while patients with LGI GVHD had superior OS than those without (HR 0.4, 95% CI 0.2-0.8, p = 0.01). On stratified analysis, patients <60 years with isolated LGI GVHD had the best outcomes with an ORR of 48% and OS of 42% at 18 months. Among older patients, OS was 14% in those with isolated LGI aGVHD and 0% in others. Pentostatin remains a viable treatment option for SR-aGVHD, especially in patients 60 years or younger with isolated LGI involvement.

Regional intra-arterial steroid treatment in 120 patients with steroid-resistant or -dependent GvHD

GvHD results in death in the majority of steroid-resistant patients. This report assesses the safety and efficacy of two regional intra-arterial steroid (IAS) treatment protocols in the largest published cohort of patients with resistant/dependent hepatic and/or gastrointestinal GvHD, as well as identification of predictors of response to IAS and survival. One hundred and twenty patients with hepatic, gastrointestinal GvHD or both were given IAS. Gastrointestinal initial response (IR) and complete response (CR) were documented in 67.9% and 47.6%, respectively, whereas hepatic IR/CR in 54.9% and 33.3%, respectively. The predictors of gastrointestinal CR were lower peak GvHD and steroid-dependent (SD) GvHD. The predictors for hepatic CR were male patient, reduced intensity conditioning and SD GvHD. Twenty-six of the 120 patients (21.6%) are currently alive (median follow-up for the survivors 91.5 months). The 12 months' overall survival is 30% with no treatment-associated deaths. Predictors of 12 months' survival were as follows: first transplant, age<20 years, non-TBI regimen and GvHD CR. Shorter time to gastrointestinal IR but not time to hepatic IR was associated with improved 12 months' survival. IAS appears to be safe and effective. Gastrointestinal treatment is more effective than hepatic treatment. In our study, we conclude our current recommendations for IAS treatment.

Unintended Immunological Consequences of Biologic Therapy

Recent advances in the understanding of immune dysregulation in autoimmune diseases have enabled the development of new monoclonal antibody-based drugs called biologics. Biologics have been used to target aberrant immune responses in many diseases, but patients with rheumatologic and other autoimmune diseases have benefited the most and improvements in outcomes have been significant. The use of biologics is not without hazard, however, as these agents block immune pathways adapted to protect the host. This has been borne out by increased rates of infections as well as induction of new autoimmune and hematologic adverse effects. As new drugs for the treatment of autoimmune conditions are entering the pipeline, it is incumbent on the practicing immunologist to understand the mechanism of these biologics and the implications of clinical use.

Combining therapeutic antibodies using basiliximab and etanercept for severe steroid-refractory acute graft-versus-host disease: A multi-center prospective study

Acute graft versus host disease (aGVHD) remains a major problem after allogeneic hematopoietic stem cell transplantation. Standard frontline therapy for aGVHD involves corticosteroids. However, fewer than half of patients have a lasting complete response. The long-term mortality rate of steroid-refractory aGVHD (SR-aGVHD) remains around 70%. To date, no consensus has been reached regarding the optimal salvage treatment for SR-aGVHD. We performed the first prospective, multi-center clinical trial to assess the efficacy and safety of a novel approach to treat severe (grades III-IV) SR-aGVHD with the combination of basiliximab and etanercept. Sixty-five patients with severe SR-aGVHD from six centers were included. The median number of basiliximab infusions was 4 (range 2-11) and of etanercept was 9 (range 2-12). At day 28 after starting the combination treatment, overall response (complete and partial response: CR+PR) to second-line treatment was 90.8% with 75.4% being CR. The incidences of CR per organ were 100%, 73.8%, and 79.7% for skin, liver, and gut involvement, respectively. Patients >30-y old (p = 0.043, RR = 3.169), development of grades III-IV liver aGVHD (p = 0.007, RR = 5.034) and cytomegalovirus (CMV) reactivation (p = 0.035, RR = 4.02) were independent predictors for incomplete response. Combined treatment with basiliximab and etanercept resulted in improved CR to visceral aGVHD and significantly superior 2-y overall survival (54.7% vs. 14.8%, p <0.001) compared with classical salvage treatments. Our data suggest that the combination of basiliximab and etanercept may constitute a promising new treatment option for SR-aGVHD.

CD25 Blockade Delays Regulatory T Cell Reconstitution and Does Not Prevent Graft-versus-Host Disease After Allogeneic Hematopoietic Cell Transplantation

Daclizumab, a humanized monoclonal antibody, binds CD25 and blocks formation of the IL-2 receptor on T cells. A study of daclizumab as acute graft-versus-host disease (GVHD) prophylaxis after unrelated bone marrow transplantation was conducted before the importance of CD25⁺FOXP3⁺ regulatory T cells (Tregs) was recognized. Tregs can abrogate the onset of GVHD. The relation between Tregs and a graft-versus-malignancy effect is not fully understood. An international, multicenter, double-blind clinical trial randomized 210 adult or pediatric patients to receive 5 weekly doses of daclizumab at 0.3 mg/kg (n = 69) or 1.2 mg/kg (n = 76) or placebo (n = 65) after unrelated marrow transplantation for treatment of hematologic malignancies or severe aplastic anemia. The risk of acute GVHD did not differ among the groups (P = .68). Long-term follow-up of clinical outcomes and correlative analysis of peripheral blood T cell phenotype suggested that the patients treated with daclizumab had an increased risk of chronic GVHD (hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.0 to 2.3; P = .08) and a decreased risk of relapse (HR, 0.57; 95% CI, 0.3 to 1.0; P = .05), but similar survival (HR, 0.89; 95% CI, 0.6 to 1.3; P = .53). T cells from a subset of patients (n = 107) were analyzed by flow cytometry. Compared with placebo, treatment with daclizumab decreased the proportion of Tregs among CD4 T cells at days 11-35 and increased the proportion of central memory cells among CD4 T cells at 1 year. Prophylactic administration of daclizumab does not prevent acute GVHD, but may increase the risk of chronic GVHD and decrease the risk of relapse. By delaying Treg reconstitution and promoting immunologic memory, anti-CD25 therapy may augment alloreactivity and antitumor immunity.

Therapeutic targets and emerging treatment options in gastrointestinal acute graft-versus-host disease

Introduction

Graft-versus-host disease (GVHD) continues to be the major lethal complication of allogeneic hematopoietic stem cell transplantation (HCT) but the standard of care, high dose steroids, has not changed in 40 years. Approximately 50% of GVHD patients will develop steroid refractory disease, typically involving the gastrointestinal (GI) tract, which has a very poor prognosis. Newly developed GVHD biomarker-based risk scores provide the first opportunity to treat patients at the onset of symptoms according to risk of steroid failure. Furthermore, improvements in our understanding of the pathobiology of GVHD, its different signaling pathways, involved cytokines, and the role of post-translational and epigenetic modifications, has identified new therapeutic targets for clinical trials.

Areas covered

This manuscript summarizes the pathophysiology, diagnosis, staging, current and new targeted therapies for GVHD, with an emphasis on GI GVHD. A literature search on PubMed was undertaken and the most relevant references included.

Expert Opinion

The standard treatment for GVHD, high dose steroids, offers less than optimal outcomes as well as significant toxicities. Better treatments, especially for GI GVHD, are needed to reduce non-relapse mortality after allogeneic HCT. The identification of high risk patients through a biomarker-defined scoring system offers a personalized approach to a disease that still requires significant research attention.

Improved Treatment-Related Mortality and Overall Survival of Patients with Grade IV Acute GVHD in the Modern Years

The impact of advances in supportive care and hematopoietic stem cell transplantation (HSCT) practices on the outcomes of patients who develop grade III or IV acute graft-versus-host disease (GVHD) is unknown. We performed a retrospective analysis of 427 patients with overall grade III or IV acute GVHD treated at 2 partner institutions between 1997 and 2012. We compared treatment-related mortality (TRM) and overall survival (OS) in 2 cohorts based on the year of transplantation, 1997 to 2006 (n = 222) and 2007 to 2012 (n = 205), using multivariate analysis, adjusting for significant patient-, disease-, and transplantation-related factors. Recipient age, reduced-intensity conditioning, unrelated donor, and peripheral blood stem cell grafts in the patients with grade III or IV acute GVHD increased over time. In the unadjusted analysis, 12-month OS increased over time (30% in 1997 to 2006 versus 42% in 2007 to 2012; P = .003) reflecting a decrease in TRM (58% in 1997 to 2006 versus 38% in 2007 to 2012; P = .0002), and an increase in PFS (29% in 1997 to 2006 versus 43% in 2007 to 2012; P = .002). On multivariate analysis, the period of transplantation remained a significant predictor for OS (hazard ratio [HR], 0.71; 95% confidence interval [CI], 0.54 to 0.94; P = .02), progression-free survival (PFS) (HR, 0.70; 95% CI, 0.52 to 0.94; P = .02), and TRM (HR, 0.57; 95% CI, 0.39 to 0.82; P = .002). In subgroup analysis, these differences were observed mainly in patients with grade IV acute GVHD. The outcomes of patients who develop overall grade III or IV acute GVHD after allogeneic HSCT has improved over time, with lower TRM and improved OS. This improvement in outcomes was seen primarily in patients with grade IV acute GVHD.

Efficacy of Mesenchymal Stem Cell Therapy for Steroid-Refractory Acute Graft-Versus-Host Disease following Allogeneic Hematopoietic Stem Cell Transplantation: A Systematic Review and Meta-Analysis

Background

Mesenchymal stem cells (MSCs) have been broadly used experimentally in various clinical contexts. The addition of MSCs to initial steroid therapy for acute graft-versus-host disease (aGVHD) may improve patient outcomes. However, investigations regarding prognostic factors affecting the efficacy of MSC therapy for steroid-refractory aGVHD remain controversial. We thus conducted a systematic review and meta-analysis of published clinical trials to determine possible prognostic factors affecting the efficacy of MSCs in treating steroid-refractory aGVHD.

Methods and Findings

Clinical trials using MSC therapy for steroid-refractory aGVHD were identified by searching PubMed and EMBASE databases. A total of 6,963 citations were reviewed, and 13 studies met the inclusion criteria. A total of 301 patients from thirteen studies were included. Of these, 136 patients showed a complete response (CR), and 69 patients displayed a partial (PR) or mixed response (MR). In total, 205 patients exhibited overall response (ORR). Patients with skin steroid-refractory aGVHD showed a better clinical response than gastrointestinal (CR: odds ratio [OR] = 1.93, 95% confidence interval [95%CI]: 1.05–3.57, p < 0.05) and liver (CR: OR = 2.30, 95%CI: 1.12–4.69, p < 0.05, and ORR: OR = 2.93, 95%CI: 1.06–8.08, p < 0.05) steroid-refractory aGVHD. Those with grade II steroid-refractory aGVHD exhibited a better clinical response following MSC therapy than recipients with grade III–IV (CR: OR = 3.22, 95%CI: 1.24–8.34, p < 0.05). Completion therapy may improve the CR but reduce ORR compared with induction therapy (CR: OR = 0.20, 95%CI: 0.09–0.44, p < 0.05; ORR: OR = 2.18, 95%CI: 1.17–4.05, p = 0.01). There was also a trend towards a better clinical response in children compared with adults (CR: OR = 2.41, 95%CI: 1.01–5.73, p = 0.05).

Conclusions

Age, skin involvement, lower aGVHD grade, and the number of infusions are the main prognostic factors affecting the efficacy of MSC therapy for steroid-refractory aGVHD.

Effects of T-Cell Depletion on Allogeneic Hematopoietic Stem Cell Transplantation Outcomes in AML Patients

Graft versus host disease (GVHD) remains one of the leading causes of morbidity and mortality associated with conventional allogeneic hematopoietic stem cell transplantation (HCT). The use of T-cell depletion significantly reduces this complication. Recent prospective and retrospective data suggest that, in patients with AML in first complete remission, CD34+ selected grafts afford overall and relapse-free survival comparable to those observed in recipients of conventional grafts, while significantly decreasing GVHD. In addition, CD34+ selected grafts allow older patients, and those with medical comorbidities or with only HLA-mismatched donors to successfully undergo transplantation. Prospective data are needed to further define which groups of patients with AML are most likely to benefit from CD34+ selected grafts. Here we review the history of T-cell depletion in AML, and techniques used. We then summarize the contemporary literature using CD34+ selection in recipients of matched or partially mismatched donors (7/8 or 8/8 HLA-matched), and provide a summary of the risks and benefits of using T-cell depletion.

Recent advances in the management of graft-versus-host disease

Graft-versus-host disease (GvHD) remains a significant hurdle in overcoming the morbidity and mortality associated with haemopoietic stem cell transplantation in children. Better understanding of its pathobiology is facilitating the development of biomarkers for the severity of acute GvHD and treatment response, and has led to the introduction of a more prognostically relevant grading system for chronic GvHD. These enable stratification of appropriate prophylactic and treatment strategies according to the risk profiles of individual patients. Steroid-refractory acute GvHD has a poor prognosis, but early reports of the use of new immunosuppressive drugs and especially cellular treatments with extracorporeal photopheresis and mesenchymal stem cells suggest improved short-term outcomes and offer the promise of increased longer-term survival rates.

Extracorporeal photopheresis (photochemotherapy) in the treatment of acute and chronic graft versus host disease: immunological mechanisms and the results from clinical studies

Extracorporeal photopheresis (ECP) is an immunomodulatory alternative for treatment of graft versus host disease (GVHD). The blood is then separated into its various components through apheresis; buffy coat cells are thereafter treated with 8-methoxypsoralen before exposure to ultraviolet light and finally reinfused into the patient. There is a general agreement that this treatment has an anti-GVHD effect, but the mechanisms of action behind this effect are only partly understood. However, altered maturation of dendritic cells (DC) and thereby indirect modulation of T-cell reactivity seems to be one important mechanism together with DC-presentation of antigens derived from apoptotic donor T cells and induction of regulatory T cells. The treatment has been best studied in patients with chronic GVHD (both pediatric and adult patients), but most studies are not randomized and it is difficult to know whether the treatment is more effective than the alternatives. The clinical studies of ECP in adults with acute GVHD are few and not randomized; it is not possible to judge whether this treatment should be a preferred second- or third-line treatment. There is no evidence for increased risk of leukemia relapse or suppression of specific graft versus leukemia reactivity by this treatment, so specific antileukemic immunotherapy may still be possible. Thus, even though the treatment seems effective in patients with GVHD, further clinical (especially randomized) as well as biological studies with careful standardization of the treatment are needed before it is possible to conclude how ECP should be used in acute and chronic GVHD.

Prognostic factors and outcomes of severe gastrointestinal GVHD after allogeneic hematopoietic cell transplantation

We hypothesized that clinical risk factors could be identified within 2 weeks of onset of severe (stage 3 or 4) acute gut GVHD for identifying a patient population with a very poor outcome. Among 1462 patients who had allogeneic hematopoietic cell transplantation (HCT) between January 2000 and December 2005, 116 (7.9%) developed stage 3-4 gut GVHD. The median time for onset of stage 3-4 gut GVHD was 35 (4-135) days after allogeneic HCT. Eighty-five of the 116 patients (73%) had corticosteroid resistance before or within 2 weeks after the onset of stage 3-4 gut GVHD. Significant risk factors for mortality included corticosteroid resistance (hazards ratio (HR)=2.93; P=0.0005), age >18 years (HR=4.95; P=0.0004), increased serum bilirubin (HR 2.53; P=0.0001) and overt gastrointestinal bleeding (HR 2.88; P=0.0004). Among patients with stage 3-4 gut GVHD, the subgroup with 0, 1 or 2 risk factors had a favorable prognosis, whereas the subgroup with 3 or 4 risk factors had a dismal prognosis. This information should be considered in designing future studies of severe gut GVHD and in counseling patients about prognosis.

Allogeneic human mesenchymal stem cell therapy (remestemcel-L, Prochymal) as a rescue agent for severe refractory acute graft-versus-host disease in pediatric patients

Severe steroid-refractory acute graft-versus-host disease (aGVHD) is related to significant mortality and morbidity after allogeneic stem cell transplantation. Early clinical trials of therapy with human mesenchymal stem cells (hMSCs) in pediatric patients with severe aGVHD resistant to multiple immunosuppressive agents showed promising results. In this study, we evaluated the risk/benefit profile of remestemcel-L (Prochymal), a third-party, off-the-shelf source of hMSCs, as a rescue agent for treatment-resistant aGVHD in pediatric patients. Children with grade B-D aGVHD failing steroids and, in most cases, other immunosuppressive agents were eligible for enrollment. Patients received 8 biweekly i.v. infusions of 2 × 10(6) hMSCs/kg for 4 weeks, with an additional 4 weekly infusions after day +28 for patients who achieved either a partial or mixed response. The enrolled patients compose a very challenging population with severe disease that was nonresponsive to the standard of care, with 88% of the patients experiencing severe aGVHD (grade C or D). Seventy-five patients (median age, 8 yr; 58.7% male; and 61.3% Caucasian) were treated in this study. Sixty-four patients (85.3%) had received an unrelated hematopoietic stem cell graft, and 28 patients (37.3%) had received a cord blood graft. At baseline, the distribution of aGVHD grades B, C, and D was 12.0%, 28.0%, and 60.0%, respectively. The median duration of aGVHD before enrollment was 30 d (range, 2 to 1639 d), and patients failed a median of 3 immunosuppressive agents. Organ involvement at baseline was 86.7% gastrointestinal, 54.7% skin, and 36.0% liver. Thirty-six patients (48.0%) had 2 organs involved, and 11 patients (14.7%) had all 3 organs involved. When stratified by aGVHD grade at baseline, the rate of overall response (complete and partial response) at day +28 was 66.7% for aGVHD grade B, 76.2% for grade C, and 53.3% for grade D. Overall response for individual organs at day +28 was 58.5% for the gastrointestinal system, 75.6% for skin, and 44.4% for liver. Collectively, overall response at day +28 for patients treated for severe refractory aGVHD was 61.3%, and this response was correlated with statistically significant improved survival at day +100 after hMSC infusion. Patients who responded to therapy by day +28 had a higher Kaplan-Meier estimated probability of 100-d survival compared with patients who did not respond (78.1% versus 31.0%; P < .001). Prochymal infusions were generally well tolerated, with no evidence of ectopic tissue formation.

Risk of tuberculosis infection in anti-TNF-α biological therapy: from bench to bedside

Anti-tumor necrosis factor-α (TNF-α) biological agents, including soluble TNF-α receptors and anti-TNF-α monoclonal antibodies, bring new hope for treating rheumatic diseases such as rheumatoid arthritis, but also increase the risk of infection, especially tuberculosis (TB) infection. Recent findings have shown that the physiological TNF-mediated signaling was somehow impaired by TNF antagonists, leading to the exacerbation of chronic infection associated with aberrant granuloma formation and maintenance. Although both receptor and antibody agents appear to pose an equally high risk in causing development of new TB infections, monoclonal anti-TNF-α antibody seems more inclined to reactivate latent TB infection. This review is focused on the underlying mechanisms that cause the TB risk in the anti-TNF-α therapy and also the strategies to deal with it, with the aim of reducing the TB incidence during anti-TNF-α biological therapies.

Application of MultiStem(®) Allogeneic Cells for Immunomodulatory Therapy: Clinical Progress and Pre-Clinical Challenges in Prophylaxis for Graft Versus Host Disease

The last decade has seen much progress in adjunctive cell therapy for immune disorders. Both corporate and institutional Phase III studies have been run using mesenchymal stromal cells (MSC) for treatment of Graft versus Host Disease (GvHD), and product approval has been achieved for treatment of pediatric GvHD in Canada and New Zealand (Prochymal(®); Osiris Therapeutics). This effectiveness has prompted the prophylactic use of adherent stem cells at the time of allogeneic hematopoietic stem cell transplantation (HSCT) to prevent occurrence of GvHD and possibly provide stromal support for hematopoietic recovery. The MultiStem(®) product is an adult adherent stem cell product derived from bone marrow which has significant clinical exposure. MultiStem cells are currently in phase II clinical studies for treatment of ischemic stroke and ulcerative colitis, with Phase I studies completed in acute myocardial infarction and for GvHD prophylaxis in allogeneic HSCT, demonstrating that MultiStem administration was well tolerated while the incidence and severity of GvHD was reduced. In advancing this clinical approach, it is important to recognize that alternate models exist based on clinical manufacturing strategies. Corporate sponsors exploit the universal donor properties of adherent stem cells and manufacture at large scale, with many products obtained from one or limited donors and used across many patients. In Europe, institutional sponsors often produce allogeneic product in a patient designated context. For this approach, disposable bioreactors producing <10 products/donor in a closed system manner are very well suited. In this review, the use of adherent stem cells for GvHD prophylaxis is summarized and the suitability of disposable bioreactors for MultiStem production is presented, with an emphasis on quality control parameters, which are critical with a multiple donor approach for manufacturing.

Long-term follow-up of children treated with daclizumab for steroid-refractory gastrointestinal GvHD in a prospective study

Daclizumab, a humanized MoAB to IL-2Ra, has been found to be safe and effective in adults with refractory GvHD; however, data in children are limited. The aim of this prospective study was to evaluate the long-term safety and efficacy of daclizumab in children with steroid-refractory GI aGvHD. This study included 13 children who developed steroid-refractory GI GvHD between 2007 and 2009. When first-line treatment failed, daclizumab was given in a regimen of 1 mg/kg intravenously and then repeated on a 10- to 14-day interval for maximum five doses if necessary. Daclizumab was well tolerated, but infections were common. Ten patients responded to daclizumab completely, one patient responded partially, and two patients failed to respond. With a median follow-up of 630 days, 10 patients were alive and free of severe infections, but among them, four patients were suffering from cGvHD. Of the three remaining patients, one died because of bacterial meningitis, and the other two patients died because of severe refractory GI GvHD. This long-term evaluation showed that daclizumab could be an effective and relatively safe treatment in most of the pediatric patients with severe steroid-refractory GI GvHD.

First- and second-line systemic treatment of acute graft-versus-host disease: recommendations of the American Society of Blood and Marrow Transplantation

Despite prophylaxis with immunosuppressive agents or a variety of other approaches, many patients suffer from acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic cell transplantation. Although consensus has emerged supporting the use of high-dose methylprednisolone or prednisone for initial treatment of aGVHD, practices differ among centers with respect to the initial glucocorticoid dose, the use of additional immunosuppressive agents, and the approach to withdrawal of treatment after initial improvement. Despite many studies, practices vary considerably with respect to the selection of agents for treatment of glucocorticoid-resistant or refractory GVHD. Investigators and clinicians have recognized the lack of progress and lamented the absence of an accepted standard of care for secondary treatment of aGVHD. The American Society of Blood and Marrow Transplantation has developed recommendations for treatment of aGVHD to be considered by care providers, based on a comprehensive and critical review of published reports. Because the literature provides little basis for a definitive guideline, this review also provides a framework for the interpretation of previous results and the design of future studies.

Secondary treatment of acute graft-versus-host disease: a critical review

Management of steroid-resistant or steroid-refractory acute graft-versus-host disease (aGVHD) poses one of the most vexing and difficult problems faced by transplantation physicians. In the current study, we used 10 criteria to evaluate 67 reports describing secondary treatment of patients with aGVHD. The goal of this exercise was not only to provide a critical summary of the literature but also to offer suggestions that could improve future studies. Areas especially in need of improvement include the use of a consistent treatment regimen, the assessment of response at a consistent prespecified time point, consideration of concomitant treatment in assessing response, documentation that selection bias was minimized, and the use of methods that test a formal statistical hypothesis based on a contemporaneous or historical benchmark. Our results suggest that previous published reports collectively offer little guidance in discerning the most effective treatments for patients with steroid-resistant or steroid-refractory aGVHD. Adherence to the proposed criteria in future reports would enable meaningful comparisons across studies and thereby accelerate progress in evaluating new treatments for patients with aGVHD.

Basiliximab for the treatment of steroid-refractory acute graft-versus-host disease after unmanipulated HLA-mismatched/haploidentical hematopoietic stem cell transplantation

BACKGROUND

Anti-CD(25) monoclonal antibodies (Mabs) have been evaluated for the treatment of steroid-refractory acute graft-versus-host disease (GVHD) in patients undergoing hematopoietic stem cell transplantation (HSCT) mainly with matched donors for years, but there is little attention concerning patients with unmanipulated human leukocyte antigen (HLA)-mismatched/haploidentical transplantations. We investigated the efficacy and safety of the chimeric Mab, basiliximab, to treat steroid-refractory acute GVHD after unmanipulated mismatched/haploidentical HSCT.

METHODS

Fifty-three patients who developed steroid-refractory acute GVHD between July 2005 and July 2009 were treated at our institute with basiliximab. No prisoners were used in this study.

RESULTS

Forty-six among 53 patients responded, including 37 complete remissions at a median response of 6 days from Mab initiation. There were 29 episodes of viral reactivations, 25 bacterial infections, and 11 probable fungal infections. Thirty-four out of 49 patients who could be evaluated developed chronic GVHD. Twenty-eight of 53 subjects (52.8%) were alive at a median follow-up of 16 months (range, 2-57) posttransplantation. The Kaplan-Meier probability of a 3-year event-free survival was 47.7%. The causes of death were infection alone (n = 15), progressive GVHD with infection (n = 3), relapse (n = 3), and other etiologies (n = 4).

CONCLUSION

These data suggested that basiliximab was effective to treat steroid-refractory acute GVHD after unmanipulated HLA-mismatched/haploidentical stem cell transplantation.

Steroid-refractory acute GVHD: lack of long-term improved survival using new generation anticytokine treatment

There is no consensus on the optimal treatment of steroid-refractory acute graft-versus-host disease (SR-aGVHD) after allogeneic hematopoietic stem cell transplantation. In our center, the treatment policy has changed over time with mycophenolate mofetil (MMF) being used from 1999 to 2003, and etanercept or inolimomab after 2004. An observational study compared survival and infection rates in all consecutive patients receiving 1 of these 3 treatments. Ninety-three patients were included. The main end point was overall survival (OS). Median age was 37 years. Acute GVHD developed at a median of 15 days after transplantation. Second-line treatment was initiated a median of 12 days after aGVHD diagnosis. Therapies were MMF in 56%, inolimomab in 22%, and etanercept in 23% of the patients. Overall, second-line treatment response rate was 45% (complete response: 28%), MMF: 55%, inolimomab: 35%, and etanercept: 28%. With 74 months median follow-up, the 2-year survival was 30% (95% confidence interval: 22-41). Risk factors significantly associated with OS in multivariate analysis were disease status at transplantation; grade III-IV aGVHD at second-line treatment institution; and liver involvement. None of the second-line therapy influenced this poor outcome. Viral and fungal infections were not statistically different among the 3 treatment options; however, bacterial infections were more frequent in patients treated with anticytokines. Over an 11-year period, 3 treatment strategies, including 2 anticytokines, give similar results in patients with SR-aGVHD.

Treatment of graft-versus-host disease with monoclonal antibodies and related fusion proteins

Allogeneic hematopoietic stem cell transplantation has evolved from an experimental treatment approach to a widely used, curative therapy to treat malignant and nonmalignant diseases of the hematopoietic system. Despite advances in donor selection, conditioning regimens and supportive care, acute and chronic graft-versus-host disease (GvHD) remain a major cause of morbidity and mortality. Steroids are the standard first-line treatment and are able to control GvHD in approximately 50% of patients. Those who fail on steroids have a poor long-term prognosis. Therefore, a large number of drugs and procedures have been evaluated as second-line therapy. Monoclonal antibodies have increasingly been used to treat malignancy and autoimmune disease during the last 20 years. Their unique ability to target specific antigens theoretically enables them to directly interfere with cellular mechanisms that are involved in GvHD pathology. For this reason, monoclonal antibodies have been studied extensively as a second-line treatment for acute and chronic GvHD. The purpose of this article is to collect published data on clinical trials from the current literature and to give an overview on efficacy and toxicity of monoclonal antibody treatment for GvHD.

Long-term follow-up of patients with moderate aplastic anemia and pure red cell aplasia treated with daclizumab

BACKGROUND

Pure red cell aplasia and moderate aplastic anemia are marrow failure states with an immune pathogenesis. Previously, we described short-term improvements in blood counts in two pilot studies treating moderate aplastic anemia (mAA) and pure red cell aplasia (PRCA) patients with daclizumab, a humanized monoclonal antibody to the interleukin-2 receptor; we now report our long-term experience with a larger cohort of patients.

DESIGN AND METHODS

After a median follow-up period of 4.8 years, 19 of 45 (42%) evaluable mAA patients and 10 of 26 (38%) patients with PRCA responded by three months and 2 additional mAA patients responded by six months following administration of the drug.

RESULTS

Seven of 28 (25%) mAA patients achieved long-term packed red blood cell PRBC transfusion independence, and all PRCA responders achieved long-term transfusion PRBC transfusion independence.

CONCLUSIONS

Red cell transfusion-independence prior to treatment in mAA patients predicted response. The only significant adverse treatment-related events were transient rashes and arthralgias. Daclizumab is safe and effective, and produces lengthy remissions in patients with PRCA and mAA.

Inflammatory cytokine inhibition with combination daclizumab and infliximab for steroid-refractory acute GVHD

Treatment options for steroid-refractory GVHD (SR-GVHD) are unsatisfactory and prognosis is poor. Inflammatory cytokines IL-2 and TNF-α are important mediators of GVHD and may be critical targets for therapy. We retrospectively reviewed our experience using combination anti-cytokine therapy of daclizumab and infliximab. Seventeen evaluable patients had a median age of 47 years (range 35-63). The conditioning regimen was myeloablative in 13 and non-myeloablative in 4 cases. GVHD occurred at a median of 49 days after transplant in 12 patients (range 21-231 days) and at a median of 46 days (range 25-119 days) after donor lymphocyte infusion in 5 patients. All patients had persistent or progressive GVHD despite 1-2 mg/kg/day of corticosteroids for a median of 7 days (range 2-26 days). They received a combination of daclizumab and infliximab for acute GVHD IBMTR severity index B (3), C (10) or D (4). Of the 17 patients analyzed, 47% responded to treatment, 24% had complete resolution of symptoms and 24% had partial responses. Survival was limited and all the patients died a median of 6.7 months (range 1.6-26) from transplant and 35 days from initiation of daclizumab/infliximab. This retrospective analysis suggests that combination anti-cytokine therapy with daclizumab/infliximab has significant activity in SR-GVHD, but outcomes remain poor. New methods to prevent and treat GVHD are urgently needed.

Management of acute graft-versus-host disease in children

Acute graft-versus-host disease (aGVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT) in children. Although 30% to 50% of children respond to corticosteroids as initial therapy, the optimal initial or second-line therapies have not yet been determined. Newer approaches with combination therapy, novel agents, monoclonal antibodies, and/or cellular therapies show some promise but require prospective well-designed trials that include children to establish their efficacy. This article reviews the clinical presentation, treatment, and practical management guidelines for children with aGVHD.

Rapamycin for refractory acute graft-versus-host disease

BACKGROUND

Rapamycin, an inhibitor of mammalian target of rapamycin kinase, is a potent immunosuppressive drug that also displays antineoplastic properties and expands regulatory T cells. Steroid-refractory acute graft-versus-host disease (GVHD) remains a significant cause of mortality after allogeneic stem-cell transplantation and therapeutic options are not codified. We retrospectively evaluated the role of rapamycin in this setting.

METHODS

In this retrospective single-center study, 22 patients were identified, from October 2004 to February 2008, as having received rapamycin for acute GVHD refractory to one or more lines of treatment. We analyzed the efficacy and tolerance of rapamycin and the outcome of these 22 patients in this setting.

RESULTS

Rapamycin resulted in a rapid and sustained complete remission of GVHD in 72% of heavily pretreated patients. Cytopenias were frequent but did not require treatment interruption. Thrombotic microangiopathy developed in 36% of patients when rapamycin was associated with calcineurin inhibitors and frequently resolved after interruption of one or both drugs. At a median follow-up of 13 months, overall survival was 41%. Previous treatment with high-dose steroid pulses was associated with a worse outcome (survival 12% vs. 69%). The major cause of death was infectious complications (77%).

CONCLUSION

Despite a small and heterogeneous population of patients, these results are encouraging and provide a rationale for prospective studies that use rapamycin in steroid-refractory acute GVHD as a second- or third-line agent.

Regenerative stromal cell therapy in allogeneic hematopoietic stem cell transplantation: current impact and future directions

Regenerative stromal cell therapy (RSCT) has the potential to become a novel therapy for preventing and treating acute graft-versus-host disease (GVHD) in the allogeneic hematopoietic stem cell transplant (HSCT) recipient. However, enthusiasm for using RSCT in allogeneic HSCT has been tempered by limited clinical data and poorly defined in vivo mechanisms of action. As a result, the full clinical potential of RSCT in supporting hematopoietic reconstitution and as treatment for GVHD remains to be determined. This manuscript reviews the immunomodulatory activity of regenerative stromal cells in preclinical models of allogeneic HSCT, and emphasizes an emerging literature suggesting that microenvironment influences RSC activation and function. Understanding this key finding may ultimately define the proper niche for RSCT in allogeneic HSCT. In particular, mechanistic studies are needed to delineate the in vivo effects of RSCT in response to inflammation and injury associated with allogeneic HSCT, and to define the relevant sites of RSC interaction with immune cells in the transplant recipient. Furthermore, development of in vivo imaging technology to correlate biodistribution patterns, desired RSC effect, and clinical outcome will be crucial to establishing dose-response effects and minimal biologic dose thresholds needed to advance translational treatment strategies for complications like GVHD.