Update on the mechanism of action and on clinical efficacy of extracorporeal photopheresis in the treatment of acute and chronic graft versus host disease in children

Chart review study of real-world clinical outcomes in patients with cutaneous T-cell lymphoma treated with extracorporeal photopheresis in the US in 2017-2019

BACKGROUND

Response rates of approved systemic therapies for cutaneous T-cell lymphoma (CTCL) hover near 30%, suggesting unmet need. This study describes real-world treatment patterns and response rates of extracorporeal photopheresis (ECP) in CTCL patients.

METHODS

A chart review was conducted in the United States of adults with CTCL who initiated ECP between January 1, 2017, and February 28, 2019, and received at least three months of ECP treatment as monotherapy or concomitant therapy. Clinical outcomes were collected quarterly for up to 18 months.

RESULTS

The 52 patients were predominantly Caucasian. Half were male; median age was 69 years. Most patients had Sézary syndrome (50%) or mycosis fungoides (36.5%). Nearly 40% of patients had stage IV disease; 33% had lymph node involvement. Nineteen patients (36.5%) achieved response (>50% reduction in BSA affected); median time to response was 6.5 months. The percentage of patients rated as at least minimally improved was 59.5% at 6 months (N = 22), 75.0% at 9 months (N = 24), and 60.0% at 12 months (N = 15) after ECP initiation.

CONCLUSIONS

Despite the ECP treated population in this study being older and having more advanced-stage disease than recent trials, response rates were comparable. These real-world findings support ECP as an effective treatment option for CTCL patients.

Extracorporeal Photopheresis with 5-Aminolevulinic Acid in Crohn's Disease-A First-in-Human Phase I/II Study

Background/Objectives: With the increasing prevalence of Crohn's disease (CD), treatment options for patients who fail conventional and advanced therapy are highly needed. Therefore, we explored the safety and efficacy of extracorporeal photopheresis (ECP) using 5-aminolevulinic acid (ALA) and blue light (405 nm). Methods: Patients with active CD who failed or were intolerant to biological therapy were eligible. Mononuclear cells (90 mL) were collected from each patient using a Spectra Optia® apheresis system and diluted with 100 mL of 0.9% sodium chloride in a collection bag. The cells were incubated with ALA at a concentration of 3 millimolar (mM) for 60 min ex vivo and illumination with an LED blue light (405 nm) source (BLUE-PIT®) before reinfusion to the patient. Recording of vital signs and adverse events were regularly performed. At week 13, we assessed the patients with colonoscopy, the Harvey Bradshaw Index (HBI), the Inflammatory Bowel disease Health Related Quality of Life Questionnaire, and the measurement of serum C-reactive protein and fecal calprotectin (FC) levels. Biopsies of the intestines were taken for immunohistochemistry. Results: Seven patients were included. Four patients completed the treatments, with a total of 24 treatments. Three of the four patients achieved a favorable response, including a lower HBI, lower FC levels, and/or endoscopic improvement. No significant adverse events were observed. The remaining three patients received only one, three, or five treatments due to technical difficulties, medical reasons, or the withdrawal of informed consent. Conclusions: ALA-based ECP appears safe and seems to give some clinical improvement for the patients with active CD who failed to respond to conventional and advanced therapies.

Extracorporeal Photopheresis in Pediatric and Adult Patients with Graft-Versus-Host Disease

Background/Objectives: Graft-versus-host disease (GVHD) is a severe complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) resulting from histocompatibility differences between donor and host cells leading to inflammation, tissue damage, and compromised patient outcome. Extracorporeal photopheresis (ECP) is considered as a second-line treatment administered to patients with GVHD who do not respond to corticosteroid treatment or who experience a relapse after an initial response and are therefore classified as steroid refractory (SR). The aim of this study is to evaluate the clinical response rates in both pediatric and adult patients with acute (a) or chronic (c) GVHD and to assess the effectiveness of ECP using the real-world data from a single center. Methods: We performed a retrospective study on 30 patients, including 11 pediatric and 19 adult patients who were treated with ECP as a second-, third-, or fourth-line therapy for (a) and (c) GVHD, alongside corticosteroids and other immunomodulatory medications. The median time from aGVHD onset to ECP was 11.5 days (range: 3 days-9 months), while for cGVHD, the median time was 90 days (range: 2 days-9 months). Results: The overall response rate (ORR) in the aGVHD patient population was 60% with a median of 9 procedures (range: 2-20). For cGVHD patients, the ORR was 70% after a median of 23.5 ECP procedures (range: 8-43). Most patients had skin involvement, with ECP achieving an ORR of 81.8% in aGVHD and 77.7% in cGVHD cases. Conclusions: ECP is a beneficial therapy for patients with (a) and (c) GVHD who have not responded to corticosteroids and other forms of immunosuppressive therapy. Specifically, ECP demonstrated efficacy in improving skin and oral symptoms and permitted reductions in or the elimination of their corticosteroid usage. The study found that extending the duration of ECP treatment was associated with better outcomes, and no detectable complications were observed over a 38-week period.

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.

European dermatology forum - updated guidelines on the use of extracorporeal photopheresis 2020 - part 1

Background

Following the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T‐cell lymphoma published in 1983, this technology has received continued use and further recognition for additional earlier as well as refractory forms. After the publication of the first guidelines for this technology in the JEADV in 2014, this technology has maintained additional promise in the treatment of other severe and refractory conditions in a multi‐disciplinary setting. It has confirmed recognition in well‐known documented conditions such as graft‐versus‐host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection including lung, heart and liver and to a lesser extent inflammatory bowel disease.

Materials and methods

In order to further provide recognized expert practical guidelines for the use of this technology for all indications, the European Dermatology Forum (EDF) again proceeded to address these questions in the hands of the recognized experts within and outside the field of dermatology. This was done using the recognized and approved guidelines of EDF for this task. All authors had the opportunity to review each contribution as it was added.

Results and conclusion

These updated 2020 guidelines provide at present the most comprehensive available expert recommendations for the use of extracorporeal photopheresis based on the available published literature and expert consensus opinion. The guidelines are divided in two parts: PART I covers cutaneous T‐cell lymphoma, chronic graft‐versus‐host disease and acute graft‐versus‐host disease while PART II will cover scleroderma, solid organ transplantation, Crohn's disease, use of ECP in paediatrics practice, atopic dermatitis, type 1 diabetes, pemphigus, epidermolysis bullosa acquisita and erosive oral lichen planus.

Selective Killing of Activated T Cells by 5-Aminolevulinic Acid Mediated Photodynamic Effect: Potential Improvement of Extracorporeal Photopheresis

Extracorporeal photopheresis (ECP), a modality that exposes isolated leukocytes to the photosensitizer 8-methoxypsoralen (8-MOP) and ultraviolet-A (UV-A) light, is used to treat conditions such as cutaneous T-cell lymphoma and graft-versus-host disease. However, the current procedure of ECP has limited selectivity and efficiency; and produces only partial response in the majority of treated patients. Additionally, the treatment is expensive and time-consuming, so the improvement for this modality is needed. In this study, we used the concept of photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA), a precursor of an endogenously synthesized photosensitizer protoporphyrin IX (PpIX) in combination with blue light to explore the possibility of targeting activated human blood T cells ex vivo. With various T-cell activation protocols, a high ALA-induced PpIX production took place in activated CD3⁺, CD4⁺CD25⁺, and CD8⁺ T cell populations with their subsequent killing after blue light exposure. By contrast, resting T cells were much less damaged by the treatment. The selective and effective killing effect on the activated cells was also seen after co-cultivating activated and resting T cells. Under our clinically relevant experimental conditions, ALA-PDT killed activated T cells more selectively and efficiently than 8-MOP/UV-A. Monocyte-derived dendritic cells (DCs) were not affected by the treatment. Incubation of ALA-PDT damaged T cells with autologous DCs induced a downregulation of the co-stimulatory molecules CD80/CD86 and also upregulation of interleukin 10 (IL-10) and indoleamine 2,3-dioxygenase expression, two immunosuppressive factors that may account for the generation of tolerogenic DCs. Overall, the data support the potential use of ALA-PDT strategy for improving ECP by selective and effective killing of activated T cells and induction of immune tolerance.

Feasibility of extracorporeal photopheresis in pediatric patients with graft-versus-host disease after hematopoietic stem cell transplantation

Graft-versus-host disease (GVHD) is a main cause of morbidity and mortality following hematopoietic stem cell transplantation. The cumulative incidence of acute and chronic GVHD (aGVHD, cGVHD) reaches 30%-50% and 20% in pediatric populations, respectively. Prednisolone and/or calcineurin inhibitors (CNI) are first-line treatments, but no superior second-line treatment has yet been established. Several treatments have been suggested, among others extracorporeal photopheresis (ECP). Technical advances have made treatment of pediatric patients possible; however, only few reports on the feasibility of ECP in children have been published. We retrospectively studied the feasibility, safety, and efficacy of ECP in 15 children with steroid-dependent/refractory acute or chronic GVHD, who initiated ECP treatment between April 2014 and January 2018. Only few and mild side effects directly related to the ECP procedure were registered, even in patients with low body weight. The most frequent cause of shortened or canceled ECP treatment was difficulties with vascular accesses, which were more rarely seen using central venous catheters with larger lumens and made of stiffer material. Nine patients had grade II-III aGVHD. Six of these experienced a response to ECP at day 28, while eight of nine had responded at the last ECP treatment. Six patients had cGVHD when ECP was initiated, and of these, four had a partial response at last ECP treatment. We found ECP to be a feasible and safe treatment, and particularly, children with aGVHD appeared to respond well to ECP.

Real-world use of extracorporeal photopheresis for patients with cutaneous T-cell lymphoma in the United States: 2010-2015

Introduction: The National Comprehensive Cancer Network and the European Organization for Research and Treatment of Cancer recommend extracorporeal photopheresis (ECP) as systemic therapy for cutaneous T-cell lymphoma (CTCL).Objective: To investigate real-world use of ECP in CTCL patients in the US.Methods: Data from the Truven MarketScan^® database (2010-2015) were used to create a cohort of CTCL patients receiving systemic treatment. Multivariable regressions were performed to compare health care resource utilization between ECP and propensity score-matched non-ECP patients.Results: Of the 1106 eligible patients, 117 (10.6%) received ECP, with an average treatment duration of 13.6 months. Psoriasis, organ transplant, graft versus host disease, and scleroderma were the most common comorbidities. ECP was used as monotherapy in 76 patients (65.0%) and combination in 41 patients (35.0%), mostly with interferon and/or a retinoid. Higher Charlson Comorbidity Index (2.6 vs 2.2, p < .05), rates of organ transplant (49.6% vs 7.8%, p < .001), and graft vs host disease (41.9% vs 3.4%, p < .001) were observed in ECP versus non-ECP patients. Post-matching analyses showed that ECP patients had shorter all-cause inpatient stay (6.67 vs 11.80 days, p = .001).Conclusions: Approximately 1 out of 10 CTCL patients receiving systemic treatment were on ECP treatment in the US. Post-matching analysis showed ECP was associated with a shorter hospital stay.

Monocytes show immunoregulatory capacity on CD4+ T cells in a human in-vitro model of extracorporeal photopheresis

Extracorporeal photopheresis (ECP) is a widely used immunomodulatory therapy for the treatment of various T cell-mediated disorders such as cutaneous T cell lymphoma (CTCL), graft-versus-host disease (GvHD) or systemic sclerosis. Although clinical benefits of ECP are already well described, the underlying mechanism of action of ECP is not yet fully understood. Knowledge on the fate of CD14⁺ monocytes in the context of ECP is particularly limited and controversial. Here, we investigated the immunoregulatory function of ECP treated monocytes on T cells in an in-vitro ECP model. We show that ECP-treated monocytes significantly induce proinflammatory T cell types in co-cultured T cells, while anti-inflammatory T cells remain unaffected. Furthermore, we found significantly reduced proliferation rates of T cells after co-culture with ECP-treated monocytes. Both changes in interleukin secretion and proliferation were dependent on cell-contact between monocytes and T cells. Interestingly, blocking interactions of programmed death ligand 1 (PD-L1) to programmed death 1 (PD-1) in the in-vitro model led to a significant recovery of T cell proliferation. These results set the base for further studies on the mechanism of ECP, especially the regulatory role of ECP-treated monocytes.

Induction of Tolerogenic Dendritic Cells by Endogenous Biomolecules: An Update

The importance of microenvironment on dendritic cell (DC) function and development has been strongly established during the last two decades. Although DCs with general tolerogenic characteristics have been isolated and defined as a particular sub-population, it is predominantly their unequivocal biological plasticity, which allows for unparalleled responsiveness to environmental ques and shaping of their tolerogenic characteristics when interacting with tolerance-inducing biomolecules. Dendritic cells carry receptors for a great number of endogenous factors, which, after ligation, can importantly influence the development of their activation state. For this there is ample evidence merely by observation of DC characteristics isolated from various anatomical niches, e.g., the greater immunosuppressive potential of DCs isolated from intestine compared to conventional blood DCs. Endogenous biomolecules present in these environments most likely play a major role as a determinant of their phenotype and function. In this review, we will concisely summarize in what way various, tolerance-inducing endogenous factors influence DC biology, the development of their particular tolerogenic state and their subsequent actions in context of immune response inhibition and induction of regulatory T cells.

A Critical Appraisal of Extracorporeal Photopheresis as a Treatment Modality for Acute and Chronic Graft-Versus-Host Disease

Although significant advances have been made in the biologic understanding of graft-versus-host disease (GVHD) and its treatment options, GVHD remains the single most challenging obstacle to the success of allogeneic hematopoietic cell transplantation (HCT) due to high risk of disabling morbidity and mortality. Extracorporeal photopheresis (ECP) has promising effects in controlling steroid-refractory GVHD, both acute and chronic, and it has been studied extensively. Its putative immunomodulatory mechanisms, while not immunosuppressive, position ECP as an attractive treatment strategy for GVHD patients who are already receiving global immunosuppression. However, ECP is relatively underutilized due in part to limited access and time commitment. Here, we review the recent findings on the ECP efficacy in both acute and chronic GVHD, primarily for steroid-refractory status, and we critically appraise its benefits. We also explore salient considerations on the optimal use of ECP in the treatment of refractory GVHD.

Extra corporeal photochemotherapy in steroid refractory graft versus host disease: A review of guidelines and recommendations

Regardless of remarkable progresses in prevention and treatment approaches, graft versus host disease (GVHD) remains a major impediment for successful allogeneic hematopoietic stem cells transplantation (HSCT) and leads to morbidity and mortality in transplanted patients. Corticosteroids are the standard therapy for GVHD; however, a great number of patients will not respond sufficiently and others will be significantly affected by adverse effects of steroids. Extracorporeal photochemotherapy (ECP), as one of the numerous second line therapies, through modulation of immune cells may improves GVHD affected organ function in steroid-refractory forms. Considering to widespread utilization of ECP as a therapeutic strategy, we performed review on current literature of ECP, regarding the treatment strategies, monitoring protocols and technical aspects in chronic and acute GVHD.

Extracorporeal photopheresis performed on the CELLEX® compared with the UVAR-XTS® instrument is more efficient and better tolerated in children with steroid-refractory graft-versus-host disease

Extracorporeal photopheresis (ECP) is an effective therapy in children with refractory graft-versus-host disease (GVHD). The two most frequently used instruments are UVAR-XTS® and CELLEX®. We performed a retrospective chart review of ten patients who underwent ECP with both UVAR-XTS® and CELLEX® instruments for steroid-refractory acute or chronic GVHD to compare instrument run times, percentages of cells treated, and complication rates. We found that compared to the UVAR-XTS® instrument, use of the CELLEX® instrument resulted in shorter run times, increased percentage of mononuclear cells treated, reduced incidence of line occlusions requiring TPA treatment, and decreased incidence of patient-related complications.

Treatment of Acute Graft-versus-Host Disease in Childhood with Extracorporeal Photochemotherapy/Photopheresis: The Padova Experience

Acute graft-versus-host disease (aGVHD) is the major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Systemic steroid treatment represents the first-line therapy for aGVHD and is associated with a response rate of 30% to 60%. Steroid-resistant patients have a poor prognosis with high transplantation-related mortality (TRM). Several second-line therapies have been proposed for the management of unresponsive aGVHD, without proven beneficial effects on patients' outcome or overall long-term survival. For these reasons, extracorporeal photochemotherapy/photopheresis (ECP), a cell-based approach to control GVHD that spares generalized immunosuppression, seems to be promising. In this study, we report the outcome of 72 consecutive pediatric patients treated with ECP between 1997 and 2013 for aGVHD. Among them, 21 patients had steroid-resistant aGVHD, 42 had steroid-dependent aGVHD, and 9 did not receive steroid as first-line therapy because of clinical contraindications. A complete response was obtained in 72% of patients, a partial response was observed in 11%, and there was no response in 17% of patients. At day +180, TRM was 4% in the whole cohort; TRM was 3% and 20% among responders and nonresponders to ECP, respectively (P < .0001). The 5-year overall survival was 71%, showing a difference between responders and nonresponders of 78% and 30%, respectively (P = .0004). The 5-year time to progression of primary disease was 81%, without any significant difference between the 2 groups. Moreover, the 5-year progression-free survival of primary disease was 72%, with a significant difference (P = .0007) between responders (79%) and nonresponders (30%) to ECP. In conclusion, this study demonstrates that ECP is highly effective in aGVHD without a negative impact on primary disease.

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We conducted a retrospective study of 72 consecutive pediatric patients treated with extracorporeal photochemotherapy/photopheresis for acute graft-versus-host disease.

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Twenty-one steroid-refractory, 21 steroid-dependent, and 30 patients with infectious complications were included.

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The infectious complications group included 9 with no steroids before extracorporeal photochemotherapy/photopheresis and 21 with steroids.

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Outcomes at the end of extracorporeal photochemotherapy/photopheresis were complete remission, 72%; transplantation-related mortality day +180, 4%; 5-year overall survival, 71%; time to progression, 81%; and progression-free survival, 72%.

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Extracorporeal photochemotherapy/photopheresis was highly effective in acute graft-versus-host disease without negative impact on primary disease.

Safety and Outcomes of Extracorporeal Photopheresis With the Therakos Cellex System for Graft-Versus-Host Disease in Pediatric Patients

Extracorporeal photopheresis (ECP) is a difficult procedure to perform in the pediatric population. This is a retrospective review of 12 pediatric patients who underwent photopheresis with the Therakos Cellex system for graft-versus-host disease (GVHD). Acute GVHD (aGVHD) occurred in 6 patients, and overlap syndrome and chronic GVHD (cGVHD) occurred in 4 and 2 patients, respectively. The ECP regimen was the same for all aGVHD and cGVHD patients: initially, every week (2 sessions/wk) for 2 months; next, every 2 weeks for 2 months; and finally, every month for at least 1 year. Improvement was observed in 7 of 10 aGVHD patients (70%) and in 4 of 6 cGVHD patients (66%). Eleven patients had skin involvement before ECP; 9 of them responded to treatment (81%). Gastrointestinal involvement occurred in 8 patients; 5 of them experienced improvement during ECP treatment (62%). All 4 patients with liver involvement failed to respond. No serious adverse reactions occurred. In conclusion, our study demonstrates that ECP with the Therakos Cellex system is a safe treatment option for GVHD in children, allowing the tapering of immunosuppressants by at least half.

Biological quality control for extracorporeal photochemotherapy: Assessing mononuclear cell apoptosis levels in ECP bags of chronic GvHD patients

Extracorporeal photochemotherapy (ECP) is a treatment approved by the FDA for cutaneous T-cell lymphoma, and it is currently used off-label for graft-versus-host disease (GvHD) and other conditions. In agreement with good practices for the therapeutic use of human cells, quality control has to be performed to validate the ECP procedure with the off-line technique. Since no gold-standard biological test is available, we assessed the apoptosis generated in the ECP bag using a flow cytometric analysis. Thirty-one ECP procedures performed on 13 patients with chronic GvHD were studied by monitoring the induction of mononuclear cell (MNC) apoptosis using annexin V/propidium iodide double staining; residual lymphocyte proliferation to standard mitogens was also measured in 17 of the procedures. The kinetics of apoptosis was analyzed at different times in MNCs untreated or treated with 8-methoxy-psoralen plus ultraviolet A; the variation (ΔAPOPTOSIS ) after 24 h revealed the efficacy of the treatment. In 88.6% of the 31 ECP procedures, ΔAPOPTOSIS was >15% (the "alerting" threshold for ΔAPOPTOSIS was set at 15% on the basis of our data); in the remainder (19.4%), the increment in apoptosis was lower. In four procedures, the proliferation assay was useful for assessing the effect of ECP on the apheretic bag. In conclusion, both flow cytometric assays enabled a biologically significant result to be obtained. In our opinion, the apoptosis test-being faster and easier than the proliferation test-could be a reliable way to validate ECP procedures.

Guidelines on the use of extracorporeal photopheresis

BACKGROUND

After the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T-cell lymphoma was published in 1983 with its subsequent recognition by the FDA for its refractory forms, the technology has shown significant promise in the treatment of other severe and refractory conditions in a multi-disciplinary setting. Among the major studied conditions are graft versus host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection and inflammatory bowel disease.

MATERIALS AND METHODS

In order to provide recognized expert practical guidelines for the use of this technology for all indications the European Dermatology Forum (EDF) proceeded to address these questions in the hands of the recognized experts within and outside the field of dermatology. This was done using the recognized and approved guidelines of EDF for this task.

RESULTS AND CONCLUSION

These guidelines provide at present the most comprehensive available expert recommendations for the use of extracorporeal photopheresis based on the available published literature and expert consensus opinion.

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.

Challenges and opportunities for international cooperative studies in pediatric hematopoeitic cell transplantation: priorities of the Westhafen Intercontinental Group

More than 20% of allogeneic hematopoietic cell transplantations (HCTs) are performed in children and adolescents at a large number of relatively small centers. Unlike adults, at least one-third of HCTs in children are performed for rare, nonmalignant indications. Clinical trials to improve HCT outcomes in children have been limited by small numbers and these pediatric-specific features. The need for a larger number of pediatric HCT centers to participate in trials has led to the involvement of international collaborative groups. Representatives of the Pediatric Blood and Marrow Transplant Consortium, European Group for Blood and Marrow Transplantation's Pediatric Working Group, International Berlin-Frankfurt-Munster (iBFm) Stem Cell Transplantation Committee, and Children's Oncology Group's Hematopoietic Stem Cell Transplantation Discipline Committee met on October 3, 2012, in Frankfurt, Germany to develop a consensus on the highest priorities in pediatric HCT. In addition, it explored the creation of an international consortium to develop studies focused on HCT in children and adolescents. This meeting led to the creation of an international HCT network, dubbed the Westhafen Intercontinental Group, to develop worldwide priorities and strategies to address pediatric HCT issues. This review outlines the priorities of need as identified by this consensus group.

Persistent complete molecular remission after nilotinib and graft-versus-leukemia effect in an acute lymphoblastic leukemia patient with cytogenetic relapse after allogeneic stem cell transplantation

We report the successful treatment and sustained molecular remission using single agent nilotinib in a relapsed Philadelphia chromosome positive (Ph+) acute lymphoblastic leukemia patient after allogeneic hematopoietic stem cell transplantation. Compared to previously published studies, this is the first report where a patient did not receive additional chemotherapy after relapse, nor did she receive donor lymphocyte infusions. With nilotinib, the patient reverted back to normal blood counts and 100% donor reconstitution by single tandem repeat (STR) chimerism analysis in the bone marrow and in peripheral blood, granulocytes, T and B-lymphocytes. This report also highlights the use of nilotinib in combination with extracorporeal photopheresis (ECP) for concomitant graft-versus-host disease. Our data suggests that ECP, together with nilotinib, did not adversely affect the overall Graft-versus-leukemia (GVL) effect.