Extracorporeal photopheresis: cellular therapy for the treatment of acute and chronic graft-versus-host disease

The Role of Extracorporeal Photopheresis in the Management of Graft Versus Host Disease: Narrative Review

Hematopoietic stem cell donation is a method used to treat both blood-related and non-blood-related malignancies. Graft-versus-host disease is a potentially life-threatening complication that can occur following a stem cell transplant from a donor. This happens after the transplanted grafts attack the recipient's body as foreign cells, causing significant morbidity and mortality. Clinically, this condition can be classified as acute or chronic based on onset and pathophysiology. This review aims to provide an overview of recent studies on extracorporeal photopheresis as a treatment strategy option for graft-versus-host-diseased patients. It will explain how it treats graft-versus-host disease, summarize its promising effects, and provide future recommendations for its use in treating this illness. Extracorporeal photopheresis is used to treat graft-versus-host disease by collecting and separating white blood cells from the patient. This blood is fractionated into different parts, and white blood cells undergo treatment with 8-methoxy psoralen, a photoactivable drug, before exposure to ultraviolet light A. Lastly, the cells that have been treated are reinfused into the recipient's body. It prompts the programmed cell death of lymphocytes and the engulfment of cellular debris by host antigen-presenting, leading to a subsequent rise in T regulatory cells. However, more experimental and randomized controlled studies are required to identify the best patient selection requirements, environments, and treatment regimens for graft-versus-host disease.

Real-world evidence of heparin and citrate use in extracorporeal photopheresis: A hypothesis-generating data review of device settings and performance

Extracorporeal photopheresis (ECP) is widely used for the treatment of cutaneous T-cell lymphoma, graft-vs-host disease, and other immune-related conditions. To avoid clotting during treatment, the ECP system used must be effectively primed with an anticoagulant. Heparin is the recommended anticoagulant for the THERAKOS CELLEX System, but acid citrate dextrose-A (ACDA) is often used. We compared system performance between these two anticoagulants for this ECP system. Deidentified data for ECP device performance were obtained at each treatment session, from automatically logged Smart Cards or labels completed by device operators. We compared the effects of ACDA or heparin on overall treatment duration, buffy coat (leukocyte) collection time, photoactivation time and the number of alarms and warnings. The variability in these parameters was also assessed. Data from 23 334 treat sessions were analyzed; ACDA was used in 34.4% and heparin in 65.6%. Overall, the ECP procedure duration, buffy coat collection time and photoactivation time were numerically similar regardless of whether ACDA or heparin was used, and regardless of needle mode. Photoactivation time variability was lower with ACDA compared with heparin in all needle modes. Among treatments that were completed automatically without any operator intervention, total treatment duration and photoactivation time were significantly reduced with ACDA use in both the double- and single-needle modes. The data presented indicate that, in both double- and single-needle modes, the THERAKOS® CELLEX® integrated ECP system performed similarly with ACDA compared to heparin, although ACDA demonstrated potential benefits in reducing variability in photoactivation time.

Chronic graft-versus-host disease. Part II: Disease activity grading and therapeutic management

Chronic graft-versus-host disease (cGVHD) is a major complication of allogeneic hematopoietic cell transplantation and a leading cause of long-term morbidity, nonrelapse mortality, and impaired health-related quality of life. The skin is commonly affected and presents heterogeneously, making the role of dermatologists critical in both diagnosis and treatment. In addition, new clinical classification and grading schemes inform treatment algorithms, which now include 3 Federal Drug Administration-approved therapies, and evolving transplant techniques are changing disease epidemiology. Part I reviews the epidemiology, pathogenesis, clinical manifestations, and diagnosis of cGVHD. Part II discusses disease grading and therapeutic management.

Extracorporeal photopheresis as graft-versus-host disease prophylaxis: a randomized controlled trial: Prophylactic extracorporeal photopheresis to prevent graft-versus-host disease

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative option for many patients diagnosed with hematological malignancies. A major obstacle is graft-versus-host disease (GvHD) causing significant morbidity and mortality. Extracorporeal photopheresis (ECP) is an increasingly applied GvHD treatment, partly due to its favourable safety profile. In contrast, the use of ECP in preventing GvHD is sparse, and randomized controlled trials (RCTs) are lacking.

OBJECTIVE

We therefore conducted a RCT to assess if ECP applied post-transplant, could prevent the development of GvHD within the first year of transplantation.

STUDY DESIGN

We enrolled 157 patients (18-74 years) with a hematological malignancy receiving first allo-HSCT: 76 randomized to the intervention group and 81 to the control group. ECP was initiated directly upon engraftment and was planned twice weekly for two weeks, then once weekly for four weeks. GvHD, relapse, and death were analyzed with Cox regression analysis.

RESULTS

During the first year, 45 patients in the intervention and 52 control patients developed GvHD (HR=0.82, 95% CI 0.55-1.22, P=0.32). There were no differences in acute or chronic GvHD or its organ distribution in this intention-to-treat RCT. A per-protocol analysis revealed a significant difference in GvHD between the intervention (per-protocol; n=39 of 76) and the control group (n=77), 46% vs 68%, respectively, (HR 0.47, 95% CI 0.27-0.80, P=0.006). Relapse occurred in 15 patients in the intervention group and in 11 patients among the controls (HR=1.38, 95% CI 0.64-3.01, P=0.42). GvHD-free relapse-free (GRFS) survival, event-free survival, overall survival and non-relapse mortality did not differ significantly between the two study groups. No significant difference in immune reconstitution between the two study groups was revealed.

CONCLUSION

This first intention-to-treat RCT, investigating ECP as GvHD prophylaxis in allo-HSCT for hematological malignancy does not support the use of ECP as adjunct to standard drug-based GvHD-prophylaxis. This trial was registered at www.

CLINICALTRIALS

gov as #NCT03204721.

A Prospective, Multicenter Study of Closed System Extracorporeal Photopheresis for Children With Steroid-Refractory Acute Graft-Versus-Host Disease

BACKGROUND

Steroid-refractory (SR) acute graft-versus-host disease (aGvHD) therapy involves intensive immunosuppression, which is associated with significant infectious risk. Extracorporeal photopheresis (ECP) is used to treat SR-aGvHD and is considered to be more immunomodulatory than immunosuppressive. However, pediatric data are mostly retrospective and often involve multi-step ECP that includes apheresis followed by separate photosensitizing/reinfusion on another device.

OBJECTIVE

To prospectively evaluate the efficacy and safety of a single-device ECP system in children with SR-aGvHD.

STUDY DESIGN

Open-label, multicenter, phase 3 study of the THERAKOS® CELLEX® Photopheresis System in children/young adults aged 1 to 21 years with SR-aGvHD. Patients were treated 3 times per week for 4 weeks, then twice weekly through week 12 while maintaining standard aGvHD prophylaxis. The primary efficacy endpoint was the proportion of patients achieving overall response (OR) at day 28 without the addition of next-line systemic treatment. Secondary endpoints included the proportion of patients achieving OR at weeks 8 and 12; the mean weekly steroid dose at weeks 4, 8, and 12; and treatment-emergent adverse events (TEAEs).

RESULTS

Twenty-nine children (median age, 8 years) were enrolled. OR was 55% by day 28, 74% by week 8, and 79% by week 12. Progressive improvements were observed in the skin and the gastrointestinal tract. Mean steroid dose decreased from 1.54 mg/kg/day at baseline to 0.90 mg/kg/day at week 4; 35% of patients achieved >50% steroid dose reduction at week 4 and 75% achieved >50% steroid dose reduction at week 12. Of 168 TEAEs reported among 25 patients (86%), 28 (17%) events were infections and 14 (8%) events were considered to be probably treatment related (all nonserious). Of 627 ECP treatments administered in children/young adults, 68% required blood priming. Treatment-related AEs, including hypotension, hypocalcemia, central line infection, and catheter-site bruising, were rare (1 event each). Three deaths occurred and were deemed unrelated to ECP by the investigators.

CONCLUSION

Use of the THERAKOS® CELLEX® Photopheresis System was effective in children with SR-aGvHD, with more than half experiencing improvement by day 28 and further responses observed over 12 weeks. Very few TEAEs were attributable to ECP, and no new safety signals were observed.

Uncovering the multifaceted roles played by neutrophils in allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a life-saving procedure used for the treatment of selected hematological malignancies, inborn errors of metabolism, and bone marrow failures. The role of neutrophils in alloHSCT has been traditionally evaluated only in the context of their ability to act as a first line of defense against infection. However, recent evidence has highlighted neutrophils as key effectors of innate and adaptive immune responses through a wide array of newly discovered functions. Accordingly, neutrophils are emerging as highly versatile cells that are able to acquire different, often opposite, functional capacities depending on the microenvironment and their differentiation status. Herein, we review the current knowledge on the multiple functions that neutrophils exhibit through the different stages of alloHSCT, from the hematopoietic stem cell (HSC) mobilization in the donor to the immunological reconstitution that occurs in the recipient following HSC infusion. We also discuss the influence exerted on neutrophils by the immunosuppressive drugs delivered in the course of alloHSCT as part of graft-versus-host disease (GVHD) prophylaxis. Finally, the potential involvement of neutrophils in alloHSCT-related complications, such as transplant-associated thrombotic microangiopathy (TA-TMA), acute and chronic GVHD, and cytomegalovirus (CMV) reactivation, is also discussed. Based on the data reviewed herein, the role played by neutrophils in alloHSCT is far greater than a simple antimicrobial role. However, much remains to be investigated in terms of the potential functions that neutrophils might exert during a highly complex procedure such as alloHSCT.

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.

Cutaneous manifestations of acute and chronic graft-versus-host disease

Graft-versus-host disease (GvHD) is a commonly occurring immunological reaction and frequent complication following allogeneic hematopoietic stem cell transplantation. Its highly diverse manifestations including skin involvement as the most common appearance of GvHD, can dramatically influence patient's quality of life, in particular in the chronic stage, in addition to patient's decreased survival outcome. Hence, the role of the dermatologist has become very crucial in an interdisciplinary setting, particularly since appearances of GvHD in the skin can be multifaceted and challenging. Clinical manifestation of the acute GvHD (aGvHD) is limited to erythematous maculopapular rash and oral mucosal lesions while the chronic form manifests in a wider range in a localized area or disseminated including involvement of nail, scalp and genital area. This article aims to provide a comprehensive overview on the variable cutaneous presentations of acute and chronic GvHD for a proper and early diagnosis on the one hand, and to discuss updated therapeutic options for both acute and chronic GvHD on the other hand, to initiate an adequate treatment to obtain the most beneficial clinical outcome.

A real life use of ruxolitinib in patients with acute and chronic graft versus host disease refractory to corticosteroid treatment in Latin American patients

Introduction

Graft-versus-host disease (GVHD) is a serious complication in allogeneic transplantation. The first-line treatment is high doses of corticosteroids. In the absence of response to corticosteroids, several immunosuppressive drugs can be used, but they entail an elevated risk of severe infections. Added to this, there are patients who do not improve on any immunosuppressive treatment, with subsequent deteriorated quality of life and high mortality. Ruxolitinib has been shown to induce responses in refractory patients. In this study we have presented our real-life experience.

Methods

A retrospective analysis was performed on patients with severe GVHD refractory to corticosteroids. Demographic, previous treatment, response and mortality data were collected.

Results

Since 2014, seventeen patients with GVHD were treated with ruxolitinib due to refractoriness to corticosteroids and immunosuppressants and a few to extracorporeal photopheresis, 8 with acute GVHD (1 pulmonary, 4 cutaneous grade IV and 3 digestive grade IV) and 9 with chronic GHVD (5 cutaneous sclerodermiform, 2 pulmonary and 1 multisystemic). The overall response to ruxolitinib treatment for acute GVHD was 80%, 40% with partial response and 40% with complete remission. Global response in chronic GVHD was 79%. The GVHD mortality was only seen in acute disease and was 40%. Causes of mortality in those patients were severe viral pneumonia, post-transplantation hemophagocytic syndrome and meningeal GVHD refractory to ruxolitinib.

Conclusions

In our series, the use of ruxolitinib as a rescue strategy in acute or chronic GVHD was satisfactory. Ruxolitinib treatment in patients with a very poor prognosis showed encouraging results. However, the GVHD mortality remains high in refractory patients, showing that better therapeutic strategies are needed.

Bacterial contamination rates in extracorporeal photopheresis

BACKGROUND

Extracorporeal photopheresis (ECP) is an immunosuppressive treatment that involves leukocyte apheresis, psoralen and UV light treatment, and subsequent reinfusion. Patients treated with ECP are usually immunosuppressed. Bacterial contamination therefore poses a much unwanted risk, but incidence data are lacking.

PATIENTS AND METHODS

We screened all 1922 consecutive ECP procedures scheduled within a roughly 3-year period for eligibility. Those with missing data on ECP method (inline or offline) or type of venous access (peripheral or central) were excluded. ECPs with complete aerobic and anaerobic microbial testing of baseline patient blood samples (n = 1637) and of ECP cell concentrates (n = 1814) were included in the analysis.

RESULTS

A test for microbial contamination was positive for 1.82% of the cell concentrates, with central venous access was the most significant risk factor for the contamination (odds ratio = 19). Patient blood samples were positive in 3.85% of cases, but no patients became septic. Staphylococcus spp. were most abundant, and products with bacterial contamination did not cause side effects after reinfusion. There were no significant differences in contamination rates between inline and offline ECP.

CONCLUSION

These findings stress the importance of sterile procedures and the benefits of using peripheral over central venous access for reducing the risk of bacterial contamination in ECP.

Therapeutic options for steroid-refractory acute and chronic GVHD: an evolving landscape

Introduction: The traditional therapeutic modalities to manage SR-acute GVHD have focused on the inhibition of the alloreactive T-cell response, while in the setting of SR-chronic GVHD the focus has been on a combination of T-cell and B-cell targeting strategies. However, new therapeutic modalities have shown promise. The purpose of this review is to summarize the current treatment landscape of SR-acute and chronic GVHD.Areas covered: A systematic search of MEDLINE, EMBASE, and clinicaltrials.gov databases for published articles, abstracts, and clinical trials pertaining to available therapeutic modalities for SR-acute and SR-chronic GVHD was conducted. Also highlighted is a number of ongoing clinical trials in both SR-acute and SR-chronic GVHD with strategies targeting the JAK-1/2 pathway, the Treg:Tcon ratio, the immunomodulation mediated by mesenchymal stem cells, and the gut microbiome, among others. Expert opinion: Ruxolitinib has emerged as the preferred therapeutic modality for SR-acute GVHD, with alpha-1-antitrypsin and extracorporeal photophoresis (ECP) being reasonable alternatives. Ruxolitinib and Ibrutinib are among the preferred options for SR-chronic GVHD, with ECP being a viable alternative particularly if the skin is involved. A number of novel therapeutic modalities, including those enhancing the activity of regulatory T-cells have shown great promise in early phase trials of SR-chronic GVHD.

Inline extracorporeal photopheresis: evaluation of cell collection efficiency

BACKGROUND

Extracorporeal photopheresis (ECP) therapy has proved to be an effective and safe treatment for graft-versus-host-disease (GvHD), an important complication after hematopoietic stem cell transplantation. In 2016, we acquired Therakos CellEx, a dedicated inline ECP device to accomplish a significant increase in ECP activity. In literature, we found few data reporting CellEx performance evaluated in terms of collection efficiency to qualify the device. Hence, we decided to collect and analyze our data in order to build a reference in terms of expected results of the procedure. Here we report our data of ECP performed using CellEx in a 12-month period focusing on collection efficiency assessment, as well as procedural and apheretic product characteristics.

STUDY DESIGN AND METHODS

We collected data of patients undergoing ECP from April 2018 to March 2019 using CellEx in order to evaluate collection efficiency.

RESULTS

Between April 2018 and March 2019 we treated 28 adult patients affected by GvHD performing 319 ECP using CellEx. CellEx mononuclear cell product was characterized by high mononuclear cell percentage and low percentage of granulocytes, resulting particularly suitable for ECP treatments. Median collection efficiency for total nucleated cells and for mononuclear cells was 31.2% and 62.3%, respectively.

CONCLUSION

Collection efficiency of CellEx was comparable to that usually obtained by cell separators designed for cell collection and was comparable to that of offline systems. Our results provide a detailed performance evaluation for inline ECP system users.