Alemtuzumab for severe steroid-refractory gastrointestinal acute graft-versus-host disease

Novel therapies for graft versus host disease with a focus on cell therapies

Graft versus host disease (GVHD) can occur at any period post allogeneic hematopoietic stem cell transplantation as a common clinical complication contributing to significant morbidity and mortality. Acute GVHD develops in approximately 30-50% of patients receiving transplants from matched related donors. High doses of steroids are used as first-line treatment, but are unsuccessful in around 40% of patients, resulting in the diagnosis of steroid-refractory acute GVHD. Consensus has yet to develop for the management of steroid-refractory acute GVHD, and prognosis at six months has been estimated at around 50%. Thus, it is critical to find effective treatments that increase survival of steroid-refractory acute GVHD. This article describes the currently known characteristics, pathophysiology, and treatments for GVHD, with a special focus on recent advances in cell therapies. In particular, a novel cell therapy using decidua stromal cells (DSCs) was recently shown to have promising results for acute GVHD, with improved effectiveness over previous treatments including mesenchymal stromal cells. At the Karolinska Institute, severe acute GVHD patients treated with placenta-derived DSCs supplemented with either 5% albumin or 10% AB plasma displayed a one-year survival rate of 76% and 47% respectively. Furthermore, patients with steroid-refractory acute GVHD, displayed survival rates of 73% with albumin and 31% with AB plasma-supplemented DSCs, compared to the 20% survival rate in the mesenchymal stromal cell control group. Adverse events and deaths were found to be attributed only to complications of hematopoietic stem cell transplant and GVHD, not to the study intervention. ASC Therapeutics, Inc, in collaboration with the Karolinska Institute, will soon initiate a phase 2 multicenter, open-label study to further assess the efficacy and safety of intravenous DSC treatment in sixty patients with Grade II-IV steroid-refractory acute GVHD. This novel cell therapy represents a promising treatment to combat the poor prognosis that steroid-refractory acute GVHD patients currently face.

Complement-mediated thrombotic microangiopathy as a link between endothelial damage and steroid-refractory GVHD

Transplant-associated thrombotic microangiopathy (TA-TMA), a complication of hematopoietic cell transplant (HCT), is associated with significant morbidity and mortality. The pathophysiology and overlap of TA-TMA with other posttransplant complications such as graft-versus-host disease (GVHD) is poorly understood. We retrospectively identified cases of TA-TMA among patients with grade 3/4 gastrointestinal (GI) GVHD, reviewed intestinal biopsy specimens, and performed correlative testing of biomarkers associated with TA-TMA. TA-TMA was more common in patients with steroid-refractory GVHD compared with steroid-responsive GVHD (79.3% vs 42.1%; P = .001). Among patients surviving 100 days post-HCT, 1-year survival from day 100 was significantly better for patients who had not developed TA-TMA in the first 100 days (69.5% vs 36.7%; P < .001). Only 1 of 7 proposed TA-TMA histology criteria (mucosal hemorrhage) differed significantly based on GVHD steroid response. In multivariable modeling, steroid-refractory GVHD was a risk factor for development of TA-TMA (hazard ratio, 3.09; 95% confidence interval, 1.68-5.67; P < .001). There were no differences in complement activation at GVHD onset; however, 2 to 6 weeks later, patients with TA-TMA had higher levels of BBPlus and C5b-9, markers of alternative and terminal pathway activation (BBPlus: median, 600 vs 209.3 ng/mL; P = .0045) (C5b-9: median, 425.9 vs 258.4 ng/mL; P = .029). TA-TMA is associated with poor overall survival (OS) following HCT and may be detected early by histologic findings and may be differentiated from GVHD by measurement of alternative and terminal complement pathway activation. It is unknown whether treatment of TA-TMA will improve survival in steroid-refractory GVHD.

Safety and Effectiveness of Vedolizumab in Patients with Steroid-Refractory Gastrointestinal Acute Graft-versus-Host Disease: A Retrospective Record Review

Allogeneic hematopoietic cell transplantation (allo-HCT) can be curative in patients with hematologic malignancies but carries a significant risk of graft-versus-host disease (GVHD). There are no standard treatments for steroid-refractory (SR) gastrointestinal (GI) acute GVHD (aGVHD). This multicenter, international, retrospective medical record review aimed to evaluate the off-label use of vedolizumab, a gut-selective immunomodulator, for treating SR GI aGVHD. Data were collected from patients' medical records; criteria for extraction included no more than 1 allo-HCT and at least 1 dose of vedolizumab as treatment for SR GI aGVHD (ie, stage 1 to 4 GI aGVHD following ≥1 previous treatment regimen(s) containing ≥1 mg/kg methylprednisolone or equivalent). Descriptive analyses of response rate, overall survival (OS), and serious adverse effects (SAEs) were performed. Twenty-nine patients were identified from 7 sites who had received 1 to 10 doses of vedolizumab 300 mg i.v. (median 3 doses) as treatment for SR GI aGVHD. The overall response rate at 6 to 10 weeks after vedolizumab initiation was 64%, and OS at 6 months was 54%. There were 29 SAEs, including 12 infections; 3 SAEs were considered possibly related to vedolizumab, 2 of which were infections. Thirteen SAEs were fatal, 1 of which was possibly vedolizumab-related. There were 8 nonserious infections and 1 serious infection with confirmed GI origin in 8 patients; there was no apparent pattern in the timing of these infections relative to the initiation of vedolizumab treatment. Further data on the efficacy and safety of vedolizumab in this setting from prospective trials are needed.

Phase I/II Trial of a Combination of Anti-CD3/CD7 Immunotoxins for Steroid-Refractory Acute Graft-versus-Host Disease

Effective therapies for treating patients with steroid-refractory acute graft-versus-host-disease (SR-aGVHD), particularly strategies that reduce the duration of immunosuppression following remission, are urgently needed. The investigated immunotoxin combination consists of a mixture of anti-CD3 and anti-CD7 antibodies separately conjugated to recombinant ricin A (CD3/CD7-IT), which induces in vivo depletion of T cells and natural killer (NK) cells and suppresses T cell receptor activation. We conducted a phase I/II trial to examine the safety and efficacy of CD3/CD7-IT in 20 patients with SR-aGVHD; 17 of these patients (85%) had severe SR-aGVHD, and all 20 patients had visceral organ involvement, including 18 (90%) with gastrointestinal (GI) involvement and 5 (25%) with liver involvement. A validated 2-biomarker algorithm classified the majority of patients (11 of 20) as high risk. On day 28 after the start of CD3/CD7-IT therapy, the overall response rate was 60% (12 of 20), with 10 patients (50%) achieving a complete response. The 6-month overall survival rate was 60% (12 of 20), including 64% (7 of 11) classified as high risk by biomarkers. The 1-week course of treatment with CD3/CD7-IT caused profound but transient depletion of T cells and NK cells, followed by rapid recovery of the immune system with a diverse TCR Vβ repertoire, and preservation of Epstein-Barr virus- and cytomegalovirus-specific T cell clones. Furthermore, our results indicate that CD3/CD7-IT appeared to be safe and well tolerated, with a relatively low prevalence of manageable and reversible adverse events, primarily worsening of hypoalbuminemia, microangiopathy, and thrombocytopenia. These encouraging results suggest that CD3/CD7-IT may improve patient outcomes in patients with SR-aGVHD.

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.

A Prospective Study of Alemtuzumab as a Second-Line Agent for Steroid-Refractory Acute Graft-versus-Host Disease in Pediatric and Young Adult Allogeneic Hematopoietic Stem Cell Transplantation

We describe a single-center prospective study of alemtuzumab as a second-line agent for steroid-refractory (SR) acute graft-versus-host disease (aGVHD) in pediatric and young adult allogeneic hematopoietic stem cell transplant recipients. Alemtuzumab was administered for grades II to IV aGVHD if patients did not improve within 5 days or worsened within 48 hours after corticosteroids. Interim analyses of alemtuzumab levels and response were performed after every 5 patients enrolled, resulting in 3 dosing cohorts, as follows: (1) .2 mg/kg alemtuzumab subcutaneously on days 1 to 5 (maximum of 31 mg over 5 days) and .2 mg/kg/dose (not exceeding 10 mg/dose) on days 15, 22, and 29; (2) .2 mg/kg alemtuzumab subcutaneously on days 1 to 5 (maximum of 43 mg over 5 days) and .2 mg/kg/dose on day 7, 10, 15, 22, and 29; and (3) .2 mg/kg subcutaneously on days 1 to 5 and .2 mg/kg/dose on day 7, 10, 15, and 22. Alemtuzumab levels were assessed before starting alemtuzumab and at days 1, 3, 6, 10, and 14 and weekly until day 99, where day 1 was the day of first alemtuzumab dose. Fifteen patients (median age, 10 years; range, 1.4 to 27) received alemtuzumab for grades II (6%), III (74%), and IV (20%) SR-aGVHD. The overall response rate was 67%, with complete response (CR) in 40%, partial response (PR) in 27%, and no response in 33%. The median day 6 alemtuzumab level was 2.79 µg/mL (interquartile range, 1.34 to 4.89) in patients with CR compared with .62 µg/mL (interquartile range, .25 to 1.45) in patients with PR + no response (P < .05). Ninety percent (n = 9) of patients with a CR or PR reduced corticosteroid doses within 8 weeks from first alemtuzumab dose. Side effects included fever (26%) and transient thrombocytopenia (53%). Asymptomatic viremias occurred in all patients but invasive viral disease occurred in 2 patients. One patient developed Epstein-Barr virus-post-transplantation lymphoproliferative disorder. Eighty percent (n = 12) of patients were alive at 6 months, of whom 53% (n = 8) were free of GVHD whereas 13% (n = 2) developed chronic GVHD. Alemtuzumab is an effective second-line agent for children and young adults with SR-aGVHD. Higher alemtuzumab levels are associated with CR. A real-time dose adjusted alemtuzumab study is needed to further optimize the dose of alemtuzumab in aGVHD.

Ruxolitinib in steroid refractory graft-vs.-host disease: a case report

Background

Allogeneic hematopoietic stem cell transplantation (HSCT) is potentially curative in a variety of hematological malignancies. Graft-vs.-host disease (GvHD) remains a life-threatening complication. Standard treatment is high-dose (HD) corticosteroids. Steroid-refractory (SR) GvHD is associated with poor prognosis. At present, second-line treatment is ill-defined and includes a number of agents. Novel insights into the pathophysiology of acute GvHD (aGvHD) highlight the relevant role of the host inflammatory response governed by several kinase families, including Janus kinases (JAK)1/2. Ruxolitinib, a JAK1/2 inhibitor approved for intermediate-2/high-risk myelofibrosis, was recently employed in SR-GvHD with encouraging overall response rates. Clinical experience however remains limited.

Case presentation

A 51-year-old male with refractory anemia with excess blast type-2 underwent a myeloablative allogeneic HSCT from a 9/10 HLA-matched unrelated donor after conditioning with busulfan and cyclophosphamide. GvHD prophylaxis consisted of cyclosporine, methotrexate, and thymoglobulin. CD34⁺ cells/kg infused were 8.69 × 10⁶ kg. On day 29, the patient developed overall grade IV aGvHD with biopsy proven stage IV gastrointestinal (GI) GvHD refractory to HD corticosteroids. Patient conditions rapidly deteriorated and became critical despite the addition of mycophenolate mofetil and budesonide. On day 33, Ruxolitinib was started, and on day 39 the patient clinical conditions gradually improved. Complete resolution of aGvHD was also confirmed by histology on day 54.

Conclusions

At 5 months from HSCT, the patient is well and in continuous hematological complete remission without flare of GvHD. Ruxolitinib was discontinued on day 156. Ruxolitinib is feasible and effective in SR-aGvHD though large prospective clinical trials are warranted.

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.

Efficacy and safety of intra-arterial steroid infusions in patients with steroid-resistant gastrointestinal acute graft-versus-host disease

There is no established second-line treatment for steroid-resistant acute graft-versus-host disease (GVHD). We prospectively assessed the safety and efficacy of intra-arterial steroid infusions (IASIs) for steroid-resistant acute gastrointestinal (GI) GVHD and compared the outcomes with those of historical controls at our institution. Nineteen consecutive, allogeneic hematopoietic stem cell transplantation subjects aged 31-67 years (median 52) were enrolled between October, 2008, and November, 2012. Acute GVHD was confirmed by biopsy in all cases. The enrolled patients were treated with infusions of methylprednisolone into the mesenteric arteries and/or gastroduodenal and left gastric arteries. Fourteen consecutive patients who developed steroid-resistant acute GI GVHD between 2001 and 2008 were used as controls. For the primary endpoint at day 28, the overall and complete responses in the IASI group trended higher (79% vs. 42%, p = 0.066) and were significantly higher (63% vs. 21%, p = 0.033) than those in the control group. Although not statistically significant, owing to the small population, the crude day-180-nonrelapse mortality rate was about 20% lower and the day-180-overall-survival rate tended to be higher than the control (11% vs. 29%, p = 0.222; 79% vs. 50%, p = 0.109, respectively). There were no serious IASI-related complications. Our results suggest that IASI can safely provide excellent efficacy for refractory acute GI GVHD without increasing infection-related complications and may improve prognosis.