Use of antithymocyte globulin for treatment of steroid-refractory acute graft-versus-host disease: an international practice survey

New investigational drugs for steroid-refractory acute graft-versus-host disease: a review of the literature

INTRODUCTION

Steroid-refractory acute graft-versus-host disease (SR-aGVHD) remains a formidable obstacle in the field of allogeneic hematopoietic cell transplantation (allo-HCT), significantly contributing to patient morbidity and mortality. The current therapeutic landscape for SR-aGVHD is limited, often yielding suboptimal results, thereby emphasizing the urgent need for innovative and effective treatments.

AREAS COVERED

In light of the pivotal REACH2 trial, ruxolitinib phosphate, a Janus kinase inhibitor, has gained prominence as the standard treatment for SR-aGVHD. Nevertheless, a considerable number of patients either do not respond to or cannot tolerate this therapy. This review delves into emerging treatments for SR-aGVHD, including mesenchymal stromal cells (MSCs), fecal microbiota transplantation (FMT), CD3/CD7 blockade, neihulizumab, begelomab, tocilizumab, and vedolizumab. While some of these agents have shown encouraging results in early-phase trials, issues such as treatment-related toxicities and inconsistent responses in larger studies highlight the necessity for ongoing research.

EXPERT OPINION

Current trials exploring new agents and combination therapies offer hope for fulfilling the unmet clinical needs in SR-aGVHD, potentially leading to more effective and precise treatment strategies.

Experimental Pharmaceuticals for Steroid-Refractory Acute Graft-versus-Host Disease

Acute GVHD (aGVHD) is a significant complication after allogeneic hematopoietic cell transplantation (HCT), occurring in up to 70% of HCT recipients. Steroid-refractory aGVHD represents a subset of patients failing initial therapy and is particularly morbid, with only 30% of patients surviving long term. Better therapies are urgently required for these patients. Here, we discuss recent advancements in the management of SR-aGVHD. We review the currently available therapies for SR-aGVHD including the results of the REACH1 and REACH2 trials, which provide the basis for the use of ruxolitinib for the treatment of SR-aGVHD. We additionally discuss newer agents under clinical investigation and will highlight the niche these agents may fill to further improve outcomes in aGVHD patient care.

[Clinical study of anti-human T cell porcine immunoglobulin with recombinant human tumor necrosis factor-α receptor II: IgG Fc in the treatment of 35 cases of grade III/IV acute graft-versus-host disease after allo-HSCT]

Objective: To evaluate the efficacy and safety of anti-human T lymphocyte porcine immunoglobulin (P-ATG) with recombinant human tumor necrosis factor-α receptor Ⅱ:IgG Fc fusion protein (rhTNFR∶Fc, Etanercept) on grade Ⅲ/Ⅳ acute graft-versus-host disease (aGVHD) after allogenic hematopoietic stem cell transplantation (allo-HSCT) . Methods: Thirty-five patients with Grade Ⅲ/Ⅳ aGVHD who received P-ATG with etanercept therapy after allo-HSCT were retrospectively analyzed. P-ATGs (5 mg·kg(-1)·d(-1)) were administrated for 3 to 5 days, and then 5mg/kg was sequentially administrated, QOD to BIW. Etanercepts were administrated 25 mg, twice a week (12.5 mg, BIW for pediatric patients) . Results: Among the 35 patients with grade Ⅲ/Ⅳ aGVHD, 21 were males and 14 females, with a median age of 10 (3-54) years. A total of 19 cases of acute myeloid leukemia, 13 of acute lymphoblastic leukemia, 1 of severe aplastic anemia, 1 of myelodysplastic syndrome, and 1 of mixed phenotypic acute leukemia were noted. The overall response (OR) rate of P-ATG with etanercept was 85.7% (30/35) , with complete response (CR) and partial response (PR) rates of 34.3% (12/35) and 51.4% (18/35) , respectively, on day 28. The OR rate of grade Ⅲ aGVHD group was higher than of grade IV aGVHD group [100% (19/19) vs. 68.8% (11/16) , P=0.004]. On day 56, the OR rate became 77.2% (27/35) , with CR and PR rates of 62.9% (22/35) and 14.3% (5/35) , respectively. The OR rate of grade Ⅲ aGVHD group was also higher than of grade Ⅳ aGVHD group [89.5% (17/19) vs. 62.5% (10/16) , P=0.009]. Thirty-five patients had no adverse effects such as fever, chills, and rash during the P-ATG infusion, and no obvious liver and kidney function damage was observed after treatment. The main treatment-related complication was infection. The reactivation rates of CMV and EBV were 77.1% (27/35) and 22.9% (8/35) , respectively, and the bacterial infection rate was 48.6% (17/35) . With a median follow-up time of 13 (1-55) months after HSCT, the 1-year and 2-year OS rates were (68.1±8.0) % and (64.3±8.4) % , respectively. The 1-year OS rate of grade Ⅲ aGVHD group was superior to grade Ⅳ aGVHD group [ (84.2±8.4) % vs. (47.6±13.1) % , χ(2)=3.38, P=0.05]. Conclusion: This study demonstrated that P-ATG with etanercept was effective and safe in treating grade Ⅲ-Ⅳ aGVHD after allo-HSCT.

Ruxolitinib: a potential treatment for corticosteroid refractory acute graft-versus-host disease

INTRODUCTION

Allogeneic transplantation represents a potentially curative procedure for various lethal conditions; however, it is associated with serious immune mediated complications. The most serious complication is graft-versus-host disease (GVHD). Acute GVHD (aGVHD) is unresponsive to initial corticosteroid therapy in ~40% of cases. Corticosteroid-refractory aGVHD (CR-aGVHD) represents a significant unmet need with nearly 60% mortality in patients developing this state.

AREAS COVERED

We review landmark trials which led to the US FDA approval of Ruxolitinb for the treatment of CR-aGVHD. Ruxolitinib phosphate is a Janus Kinase 1 and 2 inhibitor which inhibits pro-inflammatory signaling, and modulates T-cell subsets to an anti-inflammatory phenotype. Ruxolitinib was recently prospectively studied for the treatment of CR-aGVHD in the REACH1 trial, which added Ruxolitinib to corticosteroid therapy. This trial demonstrated favorable results with 73% of patients ultimately responding. Among responders, over 70% remained alive at 6 months. These results led to the US FDA to approve ruxolitinib as treatment for CR-aGVHD, the first approval of its kind.

EXPERT OPINION

Ruxolitinib represents the standard option for CR-aGVHD. Future studies should identify patients less likely to respond to ruxolitinib and/or focus on a more targeted approaches to reduce infectious complications and cytopenias seen with this drug.

Challenges in managing graft-versus-host disease in developing countries: a perspective

Hematopoietic cell transplant (HCT) activity is increasing worldwide due to safer techniques, widening indications, and more availability of donors. New HCT centers have recently been established in many developing countries including Asian and African countries. Due to limited resources, logistic, political, and social issues in developing countries, the treatment of orphan diseases like graft-versus-host disease (GVHD) can be challenging. We intended to delineate the current issues that institutions and clinicians face in managing GVHD. We conducted a comprehensive systematic electronic review of peer-reviewed published articles on GVHD management in developing countries. We used PubMed, Cochrane, and Embase databases as our primary source of data. Studies that were included described the treatments for both acute and chronic GVHD. Consensus on the use of high-dose methyl-prednisone and prednisolone as the initial therapy was widely accepted and used in practice. Socio-economic factors were found to be the major factor involved in GVHD management in lower income patients. Delayed diagnosis and treatment, lack of availability of healthcare professionals, lack of knowledge among cancer patients, and poverty are major concerns in the developing world. For optimal management, HCT programs should develop systems in place for long-term follow-up of HCT survivors and have a low threshold to initiate treatments for GVHD early. Awareness and health policy programs must be initiated at the grass-root level for long-term management of these survivors in developing countries.

Villous atrophy in the terminal ileum is a specific endoscopic finding correlated with histological evidence and poor prognosis in acute graft-versus-host disease after allo-hematopoietic stem cell transplantation

Background

Graft-versus-host disease (GVHD) is a common complication of allo-hematopoietic stem cell transplantation (allo-HSCT). Endoscopic biopsy can provide a definitive diagnosis, but the optimal endoscopic approach for diagnosis remains uncertain. This study evaluated whether ileocolonoscopic imaging can predict acute GVHD severity after allo-HSCT.

Methods

Consecutive patients who underwent allo-HSCT were referred to our institution, and those diagnosed with acute GVHD by pathology were included in this retrospective study.

Results

Fifty-one of 261 patients who underwent ileocolonoscopy were suspected to have acute intestinal GVHD. We performed univariate and multivariate conditional logistic regression with stepwise variable selection; villous atrophy in the terminal ileum remained a statistically significant predictor of GVHD severity (odds ratio, 4.69; 95% confidence interval, 1.07–20.60, P = 0.04). Patients were classified into three groups based on ileal endoscopic findings in the terminal ileum: group S, GVHD with severe villous atrophy; group M, mild atrophy; and group N, no atrophy. Compared with patients in groups M and N, those in group S had significant clinical GVHD at diagnosis (P = 0.03). In group S, three of four, compared with five of 13 patients in groups M and N, required the addition of second-line agents (P = 0.02).

Conclusions

This study showed that severe atrophy of the terminal ileum predicts severe clinical GVHD that is likely to be refractory to steroid treatment. Thus, the severity of terminal ileum atrophy may serve as a tool in predicting clinically severe GVHD.

Trial registration

Trial Registration Number UMIN 000022805, Registration date July 1, 2016.

EBMT-NIH-CIBMTR Task Force position statement on standardized terminology & guidance for graft-versus-host disease assessment

Several international recommendations address the assessment of graft-versus-host disease (GvHD) after hematopoietic cell transplantation (HCT). This position statement by GvHD experts from the European Society for Blood and Marrow Transplantation (EBMT), the National Institutes of Health (NIH) and the Center for International Blood and Marrow Transplant Research (CIBMTR) reviews the existing guidelines for both acute and chronic GvHD, addresses potential confusions that arise in daily practice and proposes consensus definitions for many key terms. We provide a historical perspective on the currently available guidelines and recommend the Mount Sinai Acute GvHD International Consortium (MAGIC) criteria for acute GvHD and the NIH 2014 criteria for chronic GvHD as the most comprehensive and detailed criteria available. This statement also offers practical guidance for the implementation of these recommendations and a set of consensus definitions for commonly used GvHD terms in order to facilitate future clinical and translational research. To assist the dissemination of these recommendations, a web-application based on this position statement is available (https://www.uzleuven.be/egvhd). We believe that adherence to a common set of GvHD assessment criteria is vitally important to improve the quality of data, compare results of retrospective studies and prospective clinical trials, and make therapeutic recommendations based on quality evidence.

The Role of Anti-Thymocyte Globulin or Alemtuzumab-Based Serotherapy in the Prophylaxis and Management of Graft-Versus-Host Disease

Allogeneic hematopoietic stem cell transplant is an established treatment modality for hematologic and non-hematologic diseases. However, it is associated with acute and long-term sequelae which can translate into mortality. Graft-versus-host disease (GVHD) remains a glaring obstacle, especially with the advent of reduced-intensity conditioning. Serotherapy capitalizes on antibodies which target T cells and other immune cells to mitigate this effect. This article focuses on the utility of two such agents: anti-thymocyte globulin (ATG) and alemtuzumab. ATG has demonstrated benefit in prophylaxis against GVHD, especially in the chronic presentation. However, there is limited impact of ATG on overall survival and it has little utility in the treatment context. There may be an initial improvement, particularly in skin manifestations, but no substantial benefit has been elicited. Alemtuzumab has shown benefit in both prophylaxis and treatment of GVHD, but at the consequence of a more profound immunosuppressive phase, mandating aggressive viral prophylaxis. There remains heterogeneity in the doses and regimens of the agents, with no standardized protocol in place. Furthermore, it seems that once steroid-refractory GVHD has been established, there is little that can be offered to offset the ultimately dismal outcome. Here we present a systematic overview of ATG- or alemtuzumab-based serotherapy in the prophylaxis and management of GVHD.

Patterns of infection and infection-related mortality in patients with steroid-refractory acute graft versus host disease

This study aimed to characterize the incidence, etiology and outcome of infectious episodes in patients with steroid refractory acute GvHD (SR-GvHD). The cohort included 127 adults treated with inolimomab (77%) or etanercept (23%) owing to acute 2-4 SR-GvHD, with a response rate of 43% on day +30 and a 4-year survival of 15%. The 1-year cumulative incidences of bacterial, CMV and invasive fungal infection were 74%, 65% and 14%, respectively. A high rate (37%) of enterococcal infections was observed. Twenty patients (15.7%) developed BK virus-hemorrhagic cystitis and five percent had an EBV reactivation with only one case of PTLD. One-third of long-term survivors developed pneumonia by a community respiratory virus and/or encapsulated bacteria, mostly associated with chronic GvHD. Infections were an important cause of non-relapse mortality, with a 4-year incidence of 46%. In multivariate analysis, use of rituximab in the 6 months before SCT (hazard ratio; HR 4.2; 95% confidence interval; CI 1.1-16.3), severe infection before SR-GvHD onset (HR 5.8; 95% CI 1.3-26.3) and a baseline C-reactive protein >15 UI/mL (HR 2.9; 95% CI 1.1-8.5) were associated with infection-related mortality. High rates of opportunistic infections with remarkable mortality warrant further efforts to optimize long-term outcomes after SR-GvHD.

Updated experience with inolimomab as treatment for corticosteroid-refractory acute graft-versus-host disease

Refractory acute graft-versus-host disease (aGVHD) remains an important cause of mortality after allogeneic stem cell transplantation. No standard therapy exists once steroids fail to obtain a good response. In 2006, our group published a series of patients who received inolimomab, an anti-interleukin-2 receptor monoclonal antibody, as salvage therapy with initial encouraging results. In this update, we analyzed a larger group of patients with prolonged follow-up. Ninety-two consecutive patients were treated with inolimomab at our center between April 1999 and December 2011. Overall response rate was 42% (complete response in 14%) on day +30. Predictors of failure to respond in the multivariate analysis were overall aGVHD grade IV, instauration of inolimomab before day 15 of aGVHD diagnosis, and severe lymphopenia. Patients without gastrointestinal involvement appeared to do better, with a 70% response rate compared with 39% in patients with gastrointestinal involvement (P = .06). However, the 2-year overall survival rate was of 18% for the entire cohort (95% confidence interval, 10% to 26%) and 33% for day 30 responders (95% confidence interval, 25% to 40%) and Acute GVHD was the main cause of death (49%) followed by opportunistic infections (27%). Results of this update show that although inolimomab is a well-tolerated drug with a moderate number of short-term responses, it is associated with long-term survival in only one-third of responding patients. These data highlight the need to investigate new rescue treatments with sustained effect and the importance of reporting long-term outcomes in GVHD studies.

Current and future approaches for control of graft-versus-host disease

Graft-versus-host disease (GVHD), both acute and chronic, remains one of the major barriers to improving outcomes after allogeneic stem cell transplantation. The pathophysiology of GVHD is complex and incompletely understood. GVHD is believed to arise from the interaction of: tissue damage and proinflammatory cytokines causing activation of antigen-presenting cells (APCs, donor T-cell activation by APCs and cytokines and host tissue injury by effector T lymphocytes and proinflammatory cytokines. There is also a role for additional lymphocyte subtypes (naive and memory T cells, regulatory T cells, natural killer T cells and B cells) in GVHD pathogenesis. Strategies to improve donor-recipient HLA match, and to minimize conditioning toxicity, cytokine release and APC and effector T-lymphocyte activation, will likely improve prophylaxis of acute (and possibly chronic) GVHD. Therapy of established acute and chronic GVHD is still heavily dependent on corticosteroids, despite their limited efficacy and considerable toxicity. Novel agents (and/or combinations of agents) comprising pharmacologic, biologic and cellular therapies targeting specific steps or subsets involved in immune activation will likely comprise future advances in GVHD control. This article reviews the current state of knowledge regarding the prevention and treatment of acute and chronic GVHD. Novel approaches currently undergoing evaluation are also highlighted.

Variation in management of immune suppression after allogeneic hematopoietic cell transplantation

Practice variation in transplant physician management of immune suppression (IS) after allogeneic hematopoietic cell transplantation (HCT) is anticipated to have important consequences, but has not been characterized to date. We conducted a national survey of transplant physician members of the American Society for Blood and Marrow Transplantation to discern variation in IS management, characterize the burden of graft-versus-host disease (GVHD) emerging in the setting of IS taper, and describe the proportion of HCT recipients who successfully discontinue IS by 2 and 5 years post-HCT. There was marked heterogeneity in IS discontinuation practice, with variation in initiation of taper, sequence of agents tapered, frequency of changes, and strategy utilized. Twenty-five percent reported no consistent strategy in their usual practice. Confidence in therapeutic decision making was limited. The majority indicated that they could not predict who would develop GVHD on taper of IS, and reported a resultant burden of both acute and chronic GVHD (aGVHD, cGVHD) emerging or recurring in the setting of IS taper. HCT physicians projected rates of IS discontinuation that increased from 2 to 5 years post-HCT, and differed significantly according to donor relation and stem cell source utilized. The marked variation in practice, burden of GVHD emerging in the setting of IS taper, and limited confidence in therapeutic decision making all highlight shortcomings in an essential component of HCT physicians' scope of practice. These data argue for more rigorous study of IS management post-HCT so that evidence-based practice guidelines can be developed.

Bone marrow transplantation: new approaches to immunosuppression and management of acute graft-versus-host disease

PURPOSE OF REVIEW

Acute graft-versus-host disease (GVHD) significantly limits the application and the success of allogeneic hematopoietic stem cell transplantation (HSCT). Novel therapies that target the aberrant immune response underlying GVHD are reviewed with particular emphasis on immunomodulatory agents currently incorporated into clinical trials. In addition, regenerative stromal cellular therapy (RSCT) is discussed as an emerging form of novel GVHD therapy.

RECENT FINDINGS

Knowledge for transplant immunology, particularly as it relates to underlying pathophysiology of GVHD, has dramatically increased over the last decade. As a result, new immunomodulatory therapies have been used to treat steroid-refractory GVHD. However, their success has been limited by their lack of clinical experience during HSCT as well as by their associated toxicity profiles. RSCT uniquely offers the potential to enhance donor-derived hematopoiesis and immunity and to ameliorate adverse sequelae associated with GVHD.

SUMMARY

An exciting era incorporating the use of cellular therapeutics during HSCT has arrived. As the experience and understanding for cellular therapies, in general, and RSCT, in particular, increases, so too will their success in benefiting the HSCT recipient beyond limitations of current pharmaceutical agents.

Current and novel therapies in acute GVHD

Despite improvements in our understanding of transplant immunology and clinical and supportive care, acute graft-versus-host disease (GVHD) remains a clinical challenge and a major cause of morbidity and mortality for patients after allogeneic hematopoietic stem-cell transplantation. While systemic corticosteroid is standard primary therapy for acute GVHD, there is no established standard treatment in the steroid-refractory setting. New generations of monoclonal antibodies, biologics, and chemotherapeutics with immunomodulatory effects have been developed over the past decade, and are being tested as novel therapies in this disease. Many of these agents - including, among others, mycophenolate mofetil, anti-tumor necrosis factor-alpha antibodies, denileukin diftitox, and anti-interleukin-2Ralpha-chain antibodies - have demonstrated promising activity in steroid-refractory acute GVHD. Despite the high response rates, however, long-term survival remains poor due to a high incidence of infections. The key to improving acute GVHD outcomes may, in fact, rest upon successful initial therapy, and timely taper of corticosteroids to promote healthier immune reconstitution. Clinical trials combining these newer agents with systemic corticosteroids as initial treatment are under way, and will determine whether fortifying initial therapy will indeed reduce the development of steroid-refractory GVHD and improve long-term outcomes. In this article, we review current and novel agents available for acute GVHD, and discuss newer investigational approaches - such as phototherapy and cellular therapies - in the management of this common transplant complication.

Individual physician practice variation in hematopoietic cell transplantation

PURPOSE

Previous studies have evaluated practice variation in hematopoietic cell transplantation (HCT) among transplant centers and countries. There are no studies investigating individual physician practice variation in HCT.

METHODS

An international Internet-based survey of transplant physicians collected data on medical decisions made by adult and pediatric HCT physicians. Multivariable analyses identified practitioner and transplant center characteristics predictive of medical decision making.

RESULTS

Analysis of 526 assessable respondents showed a wide variation in management approaches to specific clinical scenarios. Pediatric and adult transplant physicians differed significantly in their management strategies for chronic myeloid leukemia, acute and chronic graft-versus-host disease, and choice of graft source for patients with aplastic anemia. Among adult transplant physicians, there was little agreement on the patient factors favoring reduced intensity conditioning or myeloablative conditioning.

CONCLUSION

These results emphasize the heterogeneity of worldwide transplant practices. Local preferences or biases likely result in similar patients being offered different transplant and treatment procedures. The degree of practice variation also highlights the need for clinical trials to clarify areas of controversy. Where clinical trials are not feasible, data from observational studies may be the best available evidence to guide practice.

Encouraging results with inolimomab (anti-IL-2 receptor) as treatment for refractory acute graft-versus-host disease

Inolimomab [corrected] an anti-interleukin-2 receptor (anti-IL-2R) monoclonal antibody, may be useful in the treatment of steroid-refractory acute graft-versus-host disease (aGVHD) by inhibiting 1 of its putative immunopathogenic pathways. We retrospectively analyzed 40 consecutive patients who received inolimomab [corrected] as salvage treatment for steroid refractory aGVHD at a single institution between June 1999 and December 2004. Inolimomab [corrected] was given intravenously at a dose of 11 mg/d for 3 consecutive days, followed by 5.5 mg/d for 7 consecutive days and then 5.5 mg every other day for 5 doses. No infusion-related side effects were noted. Twenty-three patients (58%) responded, including 15 (38%) complete and 8 (20%) partial responses. Median overall survival was 294 days (58-996 days) for responders versus 14 days for nonresponders (P < .001), with a 1 year probability of 59% vs 0% for overall survival (P < .0001). Patients without gastrointestinal (GI) involvement showed a higher response rate (100% versus 50% for those without versus with GI involvement, P = .03) In addition, patients who showed some response by day 15 had a higher overall survival (73 +/- 12% vs 24 +/- 12%, respectively, P = .02). The results of this study suggest that inolimomab [corrected] may be an effective salvage therapy for patients with steroid-refractory aGVHD, particularly for those without GI disease, and supports further studies with this agent in prospective controlled trials.

Pulse cyclophosphamide for corticosteroid-refractory graft-versus-host disease

Corticosteroid-resistant GVHD is difficult to manage and is associated with high morbidity and mortality. Cyclophosphamide (Cy) is an established immunosuppressive and cytotoxic drug widely used as part of pretransplant conditioning regimens. In a retrospective study of 15 patients who had not responded to corticosteroids (nine with acute GVHD, three with GVHD after donor leukocyte infusion, and three progressive chronic GVHD), pulse Cy at a median dose of 1 g/m(2) was very effective in the treatment of skin (100% response), liver (70% response), and the oral cavity (100% response). Severe intestinal GVHD responded poorly. The toxicity profile was acceptable, with manageable, short-term myelosuppression in some patients. The risk of opportunistic infections, mixed chimerism, relapses, or post-transplant lymphoproliferative disease was not increased. Overall survival was 57%, with median and maximum follow-up of 9 and 37 months, respectively. The cost of the drug was negligible, especially when compared to monoclonal antibodies. Pulse Cy requires further investigation in corticosteroid-resistant GVHD.

Mycophenolate mofetil for the treatment of acute and chronic steroid-refractory graft-versus-host disease

Corticosteroid-resistant graft-versus-host disease (GvHD) is difficult to manage and is associated with high morbidity and mortality. The purpose of our study was to evaluate the safety and efficacy of mycophenolate mofetil (MMF) as the salvage therapy for steroid-refractory GvHD. Twenty one patients (10 with acute GvHD and 11 with chronic GvHD) were studied retrospectively. Steroid-resistant GvHD was defined as acute or chronic GvHD not responding to a first-line regimen of cyclosporine A and corticosteroids in a dose equivalent to 2 mg/kg methylprednisolone for at least 7 days. MMF was added at a dose of 2 g daily, and corticosteroids were tapered. Thirteen (62%) of 21 patients responded to the treatment with MMF, including 6 (60%) of 10 patients with acute refractory GvHD and 7 (64%) of 11 patients with chronic refractory GvHD. The most common adverse effects were infectious complications (67%, 14 of 21 patients) and hematological toxicity (29%, 6 of 21 patients). Median duration of MMF administration was 6 months (range 1-27 months). Sixteen of 21 patients were alive after the median follow-up of 27 months (range 1-72 months) after the initiation of MMF therapy. All 16 surviving patients were in good clinical condition and in remission of their hematological malignancy. Five patients died--two of relapses of leukemia and three of refractory intestinal GvHD. These results suggest that MMF can be an effective treatment for some cases of steroid-refractory GvHD.

Treatment of Gastrointestinal Acute Graft-Versus-Host Disease

Therapy of acute graft-versus-host disease (GVHD) aims to selectively alter the graft- host interactions to foster antitumor effect and minimize antihost effects. The immunosuppression produced by the various therapies ranges from broad, nonselective effects to relatively narrow targeted impact. Despite advances in understanding the pathophysiology of GVHD, newer agents with more selective effects have not yet produced therapeutic advances. The newer targeted agents continue to produce a degree of immunosuppression in which infection and relapse of malignancy are all too common. High-dose systemic steroids remain, as they have for two decades, the initial treatment of choice. Patients failing to respond to steroids continue to represent a challenge, as no second-line therapy is clearly superior to the others. However, some of the new agents appear to be particularly effective in certain organs involved with acute GVHD. For those patients with steroid-refractory GVHD involving primarily the gut, we favor infliximab with concomitant antifungal therapy. For those with primarily skin or liver disease, we favor extracorporeal photochemotherapy.

Dermatologic treatment of cutaneous graft versus host disease

Cutaneous involvement in graft versus host disease (GVHD) after allogeneic hematopoietic cell transplant can be separated into acute GVHD (aGVHD), lichenoid chronic GVHD (cGVHD) and sclerodermatous cGVHD. It seems clear that these syndromes result from different mechanisms and entail different treatment approaches. Standard treatment of cutaneous aGVHD involves the intensification of immunosuppressive therapy with adequate topical supportive management. In skin-limited disease, phototherapy has shown promising results. In cutaneous cGVHD, the combination of corticosteroids and cyclosporine (ciclosporin) is the recommended therapy, and other immunosuppressants may be added depending on whether lichenoid or sclerodermatous lesions are present. High response rates to phototherapy have been found in lichenoid disease, while sclerodermatous disease responds better to etretinate or extracorporeal photochemotherapy. Localized cutaneous cGVHD may be treated with topical corticosteroids alone. Few reports on the effect of treatments in GVHD clearly describe the cutaneous involvement and the influence of the treatment on the skin. Therefore, dermatologists should be deeply involved in the diagnosis and treatment of GVHD, and good dermatologic grading systems should be developed. Theses changes will increase our knowledge of cutaneous GVHD, and relevant data in the evaluation of the effect of therapy in the disease will be obtained.

Monoclonal antibodies for the prevention and treatment of graft-versus-host disease

Acute and chronic graft-versus-host disease (GvHD) remain major obstacles to successful allogeneic hematopoietic stem cell transplantation, contributing substantially to morbidity and non-relapse mortality. Better understanding of the immunopathophysiology of GvHD has identified a number of targets for intervention. Among newly developed agents suitable for the prevention and treatment of GvHD, monoclonal antibodies hold much promise. Monoclonal antibodies currently available, such as infliximab and anti-interferon-gamma (anti-IFN-gamma), are capable of blocking of the action of initiating and effector cytokines. Antibodies directed against activated T cells, including daclizumab, visilizumab and ABX-CBL, may offer more specificity than the more broadly acting pan-T-cell-depleting agents. Finally, the clinical investigation of antibodies to adhesion molecules (such as LFA-1), or distal effector mechanisms (such as FasL) may offer another level of specificity. Many of these monoclonal antibodies have already undergone clinical testing. Campath-1H has been used for the prevention of acute GvHD with success. Daclizumab, infliximab, visilizumab, and ABX-CBL have shown promising activity in steroid-resistant acute GvHD in early clinical testing. This review summarizes current experience with monoclonal antibodies in the management of acute and chronic GvHD. Over the next decade, however, the challenge will be to define the relative place of these antibodies in the therapeutic armamentarium for GvHD and their impact on long-term survival.