Mycophenolate Mofetil Is Effective and Well Tolerated in the Treatment of Refractory Acute and Chronic Graft-versus-Host Disease

Graft-Versus-Host Disease Mouse Models: A Clinical-Translational Perspective

A variety of graft-versus-host disease (GVHD) models have been developed in mice for the purpose of allowing laboratory investigation of the pathobiology, prevention, and treatment of GVHD in humans. While such models are crucial in advancing our knowledge in this field, there are some key limitations that need to be considered when translating laboratory discoveries into the clinical context. This chapter will discuss current clinical practices in transplantation and GVHD and the relative strengths and weaknesses of mouse models that attempt to replicate these states.

Mesenchymal stromal cells plus basiliximab improve the response of steroid-refractory acute graft-versus-host disease as a second-line therapy: a multicentre, randomized, controlled trial

BACKGROUND

For patients with steroid-refractory acute graft-versus-host disease (SR-aGVHD), effective second-line regimens are urgently needed. Mesenchymal stromal cells (MSCs) have been used as salvage regimens for SR-aGVHD in the past. However, clinical trials and an overall understanding of the molecular mechanisms of MSCs combined with basiliximab for SR-aGVHD are limited, especially in haploidentical haemopoietic stem cell transplantation (HID HSCT).

METHODS

The primary endpoint of this multicentre, randomized, controlled trial was the 4-week complete response (CR) rate of SR-aGVHD. A total of 130 patients with SR-aGVHD were assigned in a 1:1 randomization schedule to the MSC group (receiving basiliximab plus MSCs) or control group (receiving basiliximab alone) (NCT04738981).

RESULTS

Most enrolled patients (96.2%) received HID HSCT. The 4-week CR rate of SR-aGVHD in the MSC group was obviously better than that in the control group (83.1% vs. 55.4%, P = 0.001). However, for the overall response rates at week 4, the two groups were comparable. More patients in the control group used ≥ 6 doses of basiliximab (4.6% vs. 20%, P = 0.008). We collected blood samples from 19 consecutive patients and evaluated MSC-derived immunosuppressive cytokines, including HO1, GAL1, GAL9, TNFIA6, PGE2, PDL1, TGF-β and HGF. Compared to the levels before MSC infusion, the HO1 (P = 0.0072) and TGF-β (P = 0.0243) levels increased significantly 1 day after MSC infusion. At 7 days after MSC infusion, the levels of HO1, GAL1, TNFIA6 and TGF-β tended to increase; however, the differences were not statistically significant. Although the 52-week cumulative incidence of cGVHD in the MSC group was comparable to that in the control group, fewer patients in the MSC group developed cGVHD involving ≥3 organs (14.3% vs. 43.6%, P = 0.006). MSCs were well tolerated, no infusion-related adverse events (AEs) occurred and other AEs were also comparable between the two groups. However, patients with malignant haematological diseases in the MSC group had a higher 52-week disease-free survival rate than those in the control group (84.8% vs. 65.9%, P = 0.031).

CONCLUSIONS

For SR-aGVHD after allo-HSCT, especially HID HSCT, the combination of MSCs and basiliximab as the second-line therapy led to significantly better 4-week CR rates than basiliximab alone. The addition of MSCs not only did not increase toxicity but also provided a survival benefit.

Efficacy and safety of ruxolitinib in steroid-refractory graft-versus-host disease: A meta-analysis

Ruxolitinib is an important treatment for steroid refractory graft-versus-host disease (SR-GVHD). Therefore, we reported the updated results of a systematic review and meta-analysis of ruxolitinib as treatment for SR-GVHD. In addition, we wanted to compare the efficacy and safety between children and adults with SR-GVHD. Overall response rate (ORR) after ruxolitinib treatment was chosen as the primary end point. Complete response rate (CRR), infection, myelosuppression, and overall survival (OS) were chosen as secondary end points. A total of 37 studies were included in this meta-analysis, and 1,580 patients were enrolled. ORR at any time after ruxolitinib treatment was 0.77 [95% confidence interval (CI): 0.68–0.84] and 0.78 (95% CI: 0.74–0.81), respectively, for SR-aGVHD and SR-cGVHD. CRR at any time after ruxolitinib treatment was 0.49 (95% CI: 0.40–0.57) and 0.15 (95% CI: 0.10–0.23), respectively, for SR-aGVHD and SR-cGVHD. The ORRs at any time after treatment was highest in mouth SR-cGVHD, followed by skin, gut, joints and fascia, liver, eyes, esophagus, and lung SR-cGVHD. The incidence rate of infections after ruxolitinib treatment was 0.61 (95% CI: 0.45–0.76) and 0.47 (95% CI: 0.31–0.63), respectively, for SR-aGVHD and SR-cGVHD. The incidence rates of overall (grades I–IV) and severe (grades III–IV) cytopenia were 53.2% (95% CI: 16.0%–90.4%) and 31.0% (95% CI: 0.0–100.0%), respectively, for SR-aGVHD, and were 28.8% (95% CI:13.0%–44.6%) and 10.4% (95% CI: 0.0–27.9%), respectively, for SR-cGVHD. The probability rate of OS at 6 months after treatment was 63.9% (95% CI: 52.5%–75.2%) for SR-aGVHD. The probability rates of OS at 6 months, 1 year, and 2 years after treatment were 95% (95% CI: 79.5%–100.0%), 78.7% (95% CI: 67.2%–90.1%), and 75.3% (95% CI: 68.0%–82.7%), respectively, for SR-cGVHD. The ORR, CRR, infection events, and myelosuppression were all comparable between children and adults with SR-GVHD. In summary, this study suggests that ruxolitinib is an effective and safe treatment for SR-GVHD, and both children and adults with SR-GVHD could benefit from ruxolitinib treatment.

Ocular graft-versus-host disease after hematopoietic cell transplantation: Expert review from the Late Effects and Quality of Life Working Committee of the CIBMTR and Transplant Complications Working Party of the EBMT

Ocular graft-versus-host disease (GVHD) occurs in more than half of patients who develop chronic GVHD after allogeneic hematopoietic cell transplantation (HCT), causing prolonged morbidity, which affects activities of daily living and quality of life. Here we provide an expert review of ocular GVHD in a collaboration between transplant physicians and ophthalmologists through the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research and the Transplant Complications Working Party of the European Society of Blood and Marrow Transplantation. Recent updates in ocular GVHD, regarding pathophysiology, preclinical models, risk factors, prevention, screening, diagnosis, response criteria, evaluation measures, and treatment are discussed in this review. Ocular GVHD has at least three biological processes: lacrimal gland dysfunction, meibomian gland dysfunction, and corneoconjunctival inflammation. Preclinical models have found several novel pathogenic mechanisms, including renin angiotensin system and endoplasmic reticulum stress signaling that can be targeted by therapeutic agents. Many studies have identified reliable tests for establishing diagnosis and response assessment of ocular GVHD. Efficacy of systemic and topical treatment for ocular GVHD is summarized. It is important for all health professionals taking care of HCT recipients to have adequate knowledge of ocular GVHD for optimal care.

Ocular Graft-versus-Host Disease after Hematopoietic Cell Transplantation: Expert Review from the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research and Transplant Complications Working Party of the European Society of Blood and Marrow Transplantation

Ocular graft-versus-host disease (GVHD) occurs in more than one-half of patients who develop chronic GVHD after allogeneic hematopoietic cell transplantation (HCT), causing prolonged morbidity that affects activities of daily living and quality of life. Here we provide an expert review of ocular GVHD in a collaboration between transplantation physicians and ophthalmologists through the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research and the Transplant Complications Working Party of the European Society of Blood and Marrow Transplantation. Recent updates in ocular GVHD regarding pathophysiology, preclinical models, risk factors, prevention, screening, diagnosis, response criteria, evaluation measures, and treatment are discussed. Ocular GVHD involves at least 3 biological processes: lacrimal gland dysfunction, meibomian gland dysfunction, and corneoconjunctival inflammation. Preclinical models have identified several novel pathogenic mechanisms, including the renin angiotensin system and endoplasmic reticulum stress signaling, which can be targeted by therapeutic agents. Numerous studies have identified reliable tests for establishing diagnosis and response assessment of ocular GVHD. The efficacy of systemic and topical treatment for ocular GVHD is summarized. It is important that all health professionals caring for HCT recipients have adequate knowledge of ocular GVHD to provide optimal care.

Treatment Options in Steroid-Refractory Acute Graft-Versus-Host Disease Following Hematopoietic Stem Cell Transplantation

Objective:

To evaluate the treatment options in steroid-refractory acute graft-versus-host disease (GVHD) following hematopoietic stem cell transplantation.

Data Sources:

Literature was obtained by searching MEDLINE (1966–May 2007) and EMBASE (1980–May 2007).

Study Selection and Data Extraction:

All pertinent clinical trials, retrospective studies, case reports, and compassionate use studies were identified and evaluated for safety and efficacy of the pharmacologic agents.

Data Synthesis:

Steroid-refractory acute GVHD is associated with high rates of morbidity and mortality. Although various pharmacologic agents have been studied in the treatment of steroid-refractory acute GVHD, no treatments have been established as a salvage therapy. Preliminary data on different pharmacologic agents have been identified and evaluated for their efficacy and tolerability in the treatment of steroid-refractory acute GVHD. The effects of the pharmacologic agents varied significantly among patients: severity of the disease, involvement of different organs, and the patient's age seem to be the major factors that affect an individual's response to drug therapy. In addition, the treatments are further challenged by the high incidence of potentially fatal opportunistic infections that occur during the therapy.

Conclusions:

Selection of pharmacologic agents for the treatment of steroid-refractory acute GVHD should be based on the target organs, adverse drug reactions, and economic factors. Further studies with larger sample sizes are warranted to better understand the roles of these agents in the treatment of steroid-refractory acute GVHD.

Insurance approval of mesenchymal stem cell for acute GVHD in Japan: need of follow up for some remaining concerns

Acute graft-versus-host disease (aGVHD) is a major obstacle following allogeneic hematopoietic stem cell transplantation. Steroid is the standard treatment for aGVHD grade II-IV; however, nearly half of patients do not respond to the therapy. Many drugs have been proposed, but no standard therapy has been determined. This is because of the resistance to these drugs and of infections due to prolonged immunosuppressive states. Over the past decade a new approach using mesenchymal stem cells (MSCs) has been emerging in Japan and western countries. MSCs have unique characteristics such as specific immunosuppressive properties, no immunogenicity on their own and supportive activity for hematopoiesis. Most of the published trials have reported a favorable effect in acute GVHD, but a phase III trial failed to reach the primary endpoint, although, subgroup analyses found significant effects on gut and liver GVHD in the patients with MSCs infusion. In Japan several institutes are trying to develop MSC for clinical use in post HSCT patients. However, several limitations make it difficult to use MSC in clinical practice. Recently we conducted a phase II/III study using MSC (JR-031) for patients with steroid-refractory grade III or IV aGVHD. From the feasible clinical results, JR-031 was approved by PMDA as the first product which meets the Act to Revise the Pharmaceutical Affairs Act and the Act to Ensure the Safety of Regenerative Medicine. The cost of one series of the treatment is more than ten million yen. Now we encounter new issues such as cost, indication, safety and efficacy. The mechanism of MSC is still unclear and potential concerns about ectopic tissue formation and MSC related malignancy in vivo remain. In conclusion, MSC infusions are well tolerated and show benefit in some patients without adverse safety effects; however, long-term follow-up is needed to be more certain of this.

Treatment of chronic graft-versus-host disease: Past, present and future

Chronic GVHD was recognized as a complication of allogeneic hematopoietic cell transplantation more than 30 years ago, but progress has been slowed by the limited insight into the pathogenesis of the disease and the mechanisms that lead to development of immunological tolerance. Only 6 randomized phase III treatment studies have been reported. Results of retrospective studies and prospective phase II clinical trials suggested overall benefit from treatment with mycophenolate mofetil or thalidomide, but these results were not substantiated by phase III studies of initial systemic treatment for chronic GVHD. A comprehensive review of published reports showed numerous deficiencies in studies of secondary treatment for chronic GVHD. Fewer than 10% of reports documented an effort to minimize patient selection bias, used a consistent treatment regimen, or tested a formal statistical hypothesis that was based on a contemporaneous or historical benchmark. In order to enable valid comparison of the results from different studies, eligibility criteria, definitions of individual organ and overall response, and time of assessment should be standardized. Improved treatments are more likely to emerge if reviewers and journal editors hold authors to higher standards in evaluating manuscripts for publication.

Using genetic and clinical factors to predict tacrolimus dose in renal transplant recipients

AIMS

Tacrolimus has a narrow therapeutic window and shows significant interindividual difference in dose requirement. In this study we aim to first identify genetic factors that impact tacrolimus dose using a candidate gene association approach, and then generate a personalized algorithm combining identified genetic and clinical factors to predict individualized tacrolimus dose.

MATERIALS & METHODS

We screened 768 SNPs in 15 candidate genes in metabolism, transport and calcineurin inhibition pathways of tacrolimus, for association with tacrolimus dose in a discovery cohort of 96 patients.

RESULTS

Four polymorphisms in CYP3A5 and one polymorphism in CYP3A4 were identified to be significantly associated with tacrolimus stable dose (p < 8.46 × 10(-5)). The same SNPs were identified when dose-normalized trough tacrolimus concentration was analyzed. The CYP3A5*1 allele was associated with significantly higher stable dose, bigger dose increase, higher risk of being underdosed and lower incidence of post-transplant hyperlipidemia. ABCB1 polymorphisms were not associated with stable dose. No significant difference was found between CYP3A5 expressers and nonexpressers in incidence of acute rejection and time to first rejection. Age, ethnicity and CYP3A inhibitor use could predict 30% of tacrolimus dosing variability. Adding the identified genetic polymorphisms to the algorithm increased the predictability to 58%. In two validation cohorts of 77 and 64 patients, the algorithm containing both genetic and clinical factors produced correlation coefficients of 0.63 and 0.42, respectively. This algorithm gave a prediction of the stable doses closer to the actual doses when compared with another algorithm based only on the CYP3A5 genotype.

CONCLUSION

CYP3A5 genotype is the most significant genetic factor that impacts tacrolimus dose among the genes studied. This study generated the first pharmacogenomics model that predicts tacrolimus stable dose based on age, ethnicity, genotype and comedication use. Our results highlight the importance of incorporating both genetic and clinical, demographic factors into dose prediction.

Cord colitis syndrome in cord-blood stem-cell transplantation

BACKGROUND

Diarrhea is a frequent complication of hematopoietic stem-cell transplantation (HSCT). Important causes of diarrhea after HSCT include acute graft-versus-host disease (GVHD), infections, and medications. After the transplantation and engraftment of hematopoietic stem cells from umbilical-cord blood, we observed a new syndrome of culture-negative, antibiotic-responsive diarrhea not attributable to any known cause.

METHODS

We conducted a retrospective cohort study of all patients undergoing cord-blood HSCT at our center between March 2003 and March 2010. The cord colitis syndrome was defined as a persistent diarrheal illness in such patients that was not due to acute GVHD, viral or bacterial infection, or another identifiable cause. Clinical and histopathological features of patients meeting the case definition were further analyzed.

RESULTS

Among 104 patients who underwent cord-blood HSCT at our center, the cord colitis syndrome developed in 11 (10.6%). The 1-year Kaplan-Meier cumulative probability of meeting the case definition for the syndrome was 0.16. The median time to onset after transplantation was 131 days (range, 88 to 314). All patients had a response to a 10-to-14-day course of empirical therapy with metronidazole, alone or in combination with a fluoroquinolone. Five of the 11 patients (45%) had recurrent diarrhea shortly after discontinuation of antibiotics, and all patients who had a relapse had a response to reinitiation of antibiotic therapy. On histologic examination, all patients with the cord colitis syndrome had chronic active colitis, with granulomatous inflammation present in 7 of 11 patients (64%).

CONCLUSIONS

The cord colitis syndrome is clinically and histopathologically distinct from acute GVHD and other causes of diarrhea in patients who have undergone cord-blood HSCT and is relatively common in this patient population. The syndrome should be considered in such patients who have diarrhea that is not attributable to other causes.

Clinical tolerance in allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (HSCT) has been a curative therapeutic option for a wide range of immune hematologic malignant and non-malignant disorders including genetic diseases and inborn errors. Once in the host, allogeneic transplanted cells have not only to ensure myeloid repopulation and immunological reconstitution but also to acquire tolerance to host human leukocyte antigens via central or peripheral mechanisms. Peripheral tolerance after allogeneic HSCT depends on several regulatory mechanisms aimed at blocking alloimmune reactivity while preserving immune responses to pathogens and tumor antigens. Patients transplanted with HSCT represent an ideal model system in humans to identify and characterize the key cellular and molecular players underlying these mechanisms. The knowledge gained from these studies has allowed the development of novel therapeutic strategies aimed at inducing long-term peripheral tolerance, which can be applicable not only in allogeneic HSCT but also in autoimmune diseases and solid-organ transplantation. In the present review, we describe Type 1 regulatory T cells, initially discovered and characterized in chimeric patients transplanted with human leukocyte antigen-mismatched HSCT, and how their presence correlates to tolerance induction and maintenance. Furthermore, we summarize different cell therapy approaches with regulatory T cells, designed to facilitate tolerance induction, minimizing pharmaceutical interventions.

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.

Use of mycophenolate mofetil in patients received allogeneic hematopoietic stem cell transplantation in Japan

We evaluated the use of mycophenolate mofetil (MMF) after hematopoietic stem cell transplantation (HSCT) in Japan from 1999 to 2008. MMF was administered to 301 patients, including 157 for the prevention of graft-versus-host disease (GVHD), 94 for the treatment of acute GVHD and 50 for the treatment of chronic GVHD. The three most common doses were 500 mg twice daily, 250 mg three times daily and 1,000 mg twice daily, given to 63, 54 and 45 patients, respectively. The incidence of grade II-IV acute GVHD was 30.0% and grade III-IV was 20.0% in the GVHD prevention group. Among treated patients, disappearance or improvement of subjective symptoms occurred in 57.0% of acute GVHD patients and in 52.0% of chronic GVHD patients. With regard to safety, the following major adverse events (grade 3 or more) were recorded: 31 infections, 31 neutropenia, 28 thrombocytopenia, 25 diarrhea and 1 renal disorder. A total of 116 patients developed grade 3 or 4 adverse events, but 79 were successfully treated with supportive treatment. Thus, our findings suggest that MMF is safe and effective for the prevention and treatment of GVHD in patients who have received an allogeneic stem cell transplant.

Pathogenesis and management of graft-versus-host disease

Allogeneic hematopoietic cell transplantation (HCT) is an important therapeutic option for various malignant and nonmalignant conditions. As allogeneic HCT continues to increase, greater attention is given to improvements in supportive care, infectious prophylaxis, immunosuppressive medications, and DNA-based tissue typing. However, graft versus host disease (GVHD) remains the most frequent and serious complication following allogeneic HCT and limits the broader application of this important therapy. Recent advances in the understanding of the pathogenesis of GVHD have led to new approaches to its management, including using it to preserve the graft versus leukemia effect following allogeneic transplant. This article reviews the important elements in the complex immunologic interactions involving cytokine networks, chemokine gradients, and the direct mediators of cellular cytotoxicity that cause clinical GVHD, and discusses the risk factors and strategies for management of GVHD.

A high risk of life-threatening infectious complications in mycophenolate mofetil treatment for acute or chronic graft-versus-host disease

We describe herein the clinical courses and outcomes of 26 patients who received oral mycophenolate mofetil (MMF) for the treatment of steroid-resistant refractory or steroid-dependent acute or chronic graft-versus-host disease (GVHD) in a single institution. In most cases, 1,500 mg/day of MMF is a median dose (range 500-3,000 mg/day) and administered for 116.5 days (range 9-584 days) along with calcineurin inhibitors and steroids. Although 20 patients (77%) showed rapid improvement of GVHD symptoms, of 15 patients, 13 (87%) showed acute GVHD; of 11 patients, 7 (64%) showed chronic GVHD; most patients (54%) experienced infection during MMF administration, including 5 cases with life-threatening infection. Positive cytomegalovirus (CMV) antigenemia was also observed in 19 patients (73%), but no patients developed CMV infection. Within the median follow-up of 12.5 months (range 0.5-67 months), 10 patients (39%) died. This small study demonstrates that MMF offers an alternative tool for rescuing steroid-refractory or steroid-dependent GVHD, but increases the risk of developing life-threatening infection.

Acute graft-versus-host disease: new treatment strategies

PURPOSE OF REVIEW

Graft-versus-host disease (GVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT), despite improvements in our understanding of its pathophysiology as well as the generation of new monoclonal antibodies, immunomodulatory chemotherapy, cellular therapeutics and supportive care. Herein, we review therapies that have proven effective as well as newer agents that have recently improved GVHD response rates and survival following HCT.

RECENT FINDINGS

Novel approaches to prevent or treat GVHD are often based on evidence from experimental models. Our understanding of the pathophysiology of GVHD may lead to the development of innovative strategies that target both soluble and cellular effectors. Among such agents are sirolimus, anti-tumor necrosis factor antibodies, anti-LFA-3-IgG fusion protein, extracorporeal photopheresis, mesenchymal stem cells and regulatory T cells.

SUMMARY

Obstacles to the improvement of HCT include the tight linkage between GVHD toxicity and the beneficial graft-versus-leukemia (GVL) effect, as well as the impairment of immune reconstitution by immunomodulatory drugs leading to life-threatening infections. The design of newer phase I/II clinical trials are underway. Future therapies are likely to include modulation of cell types that play key roles in the GVH process, including regulatory T cells, dendritic cells, natural killer T cells and B cells.

Sirolimus for treatment of steroid-refractory acute graft-versus-host disease

Acute GVHD (aGVHD) is a major cause of morbidity and mortality in hematopoietic allograft recipients. The best therapy for patients failing to respond, or not tolerating, systemic glucocorticoids remains undefined. We evaluated the efficacy of sirolimus in 34 patients, median age of 49 (23-67) years, with steroid-refractory (n=31) or steroid-intolerant (n=3) aGVHD. aGVHD was diagnosed at a median of 34 (7-1042) days post allografting, and confirmed by biopsy in all cases. Initial aGVHD treatment consisted of prednisone up to 2 mg/kg. Sirolimus was initiated at a median of 9 (1-255) days after glucocorticoid initiation. A sirolimus loading dose was administered to 19 (56%) of 34 patients, median 6 (3-8) mg, followed by maintenance of 1-2 mg/day to target therapeutic trough levels between 4 and 12 ng/ml. Overall response rate was 76%. Fifteen (44%) of 34 patients achieved CR, defined as complete resolution of aGVHD sustained for at least 1 month, after sirolimus initiation without additional immunosuppressive agents. CR was achieved in 11 (42%) of 31 steroid-refractory and 2 (67%) of 3 steroid-intolerant patients. Median OS after initiation of sirolimus was 5.6 months, and 1-year OS was 44% (95% CI: 27-60%). Sirolimus is effective in controlling steroid-refractory aGVHD.

Valganciclovir-induced leukopenia in liver transplant recipients: influence of concomitant use of mycophenolate mofetil

INTRODUCTION

An increased incidence and magnitude of leukopenia during concomitant treatment with valganciclovir (VGC) and mycophenolate mofetil (MMF) has been reported.

OBJECTIVE

To evalute the incidence and severity of leukopenia and neutropenia among liver recipients treated with VGC and related factors.

PATIENTS AND METHODS

Retrospective analysis of clinical and analytical data related to leukopenia (<3000 leukocytes/mm(3)) and neutropenia (<900 neutrophils/mm(3)) in liver transplant patients who were treated with VGC from 2003 to 2007. We examined the influence of concomitant administration of MMF and development of subsequent infections.

RESULTS

Among 209 liver transplants, 40 treatments with VGC were prescribed in 37 patients (17.7%), 12 of which (30%) were associated with MMF. The patients has an average age of 49.7 +/- 12.7, body mass index (BMI) of 27.28 +/- 5.17, and Model for End-stage Liver Disease Score (MELD) 12.45 +/- 7.5. The daily average dose of VGC was 1440 +/- 446.5 mg and MMF, 1454.5 +/- 350.3 mg. We observed a decrease of 30% in initial leukocyte count (5353.7 +/- 2706.6) and 40% in neutrophil count (3600 +/- 2182.1). With no relationship to total dose or BMI-adjusted dose of VGC nor concomitant administration of MMF. The initial leukocyte count was significantly lower (4411 +/- 1930 vs 6206 +/- 3053; P = .03) and underwent a main drop (2344.7 +/- 1974.3 vs 898.1 +/- 2435.6; P = .04) when leukopenia developed. In the induced neutropenia group, previous leukocyte count (3797.1 +/- 1223.9 vs 5683.9 +/- 2829.3; P = .01), MELD (18.7 +/- 8.8 vs 11.1 +/- 6.6; P = .01), and the creatinine pretreatment (1.44 +/- 0.4 vs 1.09 +/- 0.3; P = .01) were significantly different. Subsequent infections induced by the leukopenia were not observed.

CONCLUSIONS

In our series, the concomitant use of VGC and MMF was not associated with a greater incidence of leukopenia and/or neutropenia than VGC administration alone. Previous leukocyte count was associated with them. MELD and renal dysfunction are factors related to severe neutropenia. Leukopenia was not associated with a greater incidence of infections.

Therapy with mycophenolate mofetil for refractory acute and chronic GVHD

We evaluated the pharmacokinetics and efficacy of oral mycophenolate mofetil (MMF) for treatment of refractory graft-versus-host disease (GVHD). In a prospective study of acute GVHD, 9 of 19 patients (47%) had a response and 10 (53%) had no improvement. Survival at 6 and 12 months after the start of MMF was 37% and 16%, respectively. In a retrospective study of acute GVHD, 14 of 29 patients (48%) had a response and 15 (52%) had no improvement. Survival at 6 and 12 months was 55% and 52%, respectively. In a prospective study of chronic GVHD, the cumulative incidence of disease resolution and withdrawal of all systemic immunosuppressive treatment was 9%, 17% and 26% at 12, 24 and 36 months after starting MMF, respectively. Thirteen patients (59%) required additional systemic immunosuppressive treatment for chronic GVHD. Nine of the 42 patients (21%) in the prospective studies discontinued MMF treatment because of toxicity. Area under the curve plasma concentrations of mycophenolic acid appeared to be suboptimal among patients with acute GVHD but not among those with chronic GVHD. MMF can be used effectively for treatment of GVHD.

Evaluation of mycophenolate mofetil for initial treatment of chronic graft-versus-host disease

We conducted a double-blind, randomized multicenter trial to determine whether the addition of mycophenolate mofetil (MMF) improves the efficacy of initial systemic treatment of chronic graft-versus-host disease (GVHD). The primary endpoint was resolution of chronic GVHD and withdrawal of all systemic treatment within 2 years, without secondary treatment. Enrollment of 230 patients was planned, providing 90% power to observe a 20% difference in success rates between the 2 arms. The study was closed after 4 years because the interim estimated cumulative incidence of success for the primary endpoint was 23% among 74 patients in the MMF arm and 18% among 77 patients in the control arm, indicating a low probability of positive results for the primary endpoint after completing the study as originally planned. Analysis of secondary endpoints showed no evidence of benefit from adding MMF to the systemic regimen first used for treatment of chronic GVHD. The estimated hazard ratio of death was 1.99 (95% confidence interval, 0.9-4.3) among patients in the MMF arm compared with the control arm. MMF should not be added to the initial systemic treatment regimen for chronic GVHD. This trial was registered at www.clinicaltrials.gov as #NCT00089141 on August 4, 2004.

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.

Intestinal UGTs as potential modifiers of pharmacokinetics and biological responses to drugs and xenobiotics

Uridine 5'-diphosphate-glucuronosyltransferases (UGTs) are the biological catalysts of glucuronidation, a major pathway of conjugative metabolism of drugs and xenobiotics. In addition to the liver and kidney, UGTs are highly expressed in the gastrointestinal tract, where they have the potential to influence the pharmacokinetics and biological effects of ingested drugs and xenobiotics. This paper reviews the current evidence for the contributions of intestinal UGTs to presystemic 'first-pass' metabolism and drug bioavailability, the extent of enterohepatic cycling and the clearance of drugs from plasma, as well as their influence on biological responses to drugs, including drug toxicity. The prediction of the effects of intestinal glucuronidation on these processes depends on knowledge of the types and amounts of UGTs expressed in the small intestine and their specific glucuronidating activities. Whereas the types of UGTs expressed in human gastrointestinal tract are well characterized, further research is needed to understand the absolute amounts of UGTs in the small intestine and the causes of observed high-interindividual variability in the intestinal expression of UGTs.

Chronic graft versus host disease

PURPOSE OF REVIEW

Chronic graft versus host disease is a debilitating and often fatal complication of allogeneic stem cell transplantation. The purpose of this review is to overview this disease and highlight recent findings in the literature over the past year.

RECENT FINDINGS

A new focus on chronic graft versus host disease as a long-term complication of transplantation has resulted in increased research activity in this disease. Here we review the recent in-vitro and clinical studies that focus on the pathophysiology of the disease, treatment and prevention.

SUMMARY

As more patients undergo and survive allogeneic stem cell transplantation more attention is being focused on the study of chronic graft versus host disease. Although the pathophysiology is still controversial, recent advances have been made in our understanding of this disease, including the balance of T helper type 1 and 2 cells, the role of B cells and autoantibodies, graft manipulation and prophylaxis, which may lead to advances in treatment and prevention. The series of recent publications put forward by the National Institutes of Health consensus project on criteria for clinical trials are expected to advance the standards and uniformity of chronic graft versus host disease clinical research.