Should methotrexate plus calcineurin inhibitors be considered standard of care for prophylaxis of acute graft-versus-host disease?

Treatment-Responsive Acute Graft-versus-Host Disease after Post-Transplantation Cyclophosphamide-Based Prophylaxis: Incidence and Clinical Outcomes

Post-transplantation cyclophosphamide (PTCy) following hematopoietic cell transplantation (HCT) has emerged as standard of care for graft-versus-host disease (GVHD) prevention in adult patients without increasing malignant relapse. We previously defined acute GVHD (aGVHD) treatment response categories as corticosteroid-sensitive (SS), -dependent (SD), or -resistant (SR) based on response to first-line corticosteroids and reported their clinical outcomes following non-PTCy-based prophylaxis. More than one-third of patients developed aGVHD necessitating systemic therapy. Cases were predominantly SR, with a 14% overall incidence of SR aGVHD. The incidence and clinical outcomes of these 3 distinct aGVHD treatment response groups following PTCy-based prophylaxis have not been well described. The objective of this retrospective single-institution cohort study was to assess the incidence and clinical outcomes of SS, SD, and SR aGVHD following HCT with PTCy-based prophylaxis using a prophylactic regimen of PTCy, tacrolimus, and mycophenolate mofetil (MMF). We included 196 consecutive adult and pediatric patients undergoing allogeneic HCT for malignant and non-malignant disorders at the University of Minnesota between 2017 and 2021. Patients received PTCy on days +3 and +4 plus tacrolimus and MMF prophylaxis. Bone marrow and peripheral blood stem cell graft sources and related and unrelated donors were included. Recipients received myeloablative or reduced-intensity conditioning regimens. Of the 196 allografts, 54 (28%) developed aGVHD before day +180, with a median time to onset of 50 days (interquartile range, 34 to 71 days). Of those, 32 patients (16% overall) developed maximum grade II-III aGVHD necessitating systemic corticosteroids, with the following response: 13 SS (41%), 10 SD (31%), and 9 SR (28%). The overall incidence of SR aGVHD was 4.6%. Only 12 patients (6%) developed maximum grade III aGVHD, and none had grade IV aGVHD. The 2-year overall survival analyzed from 80 days after initiation of systemic treatment was similar in the SS and SD groups (77 and 75%, respectively), comparable to those without aGVHD (81%), and was lowest in the SR group (20%), with GVHD the primary cause of death. Nonrelapse mortality was highest in the SR group. MN high-risk and higher GVHD grade at onset were risk factors for developing SR aGVHD. Overall, we report a low incidence (16%) of aGVHD requiring systemic corticosteroids with PTCy-based prophylaxis. aGVHD cases were predominantly SS aGVHD, with lower incidences of SD and SR aGVHD. Our findings suggest that PTCy-based prophylaxis reduces the rate of treatment-resistant aGVHD. Patients with SR aGVHD had the worst clinical outcomes and poorest survival. Those with SS and SD aGVHD had similar clinical outcomes, both better than seen with SR aGVHD.

[Humanized anti-CD25 monoclonal antibody as a salvage therapy for steroid-refractory acute graft-versus-host disease after hematopoietic stem cell transplantation]

Objective: To investigate the efficacy of humanized anti-CD25 monoclonal antibody for steroid-refractory acute graft-versus-host disease (SR-aGVHD) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Methods: A total of 64 patients with SR-aGVHD between June 2019 and October 2020 in Suchow Hopes Hematology Hospital were enrolled in this study. Humanized anti-CD25 monoclonal antibodies 1 mg·kg(-1)·d(-1) were administered on days 1, 3, and 8, and then once per week according to the disease progression. Efficacy was assessed at days 7, 14, and 28 after humanized anti-CD 25 treatment. Results: Of the 64 patients with a median age of 31 (15-63) years, 38 (59.4%) were male and 26 (40.6%) were female. The overall response (OR) rate of the humanized CD25 monoclonal antibody in 64 patients with SR-aGVHD on days 7, 14, and 28 were 48.4% (31/64), 53.1% (34/64), and 79.7% (51/64), respectively. Liver involvement is an independent risk factor for poor efficacy of humanized CD25 monoclonal antibody for SR-aGVHD at day 28 (OR=9.588, 95% CI 0.004-0.291, P=0.002). The median follow-up time for all patients was 17.1 (0.2-50.8) months from the start of humanized CD25 monoclonal antibody therapy. The 1- and 2-year OS rates were 63.2% (95% CI 57.1% -69.3%) and 52.6% (95% CI 46.1% -59.1%), respectively. The 1- and 2-year DFS rates were 58.4% (95% CI 52.1% -64.7%) and 49.8% (95% CI 43.4% -56.2%), respectively. The 1- and 2-year NRM rates were 28.8% (95% CI 23.1% -34.5%) and 32.9% (95% CI 26.8% -39.0%), respectively. The results of the multifactorial analysis showed that liver involvement (OR=0.308, 95% CI 0.108-0.876, P=0.027) and GVHD grade Ⅲ/Ⅳ (OR=9.438, 95% CI 1.211-73.577, P=0.032) were independent risk factors for OS. Conclusion: Humanized CD25 monoclonal antibody has good efficacy and safety for SR-aGVHD. This study shows that SR-aGVHD with pretreatment grade Ⅲ/Ⅳ GVHD and GVHD involving the liver has poor efficacy and prognosis and requires early intervention.

Phase II Study of Myeloablative 7-8/8-Matched Allotransplantation with Post-Transplantation Cyclophosphamide, Tacrolimus, and Mycophenolate Mofetil

Graft-versus-host disease (GVHD) is the major toxicity of allogeneic hematopoietic cell transplantation (HCT). We hypothesized that a GVHD prophylaxis regimen of post-transplantation cyclophosphamide (PTCy), tacrolimus (Tac), and mycophenolate mofetil (MMF) would be associated with incidences of acute and chronic GVHD in patients receiving a matched or single antigen mismatched HCT. This Phase II study was conducted at the University of Minnesota using a myeloablative regimen of either total body irradiation (TBI) at a total dose of 1320 cGy, administered in 165-cGy fractions, twice daily from day -4 to day -1, or busulfan (Bu) 3.2 mg/kg daily (cumulative area under the curve, 19,000 to 21,000 μmol/min/L) plus fludarabine (Flu) 40 mg/m2 once daily on days -5 to -2, followed by a GVHD prophylaxis regimen of PTCy 50 mg/kg on days +3 and +4, Tac, and MMF beginning on day +5. The primary endpoint was the cumulative incidence of chronic GVHD necessitating systemic immunosuppression (IST) at 1 year post-transplantation. Between March 2018 and May 2022, we enrolled 125 pediatric and adult patients, with a median follow-up of 813 days. The incidence of chronic GVHD necessitating systemic IST at 1 year was 5.5%. The rate of grade II-IV acute GVHD was 17.1%, and that of grade III-IV acute GVHD was 5.5%. Two-year overall survival was 73.7%, and 2-year graft-versus-host disease-free, relapse-free survival was 52.2%. The 2-year cumulative incidence of nonrelapse mortality was 10.2%, and the rate of relapse was 39.1%. There was no statistically significant difference in survival outcomes between recipients of matched donor transplants versus recipients of 7/8 matched donor transplants. Our data show that myeloablative HCT with PTCy/Tac/MMF results in an extremely low incidence of severe acute and chronic GVHD in well-matched allogeneic HCT.

Phase II Study of Myeloablative 8/8- or 7/8-Matched Allotransplantation with Post-Transplant Cyclophosphamide, Tacrolimus, and Mycophenolate Mofetil: Marked Reduction in GVHD Risk Without Increased Relapse Risk Compared to Historical Cyclosporine/Methotrexate

Introduction

Graft-versus host disease (GVHD) is a major limitation to the success of allogeneic hematopoietic cell transplant (HCT). We hypothesized that the GVHD prophylaxis regimen of post-transplant cyclophosphamide (PTCy), tacrolimus (Tac) and mycophenolate mofetil (MMF) would reduce the incidence of GVHD in patients receiving a matched or single antigen mismatched HCT without an increase in risk of malignant relapse.

Methods

This is a phase II study conducted at the University of Minnesota using a myeloablative regimen of either: (A) total body irradiation (TBI, total dose 1320 cGy, administered in 165 cGy fractions, twice a day from days -4 to -1) or (B) Busulfan 3.2mg/kg daily (cumulative AUC 19,000 - 21,000 μmol/min/L) plus fludarabine 160mg/m2 days -5 to -2, followed by a GVHD prophylaxis regimen of PTCy (50mg/kg days +3 and +4), Tac and MMF (beginning day +5). The primary endpoint is cumulative incidence of chronic GVHD requiring systemic immunosuppression at 1-year post-transplant. We compared results to our previous myeloablative protocol for matched donors utilizing cyclosporine/methotrexate (CSA/MTX) GVHD prophylaxis.

Results

From March 2018 - June 2022, we enrolled and treated 125 pediatric and adult patients with a median follow up of 472 days. Grade II-IV acute GVHD occurred in 16% (95% confidence interval (CI): 9-23%); Grade III-IV acute GVHD was 4% (CI: 0-8%). No patients experienced grade IV GVHD, and there were no deaths due to GVHD before day 100. Only 3 developed chronic GVHD requiring immune suppression, (4%, CI: 0-8%). Two-year overall survival (OS) was 80% (CI: 69-87%), and (graft-versus-host disease-free, relapse-free survival) GRFS 57% (CI: 45-67%), both higher than historical CSA/MTX. The incidence of grade II-IV aGVHD, cGVHD, and NRM were all lower with PTCy/Tac/MMF compared to historical CSA/MTX. One-quarter (25%) experienced relapse (CI: 15-36%) similar to historical CSA/MTX. There was no statistically significant difference in survival outcomes between recipients of matched versus 7/8 donors.

Conclusion

Myeloablative HCT with PTCy/Tac/MMF results in extremely low incidence of severe acute or chronic GVHD, the primary endpoint of this clinical trial. Relapse risk is not increased compared to our historical CSA/MTX cohort.

Post-transplant cyclophosphamide prevents xenogeneic graft-versus-host disease while depleting proliferating regulatory T cells

Graft-versus-host disease (GVHD) remains a serious limitation of allogeneic hematopoietic cell transplantation (allo-HCT). While post-transplant administration of cyclophosphamide (PTCy) is increasingly used as GVHD prophylaxis, its precise mechanisms of action and its impact on graft-versus-leukemia effects have remained debated. Here, we studied the mechanisms of xenogeneic GVHD (xGVHD) prevention by PTCy in different humanized mouse models. We observed that PTCy attenuated xGVHD. Using flow cytometry and single-cell RNA-sequencing, we demonstrated that PTCy depleted proliferative CD8⁺ and conventional CD4⁺ T cells but also proliferative regulatory T cells (Treg). Further, T-cell receptor β variable region sequencing (TCRVB) analyses demonstrated that highly xenoreactive T-cell clones were depleted by PTCy. Although Treg frequencies were significantly higher in PTCy-treated than in control mice on day 21, xGVHD attenuation by PTCy was not abrogated by Treg depletion. Finally, we observed that PTCy did not abrogate graft-versus-leukemia effects.

Predictors and Outcomes of Dose Reduction of Methotrexate and Cyclosporin Graft-Versus-Host-Disease Prophylaxis Following Allogeneic Haematopoietic Cell Transplantation

BACKGROUND

Concern regarding dose-related toxicities of methotrexate (MTX) and cyclosporin (CYA) GVHD prophylaxis occasionally lead to dose alterations post allogeneic haematopoietic cell transplant (alloHCT).

AIM

To clarify causes of MTX and CYA dose alteration and assess impact on patient outcomes including GVHD, relapse, non-relapse mortality (NRM), and overall survival (OS).

METHOD

Analysis of retrospective data was performed in a single tertiary centre of patients who underwent alloHCT for any indication and who received GVHD prophylaxis with CYA and MTX between the years 2011 and 2015. Univariate analysis was conducted using the log-rank test for OS and using competing risk regression for NRM, relapse and GVHD. Fisher exact tests were used to determine if an association existed between each of the pre-transplant variables and MTX alteration. Multivariate models for OS and NRM were constructed using Cox proportional hazards modelling and competing risk regression respectively.

RESULTS

54/196 (28%) had MTX alterations and 61/187 (33%) had CYA alterations. Reasons for MTX alteration included mucositis, renal or liver impairment, fluid overload and sepsis. Causes of CYA alteration were numerous but most commonly due to acute kidney impairment. MTX alteration was associated with inferior OS (HR 2.4, P=<0.001) and higher NRM (OR 4.6, P<0.001) at 6 years(y) post-landmark. CYA alteration was associated with greater NRM (OR 2.7, P= 0.0137) at 6y. GVHD rates were unaffected by dose alteration.

CONCLUSIONS

Our findings suggest dose alteration in MTX and CYA GVHD prophylaxis is associated with adverse survival outcomes in alloHCT, without a significant impact on GVHD rates. This article is protected by copyright. All rights reserved.

The Role of Fecal Microbiota Transplantation in the Treatment of Acute Graft-versus-Host Disease

The number of allogeneic hematopoietic stem cell transplantations conducted worldwide is constantly rising. Together with that, the absolute number of complications after the procedure is increasing, with graft-versus-host disease (GvHD) being one of the most common. The standard treatment is steroid administration, but only 40–60% of patients will respond to the therapy and some others will be steroid-dependent. There is still no consensus regarding the best second-line option, but fecal microbiota transplantation (FMT) has shown encouraging preliminary and first clinically relevant results in recent years and seems to offer great hope for patients. The reason for treatment of steroid-resistant acute GvHD using this method derives from studies showing the significant immunomodulatory role played by the intestinal microbiota in the pathogenesis of GvHD. Depletion of commensal microbes is accountable for aggravation of the disease and is associated with decreased overall survival. In this review, we present the pathogenesis of GvHD, with special focus on the special role of the gut microbiota and its crosstalk with immune cells. Moreover, we show the results of studies and case reports to date regarding the use of FMT in the treatment of steroid-resistant acute GvHD.

Comprehensive analysis of the immunomodulatory effects of rapamycin on human T cells in graft-versus-host disease prophylaxis

Graft-versus-host disease (GVHD) is a major cause of toxicity after allogeneic hematopoietic cell transplantation (allo-HCT). While rapamycin (RAPA) is commonly used in GVHD prophylaxis in combination with a calcineurin inhibitor (CNI), the understanding of its mechanism of action on human T cells is still incomplete. Here, we performed an extensive analysis of RAPA effects on human T cells in a humanized mouse model of GVHD, in ex-vivo T cell cultures and in patients given RAPA plus tacrolimus as GVHD prophylaxis after nonmyeloablative allo-HCT. We demonstrate that RAPA mitigates GVHD by decreasing T cell engraftment and differentiation, inhibiting CD8⁺ T cell activation and increasing the long-term IL-2 secretion, thereby supporting regulatory T cell (Treg) proliferation. In contrast, graft-versus-leukemia effects were not abrogated, as RAPA-treated T cells had increased resistance to apoptosis and retained their effector function and proliferative capacity upon re-stimulation. Importantly, we found that RAPA impact on Treg and CD8⁺ T cells was closely dependent upon IL-2 signaling and that therapeutic options interfering with IL-2, such as calcineurin inhibitors, antagonize the IL-2-dependent promotion of Treg mediated by RAPA. Our results suggest that RAPA immunological efficacy could be improved in combination with drugs having possible synergistic effects such as the hypomethylating agent 5-azacytidine.

Prevention of acute graft-versus-host-disease by Withaferin a via suppression of AKT/mTOR pathway

Acute Graft versus Host Disease (aGVHD) is a frequent and serious complication in patients receiving allogeneic bone marrow transplantation (allo-BMT) and often requires rigorous prophylaxis. The current treatment regimens for aGVHD are associated with several side effects which necessitates the development of novel interventions that prevent aGVHD without precluding graft-versus-tumor effects. In the present study, we show that treatment of donor graft with plant steroidal lactone Withaferin A (WA) prior to transplantation markedly reduced aGVHD mediated damage in target organs without compromising the graft-versus.-tumor activity of the transplanted lymphocytes. WA abrogated post-transplant cytokine storm associated with allo-activation of donor lymphocytes. This was attributed to the ability of WA to inhibit early signaling events in T-cell activation including lymphoblast formation and activation of AKT/mTOR pathway. Mortality and morbidity related to allo-transplantation was significantly reduced in recipients of WA treated donor splenocytes compared to recipient of vehicle treated donor splenocytes. Further, WA treatment did not have any effect on reconstitution of lymphoid and myeloid lineages in recipients, resulting in stable and complete donor chimerism. In agreement with previous reports showing the effectiveness of WA in a mouse model of partial chimerism, our data further establishes that WA is able to attenuate aGVHD in an MHC-mismatched high dose chemo-conditioned murine model without compromising engraftment. This study provides compelling scientific basis for possible application of WA for prevention and treatment of aGVHD in patients receiving allo-BMT.

Central Roles of OX40L-OX40 Interaction in the Induction and Progression of Human T Cell-Driven Acute Graft-versus-Host Disease

Graft-versus-host disease (GVHD) is one of the major obstacles for the success of allogeneic hematopoietic stem cell transplantation. Here, we report that the interaction between OX40L and OX40 is of critical importance for both induction and progression of acute GVHD (aGVHD) driven by human T cells. Anti-human OX40L monoclonal antibody (hOX40L) treatment could thus effectively reduce the disease severity in a xenogeneic-aGVHD (x-aGVHD) model in both preventative and therapeutic modes. Mechanistically, blocking OX40L-OX40 interaction with an anti-hOX40L antibody reduces infiltration of human T cells in target organs, including liver, gut, lung, and skin. It also decreases IL-21- and TNF-producing T cell responses, while promoting regulatory T cell (Treg) responses without compromising the cytolytic activity of CD8⁺ T cells. Single blockade of hOX40L was thus more effective than dual blockade of IL-21 and TNF in reducing the severity of aGVHD as well as mortality. Data from this study indicate that OX40L-OX40 interactions play a central role in the pathogenesis of aGVHD induced by human T cells. Therapeutic strategies that can efficiently interrupt OX40L-OX40 interaction in patients might have potential to provide patients with an improved clinical benefit.

Comparative Analysis of Calcineurin Inhibitor-Based Methotrexate and Mycophenolate Mofetil-Containing Regimens for Prevention of Graft-versus-Host Disease after Reduced-Intensity Conditioning Allogeneic Transplantation

The combination of a calcineurin inhibitor (CNI) such as tacrolimus (TAC) or cyclosporine (CYSP) with methotrexate (MTX) or with mycophenolate mofetil (MMF) has been commonly used for graft-versus-host disease (GVHD) prophylaxis after reduced-intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (alloHCT), but there are limited data comparing efficacy of the 2 regimens. We evaluated 1564 adult patients who underwent RIC alloHCT for acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL), chronic myelogenous leukemia (CML), and myelodysplastic syndrome (MDS) from 2000 to 2013 using HLA-identical sibling (matched related donor [MRD]) or unrelated donor (URD) peripheral blood graft and received CYSP or TAC with MTX or MMF for GVHD prophylaxis. Primary outcomes of the study were acute and chronic GVHD and overall survival (OS). The study divided the patient population into 4 cohorts based on regimen: MMF-TAC, MMF-CYSP, MTX-TAC, and MTX-CYSP. In the URD group, MMF-CYSP was associated with increased risk of grade II to IV acute GVHD (relative risk [RR], 1.78; P < .001) and grade III to IV acute GVHD (RR, 1.93; P = .006) compared with MTX-TAC. In the URD group, use of MMF-TAC (versus MTX-TAC) lead to higher nonrelapse mortality. (hazard ratio, 1.48; P = .008). In either group, no there was no difference in chronic GVHD, disease-free survival, and OS among the GVHD prophylaxis regimens. For RIC alloHCT using MRD, there are no differences in outcomes based on GVHD prophylaxis. However, with URD RIC alloHCT, MMF-CYSP was inferior to MTX-based regimens for acute GVHD prevention, but all the regimens were equivalent in terms of chronic GVHD and OS. Prospective studies, targeting URD recipients are needed to confirm these results.

Graft versus host disease: what should the oculoplastic surgeon know?

PURPOSE OF REVIEW

To provide a concise review of the oculoplastic manifestations of ocular graft versus host disease (GVHD), and to discuss their management.

RECENT FINDINGS

Ocular GVHD occurs as a common immune-mediated complication of hematopoietic stem cell transplantation that presents as a Stevens-Johnson-like syndrome in the acute phase or a Sjögren-like syndrome in the chronic phase. Cicatricial conjunctivitis may be underreported in ocular GVHD. The spectrum of oculoplastic manifestations includes GVHD of the skin, cicatricial entropion, nasolacrimal duct obstruction, and lacrimal gland dysfunction. Surgical treatment is indicated for patients with significant corneal complications from entropion. Surgical approach to repair of nasolacrimal duct obstruction is presented in this review, including modified approaches for treating patients at risk for keratitis sicca. Management of the ocular graft versus host patient may require a multidisciplinary approach involving collaboration from the oculoplastic surgeon, the corneal specialist, and the stem cell transplant physician.

SUMMARY

Oculoplastic manifestations of ocular GVHD typically present as cicatricial changes in the eyelid and lacrimal system. Careful oculoplastic and corneal evaluation are necessary when considering surgical management for the ocular GVHD patient.

70% Ethanol for Decontamination of Central Venous Lines Exposed to Calcineurin Inhibitors

BACKGROUND

Tacrolimus, commonly used for graft versus host disease prophylaxis is usually administered via a dedicated central venous line (CVL) and trough levels drawn from the unexposed lumen. Being an oil-based medication, it may be adsorbed to the inner lumen of the CVL and result in falsely high levels drawn from an inadvertently exposed lumen. There is no treatment for decontamination of such CVLs, and natural decay occurs over months before the CVL can be used to draw reliable trough levels.

OBJECTIVE

The primary objective of the study was to estimate the effectiveness of 70% ethanol locks for decontaminating CVLs exposed to tacrolimus.

METHODS

We studied the efficacy of 70% ethanol lock in decontaminating CVLs exposed to tacrolimus in patients during transplant. Trough tacrolimus levels were drawn from the exposed and unexposed (control) lumens at 8:00 am, followed by a 2-mL 70% ethanol lock instilled for a 2-hour dwell into the exposed (intervention) lumen. Trough tacrolimus levels were again drawn from both lumens at 8:00 pm and levels compared for efficacy.

RESULTS

All 20 sets showed a high 8 am trough level in the exposed intervention arm (median = 30 ng/mL), significantly greater ( P < 0.0001) than that in the control arm (median = 9.05 ng/mL), and were contaminated. After the 2-hour ethanol lock, 65% of the lumens were decontaminated. The difference between the control and intervention arms was no longer found to be statistically significant ( P = 0.0826).

CONCLUSION

A 2-hour 70% ethanol lock is effective for decontamination of CVLs exposed to tacrolimus.

Fulminant Laryngeal-tracheobronchial-pulmonary Aspergillosis: A Rare and Fatal Complication in Allogeneic Hematopoietic Stem Cell Transplantation Recipients

A 23-year-old man who had previously undergone allogeneic hematopoietic stem cell transplantation (allo-HSCT) for severe aplastic anemia was diagnosed with invasive laryngeal-tracheobronchial-pulmonary aspergillosis after presenting with a persistent dry cough at six months post-transplantation based on the findings of laryngoscopy and fiberoptic bronchoscopy. A fiberoptic bronchoscope was used to remove the obstructive material from the patient's airway and posaconazole plus caspofungin were administered to successfully to treat the patient. Our report suggests that laryngoscopy and fiberoptic bronchoscopy should be considered as alternative approaches to the diagnosis and treatment of allo-HSCT recipients with persistent respiratory symptoms when invasive laryngeal aspergillosis and invasive tracheobronchial aspergillosis are suspected.

Pharmacokinetics, Pharmacodynamics and Pharmacogenomics of Immunosuppressants in Allogeneic Haematopoietic Cell Transplantation: Part I

Although immunosuppressive treatments and target concentration intervention (TCI) have significantly contributed to the success of allogeneic haematopoietic cell transplantation (alloHCT), there is currently no consensus on the best immunosuppressive strategies. Compared with solid organ transplantation, alloHCT is unique because of the potential for bidirectional reactions (i.e. host-versus-graft and graft-versus-host). Postgraft immunosuppression typically includes a calcineurin inhibitor (cyclosporine or tacrolimus) and a short course of methotrexate after high-dose myeloablative conditioning, or a calcineurin inhibitor and mycophenolate mofetil after reduced-intensity conditioning. There are evolving roles for the antithymyocyte globulins (ATGs) and sirolimus as postgraft immunosuppression. A review of the pharmacokinetics and TCI of the main postgraft immunosuppressants is presented in this two-part review. All immunosuppressants are characterized by large intra- and interindividual pharmacokinetic variability and by narrow therapeutic indices. It is essential to understand immunosuppressants' pharmacokinetic properties and how to use them for individualized treatment incorporating TCI to improve outcomes. TCI, which is mandatory for the calcineurin inhibitors and sirolimus, has become an integral part of postgraft immunosuppression. TCI is usually based on trough concentration monitoring, but other approaches include measurement of the area under the concentration-time curve (AUC) over the dosing interval or limited sampling schedules with maximum a posteriori Bayesian personalization approaches. Interpretation of pharmacodynamic results is hindered by the prevalence of studies enrolling only a small number of patients, variability in the allogeneic graft source and variability in postgraft immunosuppression. Given the curative potential of alloHCT, the pharmacodynamics of these immunosuppressants deserves to be explored in depth. Development of sophisticated systems pharmacology models and improved TCI tools are needed to accurately evaluate patients' exposure to drugs in general and to immunosuppressants in particular. Sequential studies, first without and then with TCI, should be conducted to validate the clinical benefit of TCI in homogenous populations; randomized trials are not feasible, because there are higher-priority research questions in alloHCT. In Part I of this article, we review the alloHCT process to facilitate optimal design of pharmacokinetic and pharmacodynamics studies. We also review the pharmacokinetics and TCI of calcineurin inhibitors and methotrexate.

Novel approaches for preventing acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

INTRODUCTION

Allogeneic hematopoietic stem cell transplantation (alloHSCT) offers potential curative treatment for a wide range of malignant and nonmalignant hematological disorders. However, its success may be limited by post-transplant acute graft-versus-host disease (aGVHD), a systemic syndrome in which donor's immune cells attack healthy tissues in the immunocompromised host. aGVHD is one of the main causes of morbidity and mortality after alloHSCT. Despite standard GVHD prophylaxis regimens, aGVHD still develops in approximately 40-60% of alloHSCT recipients.

AREAS COVERED

In this review, after a brief summary of current knowledge on the pathogenesis of aGVHD, the authors review the current combination of a calcineurin inhibitor with an antimetabolite with or without added anti-thymocyte globulin (ATG) and emerging strategies for GVHD prevention.

EXPERT OPINION

A new understanding of the involvement of cytokines, intracellular signaling pathways, epigenetics and immunoregulatory cells in GVHD pathogenesis will lead to new standards for aGVHD prophylaxis allowing better prevention of severe aGVHD without affecting graft-versus-tumor effects.

The impact of graft-versus-host disease prophylaxis in reduced-intensity conditioning allogeneic stem cell transplant in acute myeloid leukemia: a study from the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation

The impact of the intensity of graft-versus-host-disease immunoprophylaxis on transplantation outcomes in patients undergoing transplantation following reduced-intensity conditioning is unclear. This study addresses this issue in 228 adult patients above 50 years of age with acute myeloid leukemia in first complete remission given peripheral blood stem cells from HLA-identical siblings after fludarabine and 2 days of intravenous busulfan reduced-intensity conditioning. A total of 152 patients received anti-thymocyte globulin, either in combination with cyclosporine A in 86 patients (group 1), or with cyclosporine A and mycophenolate mofetil or short course methotrexate in 66 patients (group 2). The remaining 76 patients did not receive anti-thymocyte globulin but were given cyclosporine A and methotrexate or mycophenolate mofetil (group 3). Incidences of grade II-IV acute graft-versus-host-disease were comparable in the three groups (16.5%, 29.5% and 19.5% in groups 1, 2 and 3, respectively, P=0.15). In multivariate analysis, the absence of anti-thymocyte globulin was the only factor associated with a higher risk of chronic graft-versus-host-disease (P=0.005), while the use of triple immunosuppression (group 3) was associated with an increased risk of relapse (P=0.003). In comparison to anti-thymocyte globulin and cyclosporine A alone, the other two strategies of graft-versus-host-disease prophylaxis were associated with reduced leukemia-free survival and overall survival (P=0.001 for each parameter), independently of the dose of anti-thymocyte globulin. These data suggest that fine tuning of the intensity of this prophylaxis can affect the outcome of transplantation and that anti-thymocyte globulin and cyclosporine A alone should be the preferred combination with the fludarabine-busulfan reduced-intensity conditioning regimen and sibling donors.

Short Course of Post-Transplantation Cyclophosphamide and Bortezomib for Graft-versus-Host Disease Prevention after Allogeneic Peripheral Blood Stem Cell Transplantation Is Feasible and Yields Favorable Results: A Phase I Study

An effective graft-versus-host disease (GVHD) preventative approach that preserves the graft-versus-tumor effect after allogeneic hematopoietic stem cell transplantation (HSCT) remains elusive. Standard GVHD prophylactic regimens suppress T cells indiscriminately and are suboptimal. Conversely, post-transplantation high-dose cyclophosphamide selectively destroys proliferating alloreactive T cells, allows the expansion of regulatory T cells, and induces long-lasting clonal deletion of intrathymic antihost T cells. It has been successfully used to prevent GVHD after allogeneic HSCT. Bortezomib has antitumor activity on a variety of hematological malignancies and exhibits a number of favorable immunomodulatory effects that include inhibition of dendritic cells. Therefore, an approach that combines post-transplantation cyclophosphamide and bortezomib seems attractive. Herein, we report the results of a phase I study examining the feasibility and safety of high-dose post-transplantation cyclophosphamide in combination with bortezomib in patients undergoing allogeneic peripheral blood HSCT from matched siblings or unrelated donors after reduced-intensity conditioning. Cyclophosphamide was given at a fixed dose (50 mg/kg on days +3 and +4). Bortezomib dose was started at .7 mg/m2, escalated up to 1.3 mg/m2, and was administered on days 0 and +3. Patients receiving grafts from unrelated donors also received rabbit antithymocyte globulin. The combination was well tolerated and allowed prompt engraftment in all patients. The incidences of acute GVHD grades II to IV and grades III and IV were 20% and 6.7%, respectively. With a median follow-up of 9.1 months (range, 4.3 to 26.7), treatment-related mortality was 13.5% with predicted 2-year disease-free survival and overall survival of 55.7% and 68%, respectively. The study suggests that the combination of post-transplantation cyclophosphamide and bortezomib is feasible and may offer an effective and practical GVHD prophylactic regimen. The combination, therefore, merits further examination.

Hematopoietic stem-cell transplantation in the developing world: experience from a center in Western India

We describe our experience of first 50 consecutive hematopoietic stem-cell transplants (HSCT) done between 2007 and 2012 at the Apollo Hospital, Gandhinagar, 35 autologous HSCT and 15 allogeneic HSCT. Indications for autologous transplant were multiple myeloma, non-Hodgkin lymphoma, Hodgkin lymphoma, and acute myeloid leukemia, and indications for allogeneic transplants were thalassemia major, aplastic anaemia, chronic myeloid leukemia, and acute lymphoblastic and myeloid leukaemia. The median age of autologous and allogeneic patient's cohort was 50 years and 21 years, respectively. Median follow-up period for all patients was 39 months. Major early complications were infections, mucositis, acute graft versus host disease, and venoocclusive disease. All of our allogeneic and autologous transplant patients survived during the first month of transplant. Transplant related mortality (TRM) was 20% (N = 3) in our allogeneic and 3% (N = 1) in autologous patients. Causes of these deaths were disease relapse, sepsis, hemorrhagic complications, and GVHD. 46% of our autologous and 47% of our allogeneic patients are in complete remission phase after a median follow-up of 39 months. 34% of our autologous patients and 13% of our allogeneic patients had disease relapse. Overall survival rate in our autologous and allogeneic patients is 65.7% and 57.1%, respectively. Our results are comparable to many national and international published reports.

Methotrexate for the Treatment of Graft-versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation

Glucocorticoids have been the primary treatment of graft-versus-host disease (GVHD) over the past decade. Complete responses to steroid therapy are usually expected in almost one-third of aGVHD cases and partial response is anticipated in another one-third of patients. However, for those patients not responding to corticosteroid treatment, there is no standard second-line therapy for acute or chronic GVHD. Methotrexate (MTX) for treatment of steroid refractory GVHD has been evaluated in a number of studies. Results from peer-reviewed original articles were identified and the pooled data analyzed. Despite several limitations in data collection and analysis, weekly administration of methotrexate at a median dose of 7.5 mg/m² seems to be safe with minimal toxicities in the context of both aGVHD and cGVHD treatments. The observed overall response (OR) in patients with aGVHD to MTX treatment in the published studies was 69.9%, with complete response (CR) in 59.2% and PR in 10.6%. In cGVHD the OR was 77.6%, with CR reported in 49.6% and PR in 28% of patients. Predictors of better responses were lower grade GVHD, cutaneous involvement, and isolated organ involvement. MTX as a steroid sparing agent might reduce long-term complications and improve the quality of life of GVHD affected individuals.

Multicenter phase II study of a combination of cyclosporine a, methotrexate and mycophenolate mofetil for GVHD prophylaxis: results of the Chinese Bone Marrow Transplant Cooperative Group (CBMTCG)

Background

Improvement of current GVHD prophylactic therapies remains an important goal in the allo-HSCT. We have described a novel prophylaxis regimen in a single institution trial. The Chinese Bone Marrow Transplant Cooperative Group (CBMTCG) initiated a phase II multicenter study.

Methods

The study was designed as a prospective, single arm phase II open-label, multicenter clinical trial. The primary endpoint was improvement of aGVHD by 25% over historical control (40%) in Chinese patients. 508 patients were enrolled. All of the patients received cyclosporine A (CsA), methotrexate (MTX) and mycophenolate mofetil (MMF) (0.5-1.0 g daily for 30 days) as GVHD prophylaxis regimen.

Results

The primary endpoint was met with cumulative incidences of grades 2 to 4 and grades 3 to 4 aGVHD of 23.2% and 10.3%, respectively. Incidence for cGVHD was 67.4%. The non-relapse mortality (NRM) rate was 18.4% at 2 years. The probabilities of leukemia free survival (LFS) for non-advanced stage and advanced stage patients at 2 years were 69.7% and 44.8% respectively (p = 0.000). Recipient age ≥ 40 years, advanced stage and Busulfan-Fludarabine(BuFlu) conditioning regimen were identified as major risk factors for aGVHD. Recipient age ≥ 40 years, BuFlu conditioning regimens, female donor/male recipient and prior aGVHD were associated with cGVHD. Despite lower RM (relapse mortality), patients with grade 2–4 aGVHD had higher NRM and worse OS and LFS compared to patients with grade 0–1 aGVHD. In contrast, patients with cGVHD had better OS and LFS and lower RM compared to patients without cGVHD.

Conclusion

The novel GVHD regimen decreased the risk for aGVHD by 42% without improving the risk for cGVHD compared to historical controls. Development of aGVHD was associated with worse OS and LFS as well as higher NRM. In contrast, cGVHD was associated with improved OS and LFS likely attributed to a GVL effect.

Is a flavonoid-rich diet with steamer cooking safe during calcineurin inhibitors therapy?

WHAT IS KNOWN AND OBJECTIVE

Dietary therapy is recommended for decreasing the symptoms of the metabolic syndrome and the risk of type 2 diabetes and cardiovascular diseases in subjects on calcineurin inhibitors. However, food-drug interactions may occur particularly with patients on such immunosuppressive therapy. This article comments on the benefit/risk assessment of a flavonoid-rich diet and steam-cooking of such food during calcineurin inhibitors therapy.

COMMENT

Patients are commonly advised against consuming citrus fruits and juices, grape juice and green tea. High vegetable intake may however increase the risk of food-diet interactions by inhibiting drug metabolic enzymes and transporters. Vegetable glucosinolates are potential interactants and may lead to adverse effects of drugs with narrow therapeutic indices and in the presence of genetic polymorphism. Examples of food components with potential drug interactants include all members of the Brassicaceae family.

WHAT IS NEW AND CONCLUSION

The potential additive and synergistic effects of flavonoids with other molecules in interfering with drug bioavailability need to be taken into account. The risk is highest with drugs with a narrow therapeutic index and in subjects with genetic polymorphisms of proteins involved in the disposition of those drugs.

Acute graft-versus-host disease: a bench-to-bedside update

Over the past 5 years, many novel approaches to early diagnosis, prevention, and treatment of acute graft-versus-host disease (aGVHD) have been translated from the bench to the bedside. In this review, we highlight recent discoveries in the context of current aGVHD care. The most significant innovations that have already reached the clinic are prophylaxis strategies based upon a refinement of our understanding of key sensors, effectors, suppressors of the immune alloreactive response, and the resultant tissue damage from the aGVHD inflammatory cascade. In the near future, aGVHD prevention and treatment will likely involve multiple modalities, including small molecules regulating immunologic checkpoints, enhancement of suppressor cytokines and cellular subsets, modulation of the microbiota, graft manipulation, and other donor-based prophylaxis strategies. Despite long-term efforts, major challenges in treatment of established aGVHD still remain. Resolution of inflammation and facilitation of rapid immune reconstitution in those with only a limited response to corticosteroids is a research arena that remains rife with opportunity and urgent clinical need.

Acute graft-versus-host disease: are we close to bringing the bench to the bedside?

Graft-versus-host disease (GVHD) is a major complication of allogeneic hematopoietic stem cell transplant (AHSCT) associated with significant morbidity and mortality. This review focuses on the pathophysiology, prevention, and treatment of acute GVHD. Specifically, we explain how new discoveries in immunology have expanded our understanding of GVHD, in which tissue damage from chemotherapy or radiation results in cytokine release, activating T cells, resulting in proliferation and differentiation, trafficking to target organs, and tissue destruction and inflammation. Insights into the mechanisms of this disease relate directly to the development of preventive strategies and therapies, such as immunosuppression, calcineurin inhibitors, T-cell depletion, CCR5 antagonists, gut decontamination, extracorporeal photopheresis, and more. Understanding the immunobiology of GVHD and developing effective preventions and treatments are critical to the continuing success of AHSCT.

Intestinal aGVHD and infection after hematopoietic stem cell transplantation

Background

We aimed to guide clinical nursing by studying the relationship between intestinal acute graft-versus-host disease and intestinal infection after hematopoietic stem cell transplantation.

Material/Methods

We present an effective nursing method by comparing and analyzing the degree, duration time, and volume of diarrhea, and the distribution of pathogens in 44 patients who developed intestinal aGVHD after hematopoietic stem cell transplantation (24 patients with no intestinal infection).

Results

21.4% of patients with grade I–II intestinal aGVHD developed into intestinal infection and 87.5% of patients with grade III–IV intestinal aGVHD developed into intestinal infection (P<0.05). Higher mortality was found in the grade III–IV intestinal aGVHD patients with intestinal infection. Patient age had no effect on the incidence of GVHD according to our data (P<0.05). We found remarkable differences in the amount and duration of diarrhea between patients with and without intestinal infection (P<0.05). The most common pathogens cultivated were Candida glabrata (24%) and Candida albicans (22.67%).

Conclusions

The incidence of intestinal infection increased remarkably after intestinal aGVHD occurred. Severe aGVHD can easily lead to fungus infection. Nursing care can decrease the incidence of intestinal infection in aGVHD.

Combination of low-dose mycophenolate mofetil with cyclosporine and methotrexate as GVHD prophylaxis in unrelated donor allogeneic stem cell transplantation

We report the results of HLA-matched unrelated donor allogeneic stem cell transplantation with new GVHD prophylaxis regimen consisted of cyclosporine, methotrexate and low-dose mycophenolate mofetil in 139 patients with hematologic malignancies. The incidence of grades II-IV and III-IV acute GVHD were 43.0% and 17.3%, respectively. The incidence of chronic GVHD was 42.1%, with 16.5% extensive grade. The cumulative incidence of transplant-related mortality at 100 days and 3 years were 7.9% and 29.7%, respectively. Three-year overall survival, disease-free survival and relapse incidence were 58.7%, 55.3% and 19.6%, respectively. These results suggest the new regime may be effective for the prophylaxis of acute and chronic GVHD in unrelated donor transplantation.

Advances in the treatment of acute graft-versus-host disease

Allogeneic hematopoietic stem cell transplantation (HSCT) has been widely used for the treatment of hematologic malignant and non-malignant hematologic diseases and other diseases. However, acute graft-versus-host disease (GVHD) is a life-threatening complication of allogeneic transplantation. Acute GVHD may occur in 30% of transplant recipients, which is a syndrome of erythematous skin eruption, cholestatic liver disease and intestinal dysfunction, resulting from the activation of donor T lymphocytes by host antigen-presenting cells, resulting in an immune-mediated inflammatory response. Recent scientific advances in the understanding of the pathogenesis involved in the development of acute GVHD and clinical investigation have provided more effective therapeutic strategies for acute GVHD. This review focuses on major scientific and clinical advances in the treatment of acute GVHD.

Pharmacologic prophylaxis regimens for acute graft-versus-host disease: past, present and future

Abstract Acute graft-versus-host disease (GVHD) has compromised and continues to compromise the benefits associated with allogeneic hematopoietic cell transplant to cure malignant and non-malignant diseases. Pharmacologic interventions to prevent GVHD have emerged as a major objective of research in the immunology and transplant fields. A better understanding of the pathobiology behind the GVHD process has led the way to novel approaches and medications. Here we review the present arsenal of medications used to prevent GVHD, focusing on past experience and the current evidence, and discuss future potential targets.

Bioequivalence and tolerability assessment of a novel intravenous ciclosporin lipid emulsion compared to branded ciclosporin in Cremophor ® EL

BACKGROUND

Ciclosporin is used as an immunosuppressant in current clinical practice but recent research implies novel indications for the drug, such as neuro- and cardioprotection. The intravenous formulation currently on the market, Sandimmune(®) Injection (Sandimmune(®)), uses Cremophor(®) EL as emulsifying excipient. Cremophor(®) EL is known to cause hypersensitivity reactions in some patients, ranging from skin reactions to potentially fatal anaphylactic shock.

OBJECTIVES

The primary objective was to assess if CicloMulsion(®), a Cremophor(®) EL-free lipid emulsion of ciclosporin for intravenous administration, is bioequivalent to Sandimmune(®), and the secondary objective was to compare the tolerability profiles of the two preparations.

METHODS

This was a single-centre, open-label, subject-blind, laboratory-blind, single-dose, randomized, two-treatment, two-period, two-sequence crossover study of the pharmacokinetics of two formulations of intravenous ciclosporin. Fifty-two healthy volunteer subjects were administered 5 mg/kg of each of the two formulations of ciclosporin as a 4-h intravenous infusion. The last blood sample was acquired 48 h after the end of the infusion. Bioequivalence assessments according to current guidelines were performed.

RESULTS

The geometric mean ratios for CicloMulsion(®)/Sandimmune(®) (90 % confidence interval [CI]) were 0.90 (0.88, 0.92) for AUC(0-last) (area under the blood concentration-time curve from time zero to time of last measurable concentration) and 0.95 (0.92, 0.97) for C(max) (maximum blood concentration). For all additional variables analysed, the 90 % CIs were also within the accepted bioequivalence range of 0.80-1.25. One anaphylactoid and one anaphylactic reaction, both classified as serious adverse events, were reported after treatment with Sandimmune(®). No serious adverse events were recorded after treatment with CicloMulsion(®).

CONCLUSION

We have assessed the pharmacokinetics and tolerability of a new Cremophor(®) EL-free lipid emulsion of ciclosporin, CicloMulsion(®), compared to Sandimmune(®). The proportion of adverse events was significantly higher for the Cremophor(®) EL-based product Sandimmune(®). We conclude that CicloMulsion(®) is bioequivalent to Sandimmune(®) and exhibits fewer adverse reactions.

Concise review: acute graft-versus-host disease: immunobiology, prevention, and treatment

Graft-versus-host disease (GVHD) is a major complication of allogeneic hematopoietic stem cell transplant (AHSCT) associated with significant morbidity and mortality. This review focuses on the pathophysiology, clinical features, prevention, and treatment of acute GVHD. Specifically, we explain how new discoveries in immunology have expanded our understanding of GVHD, in which tissue damage from chemotherapy or radiation results in cytokine release, which activates T cells, resulting in proliferation and differentiation, trafficking to target organs, and tissue destruction and inflammation. Insights into the mechanisms of this disease relate directly to the development of preventive strategies and therapies, such as immunosuppression, T-cell depletion, calcineurin inhibitors, CCR5 antagonists, gut decontamination, extracorporeal photopheresis, and more. We also discuss how GVHD affects the gut, liver, and skin, as well as diagnosis, grading, and scoring. We end by examining future directions of treatment, including new immunomodulators and biomarkers. Understanding the immunobiology of GVHD and developing effective preventions and treatments are critical to the continuing success of AHSCT.

Are we making progress in GVHD prophylaxis and treatment?

Allogeneic hematopoietic stem cell transplantation (allo-HCT) is an effective immunotherapy for human cancer. More than 20 000 allo-HCTs are performed each year worldwide, primarily for the treatment of hematologic malignancies. Several technical innovations implemented in allo-HCT over past 2 decades have reduced NRM by 50% and improved overall survival. The allo-HCT practice has changed with the introduction of peripheral blood, cord blood, and haploidentical transplantations and reduced-intensity conditioning, and the patient population is also different regarding age and diagnosis. However, both acute and chronic GVHD remain serious barriers to successful allo-HCT and it is not clear that a major improvement has occurred in our ability to prevent or treat GVHD. Nevertheless, there is an increasing knowledge of the biology and clinical manifestations and the field is getting better organized. These advances will almost certainly lead to major progress in the near future. As the long list of new potential targets and respective drugs are developed, systems need to be developed for rapid testing of them in clinical practice. The current reality is that no single agent has yet to be approved by the US Food and Drug Administration for GVHD prevention or therapy. Although a primary goal of these efforts is to develop better therapies for GVHD, the ultimate goal is to develop treatments that lead to effective prevention or preemption of life-threatening and disabling GVHD manifestations while harnessing the desirable graft-versus-tumor effects.

The combination of sirolimus plus tacrolimus improves outcome after reduced-intensity conditioning, unrelated donor hematopoietic stem cell transplantation compared with cyclosporine plus mycofenolate

Different types of graft-versus-host disease prophylaxis have been proposed in the setting of reduced intensity and non-myeloablative allogeneic stem cell transplantation. An alternative combination with sirolimus and tacrolimus has recently been tested although comparative studies against the classical combination of a calcineurin inhibitor and mycophenolate mofetil or methotrexate are lacking. We describe the results of a prospective, multicenter trial using sirolimus + tacrolimus as immunoprophylaxis, and compare this approach with our previous experience using cyclosporine + mycophenolate in the setting of unrelated donor transplantation setting after reduced-intensity conditioning. Forty-five patients received cyclosporine + mycophenolate between 2002 and mid-2007, while the subsequent 50 patients, who were transplanted from late 2007, were given sirolimus + tacrolimus. No significant differences were observed in terms of hematopoietic recovery or acute graft-versus-host disease overall, although gastrointestinal acute graft-versus-host disease grade ≥ 2 was more common in the cyclosporine + mycophenolate group (55% versus 21%, respectively, P=0.003). The 1-year cumulative incidence of chronic graft-versus-host disease was 50% versus 90% for the patients treated with the sirolimus- versus cyclosporine-based regimen, respectively (P<0.001), while the incidence of extensive chronic disease was 27% versus 49%, respectively (P=0.043). The 2-year non-relapse mortality rate was 18% versus 38% for patients receiving the sirolimus- versus the cyclosporine-based regimen, respectively (P=0.02). The event-free survival and overall survival at 2 years were 53% versus 29% (P=0.028) and 70% versus 45% (P=0.018) among patients receiving the sirolimus- versus the cyclosporine-based regimen, respectively. In conclusion, in the setting of reduced intensity transplantation from an unrelated donor, promising results can be achieved with the combination of sirolimus + tacrolimus, due to a lower risk of chronic graft-versus-host disease and non-relapse mortality, which translates into better event-free and overall survival rates, in comparison with those achieved with cyclosporine + mycophenolate.

ABCB1 C3435T genetic polymorphism on population pharmacokinetics of methotrexate after hematopoietic stem cell transplantation in Korean patients: a prospective analysis

BACKGROUND

Methotrexate (MTX) is often used to prevent graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HSCT). However, MTX has great pharmacokinetic variability and its use can result in fatal complications and/or infections after HSCT.

OBJECTIVES

The purposes of this study were to build a population pharmacokinetic model of MTX treatment in Korean patients who have undergone HSCT and to identify covariates, including genetic polymorphisms, that affect the pharmacokinetic properties of MTX.

METHODS

Clinical characteristics and MTX concentration data for 20 post-HSCT patients were collected. For each patient, ABCB1, ABCC2, ATIC, GGH, MTHFR, and TYMS genotyping was performed. Population pharmacokinetic analysis was performed using the NONMEM program. Analysis of MTX pharmacokinetic properties was accomplished using a 2-compartment pharmacokinetic model that incorporated first-order conditional estimation methods with interaction. The effects of a variety of demographic and genetic factors on MTX disposition were investigated.

RESULTS

The study population consisted of 12 men (60%) and 8 women (40%). Median age and body weight were 28 years (range, 18-49 years) and 55.6 kg (range, 44.8-80.8 kg), respectively. Within the study population, the estimated mean MTX clearance (CL) was 7.08 L/h, whereas the mean central compartment volume (V(1)) of MTX distribution was 19.4 L. MTX CL was significantly affected by glomerular filtration rate (GFR), penicillin use, and the ABCB1 3435 genotype. Interindividual variabilities for CL and V(1) were 21.6% and 73.3%. A 10-mL/min GFR increase was associated with a 32% increase in mean MTX CL, whereas penicillin use was associated with a decrease in MTX CL of 61%. MTX CL was significantly greater (by ∼21%) in patients with the ABCB1 3435 CC and CT genotype than in those with the ABCB1 3435 TT genotype (P < 0.001).

CONCLUSIONS

There was great interindividual variation in MTX pharmacokinetic properties in patients who had undergone HSCT. GFR, concurrent penicillin use, and the presence of the ABCB1 3435 C<T genotypes significantly affected MTX CL. The MTX population pharmacokinetic model developed here may provide useful information for individualizing MTX therapy after HSCT.

Mesenchymal stromal cells: a new tool against graft-versus-host disease?

Mesenchymal stromal cells (MSCs) represent a heterogeneous subset of multipotent cells that can be isolated from several tissues including bone marrow and fat. MSCs exhibit immunomodulatory and anti-inflammatory properties that prompted their clinical use as prevention and/or treatment for severe graft-versus-host disease (GVHD). Although a number of phase I-II studies have suggested that MSC infusion was safe and might be effective for preventing or treating acute GVHD, definitive proof of their efficacy remains lacking thus far. Multicenter randomized studies are ongoing to more precisely assess the impact of MSC infusion on GVHD prevention/treatment, whereas further research is performed in vitro and in animal models with the aims of determining the best way to expand MSCs ex vivo as well as the most efficient dose and schedule of MSCs administration. After introducing GVHD, MSC biology, and results of MSC infusion in animal models of allogeneic hematopoietic cell transplantation, this article reviews the results of the first clinical trials investigating the use of MSC infusion as prevention or treatment of GVHD.

Prospective evaluation of acute graft-versus-host disease

BACKGROUND

Graft-versus-host disease (GVHD) is a common complication of allogeneic bone marrow transplantation. Severe GVHD carries significant morbidity and mortality and remains one of the leading causes of treatment failure. Unfortunately, intestinal GVHD may present with a variety of non-specific symptoms and diagnosis based on clinical presentation is often inaccurate; biopsy is therefore needed for definitive diagnosis. At present, the optimal endoscopic approach to the diagnosis of gastrointestinal GVHD remains uncertain.

AIMS

The primary aims of our study were: (1) to evaluate the yield of upper versus lower endoscopy, and (2) to determine which anatomic regions were most likely to provide a histologic diagnosis.

METHODS

We conducted a prospective study of 27 consecutive patients who had undergone stem cell transplantation within the past 100 days and were referred to the Yale Gastrointestinal Procedure center between August 2002 and February 2006 for the evaluation of suspected acute GVHD. All patients underwent standardized endoscopic evaluation of the upper and lower gastrointestinal tract with biopsies. The diagnostic yield of upper versus lower endoscopy was compared in all patients.

RESULTS

GVHD was identified in 18 of the 27 patients (67%). Of those with GVHD, 15 patients (83%) had diffuse intestinal involvement. Six of 10 patients (60%) with an endoscopically normal EGD had GVHD on biopsies of the upper gastrointestinal tract. Six of 13 (46%) patients with an endoscopically normal appearing colonoscopy had GVHD on colonic biopsies. Two of 18 (11%) patients had isolated GVHD of the upper intestinal tract and 1 (6%) had isolated colonic GVHD. Rectal biopsy alone identified 89% (16 of 18) of GVHD cases and all 16 cases of GVHD with colonic involvement. A diagnosis of GVHD was not altered by the additional performance of biopsy of the proximal colon or terminal ileum.

CONCLUSIONS

In the present study, the majority of cases of acute GVHD demonstrate diffuse upper and lower gastrointestinal involvement with rectal, sigmoid, gastric and duodenal biopsies having similarly diagnostic yield. Based on our findings, we recommend starting with flexible sigmoidoscopy with rectal biopsy alone in patients who are poor candidates to undergo full colonoscopy with sedation or in those in whom GVHD is strongly suspected based on clinical findings. However, more extensive evaluations may be necessary to rule out infection and should be considered in those with no contraindications to sedation and in whom other differential diagnoses are also being considered.

High-dose cyclophosphamide for graft-versus-host disease prevention

PURPOSE OF REVIEW

Administration of high-dose cyclophosphamide after transplantation inhibits both graft rejection and graft-versus-host disease (GvHD) in mouse models of allogeneic blood or marrow transplantation (alloBMT). This strategy has recently been adapted to human transplantation.

RECENT FINDINGS

The safety and efficacy of high-dose posttransplantation cyclophosphamide, when given in combination with tacrolimus and mycophenolate mofetil, was first demonstrated after nonmyeloablative conditioning and allografting using human leukocyte antigen (HLA)-mismatched related donors. Further analysis shows that increasing HLA disparity does not worsen overall outcome. High-dose posttransplantation cyclophosphamide was also found to be effective as sole prophylaxis of acute and chronic GvHD after HLA-matched alloBMT.

SUMMARY

Taking advantage of the differential susceptibility of proliferating, alloreactive T cells over nonproliferating, nonalloreactive T cells to high-dose cyclophosphamide, and owing to the drug's stem cell sparing effects, this novel strategy provides a unique opportunity to optimize GvHD prophylaxis after HLA-matched alloBMT and increase the use of HLA-mismatched related donors. Well tolerated and effective mismatched related alloBMT provides access to essentially everyone, such as patients with sickle cell anemia, in need of the procedure.