Seok-Goo Cho

Siltuximab for multicentric Castleman's disease: a randomised, double-blind, placebo-controlled trial

BACKGROUND Multicentric Castlemans disease is a rare lymphoproliferative disorder driven by dysregulated production of interleukin 6. No randomised trials have been done to establish the best treatment for the disease. We assessed the safety and efficacy of siltuximab-a chimeric monoclonal antibody against interleukin 6-in HIV-negative patients with multicentric Castlemans disease. METHODS We did this randomised, double-blind, placebo-controlled study at 38 hospitals in 19 countries worldwide. We enrolled HIV-negative and human herpesvirus-8-seronegative patients with symptomatic multicentric Castlemans disease. Treatment allocation was randomised with a computer-generated list, with block size six, and stratification by baseline corticosteroid use. Patients and investigators were masked to treatment allocation. Patients were randomly assigned (2:1) to siltuximab (11 mg/kg intravenous infusion every 3 weeks) or placebo; all patients also received best supportive care. Patients continued treatment until treatment failure. The primary endpoint was durable tumour and symptomatic response for at least 18 weeks for the intention-to-treat population. Enrolment has been completed. The study is registered with ClinicalTrials.gov, number NCT01024036. FINDINGS We screened 140 patients, 79 of whom were randomly assigned to siltuximab (n=53) or placebo (n=26). Durable tumour and symptomatic responses occurred in 18 (34%) of 53 patients in the siltuximab group and none of 26 in the placebo group (difference 34·0%, 95% CI 11·1-54·8, p=0·0012). The incidence of grade 3 or more adverse events (25 [47%] vs 14 [54%]) and serious adverse events (12 [23%] vs five [19%]) was similar in each group despite longer median treatment duration with siltuximab than with placebo (375 days [range 1-1031] vs 152 days [23-666]). The most common grade 3 or higher were fatigue (five vs one), night sweats (four vs one), and anaemia (one vs three). Three (6%) of 53 patients had serious adverse events judged reasonably related to siltuximab (lower respiratory tract infection, anaphylactic reaction, sepsis). INTERPRETATION Siltuximab plus best supportive care was superior to best supportive care alone for patients with symptomatic multicentric Castlemans disease and well tolerated with prolonged exposure. Siltuximab is an important new treatment option for this disease. FUNDING Janssen Research & Development.

Ibrutinib versus temsirolimus in patients with relapsed or refractory mantle-cell lymphoma: an international, randomised, open-label, phase 3 study

BACKGROUND Mantle-cell lymphoma is an aggressive B-cell lymphoma with a poor prognosis. Both ibrutinib and temsirolimus have shown single-agent activity in patients with relapsed or refractory mantle-cell lymphoma. We undertook a phase 3 study to assess the efficacy and safety of ibrutinib versus temsirolimus in relapsed or refractory mantle-cell lymphoma. METHODS This randomised, open-label, multicentre, phase 3 clinical trial enrolled patients with relapsed or refractory mantle-cell lymphoma confirmed by central pathology in 21 countries who had received one or more rituximab-containing treatments. Patients were stratified by previous therapy and simplified mantle-cell lymphoma international prognostic index score, and were randomly assigned with a computer-generated randomisation schedule to receive daily oral ibrutinib 560 mg or intravenous temsirolimus (175 mg on days 1, 8, and 15 of cycle 1; 75 mg on days 1, 8, and 15 of subsequent 21-day cycles). Randomisation was balanced by using randomly permuted blocks. The primary efficacy endpoint was progression-free survival assessed by a masked independent review committee with the primary hypothesis that ibrutinib compared with temsirolimus significantly improves progression-free survival. The analysis followed the intention-to-treat principle. The trial is ongoing and is registered with ClinicalTrials.gov (number NCT01646021) and with the EU Clinical Trials Register, EudraCT (number 2012-000601-74). FINDINGS Between Dec 10, 2012, and Nov 26, 2013, 280 patients were randomised to ibrutinib (n=139) or temsirolimus (n=141). Primary efficacy analysis showed significant improvement in progression-free survival (p<0·0001) for patients treated with ibrutinib versus temsirolimus (hazard ratio 0·43 [95% CI 0·32-0·58]; median progression-free survival 14·6 months [95% CI 10·4-not estimable] vs 6·2 months [4·2-7·9], respectively). Ibrutinib was better tolerated than temsirolimus, with grade 3 or higher treatment-emergent adverse events reported for 94 (68%) versus 121 (87%) patients, and fewer discontinuations of study medication due to adverse events for ibrutinib versus temsirolimus (9 [6%] vs 36 [26%]). INTERPRETATION Ibrutinib treatment resulted in significant improvement in progression-free survival and better tolerability versus temsirolimus in patients with relapsed or refractory mantle-cell lymphoma. These data lend further support to the positive benefit-risk ratio for ibrutinib in relapsed or refractory mantle-cell lymphoma. FUNDING Janssen Research & Development, LLC.

Clinical applications of mesenchymal stem cells

Mesenchymal stem cells (MSCs) are self-renewing, multipotent progenitor cells with multilineage potential to differentiate into cell types of mesodermal origin, such as adipocytes, osteocytes, and chondrocytes. In addition, MSCs can migrate to sites of inflammation and exert potent immunosuppressive and anti-inflammatory effects through interactions between lymphocytes associated with both the innate and adaptive immune system. Along with these unique therapeutic properties, their ease of accessibility and expansion suggest that use of MSCs may be a useful therapeutic approach for various disorders. In the clinical setting, MSCs are being explored in trials of various conditions, including orthopedic injuries, graft versus host disease following bone marrow transplantation, cardiovascular diseases, autoimmune diseases, and liver diseases. Furthermore, genetic modification of MSCs to overexpress antitumor genes has provided prospects for clinical use as anticancer therapy. Here, we highlight the currently reported uses of MSCs in clinical trials and discuss their efficacy as well as their limitations.

Validation of recently proposed consensus criteria for thrombotic microangiopathy after allogeneic hematopoietic stem-cell transplantation.

Background. The lack of an accepted definition of transplantation-associated thrombotic microangiopathy (TMA) has led the Blood and Marrow Transplants Clinical Trials Network (CTN) and International Working Group (IWG) to propose a definition for TMA with some differences. However, there have been few studies validating and comparing both newly proposed criteria for TMA. Methods. To validate recently proposed criteria for TMA by CTN and IWG, we analyzed 672 patients who underwent allogeneic stem-cell transplantation between January 2002 and December 2006. Results. The cumulative incidences of TMA by CTN and IWG were 6.1% and 2.5%, respectively. The cumulative incidence of overall TMA (O-TMA) including probable-TMA defined as meeting CTN criteria without renal or neurologic dysfunction, as well as TMA by CTN (definite-TMA), was 12.7%. Sixty-six percent of TMA by CTN did not have any degree of schistocytosis by IWG criteria (≥4%), and 18% of TMA by IWG criteria did not have renal or neurologic dysfunction. On multivariate analyses, probable-TMA as well as definite-TMA adversely affected the survival of a cohort including all patients. In patients with O-TMA, the degree of schistocytosis (≥4% or not) failed to show prognostic significance, whereas renal involvement was a significant prognostic factor associated with poor survival. Conclusions. Both proposed consensus criteria have major pitfalls in their use as uniformly accepted diagnostic criteria for TMA. The use of O-TMA as a broad definition for TMA and the grading system by the presence of renal involvement may be a counterproposal for future trials.

IL-10 suppresses Th17 cells and promotes regulatory T cells in the CD4+ T cell population of rheumatoid arthritis patients.

Interleukin-17-producing CD4(+) T cells (Th17 cells) are the dominant pathogenic cellular component in autoimmune inflammatory diseases, including autoimmune arthritis. IL-10 promotes the generation of Foxp3(+) regulatory T cells via the IL-10 receptor signal. The objective of this study was to examine whether IL-10, which acts as an anti-inflammatory cytokine, has a suppressive effect on the activation of human Th17 cells. Expression of IL-17 and IL-10 was examined immunohistochemically in tissue obtained from rheumatoid arthritis patients. Human peripheral blood CD4(+) T cells were isolated and cultured under various stimulatory conditions. Th17 cells and regulatory T (Treg) cells were detected by flow cytometry. The gene expression of related cytokines and transcription factors were assessed by ELISA and RT-PCR. IL-17 was overexpressed in rheumatoid arthritis patients. IL-10 treatment significantly decreased the numbers of IL-17-producing and RORc-expressing cells among human CD4(+) T cells that had been activated in vitro by Th17-differentiating conditions in autoimmune arthritis patients. IL-10 induced Foxp3(+) regulatory T cells in the human CD4(+) T cell population. Our results demonstrate that IL-17 is overexpressed in autoimmune disease patients and that IL-10 suppresses IL-17 expression. IL-10 may be useful in the treatment of autoimmune diseases.

Feasibility of NIH consensus criteria for chronic graft-versus-host disease

To assess the applicability of the National Institutes of Health (NIH) consensus criteria (NCC) for chronic graft-versus-host disease (cGVHD), 211 patients who developed GVHD more than 100 days after allogeneic transplantation were reclassified using NCC. Classifications were: late acute GVHD (44 patients, 21%), overlap syndrome (64 patients, 30%) and classic cGVHD (103 patients, 49%). Classic cGVHD and overlap syndrome patients (n=167) were graded using both the revised Seattle criteria (RSC) and NIH global scoring (NGS). Twenty-three patients (14%) had mild, 81 (48%) had moderate and 63 (38%) had severe cGVHD. After a median follow-up of 46 months (range 5–71 months), the 4-year GVHD-specific survival was not significantly different among the different subtypes of NCC. Among patients with late acute GVHD, however, the pattern of acute GVHD onset (late, persistent or recurrent) was significantly different with respect to GVHD-specific survival. Among patients with overlap syndrome and classic cGVHD, multivariate analysis showed that NGS as well as RSC were useful in predicting survival and discontinuation of immunosuppressive therapy despite of more detailed grouping. Our study indicates that NCC is applicable. The clinical impact of NIH types and NGS should be verified through prospective studies.

Transforming growth factor β-transduced mesenchymal stem cells ameliorate experimental autoimmune arthritis through reciprocal regulation of Treg/Th17 cells and osteoclastogenesis.

OBJECTIVE Bone marrow-derived mesenchymal stem cells (MSCs) can prevent various autoimmune diseases. We examined the therapeutic potential of transforming growth factor β (TGFβ)-transduced MSCs in experimental autoimmune arthritis, using an accepted animal model of collagen-induced arthritis (CIA). METHODS DBA/1J mice with CIA were treated with syngeneic TGFβ-induced MSCs, whereas control mice received either vehicle or MSCs alone. Arthritis severity was assessed by clinical and histologic scoring. TGFβ-transduced MSCs were tested for their immunosuppressive ability and differential regulation in mice with CIA. T cell responses to type II collagen were evaluated by determining proliferative capacity and cytokine levels. The effects of TGFβ-transduced MSCs on osteoclast formation were analyzed in vitro and in vivo. RESULTS Systemic infusion of syngeneic TGFβ-transduced MSCs prevented arthritis development and reduced bone erosion and cartilage destruction. Treatment with TGFβ-transduced MSCs potently suppressed type II collagen-specific T cell proliferation and down-regulated proinflammatory cytokine production. These therapeutic effects were associated with an increase in type II collagen-specific CD4+FoxP3+ Treg cells and inhibition of Th17 cell formation in the peritoneal cavity and spleen. Furthermore, TGFβ-transduced MSCs inhibited osteoclast differentiation. CONCLUSION TGFβ-transduced MSCs suppressed the development of autoimmune arthritis and joint inflammation. These data suggest that enhancing the immunomodulatory activity of MSCs and modulating T cell-mediated immunity using gene-modified MSCs may be a gateway for new therapeutic approaches to clinical rheumatoid arthritis.

Vascular endothelial growth factor (VEGF) is associated with reduced severity of acute graft-versus-host disease and nonrelapse mortality after allogeneic stem cell transplantation

This study investigated whether or not there is a correlation between the changes in the serum levels of vascular endothelial growth factor (VEGF) and the outcome of allogeneic stem cell transplantation (allo-SCT). Eighty-five patients undergoing allo-SCT were prospectively studied. The serum VEGF levels were measured on days 0, +7 and +14 after transplantation. The VEGF levels decreased significantly on day +7 and recovered on day +14. The highest levels from day +7 through day +14 were categorized by cluster analysis, which were then correlated with the nonrelapse mortality (NRM). There was a significant correlation between a low VEGF level and the occurrence of severe acute graft-versus-host disease (GVHD) including grade III–IV (P=0.029). The 1-year probability of NRM in patients with a low VEGF level was 22.5% compared with 3.5% for those with a high VEGF level (P=0.024). Multivariate analysis revealed clinically defined infections (P=0.011), advanced disease (P=0.014) and a low VEGF cluster (P=0.05) to be significantly associated with the occurrence of NRM in the cohort. In conclusion, low VEGF levels after allo-SCT are associated with NRM with an exacerbated severity of acute GVHD. VEGF monitoring after a transplant might identify those patients at risk of severe transplant-related mortality.

Mesenchymal stem cells for the treatment and prevention of graft-versus-host disease: experiments and practice

Mesenchymal stem cells (MSCs) have emerged as a therapeutic approach in a range of medical fields, including regenerative medicine, cancer, autoimmune diseases, and inflammatory diseases, because of their unique properties of tissue repair and major histocompatibility complex-unmatched immunosuppression. Because both in vitro and in vivo findings demonstrate that MSCs possess potent immunoregulatory functions, there has been increasing interest in the role of MSCs in allogeneic hematopoietic stem cell transplantation, especially in the prevention and treatment of graft-versus-host disease (GVHD). GVHD is a major cause of transplantation-related mortality, and conventional immunosuppressants frequently fail to treat patients suffering from GVHD. Following Ringden’s pilot study that used third-party MSCs to treat a steroid-refractory GVHD patient, MSCs have created growing interest as a therapeutic agent for GVHD. There have been further studies which demonstrated the potentials of MSC treatment in steroid-refractory GVHD, de novo GVHD, and also GVHD prevention. However, MSCs still present limitations. The need for MSCs to be “licensed” in a pro-inflammatory environment, especially in the presence of interferon gamma, allows only a narrow window for their administration. Thus, their effects have been less clear as a preventive measure before the inflammatory environment of GVHD is established and also when administered during a chronic setting where MSCs may be alternatively licensed. In this review, we focus on the immunomodulatory properties of MSCs and their effects in relation to GVHD. Given the efficacy of MSCs in murine models of GVHD and their safety in clinical trials, it is crucial that larger clinical trials are conducted and further modifications are investigated.

Successful Prevention of Acute Graft-versus-Host Disease Using Low-Dose Antithymocyte Globulin after Mismatched, Unrelated, Hematopoietic Stem Cell Transplantation for Acute Myelogenous Leukemia

In this study, we investigated the effects of low-dose antithymocyte globulin (ATG, thymoglobulin) in the prevention of acute graft-versus-host disease (aGVHD) in mismatched, unrelated hematopoietic stem cell transplantations (uHSCTs) in patients with the single disease entity of acute myelogenous leukemia (AML). Patients (n = 103) with a variable risk for AML who received uHSCTs from available Asian and Caucasian donors were enrolled. First, we compared HLA-matched (group 1, n = 54) and HLA-mismatched (group 2, n = 49) transplantation patients. Then, we divided the patients in group 2, who had received transplants from allele(s)/antigen-mismatched donors, into 2 subgroups: patients who used ATG (group 3, n = 24) and those who did not (group 4, n = 25). To prevent the development of aGVHD, the patients in group 3 received ATG at a dose of 1.25 mg/kg body weight per day for 2 consecutive days, together with our standard regimen of methotrexate (MTX) and tacrolimus. The median CD34(+) cell infusion was 4.2 x 10(6)/kg (range: 1.2-34.4). The median patient age was 41 years (range: 16-57), and the median follow-up duration of patients who were event-free survivors was 23 months (range: 2-72). The overall incidences of aGVHD and chronic GVHD (cGVHD) were 38% and 56%, respectively. Of 48 evaluable patients in group 2, 10 (21%) developed moderate to severe aGVHD (grades II-IV). In contrast, 2 (8%) of the 24 patients in group 3 and 7 (29%) of the 24 evaluated patients in group 4 required therapy for aGVHD (grades II-IV; P = .038). The incidence of cGVHD was not different between groups 3 and 4. The estimated probabilities of overall survival (OS) and event-free survival (EFS) at 2 years for group 2 were 55% and 44%, respectively. In comparison, the estimated probabilities of OS and EFS at 2 years for groups 3 and 4 were 68% versus 38% (P = .043) and 58% versus 38% (P = .103), respectively. The overall cumulative incidence of nonrelapse mortality (NRM) was 29% in group 2. The cumulative incidence of NRM differed markedly between group 3 (16%; 95% confidence interval [CI], 4%-28%) and group 4 (44%, 95% CI, 34%-54%) (P = .013). We found no difference in cytomegalovirus (CMV) reactivation between groups 3 and 4. These results suggest that in mismatched uHSCT, a low dose of ATG (total 2.5 mg/kg) may prevent moderate to severe aGVHD, with comparable rates of relapse and CMV reactivation and a greatly decreased rate of NRM.