Vorinostat plus tacrolimus and mycophenolate to prevent graft-versus-host disease after related-donor reduced-intensity conditioning allogeneic haemopoietic stem-cell transplantation: a phase 1/2 trial.

BACKGROUND: Acute graft-versus-host disease (GVHD) remains a barrier to more widespread application of allogeneic haemopoietic stem-cell transplantation. Vorinostat is an inhibitor of histone deacetylases and was shown to attenuate GVHD in preclinical models. We aimed to study the safety and activity of vorinostat, in combination with standard immunoprophylaxis, for prevention of GVHD in patients undergoing related-donor reduced-intensity conditioning haemopoietic stem-cell transplantation. METHODS: Between March 31, 2009, and Feb 8, 2013, we did a prospective, single-arm, phase 1/2 study at two centres in the USA. We recruited adults (aged ≥18 years) with high-risk haematological malignant diseases who were candidates for reduced-intensity conditioning haemopoietic stem-cell transplantation and had an available 8/8 or 7/8 HLA-matched related donor. All patients received a conditioning regimen of fludarabine (40 mg/m(2) daily for 4 days) and busulfan (3.2 mg/kg daily for 2 days) and GVHD immunoprophylaxis of mycophenolate mofetil (1 g three times a day, days 0-28) and tacrolimus (0.03 mg/kg a day, titrated to a goal level of 8-12 ng/mL, starting day -3 until day 180). Vorinostat (either 100 mg or 200 mg, twice a day) was initiated 10 days before haemopoietic stem-cell transplantation until day 100. The primary endpoint was the cumulative incidence of grade 2-4 acute GVHD by day 100. This trial is registered with ClinicalTrials.gov, number NCT00810602. FINDINGS: 50 patients were assessable for both toxic effects and response; eight additional patients were included in the analysis of toxic effects. All patients engrafted neutrophils and platelets at expected times after haemopoietic stem-cell transplantation. The cumulative incidence of grade 2-4 acute GVHD by day 100 was 22% (95% CI 13-36). The most common non-haematological adverse events included electrolyte disturbances (n=15), hyperglycaemia (11), infections (six), mucositis (four), and increased activity of liver enzymes (three). Non-symptomatic thrombocytopenia after engraftment was the most common haematological grade 3-4 adverse event (nine) but was transient and all cases resolved swiftly. INTERPRETATION: Administration of vorinostat in combination with standard GVHD prophylaxis after related-donor reduced-intensity conditioning haemopoietic stem-cell transplantation is safe and is associated with a lower than expected incidence of severe acute GVHD. Future studies are needed to assess the effect of vorinostat for prevention of GVHD in broader settings of haemopoietic stem-cell transplantation. FUNDING: Merck, Leukemia and Lymphoma Society, National Institutes of Health, St Baldrick's Foundation, Michigan Institute for Clinical and Health Research.

A crucial role for antigen-presenting cells and alloantigen expression in graft-versus-leukemia responses.

Graft-versus-leukemia (GVL) response after allogeneic bone marrow transplantation (BMT) represents one of the most potent forms of immunotherapy against malignant diseases. Antigen-presenting cells (APCs) are crucial for the induction of graft-versus-host disease (GVHD), the most serious complication of allogeneic BMT, but their role in GVL responses is unclear. Using a series of clinically relevant mouse GVL tumor models, we found that APCs and alloantigen expression on tumors are crucial for GVL. Moreover, APCs of host origin predominated in GVL responses although donor APCs contributed as the acuity of tumor burden decreased.

Histone deacetylase inhibition modulates indoleamine 2,3-dioxygenase-dependent DC functions and regulates experimental graft-versus-host disease in mice.

Histone deacetylase (HDAC) inhibitors are antitumor agents that also have antiinflammatory properties. However, the mechanisms of their immunomodulatory functions are not known. We investigated the mechanisms of action of 2 HDAC inhibitors, suberoylanilide hydroxamic acid (SAHA) and ITF 2357, on mouse DC responses. Pretreatment of DCs with HDAC inhibitors significantly reduced TLR-induced secretion of proinflammatory cytokines, suppressed the expression of CD40 and CD80, and reduced the in vitro and in vivo allostimulatory responses induced by the DCs. In addition, injection of DCs treated ex vivo with HDAC inhibitors reduced experimental graft-versus-host disease (GVHD) in a murine allogeneic BM transplantation model. Exposure of DCs to HDAC inhibitors increased expression of indoleamine 2,3-dioxygenase (IDO), a suppressor of DC function. Blockade of IDO in WT DCs with siRNA and with DCs from IDO-deficient animals caused substantial reversal of HDAC inhibition-induced in vitro suppression of DC-stimulated responses. Direct injection of HDAC inhibitors early after allogeneic BM transplantation to chimeric animals whose BM-derived cells lacked IDO failed to protect from GVHD, demonstrating an in vivo functional role for IDO. Together, these data show that HDAC inhibitors regulate multiple DC functions through the induction of IDO and suggest that they may represent a novel class of agents to treat immune-mediated diseases.

A biomarker panel for acute graft-versus-host disease.

No validated biomarkers exist for acute graft-versus-host disease (GVHD). We screened plasma with antibody microarrays for 120 proteins in a discovery set of 42 patients who underwent transplantation that revealed 8 potential biomarkers for diagnostic of GVHD. We then measured by enzyme-linked immunosorbent assay (ELISA) the levels of these biomarkers in samples from 424 patients who underwent transplantation randomly divided into training (n = 282) and validation (n = 142) sets. Logistic regression analysis of these 8 proteins determined a composite biomarker panel of 4 proteins (interleukin-2-receptor-alpha, tumor-necrosis-factor-receptor-1, interleukin-8, and hepatocyte growth factor) that optimally discriminated patients with and without GVHD. The area under the receiver operating characteristic curve distinguishing these 2 groups in the training set was 0.91 (95% confidence interval, 0.87-0.94) and 0.86 (95% confidence interval, 0.79-0.92) in the validation set. In patients with GVHD, Cox regression analysis revealed that the biomarker panel predicted survival independently of GVHD severity. A panel of 4 biomarkers can confirm the diagnosis of GVHD in patients at onset of clinical symptoms of GVHD and provide prognostic information independent of GVHD severity.

Change in plasma tumor necrosis factor receptor 1 levels in the first week after myeloablative allogeneic transplantation correlates with severity and incidence of GVHD and survival.

Acute graft-versus-host disease (GVHD) remains a significant cause of mortality after hematopoietic cell transplantation (HCT). Tumor necrosis factor-alpha (TNF-alpha) mediates GVHD by amplifying donor immune responses to host tissues and by direct toxicity to target organs. We measured TNF receptor 1 (TNFR1) as a surrogate marker for TNF-alpha in 438 recipients of myeloablative HCT before transplantation and at day 7 after transplantation. Increases in TNFR1 levels more than or equal to 2.5 baseline correlated with eventual development of GVHD grade 2 to 4 (58% vs 32%, P < .001) and with treatment-related mortality (39% vs 17%, P < .001). In a multivariate analysis including age, degree of HLA match, donor type, recipient and donor sex, disease, and status at HCT, the increase in TNFR1 level at day 7 remained a significant predictor for outcome. Measurement of TNFR1 levels early after transplantation provides independent information in advance of important clinical outcomes, such as GVHD and death.

Emerging drugs for acute graft-versus-host disease.

The number of allogeneic hematopoietic cell transplantations (HCT) continues to increase. More than 15,000 allogeneic transplantations are performed annually. The graft-versus-leukemia/tumor effect during allogeneic HCT effectively eradicates many hematological malignancies. The development of novel strategies that use donor leukocyte infusions, nonmyeloablative conditioning and umbilical cord blood transplantation have helped expand the indications for allogeneic HCT over the past several years, especially among older patients. Yet the major complication of allogeneic HCT, graft-versus-host disease, remains lethal and limits wider application of allogeneic HCT. In this article, we review current practice and recent advances made in prevention and treatment of graft-versus-host disease.

Improved survival after transplantation of more donor plasmacytoid dendritic or naïve T cells from unrelated-donor marrow grafts: results from BMTCTN 0201.

PURPOSE: To characterize relationships between specific immune cell subsets in bone marrow (BM) or granulocyte colony-stimulating factor-mobilized peripheral blood (PB) stem cells collected from unrelated donors and clinical outcomes of patients undergoing transplantation in BMTCTN 0201. PATIENTS AND METHODS: Fresh aliquots of 161 BM and 147 PB stem-cell allografts from North American donors randomly assigned to donate BM or PB stem cells and numbers of transplanted cells were correlated with overall survival (OS), relapse, and graft-versus-host disease (GvHD). RESULTS: Patients with evaluable grafts were similar to all BMTCTN 0201 patients. The numbers of plasmacytoid dendritic cells (pDCs) and naïve T cells (Tns) in BM allografts were independently associated with OS in multivariable analyses including recipient and donor characteristics, such as human leukocyte antigen mismatch, age, and use of antithymocyte globulin. BM recipients of > median number of pDCs, naïve CD8(+) T cells (CD8Tns), or naïve CD4(+) T cells (CD4Tns) had better 3-year OS (pDCs, 56% v 35%; P = .025; CD8Tns, 56% v 37%; P = .012; CD4Tns, 55% v 37%; P = .009). Transplantation of more BM Tns was associated with less grade 3 to 4 acute GvHD but similar rates of relapse. Transplantation of more BM pDCs was associated with fewer deaths resulting from GvHD or from graft rejection. Analysis of PB grafts did not identify a donor cell subset significantly associated with OS, relapse, or GvHD. CONCLUSION: Donor immune cells in BM but not PB stem-cell grafts were associated with survival after unrelated-donor allogeneic hematopoietic stem-cell transplantation. The biologic activity of donor immune cells in allogeneic transplantation varied between graft sources. Donor grafts with more BM-derived Tns and pDCs favorably regulated post-transplantation immunity in allogeneic hematopoietic stem-cell transplantation.

Etanercept plus methylprednisolone as initial therapy for acute graft-versus-host disease.

Graft-versus-host disease (GVHD) is a principal cause of morbidity following allogeneic hematopoietic cell transplantation (HCT). Standard therapy for GVHD, high-dose steroids, results in complete responses (CRs) in 35% of patients. Because tumor necrosis factor-alpha (TNFalpha) is an important effector of experimental GVHD, we treated patients with new-onset GVHD with steroids plus the TNFalpha inhibitor etanercept on a previously reported pilot trial (n = 20) and a phase 2 trial (n = 41). We compared their outcomes with those of contemporaneous patients with GVHD (n = 99) whose initial therapy was steroids alone. Groups were similar with respect to age, conditioning, donor, degree of HLA match, and severity of GVHD at onset. Patients treated with etanercept were more likely to achieve CR than were patients treated with steroids alone (69% vs 33%; P < .001). This difference was observed in HCT recipients of both related donors (79% vs 39%; P = .001) and unrelated donors (53% vs 26%; P < .001). Plasma TNFR1 levels, a biomarker for GVHD activity, were elevated at GVHD onset and decreased significantly only in patients with CR. We conclude that etanercept plus steroids as initial therapy for acute GVHD results in a substantial majority of CRs. This trial was referenced at www.clinicaltrials.gov as NCT00141713.