Brad Pohlman

Randomized Controlled Trial of Yttrium-90–Labeled Ibritumomab Tiuxetan Radioimmunotherapy Versus Rituximab Immunotherapy for Patients With Relapsed or Refractory Low-Grade, Follicular, or Transformed B-Cell Non-Hodgkin’s Lymphoma

PURPOSE Radioimmunotherapy combines biologic and radiolytic mechanisms to target and destroy tumor cells, thus offering a needed therapeutic alternative for refractory non-Hodgkins lymphoma (NHL) patients. This phase III randomized study compares the novel radioimmunotherapy yttrium-90 ((90)Y) ibritumomab tiuxetan with a control immunotherapy, rituximab, in 143 patients with relapsed or refractory low-grade, follicular, or transformed CD20(+) transformed NHL. PATIENTS AND METHODS Patients received either a single intravenous (IV) dose of (90)Y ibritumomab tiuxetan 0.4 mCi/kg (n = 73) or rituximab 375 mg/m(2) IV weekly for four doses (n = 70). The radioimmunotherapy group was pretreated with two rituximab doses (250 mg/m(2)) to improve biodistribution and one dose of indium-111 ibritumomab tiuxetan for imaging and dosimetry. The primary end point, overall response rate (ORR), was assessed by an independent, blinded, lymphoma expert panel. RESULTS ORR was 80% for the (90)Y ibritumomab tiuxetan group versus 56% for the rituximab group (P =.002). Complete response (CR) rates were 30% and 16% in the (90)Y ibritumomab tiuxetan and rituximab groups, respectively (P =.04). An additional 4% achieved an unconfirmed CR in each group. Kaplan-Meier estimated median duration of response was 14.2 months in the (90)Y ibritumomab tiuxetan group versus 12.1 months in the control group (P =.6), and time to progression was 11.2 versus 10.1 months (P =.173) in all patients. Durable responses of > or = 6 months were 64% versus 47% (P =.030). Reversible myelosuppression was the primary toxicity noted with (90)Y ibritumomab tiuxetan. CONCLUSION Radioimmunotherapy with (90)Y ibritumomab tiuxetan is well tolerated and produces statistically and clinically significant higher ORR and CR compared with rituximab alone.

A prospective randomized trial comparing cyclosporine and short course methotrexate with cyclosporine and mycophenolate mofetil for GVHD prophylaxis in myeloablative allogeneic bone marrow transplantation

Summary:Cyclosporine (CSP) and short course methotrexate (MTX) have been the gold standard for GVHD prophylaxis for decades. Problems associated with MTX include increased time to hematopoietic engraftment, mucositis, and other organ toxicities. The combination of CSP with mycophenolate mofetil (MMF) has been used successfully for the prevention of graft rejection and GVHD in nonmyeloablative transplantation. We performed a prospective randomized trial comparing CSP and MTX with CSP and MMF in myeloablative (busulfan based) allogeneic 6/6 matched sibling bone marrow transplantation (BMT). The group receiving MMF (n=21) had significantly less severe mucositis than did the group receiving MTX (n=19) (21 vs 65%, P=0.008). Median time to neutrophil engraftment was more rapid in the MMF group (11 vs 18 days, P<0.001). The incidence of acute GVHD, as well as 100 day survival, was similar for both groups. The reduced toxicity of the CSP and MMF arm resulted in premature study closure. We conclude that a GVHD prophylaxis regimen of CSP and MMF after a myeloablative allogeneic preparative regimen is associated with faster hematopoietic engraftment, decreased incidence of mucositis, similar incidence of aGVHD, and comparable survival as compared to CSP and MTX.

LMO2 Protein Expression Predicts Survival in Patients With Diffuse Large B-Cell Lymphoma Treated With Anthracycline-Based Chemotherapy With and Without Rituximab

PURPOSE The heterogeneity of diffuse large B-cell lymphoma (DLBCL) has prompted the search for new markers that can accurately separate prognostic risk groups. We previously showed in a multivariate model that LMO2 mRNA was a strong predictor of superior outcome in DLBCL patients. Here, we tested the prognostic impact of LMO2 protein expression in DLBCL patients treated with anthracycline-based chemotherapy with or without rituximab. PATIENTS AND METHODS DLBCL patients treated with anthracycline-based chemotherapy alone (263 patients) or with the addition of rituximab (80 patients) were studied using immunohistochemistry for LMO2 on tissue microarrays of original biopsies. Staining results were correlated with outcome. RESULTS In anthracycline-treated patients, LMO2 protein expression was significantly correlated with improved overall survival (OS) and progression-free survival (PFS) in univariate analyses (OS, P = .018; PFS, P = .010) and was a significant predictor independent of the clinical International Prognostic Index (IPI) in multivariate analysis. Similarly, in patients treated with the combination of anthracycline-containing regimens and rituximab, LMO2 protein expression was also significantly correlated with improved OS and PFS (OS, P = .005; PFS, P = .009) and was a significant predictor independent of the IPI in multivariate analysis. CONCLUSION We conclude that LMO2 protein expression is a prognostic marker in DLBCL patients treated with anthracycline-based regimens alone or in combination with rituximab. After further validation, immunohistologic analysis of LMO2 protein expression may become a practical assay for newly diagnosed DLBCL patients to optimize their clinical management.

The Ratio of FOXP3+ Regulatory T Cells to Granzyme B+ Cytotoxic T/NK Cells Predicts Prognosis in Classical Hodgkin Lymphoma and Is Independent of bcl-2 and MAL Expression

We studied the prognostic importance of tumor-infiltrating regulatory T lymphocytes (Tregs) and cytotoxic T/NK lymphocytes (CTLs) in 98 diagnostic biopsy specimens from patients with classical Hodgkin lymphoma (cHL). Immunohistochemical analysis was performed for FOXP3 to identify Tregs and for granzyme B (GrB) to identify activated CTLs. Failure-free survival (FFS) and overall survival (OS) were clinical end points. Patients with fewer than 25 FOXP3+ cells per high-power field (HPF) had a mean +/- SD 5-year FFS of 64% +/- 7% vs 85% +/- 5% for patients with 25 or more FOXP3+ cells/HPF (P = .05). A FOXP3/GrB ratio of 1 or less was associated with poor FFS (46% +/- 10% vs 86% +/- 4%; P < .001) and OS (67% +/- 10% vs 93% +/- 3%; P < .001). When prior available MAL and bcl-2 expression data were included in a multivariate analysis of all clinical and biologic factors, a FOXP3/GrB ratio of 1 or less and tumor cell expression of MAL and bcl-2 all independently predicted poor FFS. This demonstrates the importance of evaluating tumor cell markers and the tumor immune infiltrate when considering biologic prognostic markers in cHL.

Use of leflunomide in an allogeneic bone marrow transplant recipient with refractory cytomegalovirus infection

Summary:Ganciclovir-resistant cytomegalovirus (CMV) infection is an emerging problem in transplant recipients. Foscarnet resistance and cidofovir resistance have also been described, but no previous reports have suggested treatment regimens for patients with CMV refractory to all three of these drugs. Leflunomide, an immunosuppressive drug used in rheumatoid arthritis and in rejection in solid-organ transplantation, has been reported to have novel anti-CMV activity. However, its clinical utility in CMV treatment has not been described previously. We report an allogeneic bone marrow transplant recipient who developed CMV infection refractory to sequential therapy with ganciclovir, foscarnet, and cidofovir. The patient was ultimately treated with a combination of leflunomide and foscarnet. Both phenotypic and genotypic virologic analysis was performed on sequential CMV isolates. The patients high CMV-DNA viral load became undetectable on leflunomide and foscarnet, but the patient, who had severe graft-versus-host disease (GVHD) of the liver, expired with progressive liver failure and other complications. We concluded that leflunomide is a new immunosuppressive agent with anti-CMV activity, which may be useful in the treatment of multiresistant CMV. However, the toxicity profile of leflunomide in patients with underlying GVHD remains to be defined.

Elevated pretransplant ferritin is associated with a lower incidence of chronic graft-versus-host disease and inferior survival after myeloablative allogeneic haematopoietic stem cell transplantation

Elevated pretransplant serum ferritin levels have been associated with an increased incidence of morbidity and mortality after allogeneic haematopoietic stem cell transplantation (HCT). We studied 222 patients who underwent myeloablative allogeneic HCT in whom pretransplantation serum ferritin levels were available. Pretransplantation ferritin > 1910 μg/l was associated with lower overall survival (P = 0·003), lower relapse‐free survival (P = 0·003), decreased chronic graft‐versus‐host disease (GVHD) (P = 0·019) and increased non‐relapse mortality (NRM) (P = 0·042). Similar results were obtained when pretransplantation ferritin was analysed as a continuous variable and by quartiles. Our results indicate that an elevated pretransplant ferritin level adversely impacts transplantation outcomes. The adverse impact of elevated ferritin on NRM and survival was despite its association with lower incidences of acute and chronic GVHD, which are major causes of NRM. The association of ferritin with iron overload and its influence on HCT outcomes requires further prospective validation.

Prognostic significance of VEGF, VEGF receptors, and microvessel density in diffuse large B cell lymphoma treated with anthracycline-based chemotherapy

Vascular endothelial growth factor-mediated signaling has at least two potential roles in diffuse large B cell lymphoma: potentiation of angiogenesis, and potentiation of lymphoma cell proliferation and/or survival induced by autocrine vascular endothelial growth factor receptor-mediated signaling. We have recently shown that diffuse large B cell lymphomas expressing high levels of vascular endothelial growth factor protein also express high levels of vascular endothelial growth factor receptor-1 and vascular endothelial growth factor receptor-2. We have now assessed a larger multi-institutional cohort of patients with de novo diffuse large B cell lymphoma treated with anthracycline-based therapy to address whether tumor vascularity, or expression of vascular endothelial growth factor protein and its receptors, contribute to patient outcomes. Our results show that increased tumor vascularity is associated with poor overall survival (P=0.047), and is independent of the international prognostic index. High expression of vascular endothelial growth factor receptor-1 by lymphoma cells by contrast is associated with improved overall survival (P=0.044). The combination of high vascular endothelial growth factor and vascular endothelial growth factor receptor-1 protein expression by lymphoma cells identifies a subgroup of patients with improved overall (P=0.003) and progression-free (P=0.026) survival; these findings are also independent of the international prognostic index. The prognostic significance of overexpression of this ligand-receptor pair suggests that autocrine signaling via vascular endothelial growth factor receptor-1 may represent a survival or proliferation pathway in diffuse large B cell lymphoma. Dependence on autocrine vascular endothelial growth factor receptor-1-mediated signaling may render a subset of diffuse large B-cell lymphomas susceptible to anthracycline-based therapy.

Follicular programmed death 1-positive lymphocytes in the tumor microenvironment are an independent prognostic factor in follicular lymphoma.

We enumerated programmed death 1 (PD-1)-positive follicular helper T cells, a potentially important regulator of immune response, in the tumor microenvironment of a series of 91 newly diagnosed follicular lymphomas managed at a single institution. Clinical data were obtained for sex, age, Follicular Lymphoma International Prognostic Index (FLIPI) risk group, presence of bulky disease, presence of B symptoms, and overall survival. Immunohistochemical staining for PD-1 was performed on tissue microarray sections, and the mean number of follicular PD-1-positive cells per 9 high-power fields (1000×, 3 follicles with 3 fields per follicle) was quantified. B-cell CLL/lymphoma 2 (BCL-2) expression, CD68(+) extrafollicular lymphoma-associated macrophages, and forkhead box P3 (FOXP3)+ regulatory T cells were evaluated as reported previously. Ninety-one patients were evaluated, with a median age at diagnosis of 58 years and median survival of 11.6 years. PD-1-positive cells correlated with the number of FOXP3+ regulatory T cells (P = .01). On multivariate analysis, independent poor prognostic factors were age 55 years or greater (hazard ratio, 2.77; 95% confidence interval, 1.34-5.73; P = .006), bulky disease (hazard ratio, 2.27; 95% confidence interval, 1.03-5.00; P = .04), CD68(+) extrafollicular lymphoma-associated macrophages greater than 16.8 cells/high-power field (hazard ratio, 2.15; 95% confidence interval, 1.14-4.06; P = .02), and PD-1-positive cells greater than 35.6 cells/high-power field (hazard ratio, 1.98; 95% confidence interval, 1.09-3.60; P = .03). These factors allowed construction of a risk score defining 3 distinct prognostic groups with 10-year overall survival of 85%, 60%, and 15%. PD-1-positive follicular helper T cells and CD68(+) extrafollicular lymphoma-associated macrophages appear to predict overall survival in follicular lymphoma, and our findings support strategies aimed at modulating their function in follicular lymphoma. Future studies, performed prospectively on uniformly treated patient cohorts, should be performed to validate these findings.

A Phase II trial of Belinostat (PXD101) in patients with relapsed or refractory peripheral or cutaneous T-cell lymphoma

Belinostat is a pan‐histone deacetylase inhibitor with antitumour and anti‐angiogenic properties. An open label, multicentre study was conducted in patients with peripheral T‐cell lymphoma (PTCL) or cutaneous T‐cell lymphoma (CTCL) who failed ≥1 prior systemic therapy and were treated with belinostat (1000 mg/m2 intravenously ×5 d of a 21‐d cycle). The primary endpoint was objective response rate (ORR). Patients with PTCL (n = 24) had received a median of three prior systemic therapies (range 1–9) and 40% had stage IV disease. Patients with CTCL (n = 29) had received a median of one prior skin‐directed therapy (range 0–4) and four prior systemic therapies (range 1–9); 55% had stage IV disease. The ORRs were 25% (PTCL) and 14% (CTCL). Treatment‐related adverse events occurred in 77% of patients; nausea (43%), vomiting (21%), infusion site pain (13%) and dizziness (11%) had the highest incidence. Treatment‐related serious adverse events were Grade 5 ventricular fibrillation; Grade 4 thrombocytopenia; Grade 3 peripheral oedema, apraxia, paralytic ileus and pneumonitis; and Grade 2 jugular vein thrombosis. Belinostat monotherapy was well tolerated and efficacious in patients with recurrent/refractory PTCL and CTCL. This trial was registered at www.clinicaltrials.gov as NCT00274651.

Early vancomycin-resistant enterococcus (VRE) bacteremia after allogeneic bone marrow transplantation is associated with a rapidly deteriorating clinical course.

Summary:Vancomycin-resistant enterococcal (VRE) infection is a growing threat. We studied the incidence, risk factors, and clinical course of early-onset VRE bacteremia in allogeneic hematopoietic stem cell transplant recipients. We carried out a chart review of 281 allogeneic hematopoietic stem cell transplant recipients from 1997–2003, including preparative regimen, diagnosis, status of disease, graft-versus-host disease prophylaxis, antimicrobial therapy, and survival. VRE bacteremia developed in 12/281 (4.3%) recipients; 10 (3.6%) were within 21 days of transplant. Diagnoses were acute leukemia (7), NHL (2), and MDS (1). In all, 70% had refractory/relapsed disease; 30% were in remission. In total, 50% had circulating blasts. Nine of 10 had matched unrelated donors (7/9 with CD8+ T-cell depletion). The average time to positive VRE cultures was 15 days; average WBC was 0.05, and 80% had concomitant infections. Despite treatment, all patients died within 73 days of VRE bacteremia. Intra-abdominal complications were common. Causes of death included bacterial or fungal infection, multiorgan failure, VOD, ARDS, and relapse. A total of 60% of patients engrafted neutrophils, but none engrafted platelets. Early VRE bacteremia after allogeneic bone marrow transplant is associated with a rapidly deteriorating clinical course, although not always directly due to VRE. Early VRE may be a marker for the critical condition of these high-risk patients at the time of transplant.