Universal posttransplant cyclophosphamide after allogeneic transplant, a retrospective single institution study.

BACKGROUND: The excellent results of posttransplant cyclophosphamide in decreasing graft-versus-host disease (GVHD) after haploidentical (HI) allogeneic transplant have challenged current donor selection algorithms. PATIENTS AND METHODS: We compared outcomes after matched sibling (MSD) versus alternative donor transplant using identical graft-versus-host disease (GVHD) prophylaxis including posttransplant cyclophosphamide (PTCy. Endpoints included engraftment, time outside of the hospital in the first 100 days after transplant, overall survival (OS), non-relapse mortality (NRM) and percentage of patients disease-free and off immunosuppression (DFOI) at one year and at the last follow-up. RESULTS: There were significant differences at baseline between matched donor versus HI donor transplants with higher disease-risk index (DRI), more female-to-male donor recipient pairs and a higher percentage of Black patients in the HI group. Engraftment and time out of the hospital favored MSD and matched unrelated donor transplants. Multivariate analysis showed that high DRI and Black race were associated with decreased survival and Black race was associated with a higher NRM. CONCLUSIONS: With the use of PTCy, our results support current donor selection algorithms. The finding of decreased survival and increased NRM in Black patients requires confirmation in a larger number of patients as well as the development of mitigation strategies.

Incorporation of posttransplant cyclophosphamide as part of standard immunoprophylaxis for all allogeneic transplants: a retrospective, single institution study.

The addition of posttransplant cyclophosphamide (PTCy) to standard graft-versus-host disease (GVHD) prophylaxis following haploidentical blood stem transplants has resulted in relatively low rates of GVHD. As GVHD remains a major cause of morbidity and mortality in patients receiving transplants from matched donors, we began to use PTCy in all blood stem cell transplants in 2016 and compared our recent experience with PTCy after matched sibling and unrelated donor transplants (N = 49) to the earlier 2-year period (N = 41) when PTCy was not used. Endpoints included graft-versus-host, relapse-free-survival (GRFS), overall survival, non-relapse mortality, and percentage of patients disease-free and off immunosuppression (DFOI) at 1 year and at the last follow-up. The difference in GRFS between the standard and the PTCy cohort was not statistically significant. There was a statistically improved relapse-free and overall survival in the PTCY cohort that was due to a significant decrease in non-relapse mortality secondary to GVHD. There was also a borderline statistically improved DFOI at 1 year and at last follow-up in the PTCY group. These results suggest that PTCy after HLA-matched transplants provides at least comparable efficacy to other GVHD strategies and may allow more frequent discontinuation of immunosuppression.

Incorporation of extracorporeal photopheresis into a reduced intensity conditioning regimen in myelodysplastic syndrome and aggressive lymphoma: results from ECOG 1402 and 1902.

BACKGROUND: Extracorporeal photopheresis (ECP) is an immunomodulatory cellular therapy which has been shown to induce a tolerogenic state in patients with acute and chronic graft-vs-host disease. ECOG-ACRIN explored the activity of ECP as a part of a reduced intensity conditioning regimen in two multicenter trials in patients with MDS (E1902) and lymphomas (E1402). While both studies closed before completing accrual, we report results in 23 patients (17 MDS and 6 lymphoma). STUDY DESIGN AND METHODS: Patients received 2 days of ECP followed by pentostatin 4 mg/m2 /day for two consecutive days, followed by 600 cGy of total body irradiation prior to stem cell infusion. Immunosuppression for aGVHD was infusional cyclosporine A or tacrolimus and methotrexate on day +1, +3, with mycophenolate mofetil starting on day 100 for chronic GVHD prophylaxis. RESULTS: All patients engrafted, with median time to neutrophil and platelet engraftment of 15-18 days and 10-18 days respectively. Grade 3 or 4 aGVHD occurred in 13% and chronic extensive GVHD in 30%. CONCLUSIONS: These studies demonstrate that ECP/pentostatin/TBI is well tolerated and associated with adequate engraftment of neutrophils and platelets in patients with lymphomas and MDS.

A Phase II Trial of Bortezomib and Vorinostat in Mantle Cell Lymphoma and Diffuse Large B-cell Lymphoma.

BACKGROUND: The proteasome inhibitor bortezomib has demonstrated marked preclinical activity when combined with the histone deacetylase inhibitor vorinostat in leukemia, multiple myeloma, and mantle cell lymphoma (MCL) cells. The present study evaluated the efficacy and safety of the combination in patients with relapsed or refractory MCL and diffuse large B-cell lymphoma (DLBCL). PATIENTS AND METHODS: The present multicenter, nonrandomized phase II trial used a Simon 2-stage design with 3 cohorts: cohort A, MCL with no previous bortezomib (including untreated MCL); cohort B, MCL with previous bortezomib; and cohort C, relapsed or refractory DLBCL with no previous bortezomib. Vorinostat (400 mg) was administered orally on days 1 to 5 and 8 to 12 before bortezomib (1.3 mg/m2), which was administered intravenously on days 1, 4, 8, and 11 of each 21-day cycle. RESULTS: For the 65 treated patients (22 in cohort A, 4 in cohort B, and 39 in cohort C), the overall response rate was 31.8%, 0%, and 7.7%, respectively. The median progression-free survival was 7.6 months for cohort A and 1.8 months for cohort C. In cohort A, 7 patients had a partial response (PRs), 5 had stable disease (SD), 7 had progressive disease (PD), 1 was not assessed, and 2 were not evaluable. In cohort B, 2 had SD and 2 had PD. In cohort C, 3 had a PR, 8 had SD, 23 had PD, and 5 were not assessed. Baseline NF-κB activation, measured as nuclear RelA by immunohistochemistry, did not correlate with clinical response. CONCLUSION: The combination of bortezomib and vorinostat is safe and has modest activity in MCL and limited activity in DLBCL.

Universal Health Care: The Cost of Being Human.

In this article I argue that the biological processes that make us human have error rates that distribute illness on a no-fault basis. I propose this as an ethical foundation for universal healthcare.

The enteric toxicity of gluten enhances graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.

Pro-inflammatory peptides present in wheat and related grains are associated with celiac disease and non-celiac gluten sensitivity. We hypothesize that these peptides induce enteric responses that may exacerbate the gastrointestinal manifestations of graft-versus-host disease after an allogeneic hematopoietic stem cell transplant. Therefore, we propose that a gluten free diet should be tested as a prophylactic and/or therapeutic intervention against gastrointestinal graft-versus-host disease for patients undergoing an allogeneic hematopoietic stem cell transplant.

Lactobacillus rhamnosus GG probiotic enteric regimen does not appreciably alter the gut microbiome or provide protection against GVHD after allogeneic hematopoietic stem cell transplantation.

Graft-versus-host disease (GVHD) is a major adverse effect associated with allogeneic stem cell transplant. Previous studies in mice indicated that administration of the probiotic Lactobacillus rhamnosus GG can reduce the incidence of GVHD after hematopoietic stem cell transplant. Here we report results from the first randomized probiotic enteric regimen trial in which allogenic hematopoietic stem cell patients were supplemented with Lactobacillus rhamnosus GG. Gut microbiome analysis confirmed a previously reported gut microbiome association with GVHD. However, the clinical trial was terminated when interim analysis did not detect an appreciable probiotic-related change in the gut microbiome or incidence of GVHD. Additional studies are necessary to determine whether probiotics can alter the incidence of GVHD after allogeneic stem cell transplant.

Clinical Studies in Hematologic Microtransplantation.

The anti-tumor effects of allogeneic hematopoietic stem cell transplantation depend upon engraftment of donor cells followed by a graft-versus-tumor (GVT) effect. However, pre-clinical and clinical studies have established that under certain circumstances, anti-tumor responses can occur despite the absence of high levels of durable donor cell engraftment. Tumor response with little or no donor engraftment has been termed "microtransplantation." It has been hard to define conditions leading to tumor responses without donor cell persistence in humans because the degree of engraftment depends very heavily upon many patient-specific factors, including immune status and degree of prior therapy. Likewise, it is unknown to what degree donor chimerism in the blood or tissue is required for an anti-tumor effect under conditions of microtransplantation. In this review, we summarize some key studies supporting the concept of microtransplantation and emphasize the importance of recent large studies of microtransplantation in patients with acute myelogenous leukemia (AML). These AML studies provide the first evidence of the efficacy of microtransplantation as a therapeutic strategy and lay the foundation for additional pre-clinical studies and clinical trials that will refine the understanding of the mechanisms involved and guide its further development as a treatment modality.

Results of the Phase I Trial of RG7112, a Small-Molecule MDM2 Antagonist in Leukemia.

PURPOSE: RG7112 is a small-molecule MDM2 antagonist. MDM2 is a negative regulator of the tumor suppressor p53 and frequently overexpressed in leukemias. Thus, a phase I study of RG7112 in patients with hematologic malignancies was conducted. EXPERIMENTAL DESIGN: Primary study objectives included determination of the dose and safety profile of RG7112. Secondary objectives included evaluation of pharmacokinetics; pharmacodynamics, such as TP53-mutation status and MDM2 expression; and preliminary clinical activity. Patients were divided into two cohorts: Stratum A [relapsed/refractory acute myeloid leukemia (AML; except acute promyelocytic leukemia), acute lymphoblastic leukemia, and chronic myelogenous leukemia] and Stratum B (relapsed/refractory chronic lymphocytic leukemia/small cell lymphocytic leukemia; CLL/sCLL). Some Stratum A patients were treated at the MTD to assess clinical activity. RESULTS: RG7112 was administered to 116 patients (96 patients in Stratum A and 20 patients in Stratum B). All patients experienced at least 1 adverse event, and 3 dose-limiting toxicities were reported. Pharmacokinetic analysis indicated that twice-daily dosing enhanced daily exposure. Antileukemia activity was observed in the 30 patients with AML assessed at the MTD, including 5 patients who met International Working Group (IWG) criteria for response. Exploratory analysis revealed TP53 mutations in 14% of Stratum A patients and in 40% of Stratum B patients. Two patients with TP53 mutations exhibited clinical activity. p53 target genes were induced only in TP53 wild-type leukemic cells. Baseline expression levels of MDM2 correlated positively with clinical response. CONCLUSIONS: RG7112 demonstrated clinical activity against relapsed/refractory AML and CLL/sCLL. MDM2 inhibition resulted in p53 stabilization and transcriptional activation of p53-target genes. We provide proof-of-concept that MDM2 inhibition restores p53 function and generates clinical responses in hematologic malignancies.

Cobblestone-area forming cells derived from patients with mantle cell lymphoma are enriched for CD133+ tumor-initiating cells.

Mantle cell lymphoma (MCL) is associated with a significant risk of therapeutic failure and disease relapse, but the biological origin of relapse is poorly understood. Here, we prospectively identify subpopulations of primary MCL cells with different biologic and immunophenotypic features. Using a simple culture system, we demonstrate that a subset of primary MCL cells co-cultured with either primary human mesenchymal stromal cells (hMSC) or murine MS-5 cells form in cobblestone-areas consisting of cells with a primitive immunophenotype (CD19-CD133+) containing the chromosomal translocation t (11;14)(q13;q32) characteristic of MCL. Limiting dilution serial transplantation experiments utilizing immunodeficient mice revealed that primary MCL engraftment was only observed when either unsorted or CD19-CD133+ cells were utilized. No engraftment was seen using the CD19+CD133- subpopulation. Our results establish that primary CD19-CD133+ MCL cells are a functionally distinct subpopulation of primary MCL cells enriched for MCL-initiating activity in immunodeficient mice. This rare subpopulation of MCL-initiating cells may play an important role in the pathogenesis of MCL.

Transfusion strategies in hematologic and nonhematologic disease.

Substantial progress has been made in our understanding of the risks and benefits of RBC transfusion through the performance of large clinical trials. More than 7000 patients have been enrolled in trials randomly allocating patients to higher transfusion thresholds (∼9-10 g/dL), referred to as liberal transfusion, or lower transfusion thresholds (∼7-8 g/dL), referred to as restrictive transfusion. The results of most of the trials suggest that a restrictive transfusion strategy is safe and, in some cases, superior to a liberal transfusion strategy. However, in patients with myocardial infarction, brain injury, stroke, or hematological disorders, more large trials are needed because preliminary evidence suggests that liberal transfusion might be beneficial or trials have not been performed at all.

Duplication of chromosome 1 [dup(1)(q21q32)] as the sole cytogenetic abnormality in a patient previously treated for AML.

A nonrandom structural gain of 1q may be seen in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), and often it is due to an unbalanced translocation. Dup(1)(q21q32) as the sole abnormality has only rarely been reported. Reports have suggested that the dup(1)(q21q32) is predictive of a poor prognosis. We describe a case report of a 55 year old male who presented in 2002 with AML-M2, t(8;21)(q22;q22). He underwent induction with "7+3" followed by consolidation chemotherapy resulting in a complete remission. Two years later, his bone marrow revealed a dup(1)(q21q32) as an isolated aberration for the first time. In 2010, cytogenetic analysis of the bone marrow again confirmed this finding and FISH for AML1/ETO t(8;21) remained negative. Dup(1q) developed as an isolated abnormality two years after AML treatment, and to date, there is no evidence of progression to MDS. This is the first report of an acquired dup(1)(q21q32) as the sole abnormality in a patient treated for AML. This suggests that the dup(1q) may not be exclusively associated with a poor prognosis.

Mesenchymal stromal cells protect mantle cell lymphoma cells from spontaneous and drug-induced apoptosis through secretion of B-cell activating factor and activation of the canonical and non-canonical nuclear factor κB pathways.

BACKGROUND: There is increasing evidence that stromal cell interactions are required for the survival and drug resistance of several types of B-cell malignancies. There is relatively little information regarding the role of the bone marrow/lymphoid microenvironment in the pathogenesis of mantle cell lymphoma. In this study we investigated the interaction of primary mantle cell lymphoma cells with stromal cells in an ex vivo co-culture system. DESIGN AND METHODS: The murine stromal cell line MS-5 and human bone marrow mesenchymal stromal cells were each co-cultured with primary mantle cell lymphoma cells for up to 7 months. Mantle cell lymphoma cultures alone or combined with human stromal cells were analyzed for cell number, cell migration, nuclear factor-κB activation and drug resistance. RESULTS: Co-culture of mantle cell lymphoma cells and human stromal cells results in the survival and proliferation of primary mantle cell lymphoma cells for at least 7 months compared to mantle cell lymphoma cells cultured alone. Mantle cell lymphoma-human stromal cell interactions resulted in activation of the B-cell activating factor/nuclear factor-κB signaling axis resulting in reduced apoptosis, increased mantle cell lymphoma migration and increased drug resistance. CONCLUSIONS: Direct mantle cell lymphoma-human stromal cell interactions support long-term expansion and increase the drug-resistance of primary mantle cell lymphoma cells. This is due in part to activation of the canonical and non-canonical nuclear factor κB pathways. We also demonstrated the ability of B-cell activating factor to augment CXCL12- and CXCL13-induced cell migration. Collectively, these findings demonstrate that human stromal cell-mantle cell lymphoma interactions play a pivotal role in the pathogenesis of mantle cell lymphoma and that analysis of mantle cell lymphoma-human stromal cell interactions may help in the identification of novel targets for therapeutic use.

Differentiation-associated miR-22 represses Max expression and inhibits cell cycle progression.

Differentiation agents such as 12-O-tetradecanoylphorbol-13-acetate (TPA) engage cell signaling pathways that activate downstream transcriptional programs necessary for cell differentiation. Recent evidence has indicated microRNAs (miRNAs) are an integral part of these transcriptional programs, which target key proteins and impact cell growth thereby facilitating changes required for differentiation. To further investigate the role of miRNAs in cell growth and differentiation, we focused on miR-22, a miRNA induced by TPA in the HL-60 leukemia cell line model of monocytic differentiation. TPA-induced miR-22 transcription was found to be downstream of the protein kinase c (PKC)-extracellular regulated kinase (ERK) signaling module, a pathway central to the growth and differentiation of many different cell types. Enforced miR-22 expression inhibited the growth of several different cancer cell lines, causing an accumulation of cells in the G1 phase of the cell cycle. The mechanism of miR-22's inhibitory effects involves targeting of the obligate c-Myc binding partner Max. Enforced miR-22 expression presumably lowers Max levels available for Myc binding, which differentially influenced the transcription of downstream targets of the Myc-Max complex. Our study provides additional support for miRNAs targeting key cellular regulatory microcircuits such as those governed by the Myc-Max transcriptional complex as well as their being active participants in cell growth and differentiation.

Acute myelogenous leukemia and myelodysplasia secondary to breast cancer treatment: case studies and literature review.

BACKGROUND AND PURPOSE: Chemotherapy and radiation therapy for breast cancer are known to increase the risk of developing a myelodysplastic syndrome (MDS) and/or acute myelogenous leukemia (AML). Alkylating agents and topoisomerase II inhibitors, fundamental to the treatment of breast cancer, are the most likely contributors to this increase in risk. Radiation therapy adds to the risk, and there is speculation that granulocyte colony-stimulating factor (G-CSF) may also predispose to leukemia. The purpose of this systemic review is to bring to the attention of family physicians the unintended consequence of leukemia secondary to aggressively treated breast cancer. METHODS: The medical records of several patients from Robert Wood Johnson University Hospital, with previously treated breast cancer admitted for therapy for AML or myelodysplasia, were reviewed. In addition, the recent literature on this topic was reviewed. RESULTS: Cases of patients whose AML was likely secondary to their treatment for breast cancer were used to illustrate the role of chemotherapy, radiation therapy, and perhaps G-CSF in the development of leukemia. CONCLUSIONS: Chemotherapy and radiation therapy administered for breast cancer predispose patients to the development of MDS or AML. We hypothesize that the breast cancer (BRCA) gene mutations might add to the risk and that primary care physicians must be aware of the long-term risks of cytotoxic therapy, including the development of MDS or AML.