Miles Prince

Activation of HIV Transcription with Short-Course Vorinostat in HIV-Infected Patients on Suppressive Antiretroviral Therapy

Human immunodeficiency virus (HIV) persistence in latently infected resting memory CD4+ T-cells is the major barrier to HIV cure. Cellular histone deacetylases (HDACs) are important in maintaining HIV latency and histone deacetylase inhibitors (HDACi) may reverse latency by activating HIV transcription from latently infected CD4+ T-cells. We performed a single arm, open label, proof-of-concept study in which vorinostat, a pan-HDACi, was administered 400 mg orally once daily for 14 days to 20 HIV-infected individuals on suppressive antiretroviral therapy (ART). The primary endpoint was change in cell associated unspliced (CA-US) HIV RNA in total CD4+ T-cells from blood at day 14. The study is registered at ClinicalTrials.gov (NCT01365065). Vorinostat was safe and well tolerated and there were no dose modifications or study drug discontinuations. CA-US HIV RNA in blood increased significantly in 18/20 patients (90%) with a median fold change from baseline to peak value of 7.4 (IQR 3.4, 9.1). CA-US RNA was significantly elevated 8 hours post drug and remained elevated 70 days after last dose. Significant early changes in expression of genes associated with chromatin remodeling and activation of HIV transcription correlated with the magnitude of increased CA-US HIV RNA. There were no statistically significant changes in plasma HIV RNA, concentration of HIV DNA, integrated DNA, inducible virus in CD4+ T-cells or markers of T-cell activation. Vorinostat induced a significant and sustained increase in HIV transcription from latency in the majority of HIV-infected patients. However, additional interventions will be needed to efficiently induce virus production and ultimately eliminate latently infected cells. Trial Registration ClinicalTrials.gov NCT01365065

Fluorine-18 fluorodeoxyglucose Positron emission tomography, Gallium-67 scintigraphy, and conventional staging for Hodgkin's disease and non-Hodgkin's lymphoma

PURPOSE To compare fluorine-18 fluorodeoxyglucose positron emission tomography (PET) and gallium scanning with each other and with conventional staging, for patients with Hodgkins disease or non-Hodgkins lymphoma. SUBJECTS AND METHODS Fifty patients had PET, gallium scanning, and conventional staging of newly diagnosed or progressive Hodgkins disease or non-Hodgkins lymphoma. Disease sites, stage, and treatment plans were assessed retrospectively. RESULTS Positron emission tomography and gallium scanning each upstaged 14% of patients (n = 7). Management was altered by PET in 9 cases (18%) and by gallium scanning in 7 (14%, P = 0.6). Disease was evident in 117 sites in 42 patients. The case positivity rate for conventional assessment was 90%; for PET, 95%; for gallium scanning, 88%; for conventional assessment plus PET, 100%; and for conventional assessment plus gallium scanning, 98%. Site positivity rates for conventional assessment were 68%; for PET, 82%; for gallium scanning, 69% (conventional vs. PET, P = 0.01; conventional vs. gallium scanning, P = 0.9; PET vs. gallium scanning, P = 0.01); for conventional assessment plus PET, 96%; and for conventional assessment plus gallium scanning, 94%. Positron emission tomography and gallium scanning were entirely concordant in 31 patients; in the other 19 patients, PET identified 25 sites missed by gallium scanning, whereas gallium scanning identified 10 sites missed by PET. CONCLUSION In this retrospective study, PET demonstrated a higher site positivity rate than did gallium scanning, with similar case positivity rates. These data support the use of PET in place of gallium scanning for the staging of patients with Hodgkins disease or non-Hodgkins lymphoma.

Lenalidomide in combination with dexamethasone at first relapse in comparison with its use as later salvage therapy in relapsed or refractory multiple myeloma

This subset analysis of data from two phase III studies in patients with relapsed or refractory multiple myeloma (MM) evaluated the benefit of initiating lenalidomide plus dexamethasone at first relapse. Multivariate analysis showed that fewer prior therapies, along with β2‐microglobulin (≤2.5 mg/L), predicted a better time to progression (TTP; study end‐point) with lenalidomide plus dexamethasone treatment. Patients with one prior therapy showed a significant improvement in benefit after first relapse compared with those who received two or more therapies. Patients with one prior therapy had significantly prolonged median TTP (17.1 vs. 10.6 months; P = 0.026) and progression‐free survival (14.1 vs. 9.5 months, P = 0.047) compared with patients treated in later lines. Overall response rates were higher (66.9% vs. 56.8%, P = 0.06), and the complete response plus very good partial response rate was significantly higher in first relapse (39.8% vs. 27.7%, P = 0.025). Importantly, overall survival was significantly prolonged for patients treated with lenalidomide plus dexamethasone with one prior therapy, compared with patients treated later in salvage (median of 42.0 vs. 35.8 months, P = 0.041), with no differences in toxicity, dose reductions, or discontinuations despite longer treatment. Therefore, lenalidomide plus dexamethasone is both effective and tolerable for second‐line MM therapy and the data suggest that the greatest benefit occurs with earlier use.

An Australian survey of clinical practices in management of neutropenic fever in adult cancer patients 2009

Background:  An abundance of new evidence regarding treatment strategies for neutropenic fever is likely to contribute to variability in practice across institutions and clinicians alike.

Introduction to the Australian consensus guidelines for the management of neutropenic fever in adult cancer patients, 2010/2011

The current consensus guidelines were developed to standardize the clinical approach to the management of neutropenic fever in adult cancer patients throughout Australian treating centres. The three areas of clinical practice covered by the guidelines, the process for developing consensus opinion, and the system used to grade the evidence and relative strength of recommendations are described. The health economics implications of establishing clinical guidance are also discussed.

Induction of multi-functional T cells in a phase I clinical trial of dendritic cell immunotherapy in hepatitis C virus infected individuals

We have previously reported a world-first phase I clinical trial to treat HCV patients using monocyte-derived dendritic cells (Mo-DC) loaded with HCV-specific lipopeptides. While the brief treatment proved to be safe, it failed to reduce the viral load and induced only transient cell-mediated immune responses, measured by IFNγ ELIspot. Here we reanalysed the PBMC samples from this trial to further elucidate the immunological events associated with the Mo-DC therapy. We found that HCV-specific single- and multi-cytokine secreting T cells were induced by the Mo-DC immunotherapy in some patients, although at irregular intervals and not consistently directed to the same HCV antigen. Despite the vaccination, the responses were generally poor in quality and comprised of primarily single-cytokine secreting cells. The frequency of FOXP3+ regulatory T cells (Treg) fluctuated following DC infusion and eventually dropped to below baseline by week 12, an interesting trend suggesting that the vaccination may have resulted in a more subtle outcome than was initially apparent. Our data suggested that Mo-DC therapy induced complex immune responses in vivo that may or may not lead to clinical benefit.

The use of experimental murine models to assess novel agents of hematopoietic stem and progenitor cell mobilization.

The recent explosion in the understanding of the cellular and molecular mechanisms underlying hematopoietic stem and progenitor cell (HSPC) mobilization has facilitated development of novel therapeutic agents, targeted at improving mobilization kinetics as well as HSPC yield. With the development of new agents comes the challenge of choosing efficient and relevant preclinical studies for the testing of the HSPC mobilization efficacy of these agents. This article reviews the use of the mouse as a convenient small animal model of HSPC mobilization and transplantation, and outlines the range of murine assays that can be applied to assess novel HSPC mobilizing agents. Techniques to demonstrate murine HSPC mobilization are discussed, as well as the role of murine assays to confirm human HSPC mobilization, and techniques to investigate the biologic phenotype of HSPC mobilized by these novel agents. Technical aspects regarding mobilization regimens and control arms, and choice of experimental animals are also discussed.

Introduction to the Australian consensus guidelines for the management of neutropenic fever in adult cancer patients, 2010/2011. Australian Consensus Guidelines 2011 Steering Committee.

The current consensus guidelines were developed to standardize the clinical approach to the management of neutropenic fever in adult cancer patients throughout Australian treating centres. The three areas of clinical practice covered by the guidelines, the process for developing consensus opinion, and the system used to grade the evidence and relative strength of recommendations are described. The health economics implications of establishing clinical guidance are also discussed.

A prospective study of the separate predictive capabilities of 18[F]-FDG-PET and molecular response in patients with relapsed indolent non-Hodgkin’s lymphoma following treatment with iodine-131-rituximab radio-immunotherapy

Recent data have demonstrated the efficacy of anti-CD20 radio-immunotherapy (RIT) in patients with newly diagnosed advanced follicular non-Hodgkin’s lymphoma (NHL).[1][1],[2][2] A significant proportion of treated patients have extended event-free survival (EFS). Although there is as yet no clear

A role for multiple chimeric antigen receptor-expressing leukocytes in antigen-specific responses to cancer.

While adoptive immunotherapy using chimeric antigen receptor (CAR)-modified T cells can induce remission of some tumors, the role of other CAR-modified leukocytes is not well characterized. In this study, we characterize the function of leukocytes including natural killer (NK) cells, macrophages and CAR T cells from transgenic mice expressing a CAR under the control of the pan-hematopoietic promoter, vav, and determine the ability of these mice to respond to ERB expressing tumors. We demonstrate the anti-tumor functions of leukocytes, including antigen specific cytotoxicity and cytokine secretion. The adoptive transfer of CAR T cells provided a greater survival advantage in the E0771ERB tumor model than their wildtype (WT) counterparts. In addition, CAR NK cells and CAR T cells also mediated increased survival in the RMAERB tumor model. When challenged with Her2 expressing tumors, F38 mice were shown to mount an effective immune response, resulting in tumor rejection and long-term survival. This was shown to be predominantly dependent on both CD8+ T cells and NK cells. However, macrophages and CD4+ T cells were also shown to contribute to this response. Overall, this study highlights the use of the vav-CAR mouse model as a unique tool to determine the anti-tumor function of various immune subsets, either alone or when acting alongside CAR T cells in adoptive immunotherapy.