PD-1 Blockade in Chronically HIV-1-Infected Humanized Mice Suppresses Viral Loads

An estimated 34 million people are living with HIV worldwide (UNAIDS, 2012), with the number of infected persons rising every year. Increases in HIV prevalence have resulted not only from new infections, but also from increases in the survival of HIV-infected persons produced by effective anti-retroviral therapies. Augmentation of anti-viral immune responses may be able to further increase the survival of HIV-infected persons. One strategy to augment these responses is to reinvigorate exhausted anti-HIV immune cells present in chronically infected persons. The PD-1-PD-L1 pathway has been implicated in the exhaustion of virus-specific T cells during chronic HIV infection. Inhibition of PD-1 signaling using blocking anti-PD-1 antibodies has been shown to reduce simian immunodeficiency virus (SIV) loads in monkeys. We now show that PD-1 blockade can improve control of HIV replication in vivo in an animal model. BLT (Bone marrow-Liver-Thymus) humanized mice chronically infected with HIV-1 were treated with an anti-PD-1 antibody over a 10-day period. The PD-1 blockade resulted in a very significant 45-fold reduction in HIV viral loads in humanized mice with high CD8+ T cell expression of PD-1, compared to controls at 4 weeks post-treatment. The anti-PD-1 antibody treatment also resulted in a significant increase in CD8+ T cells. PD-1 blockade did not affect T cell expression of other inhibitory receptors co-expressed with PD-1, including CD244, CD160 and LAG-3, and did not appear to affect virus-specific humoral immune responses. These data demonstrate that inhibiting PD-1 signaling can reduce HIV viral loads in vivo in the humanized BLT mouse model, suggesting that blockade of the PD-1-PD-L1 pathway may have therapeutic potential in the treatment of patients already infected with the AIDS virus

Phase 1/2 Dose Escalating Study of Twice-Monthly Pemetrexed and Gemcitabine in Patients with Advanced Cancer and Non-small Cell Lung Cancer

IntroductionPemetrexed is synergistic with gemcitabine in preclinical models of non-small cell lung cancer (NSCLC). The optimal dose and utility of gemcitabine and pemetrexed was evaluated in a dose-escalating study.MethodsThe phase 1 study included patients with advanced tumors, whereas the phase 2 study included patients with locally advanced or metastatic NSCLC. Gemcitabine was infused over 30 minutes, followed by pemetrexed administered over 10 minutes on day 1 of a 14-day cycle. Treatment continued for 12 cycles or until disease progression. All patients received folic acid, Vitamin B12, and steroid prophylaxis.ResultsMaximum tolerated dose was gemcitabine 1500 mg/m2, followed by pemetrexed 500 mg/m2. Fifty-three patients (29 male, 24 female) were enrolled in the phase 2 study. Response rate was 20.8% (95% CI: 0.108–0.341), and the clinical benefit rate (CR + PR + SD) was 64.2%. Median time to disease progression was 4.6 months (95% CI: 2.79–6.18), median survival was 10.1 month (95% CI: 5.95–14.09, censorship = 20.75%), and 1-year survival was 41.0%. Common grade 3 or 4 adverse events (% of patients) were neutropenia (28.3%), fatigue (22.6%), and febrile neutropenia (9.4%).ConclusionsTwice-monthly gemcitabine and pemetrexed was well tolerated, with overall survival and clinical benefit indicating disease activity in NSCLC patients

Ticagrelor with or without Aspirin in High-Risk Patients after PCI.

BACKGROUND: Monotherapy with a P2Y12 inhibitor after a minimum period of dual antiplatelet therapy is an emerging approach to reduce the risk of bleeding after percutaneous coronary intervention (PCI). METHODS: In a double-blind trial, we examined the effect of ticagrelor alone as compared with ticagrelor plus aspirin with regard to clinically relevant bleeding among patients who were at high risk for bleeding or an ischemic event and had undergone PCI. After 3 months of treatment with ticagrelor plus aspirin, patients who had not had a major bleeding event or ischemic event continued to take ticagrelor and were randomly assigned to receive aspirin or placebo for 1 year. The primary end point was Bleeding Academic Research Consortium (BARC) type 2, 3, or 5 bleeding. We also evaluated the composite end point of death from any cause, nonfatal myocardial infarction, or nonfatal stroke, using a noninferiority hypothesis with an absolute margin of 1.6 percentage points. RESULTS: We enrolled 9006 patients, and 7119 underwent randomization after 3 months. Between randomization and 1 year, the incidence of the primary end point was 4.0% among patients randomly assigned to receive ticagrelor plus placebo and 7.1% among patients assigned to receive ticagrelor plus aspirin (hazard ratio, 0.56; 95% confidence interval [CI], 0.45 to 0.68; P<0.001). The difference in risk between the groups was similar for BARC type 3 or 5 bleeding (incidence, 1.0% among patients receiving ticagrelor plus placebo and 2.0% among patients receiving ticagrelor plus aspirin; hazard ratio, 0.49; 95% CI, 0.33 to 0.74). The incidence of death from any cause, nonfatal myocardial infarction, or nonfatal stroke was 3.9% in both groups (difference, -0.06 percentage points; 95% CI, -0.97 to 0.84; hazard ratio, 0.99; 95% CI, 0.78 to 1.25; P<0.001 for noninferiority). CONCLUSIONS: Among high-risk patients who underwent PCI and completed 3 months of dual antiplatelet therapy, ticagrelor monotherapy was associated with a lower incidence of clinically relevant bleeding than ticagrelor plus aspirin, with no higher risk of death, myocardial infarction, or stroke. (Funded by AstraZeneca; TWILIGHT ClinicalTrials.gov number, NCT02270242.)

Integrated Approach Reveals Role of Mitochondrial Germ-Line Mutation F18L in Respiratory Chain, Oxidative Alterations, Drug Sensitivity, and Patient Prognosis in Glioblastoma

Glioblastoma is the most common and malignant primary brain tumour in adults, with a dismal prognosis. This is partly due to considerable inter- and intra-tumour heterogeneity. Changes in the cellular energy-producing mitochondrial respiratory chain complex (MRC) activities are a hallmark of glioblastoma relative to the normal brain, and associate with differential survival outcomes. Targeting MRC complexes with drugs can also facilitate anti-glioblastoma activity. Whether mutations in the mitochondrial DNA (mtDNA) that encode several components of the MRC contribute to these phenomena remains underexplored. We identified a germ-line mtDNA mutation (m. 14798T &gt; C), enriched in glioblastoma relative to healthy controls, that causes an amino acid substitution F18L within the core mtDNA-encoded cytochrome b subunit of MRC complex III. F18L is predicted to alter corresponding complex III activity, and sensitivity to complex III-targeting drugs. This could in turn alter reactive oxygen species (ROS) production, cell behaviour and, consequently, patient outcomes. Here we show that, despite a heterogeneous mitochondrial background in adult glioblastoma patient biopsy-derived cell cultures, the F18L substitution associates with alterations in individual MRC complex activities, in particular a 75% increase in MRC complex II_III activity, and a 34% reduction in CoQ10, the natural substrate for MRC complex III, levels. Downstream characterisation of an F18L-carrier revealed an 87% increase in intra-cellular ROS, an altered cellular distribution of mitochondrial-specific ROS, and a 64% increased sensitivity to clomipramine, a repurposed MRC complex III-targeting drug. In patients, F18L-carriers that received the current standard of care treatment had a poorer prognosis than non-carriers (373 days vs. 415 days, respectively). Single germ-line mitochondrial mutations could predispose individuals to differential prognoses, and sensitivity to mitochondrial targeted drugs. Thus, F18L, which is present in blood could serve as a useful non-invasive biomarker for the stratification of patients into prognostically relevant groups, one of which requires a lower dose of clomipramine to achieve clinical effect, thus minimising side-effects

Phonons in Slow Motion: Dispersion Relations in Ultra-Thin Si Membranes

We report the changes in dispersion relations of hypersonic acoustic phonons in free-standing silicon membranes as thin as \sim 8 nm. We observe a reduction of the phase and group velocities of the fundamental flexural mode by more than one order of magnitude compared to bulk values. The modification of the dispersion relation in nanostructures has important consequences for noise control in nano and micro-electromechanical systems (MEMS/NEMS) as well as opto-mechanical devices.Comment: 5 page

A phase I oncolytic virus trial with vesicular stomatitis virus expressing human interferon beta and tyrosinase related protein 1 administered intratumorally and intravenously in uveal melanoma: safety, efficacy, and T cell responses

IntroductionMetastatic uveal melanoma (MUM) has a poor prognosis and treatment options are limited. These patients do not typically experience durable responses to immune checkpoint inhibitors (ICIs). Oncolytic viruses (OV) represent a novel approach to immunotherapy for patients with MUM.MethodsWe developed an OV with a Vesicular Stomatitis Virus (VSV) vector modified to express interferon-beta (IFN-β) and Tyrosinase Related Protein 1 (TYRP1) (VSV-IFNβ-TYRP1), and conducted a Phase 1 clinical trial with a 3 + 3 design in patients with MUM. VSV-IFNβ-TYRP1 was injected into a liver metastasis, then administered on the same day as a single intravenous (IV) infusion. The primary objective was safety. Efficacy was a secondary objective.Results12 patients with previously treated MUM were enrolled. Median follow up was 19.1 months. 4 dose levels (DLs) were evaluated. One patient at DL4 experienced dose limiting toxicities (DLTs), including decreased platelet count (grade 3), increased aspartate aminotransferase (AST), and cytokine release syndrome (CRS). 4 patients had stable disease (SD) and 8 patients had progressive disease (PD). Interferon gamma (IFNγ) ELIspot data showed that more patients developed a T cell response to virus encoded TYRP1 at higher DLs, and a subset of patients also had a response to other melanoma antigens, including gp100, suggesting epitope spreading. 3 of the patients who responded to additional melanoma antigens were next treated with ICIs, and 2 of these patients experienced durable responses.DiscussionOur study found that VSV-IFNβ -TYRP1 can be safely administered via intratumoral (IT) and IV routes in a previously treated population of patients with MUM. Although there were no clear objective radiographic responses to VSV-IFNβ-TYRP1, dose-dependent immunogenicity to TYRP1 and other melanoma antigens was seen

Effects of anti-PD-1 mAb or control treatment on HIV viral loads in chronically infected BLT mice.

<p>BLT mice infected with HIV-1 for 13 weeks were injected intraperitoneally with anti-PD-1 mAb, control mAb, or no Ab on days 0, 3, 7 and 10 (200 µg/dose, arrow). Peripheral blood was collected at multiple time points and HIV-1 plasma viral load was measured by quantitative RT-PCR. Graph represents mean viral load of Control (n = 10, control mAb or no Ab), anti-PD-1 mAb-treated PD1-LO mice (n = 3), and anti-PD-1 mAb-treated PD1-HI mice (n = 5). *<i>P</i><0.05, Mann-Whitney test.</p