Efficacy, safety, and tolerability of a monoclonal antibody to proprotein convertase subtilisin/kexin type 9 in combination with a statin in patients with hypercholesterolaemia (LAPLACE-TIMI 57): a randomised, placebo-controlled, dose-ranging, phase 2 study.

BACKGROUND: LDL cholesterol (LDL-C) is a well established risk factor for cardiovascular disease. Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds LDL receptors, targeting them for degradation. We therefore assessed the efficacy, safety, and tolerability of AMG 145, a human monoclonal IgG2 antibody against PCSK9, in stable patients with hypercholesterolemia on a statin. METHODS: In a phase 2, dose-ranging study done in 78 centres in the USA, Canada, Denmark, Hungary, and Czech Republic, patients (aged 18-80 years) with LDL-C greater than 2·2 mmol/L on a stable dose of statin (with or without ezetimibe), were randomly assigned equally, through an interactive voice response system, to subcutaneous injections of AMG 145 70 mg, 105 mg, or 140 mg, or matching placebo every 2 weeks; or subcutaneous injections of AMG 145 280 mg, 350 mg, or 420 mg, or matching placebo every 4 weeks. Everyone was masked to treatment assignment within the every 2 weeks and every 4 weeks schedules. The primary endpoint was the percentage change in LDL-C concentration from baseline after 12 weeks. Analysis was by modified intention to treat. This study is registered with ClinicalTrials.gov, number NCT01380730. FINDINGS: 631 patients with hypercholesterolaemia were randomly assigned to AMG 145 70 mg (n=79), 105 mg (n=79), or 140 mg (n=78), or matching placebo (n=78) every 2 weeks; or AMG 145 280 mg (n=79), 350 mg (n=79), and 420 mg (n=80), and matching placebo (n=79) every 4 weeks. At the end of the dosing interval at week 12, the mean LDL-C concentrations were reduced generally dose dependently by AMG 145 every 2 weeks (ranging from 41·8% to 66·1%; p<0·0001 for each dose vs placebo) and AMG 145 every 4 weeks (ranging from 41·8% to 50·3%; p<0·0001). No treatment-related serious adverse events occurred. The frequencies of treatment-related adverse events were similar in the AMG 145 and placebo groups (39 [8%] of 474 vs 11 [7%] of 155); none of these events were severe or life-threatening. INTERPRETATION: The results suggest that PCSK9 inhibition could be a new model in lipid management. Inhibition of PCSK9 warrants assessment in phase 3 clinical trials. FUNDING: Amgen.

Pathogenesis of hepatitis E virus and hepatitis C virus in chimpanzees: similarities and differences.

The chimpanzee is the only animal model for investigating the pathogenesis of viral hepatitis types A through E in humans. Studies of the host response, including microarray analyses, have relied on the close relationship between these two primate species: chimpanzee samples are commonly tested with human-based reagents. In this study, the host responses to two dissimilar viruses, hepatitis E virus (HEV) and hepatitis C virus (HCV), were compared in multiple experimentally infected chimpanzees. Affymetrix U133+2.0 human microarray chips were used to assess the entire transcriptome in serial liver biopsies obtained over the course of the infections. Respecting the limitations of microarray probes designed for human target transcripts to effectively assay chimpanzee transcripts, we conducted probe-level analysis of the microarray data in conjunction with a custom mapping of the probe sequences to the most recent human and chimpanzee genome sequences. Time points for statistical comparison were chosen based on independently measured viremia levels. Regardless of the viral infection, the alignment of differentially expressed genes to the human genome sequence resulted in a larger number of genes being identified when compared with alignment to the chimpanzee genome sequence. This probably reflects the lesser refinement of gene annotation for chimpanzees. In general, the two viruses demonstrated very distinct temporal changes in host response genes, although both RNA viruses induced genes that were involved in many of the same biological systems, including interferon-induced genes. The host response to HCV infection was more robust in the magnitude and number of differentially expressed genes compared to HEV infection.

Expression analysis of genes identified by molecular profiling of VGP melanomas and MGP melanoma-positive lymph nodes.

Microarray profiling is a powerful approach to establish gene expression patterns for different histopathological stages of a malignancy, and at the same time, to identify individual genes that may have important functions in the early and/or advanced stages of a neoplasm. To identify genes that hitherto have not been shown to be expressed or play a role in advanced-stage melanomas, we conducted microarray analyses with RNAs from primary melanoma and melanoma-positive lymph node specimens. Using RT-PCR, quantitative, real-time RT-PCR, and fluorochrome oligonucleotide-based optical imaging, we established the level and pattern of expression of five of the identified known genes [Suppression of Tumorigenicity 13 (ST13), Cystatin 8 (CST-8), Dyskeratosis Congentia 1 (DKC1), Neuroendocrine Secretory Protein 55 (NESP55), Niemann-Pick Disease, type C2 (NP-C2)], and a gene with unknown function (16.7 kD Hypothetical Protein) in benign and atypical nevocytic lesions, advanced-stage melanomas, and melanoma-positive lymph nodes.

Design and rationale of the LAPLACE-TIMI 57 trial: a phase II, double-blind, placebo-controlled study of the efficacy and tolerability of a monoclonal antibody inhibitor of PCSK9 in subjects with hypercholesterolemia on background statin therapy.

Lowering low-density lipoprotein cholesterol (LDL-C) is a cornerstone for the prevention of atherosclerotic heart disease, improving clinical outcomes and reducing vascular mortality in patients with hypercholesterolemia. The clinical benefits of LDL-C reduction appear to extend even to patients starting with LDL-C as low as 60-80 mg/dL prior to initiating therapy. Statins are the first-line agents for treating hypercholesterolemia and are effective in reducing LDL-C, but many patients are unable to achieve their optimal lipid targets despite intensive statin therapy. Therefore, there has been a strong impetus for the development of novel pharmacologic agents designed to lower LDL-C further in patients already on statin therapy. Genetic mutations resulting in altered cholesterol homeostasis provide valuable information regarding novel approaches for treating hypercholesterolemia. To that end, mutations in proprotein convertase subtilisin/kexin type 9 (PCSK9) were linked to altered levels of LDL-C, illustrating this protein's role in lipid metabolism. PCSK9 promotes degradation of the LDL receptor, preventing its transport back to the cell surface and thereby increasing circulating LDL-C. Conversely, inhibition of PCSK9 can profoundly decrease circulating LDL-C, and thus is an attractive new target for LDL-C-lowering therapy. AMG 145 is a fully human monoclonal immunoglobulin G2 antibody that binds specifically to human PCSK9 and inhibits its interaction with the low-density lipoprotein receptor. In this manuscript, we describe the rationale and design of LDL-C Assessment with PCSK9 Monoclonal Antibody Inhibition Combined With Statin Therapy-Thrombolysis In Myocardial Infarction 57 (LAPLACE-TIMI 57; NCT01380730), a 12-week, randomized, double-blind, dose-ranging, placebo-controlled study designed to assess the safety and efficacy of AMG 145 when added to statin therapy in patients with hypercholesterolemia.

Susceptibility of human T cell leukemia virus type I to nucleoside reverse transcriptase inhibitors.

A single-cycle infection assay with recombinant viral vectors was developed to study human T cell leukemia virus type I (HTLV-I) replication and its inhibition by antiviral agents. The susceptibility of HTLV-I to 6 nucleoside reverse-transcriptase inhibitors was examined. HTLV-I replication was inhibited by tenofovir, abacavir, lamivudine, zalcitabine, stavudine, and zidovudine.