Epigenetic proteins are intently pursued targets in ligand discovery. To date, successful efforts have been limited to chromatin modifying enzymes, or so-called epigenetic “writers” and “erasers”. Potent inhibitors of histone binding modules have not yet been described. Here we report a cell-permeable small molecule (JQ1) which binds competitively to acetyl-lysine recognition motifs, or bromodomains. High potency and specificity toward a subset of human bromodomains is explained by co-crystal structures with BRD4, revealing excellent shape complementarity with the acetyl-lysine binding cavity. Recurrent translocation of BRD4 is observed in a genetically-defined, incurable subtype of human squamous carcinoma. Competitive binding by JQ1 displaces the BRD4 fusion oncoprotein from chromatin, prompting squamous differentiation and specific anti-proliferative effects in BRD4-dependent cell lines and patient-derived xenograft models. These data establish proof of concept for targeting protein-protein interactions of epigenetic “readers” and provide a versatile chemical scaffold for the development of chemical probes more broadly throughout the bromodomain family.

BACKGROUND Hereditary angioedema is characterized by recurrent attacks of angioedema of the skin, larynx, and gastrointestinal tract. Bradykinin is the key mediator of symptoms. Icatibant is a selective bradykinin B2 receptor antagonist. METHODS In two double-blind, randomized, multicenter trials, we evaluated the effect of icatibant in patients with hereditary angioedema presenting with cutaneous or abdominal attacks. In the For Angioedema Subcutaneous Treatment (FAST) 1 trial, patients received either icatibant or placebo; in FAST-2, patients received either icatibant or oral tranexamic acid, at a dose of 3 g daily for 2 days. Icatibant was given once, subcutaneously, at a dose of 30 mg. The primary end point was the median time to clinically significant relief of symptoms. RESULTS A total of 56 and 74 patients underwent randomization in the FAST-1 and FAST-2 trials, respectively. The primary end point was reached in 2.5 hours with icatibant versus 4.6 hours with placebo in the FAST-1 trial (P = 0.14) and in 2.0 hours with icatibant versus 12.0 hours with tranexamic acid in the FAST-2 trial (P<0.001). In the FAST-1 study, 3 recipients of icatibant and 13 recipients of placebo needed treatment with rescue medication. The median time to first improvement of symptoms, as assessed by patients and by investigators, was significantly shorter with icatibant in both trials. No icatibant-related serious adverse events were reported. CONCLUSIONS In patients with hereditary angioedema having acute attacks, we found a significant benefit of icatibant as compared with tranexamic acid in one trial and a nonsignificant benefit of icatibant as compared with placebo in the other trial with regard to the primary end point. The early use of rescue medication may have obscured the benefit of icatibant in the placebo trial. (Funded by Jerini; ClinicalTrials.gov numbers, NCT00097695 and NCT00500656.)

Gain-of-function mutations in a serine protease, proprotein convertase subtilisin/kexin 9 (PCSK9), have been associated with high plasma levels of low-density lipoprotein (LDL) cholesterol and an increased incidence of coronary heart disease. Previous studies showed that PCSK9 loss-of-function mutations in patients were associated with low levels of LDL cholesterol and a reduced incidence of coronary heart disease. This suggested that pharmacologic inhibition of PCSK9 could lower LDL cholesterol levels in patients with hypercholesterolemia. REGN727/SAR236553 (REGN727) is an investigational, fully human monoclonal antibody highly specific for human PCSK9. This antibody blocks the interaction of PCSK9 with LDL receptors.This report presents the results of 3 phase 1 studies of REGN727 in humans. The participants were healthy volunteers and patients with familial or nonfamilial hypercholesterolemia. Three separate clinical studies of REGN727 were conducted. The first two compared the effect of single doses of REGN727, administered either intravenously (n = 40) or subcutaneously (n = 32), in healthy volunteers and a placebo. After these 2 single-dose studies, a randomized, placebocontrolled multiple-dose trial that investigated the effect of REGN727in 3 separate cohorts with hypercholesterolemia was conducted. The first cohort was composed of 21 subjects with heterozygous familial hypercholesterolemia and the second cohort consisted of 30 subjects with nonfamilial hypercholesterolemia. All patients in these 2 cohorts were receiving atorvastatin therapy and had a baseline LDL cholesterol level greater than 100 mg/dL (2.6 mM). The third cohort was composed of 10 subjects with nonfamilial hypercholesterolemia who had a baseline LDL cholesterol level greater than 130 mg/dL (3.4 mM); these patients were treated only with a modified diet.Patients in the multiple-dose study were randomly assigned to receive subcutaneous REGN727 (50, 100, or 150 mg) or placebo administered on days 1, 29, and 43. The primary study outcome was the incidence of adverse events. The major secondary end point evaluated was the effect of REGN727 on the lipid profile.None of the subjects receiving REGN727 withdrew from the study early because of an adverse event. There was a significant reduction in levels of LDL cholesterol among patients receiving REGN727 in all studies. Levels of LDL in the multiple-dose study were as follows: REGN727 doses of 50, 100, and 150 mg reduced LDL levels in the combined atorvastatin-treated populations to 77.5 mg/dL (2.00 mL), 61.3 mg/dL (1.59 mL), and 53.8 mg/dL (1.39 mL), respectively; differences in the change from baseline with the 50-, 100-, and 150-mg doses were j39.2, j53.7, and j61.0 percentage points compared with placebo (P G 0.001 for all 3 comparisons).These phase 1 trials suggest a role for PCSK9 in the regulation of LDL cholesterol in humans.

Diuretics are frequently required to treat fluid retention in patients with congestive heart failure (CHF). Unfortunately, they can lead to a decline in renal function, electrolyte depletion, and neurohumoral activation. Arginine vasopressin (AVP) promotes renal water reabsorption via the V2 receptor, and its levels are increased in CHF. This study was designed to assess the effects of a single oral dose of tolvaptan, a selective V2-receptor blocker, in the absence of other medications, on renal function in human CHF and to compare this to the effects of a single oral dose of furosemide. We hypothesized that V2-receptor antagonism would yield a diuresis comparable to furosemide but would not adversely affect renal hemodynamics, plasma electrolyte concentration, or neurohumoral activation in stable human CHF. Renal and neurohumoral effects of tolvaptan and furosemide were assessed in an open-label, randomized, placebo-controlled crossover study in 14 patients with NYHA II-III CHF. Patients received placebo or 30 mg of tolvaptan on day 1 and were crossed over to the other medication on day 3. On day 5, all subjects received 80 mg of furosemide. Tolvaptan and furosemide induced similar diuretic responses. Unlike tolvaptan, furosemide increased urinary sodium and potassium excretion and decreased renal blood flow. Tolvaptan, furosemide, and placebo did not differ with respect to mean arterial pressure, glomerular filtration rate, or serum sodium and potassium. We conclude that tolvaptan is an effective aquaretic with no adverse effects on renal hemodynamics or serum electrolytes in patients with mild to moderate heart failure.

In three phase 1 trials, a monoclonal antibody to PCSK9 significantly reduced LDL cholesterol levels in healthy volunteers and in subjects with familial or nonfamilial hypercholesterolemia. (Funded by Regeneron Pharmaceuticals and Sanofi; ClinicalTrials.gov numbers, NCT01026597, NCT01074372, and NCT01161082.).

The bioavailability, pharmacokinetics, and pharmacodynamics of torsemide (10 mg orally and intravenously) and furosemide (40 mg orally and 20 mg intravenously) were determined in a randomized crossover clinical trial in 16 patients with compensated congestive heart failure. Torsemide (time to reach maximum concentration [tmax], 1.1 +/- 0.9 hour) was more rapidly absorbed than furosemide (tmax, 2.4 +/- 2.5 hours), the absorption of which was delayed compared with that in healthy volunteers. Bioavailability of torsemide was also greater and less variable than that of furosemide. All four treatments yielded comparable changes from baseline in 24-hour electrolyte excretion. Based on the relationships between sodium excretion rate and fractional sodium and urinary drug excretion rate, response to both diuretic agents at the level of the nephron was decreased compared with previous studies with healthy subjects. Assessment of the clinical relevance, if any, of the difference in the variability of absorption warrants further study.

Neuropsychological investigations of art production and perception have the potential to offer critical insight into the biology of visual aesthetics. Thus far, however, investigations of art production in patients have been limited to anecdotal observations and investigations of art perception are non-existent. Progress in the field is hampered by the lack of an adequate instrument to provide basic quantification of artwork attributes. Motivated by the need to move neuropsychology of art beyond the fascinating anecdote, we present the Assessment of Art Attributes (AAA). The AAA is an instrument designed to assess six formal-perceptual and six conceptual-representational attributes using 24 paintings from the Western canon. Both artistically naïve and experienced participants were given the AAA. We found high degrees of agreement in the assessment of these attributes in both groups and few differences between the groups. We expect that the AAA's componential and quantitative approach will be useful in advancing neuropsychological studies as well as any investigations in which style and content of art works need to be quantified and compared.Since the time of Broca and Wernicke, the study of individuals with brain damage has provided unique insights into the biological basis of behavior. Thus, by the 207 Ó 2010, Baywood Publishing Co., Inc.

A vast number of small-molecule ligands, including therapeutic drugs under development and in clinical use, elicit their effects by binding specific proteins associated with the genome. An ability to map the direct interactions of a chemical entity with chromatin genome-wide could provide new and important insights into chemical perturbation of cellular function. Here we describe a method that couples ligand-affinity capture and massively parallel DNA sequencing (Chem-seq) to identify the sites bound by small chemical molecules throughout the human genome. We show how Chem-seq can be combined with ChIP-seq to gain unique insights into the interaction of drugs with their target proteins throughout the genome of tumor cells. These methods provide a powerful approach to enhance understanding of therapeutic action and characterize the specificity of chemical entities that interact with DNA or genome-associated proteins.