Identification of an antibody-based immunoassay for measuring direct target binding of RIPK1 inhibitors in cells and tissues.

Therapies that suppress RIPK1 kinase activity are emerging as promising therapeutic agents for the treatment of multiple inflammatory disorders. The ability to directly measure drug binding of a RIPK1 inhibitor to its target is critical for providing insight into pharmacokinetics, pharmacodynamics, safety and clinical efficacy, especially for a first-in-class small-molecule inhibitor where the mechanism has yet to be explored. Here, we report a novel method for measuring drug binding to RIPK1 protein in cells and tissues. This TEAR1 (Target Engagement Assessment for RIPK1) assay is a pair of immunoassays developed on the principle of competition, whereby a first molecule (ie, drug) prevents the binding of a second molecule (ie, antibody) to the target protein. Using the TEAR1 assay, we have validated the direct binding of specific RIPK1 inhibitors in cells, blood and tissues following treatment with benzoxazepinone (BOAz) RIPK1 inhibitors. The TEAR1 assay is a valuable tool for facilitating the clinical development of the lead RIPK1 clinical candidate compound, GSK2982772, as a first-in-class RIPK1 inhibitor for the treatment of inflammatory disease.

The Identification and Pharmacological Characterization of 6-(tert-Butylsulfonyl)-N-(5-fluoro-1H-indazol-3-yl)quinolin-4-amine (GSK583), a Highly Potent and Selective Inhibitor of RIP2 Kinase.

RIP2 kinase is a central component of the innate immune system and enables downstream signaling following activation of the pattern recognition receptors NOD1 and NOD2, leading to the production of inflammatory cytokines. Recently, several inhibitors of RIP2 kinase have been disclosed that have contributed to the fundamental understanding of the role of RIP2 in this pathway. However, because they lack either broad kinase selectivity or strong affinity for RIP2, these tools have only limited utility to assess the role of RIP2 in complex environments. We present, herein, the discovery and pharmacological characterization of GSK583, a next-generation RIP2 inhibitor possessing exquisite selectivity and potency. Having demonstrated the pharmacological precision of this tool compound, we report its use in elucidating the role of RIP2 kinase in a variety of in vitro, in vivo, and ex vivo experiments, further clarifying our understanding of the role of RIP2 in NOD1 and NOD2 mediated disease pathogenesis.

Incidence of sinusoidal obstruction syndrome following Mylotarg (gemtuzumab ozogamicin): a prospective observational study of 482 patients in routine clinical practice.

The purpose of this prospective observational study was to determine the incidence of hepatic sinusoidal obstruction syndrome (SOS), following gemtuzumab ozogamicin (GO) therapy in routine clinical practice. Patients receiving GO for acute myeloid leukemia (AML) were eligible. Assessments were requested to be performed weekly for 6 weeks after the start of GO therapy or 4 weeks after the last dose (whichever was later), and after 6 months. The primary outcome variable was the incidence of SOS as judged by a panel of independent experts. A total of 512 patients were enrolled at 54 US centers and 482 were evaluable. The incidence of SOS in this study population was 9.1 % (44/482; 95 % confidence interval 6.9-12.0 %). Of the 44 patients classified as having SOS, 8 were mild, 17 moderate, and 19 severe; 33 died within 6 months (20 of disease progression and 13 of SOS and multiorgan failure). Most (68 %) patients in the study died within 6 months; most of these deaths (73 %) were due to progression of AML. Serious adverse events occurred in 85 % of patients, most (81 %) due to AML, febrile neutropenia, pyrexia, and sepsis. GO administered in routine clinical practice carries an overall 9.1 % risk of SOS and a 2.7 % risk of death from SOS and multiorgan failure. No risk factors were identified for the development of SOS.

Autolytic proteolysis within the function to find domain (FIIND) is required for NLRP1 inflammasome activity.

Nucleotide-binding domain leucine-rich repeat proteins (NLRs) play a key role in immunity and disease through their ability to modulate inflammation in response to pathogen-derived and endogenous danger signals. Here, we identify the requirements for activation of NLRP1, an NLR protein associated with a number of human pathologies, including vitiligo, rheumatoid arthritis, and Crohn disease. We demonstrate that NLRP1 activity is dependent upon ASC, which associates with the C-terminal CARD domain of NLRP1. In addition, we show that NLRP1 activity is dependent upon autolytic cleavage at Ser(1213) within the FIIND. Importantly, this post translational event is dependent upon the highly conserved distal residue His(1186). A disease-associated single nucleotide polymorphism near His(1186) and a naturally occurring mRNA splice variant lacking exon 14 differentially affect this autolytic processing and subsequent NLRP1 activity. These results describe key molecular pathways that regulate NLRP1 activity and offer insight on how small sequence variations in NLR genes may influence human disease pathogenesis.

Prevalence of apolipoprotein E4 genotype and homozygotes (APOE e4/4) among patients diagnosed with Alzheimer's disease: a systematic review and meta-analysis.

BACKGROUND: Population allele frequencies of apolipoprotein E (APOE) vary by geographic region. The purpose of this study is to summarize and evaluate published estimates for the prevalence of APOE e4 carrier status among the population diagnosed with Alzheimer's disease (AD) by geographic region and country. METHODS: A systematic review of English-language publications from January 1, 1985, through May 31, 2010, was conducted. Studies reporting APOE e4 status for patients diagnosed with AD were included in the analysis; trials and autopsies were excluded. APOE e4 data were pooled, and prevalence and 95% confidence intervals (CIs) were calculated. RESULTS: Pooled estimates for APOE e4 carrier prevalence data were derived from 142 independent samples: 48.7% (95% CI: 46.5-51.0), and from 73 samples for e4/4 (homozygotes): 9.6% (95% CI: 8.4-10.8). The highest estimates were in Northern Europe: 61.3% (95% CI: 55.9-66.7), e4/4 prevalence: 14.1% (95% CI: 12.2-16.0). The lowest estimates were in Asia and Southern Europe. Substantial heterogeneity of these prevalence estimates was observed. CONCLUSIONS: APOE e4 genotype prevalence varies among AD patients by region and within each country. Further exploration is warranted to better understand the substantial heterogeneity of these prevalence estimates.

Hip fracture risk and subsequent mortality among Alzheimer's disease patients in the United Kingdom, 1988-2007.

BACKGROUND: hip fractures result in a significant burden to the patient, their caregivers and the health care system. Patients with Alzheimer's disease (AD) have a higher incidence of hip fracture compared with other older people without AD, although it is not clear if AD is an independent risk factor for hip fracture. METHODS: a retrospective cohort study was conducted using anonymised electronic medical records from primary care practices in the United Kingdom. Proportional hazards regression modelling with adjustment for potential confounders was used to evaluate AD as an independent risk factor for predicting hip fractures. RESULTS: the incidence of hip fracture among patients with and without AD was 17.4 (95% CI, 15.7-19.2) and 6.6 (95% CI, 5.8-7.6) per 1,000 person years, respectively. Patients with AD had a hazard that was 3.2 (95% CI, 2.4-4.2) times that of non-AD patients after controlling for potential confounders. AD patients who experienced a hip fracture also had an increased mortality rate compared with non-AD patients who experienced a hip fracture (hazard ratio = 1.5; 95% CI, 1.1-1.9). CONCLUSION: patients with AD and their caregivers should be advised on how to prevent hip fractures and more attention should be given to AD patients who are undergoing rehabilitation following a hip fracture.

Apolipoprotein E ε4 prevalence in Alzheimer's disease patients varies across global populations: a systematic literature review and meta-analysis.

BACKGROUND: The ε4 allele of apolipoprotein E (APOE) is associated with Alzheimer's disease (AD). However, attributable risk due to APOE4 varies by region and by race/ethnicity. METHODS: A literature review and meta-analysis were conducted to estimate the prevalence of APOE4 by geographic area among AD patients. RESULTS: Although estimates varied significantly by study design and case definition, AD patients recruited in Asian and southern European/Mediterranean communities seemed to have significantly lower E4 carrier status estimates (37 and 43%) than those recruited in North America (58%) or northern Europe (64%; all: p < 0.05). CONCLUSIONS: APOE4 genotype frequency varies among AD patients in regional patterns similar to that of the general population. Study level differences may also contribute to the heterogeneity of published estimates of APOE4 in AD cases.

Glycemic control continues to deteriorate after sulfonylureas are added to metformin among patients with type 2 diabetes.

OBJECTIVE: To describe the course and predictors of glycemic control among patients with type 2 diabetes after sulfonylureas (SUs) are added to metformin (MF). RESEARCH DESIGN AND METHODS: Patients (n = 2,220) treated with MF monotherapy for >90 days before initiating MF plus SU combination therapy between January 1998 and March 2004 were studied in a retrospective analysis of electronic medical records from U.K. primary care practices using the General Practice Research Database. Median glycoslyated hemoglobin A(1c) (A1C) before and after SU initiation was described, and patient characteristics were evaluated as predictors of time until A1C > or =8.0% or glucose-lowering therapy was intensified (by starting insulin or adding a third oral agent). RESULTS: At 6 months post-SU initiation, median A1C resumed deteriorating at a somewhat comparable rate to that observed on MF monotherapy. Higher pre-SU A1C, younger age, female sex, shorter diabetes duration, higher serum creatinine, and being an ex-smoker predicted time until A1C > or =8.0% or glucose-lowering therapy was intensified in various analyses. Median A1C was 9.5% when therapy was intensified. A1C > or =8.0% was estimated to occur in 85% of patients 4 years after SU initiation and in 68% 4 years after initially achieving A1C <7% on MF plus SU therapy. CONCLUSIONS: In this population, glycemic control is improved following the addition of SUs to MF, but deterioration resumes as early as 6 months. The high proportion of patients remaining on MF plus SU therapy despite having A1C > or =8.0% suggests that there are significant barriers to starting insulin or adding a third agent when treatment goals are not achieved with this combination.

Maternal medication use and neuroblastoma in offspring.

The association between a mother's use of specific medications during pregnancy and lactation and neuroblastoma in her offspring was evaluated in a case-control study. Newly diagnosed cases of neuroblastoma (n=504) in the United States and Canada were identified between 1992 and 1994 at 139 hospitals affiliated with the Pediatric Oncology Group or the Children's Cancer Group clinical trial programs. One age-matched control was sampled from the community of each case by means of random digit dialing. Exposure information was ascertained retrospectively from mothers in a structured telephone interview. Odds ratios were estimated using conditional logistic regression, with adjustment for maternal sociodemographic factors. The results did not support an association between neuroblastoma and maternal exposure to diuretic agents, antiinfective agents, estrogens, progestins, sedatives, anticonvulsant drugs, or drugs that may form N-nitroso derivatives. Mothers of cases were more likely to report using medications containing opioid agonists while they were pregnant or nursing than were mothers of controls (odds ratio=2.4, 95% confidence interval: 1.3, 4.3). Specifically, more mothers of cases reported using medications containing codeine while pregnant or nursing than did mothers of controls (odds ratio=3.4, 95% confidence interval: 1.4, 8.4). This preliminary finding may be due to bias, confounding, or chance, and additional studies are needed for confirmation.

Proteoglycan degradation after injurious compression of bovine and human articular cartilage in vitro: interaction with exogenous cytokines.

OBJECTIVE: Traumatic joint injury leads to an increased risk of osteoarthritis (OA), but the progression to OA is not well understood. We undertook this study to measure aspects of proteoglycan (PG) degradation after in vitro injurious mechanical compression, including up-regulation of enzymatic degradative expression and cytokine-stimulated degradation. METHODS: Articular cartilage tissue explants were obtained from newborn bovine femoropatellar groove and from adult normal human donor knee and ankle tissue. Following injurious compression of the cartilage, matrix metalloproteinase 3 (MMP-3) and MMP-13 messenger RNA (mRNA) expression levels were measured by Northern analysis, and PG loss to the medium after cartilage injury was measured in the presence and absence of added exogenous cytokine (interleukin-1alpha [IL-1alpha] or tumor necrosis factor alpha [TNFalpha]). RESULTS: During the first 24 hours after injury in bovine cartilage, MMP-3 mRNA levels increased 10-fold over the levels in control cartilage (n = 3 experiments), whereas MMP-13 mRNA levels were unchanged. PG loss was significantly increased after injury, but only by 2% of the total PG content and only for the first 3 days following injury. However, compared with injury alone or cytokine treatment alone, treatment of injured tissue with either 1 ng/ml IL-1alpha or 100 ng/ml TNFalpha caused marked increases in PG loss (35% and 54%, respectively, of the total cartilage PG content). These interactions between cytokine treatment and injury were statistically significant. In human knee cartilage, the interaction was also significant for both IL-1alpha and TNFalpha, although the magnitude of increase in PG loss was lower than that in bovine cartilage. In contrast, in human ankle cartilage, there was no significant interaction between injury and IL-1alpha. CONCLUSION: The cytokines IL-1alpha and TNFalpha can cause a synergistic loss of PG from mechanically injured bovine and human cartilage. By attempting to incorporate interactions with other joint tissues that may be sources of cytokines, in vitro models of mechanical cartilage injury may explain aspects of the interactions between mechanical forces and degradative pathways which lead to OA progression.