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Immunogenicity, the potential to elicit an antidrug immune response, is a critical concern in developing biological products, but its consequences are difficult to predict with animal studies. The aims of the present study are to investigate the evolution of immunogenicity information in labeling and to identify attributes associated with immunogenicity labeling updates. Biologics License Applications (BLAs) approved by the Center for Drug Evaluation and Research, US Food and Drug Administration between 2008 and 2017 were studied. A majority of BLAs described the incidence/prevalence of antidrug antibodies (ADAs) (94.9%) and neutralizing antibodies (NAbs) (68.4%) in their original labeling documents. However, less than one third of the BLAs mentioned the impact of ADAs/NAbs in the original (20.3%) and most recent (29.1%) labeling documents. BLAs with a priority review status (57.4% vs. 33.3%), orphan designation (61.5% vs. 34.2%), or a mention of ADA impact in the latest label (69.6% vs. 38.9%) had higher percentages of applications with postmarketing requirements (PMRs) directly related to immunogenicity concerns in comparison with applications without those characteristics. Among the BLAs with updated immunogenicity information, the mean time to the first update was 1,077 days, while that for BLAs with accelerated approval was shorter (709.1 ± 492.2 days vs. 1173.8 ± 661.8 days). The results suggest that there is a substantial amount of critical information lacking in the original labeling documents and an overdependence on PMRs for more evidence. Additional efforts should be made to investigate the impact of ADAs to provide timely information for improved patient care.

The pace of innovation, the creative engine of the pharmaceutical industry, has been variably described as stagnant, stable, or accelerating depending on the metric used for assessment or the quality of evidence. If the predominant perception holds that the speed of innovation is sluggish, pressure for changes in the regulatory environment intensifies. A systematic evaluation of the course of innovation in this industry was performed by applying a formula derived from economic market share theory to estimate the innovative contribution of each new molecular entity approved since 1938. The total and average innovation scores per year are described based on the therapeutic class, mechanism, and drug target. These data are compared to the number and percent of first-in-class drugs per year. The average annual score based on therapeutic class novelty has been declining; however, the therapeutic class total innovation score has been stable since the mid-1970s with occasional significant peaks of activity. While the average score based on mechanism or target experienced a decline beginning in the 1950s and 1960s, it has begun to rise since the early 1990s. Notably, the total innovation score has steadily increased since the 1970s. These variations closely parallel the number of first-in-class drugs approved on an annual basis. While the reasons underlying these activities are likely complex, there is a temporal association between regulatory efforts to expedite drug development and approval. These findings should be considered when considering future incentivizing regulations and policies.

The aims of this study were to identify types of deficiencies resulting in delay of approvals for drugs eventually approved by the US FDA and to search for factors associated with higher first-cycle approval rates. Review documents of New Drug Applications approved between 2008 and 2017 were retrieved from the Drugs@FDA database. Basic characteristics of the applications, regulatory actions, and reasons for non-approvals and/or major amendments after first review cycle were investigated. Of 825 applications studied, 446 (54.1%) applications received first-cycle approvals without a review extension resulting from a major amendment. Non-approvals (240, 29.1%) were based primarily on chemistry/manufacturing/controls and safety reasons. A higher first-cycle approval rate was associated with factors related to unmet medical needs or innovative development. The association between higher first-cycle approval rates and innovative drugs or those addressing unmet needs reveals the FDA’s commitment in advancing innovation and protecting public health.

The drug development cycle is classically divided into a clinical phase and review phase, with the clinical phase typically being further partitioned based on the planning and conduct of adequate and well controlled trials. Factors affecting the duration of the development intervals have not previously been systematically investigated. Here, we analyze a large population (N=825) of New Drug Applications (NDAs) approved between 2008 and 2017 to characterize the typical duration of these intervals and the development factors associated with their duration. These data and analyses will help those involved in pharmaceutical development by enabling data-driven planning and by providing insight into the effect of certain factors on the duration of drug development programs.

Algorithmic Standardised MedDRA® Queries (aSMQs) are increasingly used to enhance the efficiency of safety signal detection. The manner that aSMQs affect capture of potential safety cases is unclear. Our objective was to characterise the performance of aSMQs with respect to their potential for double counting, the likelihood of events in aSMQ positive cases being clinically related, how frequently terms are used for algorithmically positive cases, and the face validity of positive cases based on the drug inducing events. We were also interested in what effect requiring symptoms to overlap temporally would have on performance. We reviewed adverse event (AE) datasets of New Drug Applications and Biological License Applications and compiled a database including preferred terms and corresponding SMQs, SMQ term categories, AE start day, AE duration, drug name, and Anatomical Therapeutic Chemical class. Two reviewers independently determined if the algorithm was met and, if so, whether the broad terms overlapped temporally. A total of 107 marketing applications were reviewed, including 103,928 patients and 277,430 AEs. Use of algorithms condensed the number of AEs to between 5 and 8% and the incidence to about 1.5% relative to when the SMQs are used without the algorithm. Certain aSMQs exhibited a potential for overcounting. Requiring symptoms to temporally overlap helped to eliminate irrelevant cases. Our findings demonstrate that algorithmic and temporal assessment increased specificity of case retrieval, though the reduction in the number of terms or incidence seemed excessive for certain aSMQs. Evaluating the day of AE onset and duration improve specificity through identification of outlying events. Identification of drug classes known to cause the aSMQ’s clinical condition provides face validity for this tool, yet detection of cases associated with novel classes may provide new understanding of these disorders. Improvements in some of the SMQ term lists may improve the performance of SMQs in general.

Purpose Biological drug products, or products derived from living cells, represent an increasingly important part of the pharmaceutical market. Despite this, little is known about how sponsors determine the dose to be studied in registrational trials or to be proposed in labeling for biologics. We examined how exposure–response and dose–response analyses were used to determine dosing in pivotal trials or the labeling for all biologics approved by the Center for Drug Evaluation and Research, the US Food and Drug Administration (FDA) between 2003 and 2016. Methods We extracted relevant characteristics of each biologic from its review package by FDA. We used descriptive statistics to characterize the rationale for the selected dose(s) in registration trials, with a particular focus on the role of exposure–response/dose–response analyses. We also examined how exposure–response/dose–response analyses were used to support the labeling dose and the basis for postmarketing requirements or commitments related to dose optimization. Findings A total of 79 biologics license applications were examined. Dose selection in registrational trials was more often attributed to clinical efficacy (73% of applications) than to clinical safety (42%). The dosing of products whose dose was apparently selected based on clinical efficacy was often (72%) determined by the dose–response relationship. In support of doses that were described in labeling, exposure–response analyses for efficacy were performed more commonly (53%) than dose–response analyses (21%). This trend was apparent after 2012. Implications This is the first study to summarize the justification of dose selection and the labeled dose of biologics approved by the FDA. Dose–response analyses have been often used as the rationale for dose selection of registrational studies, although exposure–response analyses are becoming more prevalent in support of the dosing guidelines in labeling.

Target product profiles (TPPs) are used as a regulatory tool for dialog on clinical development or manufacturing plans. Drugs and biologics approved by the FDA that mention TPPs are associated with more efficient regulatory review times, perhaps as a result of increased planning or because the TPP promotes well-organized regulatory dialog.

Purpose Standardised MedDRA Queries (SMQs) have been developed since the early 2000’s and used by academia, industry, public health, and government sectors for detecting safety signals in adverse event safety databases. The purpose of the present study is to characterize how SMQs are used and the impact in safety analyses for New Drug Application (NDA) and Biologics License Application (BLA) submissions to the United States Food and Drug Administration (USFDA). Methods We used the PharmaPendium database to capture SMQ use in Summary Basis of Approvals (SBoAs) of drugs and biologics approved by the USFDA. Characteristics of the drugs and the SMQ use were employed to evaluate the role of SMQ safety analyses in regulatory decisions and the veracity of signals they revealed. Results A comprehensive search of the SBoAs yielded 184 regulatory submissions approved from 2006 to 2015. Search strategies more frequently utilized restrictive searches with “narrow terms” to enhance specificity over strategies using “broad terms” to increase sensitivity, while some involved modification of search terms. A majority (59%) of 1290 searches used descriptive statistics, however inferential statistics were utilized in 35% of them. Commentary from reviewers and supervisory staff suggested that a small, yet notable percentage (18%) of 1290 searches supported regulatory decisions. The searches with regulatory impact were found in 73 submissions (40% of the submissions investigated). Most searches (75% of 227 searches) with regulatory implications described how the searches were confirmed, indicating prudence in the decision-making process. Conclusions SMQs have an increasing role in the presentation and review of safety analysis for NDAs/BLAs and their regulatory reviews. This study suggests that SMQs are best used for screening process, with descriptive statistics, description of SMQ modifications, and systematic verification of cases which is crucial for drawing regulatory conclusions.

Standardized MedDRA Queries (SMQs) are sets of terms determined by experts that are used to identify adverse events (AEs) related to different disease processes. Their use can be challenging because most SMQs have 50 to 100 preferred terms and AE databases can have many thousands of events. The aim of this study is to develop a technique where AEs corresponding to preferred terms in SMQs may be easily detected. The method I developed uses the Table Join function of the JMP ® software program to quickly and easily probe clinical trial AE databases. The SMQ Severe cutaneous adverse reactions was used as a probe in a mock AE dataset. Potentially confounding demographic or study-specific factors were evaluated by combining these datasets with the dataset containing the AEs identified with the SMQs. AEs were successfully detected in an AE database using the method described. Cases with potential confounding factors, such as concomitant medications, were identified. The method developed allows for AEs to be found in clinical trial databases and evaluated using software programs that are readily available to clinical researchers.

Objective: Major mental disorders are associated with an increased risk for obesity-related cardiovascular mortality, leading to interest in risk-reduction approaches that target weight and risk-related plasma lipids, including use of antipsychotic agents with low metabolic risk. This multicenter, randomized, double-blind study compared the metabolic effects of aripiprazole versus olanzapine in overweight persons with schizophrenia or schizoaffective disorder who were previously on olanzapine treatment. Method: In total, 173 subjects with DSM-IV-TR-defined schizophrenia or schizoaffective disorder were randomly assigned to receive aripiprazole (N = 88) or olanzapine (N = 85) for 16 weeks in a study conducted from March 30, 2004, to August 8, 2006. Primary and secondary endpoints were mean weight change from baseline and percentage change from baseline in fasting triglyceride levels, respectively. Results: At week 16, weight decreased significantly with aripiprazole versus olanzapine (-1.8 vs. +1.41 kg; p

The purpose of this study was to compare the efficacy and safety of aripiprazole with placebo in the treatment of alcoholics. In this 12-week multicenter, double-blind study, 295 patients with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition alcohol dependence were randomized to treatment with aripiprazole (initiated at 2 mg/d, titrated to a maximum dose of 30 mg/d at day 28) or placebo after screening, wherein patients maintained alcohol abstinence for 3 days or more. The primary efficacy measure was the percentage of days abstinent over 12 weeks. Discontinuations (40.3% vs 26.7%) and treatment-related adverse events (82.8% vs 63.6%) were higher with aripiprazole than with placebo. Mean percentage of days abstinent was similar between aripiprazole and placebo (58.7% vs 63.3%; P = 0.227). Percentage of subjects without a heavy drinking day and the time to first drinking day were also comparable between groups, although the aripiprazole group had fewer drinks per drinking day (4.4 vs 5.5 drinks; P < 0.001). The aripiprazole group showed a larger decrease in percent carbohydrate-deficient transferrin, a biomarker of heavy alcohol consumption at weeks 4 (-14.91% vs -2.23%; P = 0.020) and 8 (-16.92% vs -5.33%; P = 0.021), although not at week 12 (-9.06% vs -4.12%; P = 0.298). At study end point, aripiprazole-treated subjects reported more positive subjective treatment effects and less overall severity of alcohol dependence than placebo-treated subjects. Although there was no difference between aripiprazole and placebo on the primary end point, possibly because of dose-related attrition, effects on the secondary outcomes suggest that further study of aripiprazole for treatment of alcohol dependence may be warranted at lower doses.

Regulatory watch: The target product profile as a tool for regulatory communication: advantageous but underused

Study Objective: To determine whether intraoperative fluid management in spine surgery predicts postoperative intensive care unit length of stay (ICU LOS). Design: Retrospective case series. Setting: University-affiliated medical center. Patients: 103 adult ASA physical status I, II, and III patients undergoing spine surgery. Interventions: Patients were divided into three LOS groups: no ICU stay (LOS0) (n = 26), 1 day ICU stay (LOS1) (n = 48), and ICU stay > 1 day (LOS2) (n = 29). Measurements were analyzed by groups using the Kruskal-Wallis and Mann-Whitney tests, and linear regression. Measurements: Demographics, comorbidity, length of surgery, surgical procedure, and intraoperative fluids were recorded. Main Results: The important differences in perioperative fluid management among the three groups included estimated blood loss (612 ± 480 mL, 1853 ± 1175 mL, 2702 ± 1771 mL, means ± SD); total crystalloid administration (2715 ± 1396 mL, 5717 ± 2574 mL, 7281 ± 3417 mL); and total blood administration (92 ± 279 mL, 935 ± 757 mL, 1542 ± 1230 mL) in LOS0, LOS1, and LOS2, respectively. The mixture of surgical procedures was similar in LOS1 and LOS2; and differed from LOS0. Predictors of ICU LOS included age, ASA physical status, surgical procedure, total crystalloid administration, and platelet administration. Surgical procedure and total crystalloid administration correlated (Pearson correlation coefficient=0.441; p = 0.000) and were not related to age or ASA physical status. Conclusions: Total crystalloid administration during spine surgery does predict ICU LOS. In addition, total crystalloid administration is closely related to the surgical procedure. Given that the mixture of surgical procedures was similar in LOS1 and LOS2, but differed in estimated blood loss, total crystalloid administration, and total blood administration; intraoperative fluid management during spine surgery only predicts ICU LOS insofar as total crystalloid administration is related to the surgical procedure.

Production of prostaglandins is a critical step in transducing immune stimuli into central nervous system (CNS) responses, but the cellular source of prostaglandins responsible for CNS signalling is unknown. Cyclooxygenase catalyzes the rate-limiting step in the synthesis of prostaglandins and exists in two isoforms. Regulation of the inducible isoform, cyclooxygenase 2, is thought to play a key role in the brain's response to acute inflammatory stimuli. In this paper, we report that intravenous lipopolysaccharide (LPS or endotoxin) induces cyclooxygenase 2-like immunoreactivity in cells closely associated with brain blood vessels and in cells in the meninges. Neuronal staining was not noticeably altered or induced in any brain region by endotoxin challenge. Furthermore, many of the cells also were stained with a perivascular microglial/macrophage-specific antibody, indicating that intravenous LPS induces cyclooxygenase in perivascular microglia along blood vessels and in meningeal macrophages at the edge of the brain. These findings suggest that perivascular microglia and meningeal macrophages throughout the brain may be the cellular source of prostaglandins following systemic immune challenge. We hypothesize that distinct components of the CNS response to immune system activation may be mediated by prostaglandins produced at specific intracranial sites such as the preoptic area (altered sleep and thermoregulation), medulla (adrenal corticosteroid response), and cerebral cortex (headache and encephalopathy).

Cyclooxygenase (COX) is an enzyme involved in the biosynthesis of prostaglandins and is one of the principle targets of non-steroidal anti-inflammatory drugs. Two isoforms of this enzyme are known to exist in the brain; one of these (type 1 COX or COX1) is constitutively expressed, whereas the other form of the enzyme, which is inducible, has been called type 2 COX (COX2). We have used systemic administration of bacterial lipopolysaccharide (LPS) as a model of the acute phase response to study the expression of COX2 in the murine CNS. We observed COX2 expression in neurons of several regions of the normal murine telencephalon. Robust expression of COX2 mRNA was induced in perivascular cells between 45 min and 6 h after LPS injection. The role of prostaglandins produced by these perivascular cells in the cerebral components of the acute phase response remains to be elucidated.

Considerable debate exists regarding the cellular source of prostaglandins in the mammalian central nervous system (CNS). At least two forms of prostaglandin endoperoxide synthase, or cyclooxygenase (COX), the principal enzyme in the biosynthesis of these mediators, are known to exist. Both forms have been identified in the CNS, but only the distribution of COX 1 has been mapped in detail. In this study, we used Western blot analysis and immunohistochemistry to describe the biochemical characterization and anatomical distribution of the second, mitogen-inducible form of this enzyme, COX 2 in the rat brain. COX 2-like immunoreactive (COX 2-ir) staining occurred in dendrites and cell bodies of neurons, structures that are typically postsynaptic. It was noted in distinct portions of specific cortical laminae and subcortical nuclei. The distribution in the CNS was quite different from COX 1. COX 2-ir neurons were primarily observed in the cortex and allocortical structures, such as the hippocampal formation and amygdala. Within the amygdala, neurons were primarily observed in the caudal and posterior part of the deep and cortical nuclei. In the diencephalon, COX 2-ir cells were also observed in the paraventricular nucleus of the hypothalamus and in the nuclei of the anteroventral region surrounding the third ventricle, including the vascular organ of the lamina terminalis. COX 2-ir neurons were also observed in the subparafascicular nucleus, the medial zona incerta, and pretectal area. In the brainstem, COX 2-ir neurons were observed in the dorsal raphe nucleus, the nucleus of the brachium of the inferior colliculus, and in the region of the subcoeruleus. The distribution of COX 2-ir neurons in the CNS suggests that COX 2 may be involved in processing and integration of visceral and special sensory input and in elaboration of the autonomic, endocrine, and behavioral responses.

Fever is a complex, coordinated autonomic, neuroendocrine, and behavioral response that is adaptive and is used by nearly all vertebrates as part of the acute-phase reaction to immune challenge. Although the febrile response can be elicited by a wide variety of infectious organisms and may also occur during noninfectious inflammatory conditions, its manifestations are stereotyped and largely independent of the causative agent. Like other integrated responses, such as the regulation of energy metabolism, blood pressure and volume, and reproduction, fever depends on humoral cues from the body, is orchestrated largely by the hypothalamus, and involves the coordination of a wide . . .

Tumor necrosis factor-alpha (TNF alpha) is a protein released from macrophages during infection and inflammation. Recent studies suggest that it has several effects within the central nervous system, including generation of fever, enhancement of slow wave sleep, and stimulation of pituitary hormone secretion. We have proposed that TNF alpha may be synthesized by neurons in the CNS and used as a neuromodulator in the pathways involved in the central control of these activities. To test this hypothesis, we have used an antiserum raised against recombinant murine (rm) TNF alpha with an indirect immunoperoxidase technique to stain the murine CNS immunohistochemically. Western blot analysis of mouse brain homogenates revealed one band with electrophoretic mobility identical to that of rmTNF alpha. We identified TNF alpha-like immunoreactive (ir) neurons in the hypothalamus, in the bed nucleus of the stria terminalis, in the caudal raphe nuclei, and along the ventral pontine and medullary surface. TNF alpha ir innervation was widespread within the CNS, particularly in areas involved in autonomic and endocrine regulation, including the hypothalamus, amygdala, bed nucleus of the stria terminalis, parabrachial nucleus, dorsal vagal complex, nucleus ambiguus, and thoracic sympathetic preganglionic cell column. Our data suggest that TNF alpha may serve as a neuromodulator in central pathways involved in the regulation of the autonomic, endocrine and behavioral components of the acute-phase response to inflammation and infection.

The gene encoding a novel mouse somatostatin receptor termed mSSTR3 was isolated and characterized. The sequence of mSSTR3 shows 46 and 47% identity with mSSTR1 and mSSTR2, respectively. mSSTR3 binds somatostatin-14 and somatostatin-28 with high affinity, but shows very low affinity for the somatostatin analogs MK-678 and SMS-201-995. In addition, mSSTR3 is coupled to pertussis toxin-sensitive G proteins and mediates somatostatin inhibition of forskolin-stimulated and dopamine D1 receptor-stimulated cAMP formation, indicating that it is coupled to adenylylcyclase. The pharmacological properties of mSSTR3 and its ability to couple with adenylylcyclase distinguish SSTR3 from the other cloned somatostatin receptors and indicates that it mediates biological functions different from SSTR1 or SSTR2. In situ hybridization indicates that SSTR3 mRNA is widely distributed in the mouse brain, and its expression in the nucleus of the lateral olfactory tract and in the piriform cortex, the primary olfactory cortex in the rodent brain, suggests that SSTR3 may participate in the processing and modulation of primary sensory information.

The tetradecapeptide somatostatin has been implicated as an important regulator of neuronal and neuroendocrine function in the CNS. The cellular actions of somatostatin are mediated by specific receptors. The genes encoding two different somatostatin receptors (SSTRs) have been isolated and characterized, and RNA blotting studies have shown that both SSTR1 and SSTR2 are expressed in the brain. In order to gain a better understanding of the functions of somatostatin in the CNS, the distribution of SSTR1 and SSTR2 mRNAs was determined using the technique of in situ hybridization. SSTR1 mRNA was present throughout the mouse brain, particularly in the supra- and infragranular layers of the cortex, the amygdala, hippocampus, bed nucleus of the stria terminalis, substantia innominata, hypothalamus, pretectum, substantia nigra, parabrachial nucleus, and nucleus of the solitary tract. SSTR2 mRNA was primarily observed in the infragranular layers of the cortex, the amygdala, claustrum, endopiriform nucleus, arcuate and paraventricular nuclei of the hypothalamus, and medial habenular nucleus. Several regions of the brain reported to contain dense somatostatin-like immunoreactive terminal fields and receptor binding sites were devoid of both SSTR1 and SSTR2 mRNA, suggesting the existence of additional SSTR subtypes.

Evidence from tissue culture studies suggests that glial cells are the principal source of prostaglandins in the brain. We have used immunohistochemistry, Western blot analysis, and enzyme activity assays to localize cyclooxygenase (COX), the enzyme responsible for the conversion of arachidonic acid to prostaglandins, in situ in the normal ovine brain. We observed very few immunoreactive glial cells. In contrast, an extensive distribution of COX-like immunoreactive (ir) neuronal cell bodies and dendrites and a corresponding pattern of COX enzyme activity were observed. COXir neurons were most abundant in forebrain sites involved in complex, integrative functions and autonomic regulation such as the cerebral cortex, hippocampus, amygdala, bed nucleus of the stria terminalis, substantia innominata, dorsomedial nucleus of the hypothalamus, and tuberomammillary nucleus. Moderate populations were observed in other regions of the central nervous system implicated in sensory afferent processing, including the dorsal column nuclei, spinal trigeminal nucleus, and superior colliculus, and in structures involved in autonomic regulation, such as the nucleus of the solitary tract, parabrachial nucleus, and the periaqueductal gray matter. We did not observe COXir axons or terminal fields, however. Our results suggest that neurons may use prostaglandins as intracellular or perhaps paracrine, but probably not synaptic, mediators in the normal brain.

Objective To evaluate the efficacy and safety of aripiprazole treatment for psychotic symptoms associated with Alzheimer disease (AD). Methods In this parallel group, randomized, double-blind, placebo-controlled, flexible-dose trial, institutionalized subjects with AD and psychotic symptoms were randomized to aripiprazole (n = 131) or placebo (n = 125) for 10 weeks. The aripiprazole starting dose was 2 mg/day, and could be titrated to higher doses (5, 10, and 15 mg/day) based on efficacy and tolerability. Results No significant differences in mean change [2 × SD] from baseline between aripiprazole (mean dose ∼9 mg/day at endpoint; range=0.7–15.0 mg) and placebo were detected in the coprimary efficacy endpoints of Neuropsychiatric Inventory–Nursing Home Version (NPI-NH) Psychosis score (aripiprazole, −4.53 [9.23]; placebo, −4.62 [9.56]; F= 0.02 , df=1, 222, p=0.883 [ANCOVA]) and Clinical Global Impression (CGI)–Severity score (aripiprazole, −0.57 [1.63]; placebo, −0.43 [1.65]; F=1.67, df=1, 220, p=0.198 [ANCOVA]) at endpoint. However, improvements in several secondary efficacy measures (NPI-NH Total, Brief Psychiatric Rating Scale Total, CGI – improvement, Cohen–Mansfield Agitation Inventory and Cornell Depression Scale scores) indicated that aripiprazole may confer clinical benefits beyond the primary outcome measures. Treatment-emergent adverse events (AEs) were similar in both groups, except for somnolence (aripiprazole, 14%; placebo, 4%). Somnolence with aripiprazole was of mild or moderate intensity, and not associated with accidental injury. Incidence of AEs related to extrapyramidal symptoms was low with aripiprazole (5%) and placebo (4%). Conclusions In nursing home residents with AD and psychosis, aripiprazole did not confer specific benefits for the treatment of psychotic symptoms; but psychological and behavioral symptoms, including agitation, anxiety, and depression, were improved with aripiprazole, with a low risk of AEs.

Objective To assess the efficacy and safety of aripiprazole for psychosis associated with Alzheimer dementia (AD). Methods In this double-blind, multicenter study, 487 institutionalized patients with psychosis associated with AD were randomized to placebo or aripiprazole, 2, 5 or 10 mg/day. Primary efficacy assessment was the mean change from baseline to week 10 on the Neuropsychiatric Inventory–Nursing Home (NPI-NH) version Psychosis Subscale score. Secondary measures included NPI-NH Total, Clinical Global Impression–Severity of Illness (CGI-S), Brief Psychiatric Rating Scale (BPRS) Core and Total, and the Cohen–Mansfield Agitation Inventory (CMAI) scores. Results Aripiprazole 10 mg/day showed significantly greater improvements (mean change [2 × SD]) than placebo on the NPI-NH Psychosis Subscale (−6.87 [8.6] versus −5.13 [10.0]; F=6.29, df=1, 422, p=0.013 by analysis of covariance [ANCOVA]); CGI-S (−0.72 [1.8] versus −0.46 [1.6]; F=4.68, df=1, 419, p=0.031 [ANCOVA]); BPRS Total (−7.12 [18.4] versus −4.17 [21.6]; F=4.72, df=1, 399, p=0.030 [ANCOVA]); BPRS Core (−3.07 [6.9] versus −1.74 [7.8]; F=7.30, df=1, 407, p=0.007 [ANCOVA]); CMAI (−10.96 [22.6] versus −6.64 [28.6]; F=5.23, df=1, 410, p=0.023 [ANCOVA]), and NPI-NH Psychosis response rate (65 versus 50%; χ 2 = 5.52, df=1, p=0.019 [CMH]). Aripiprazole 5 mg/day showed significant improvements versus placebo on BPRS and CMAI scores. Aripiprazole 2 mg/day was not efficacious. Cerebrovascular adverse events were reported: aripiprazole 2 mg/day, N=1; 5 mg/day, N=2; 10 mg/day, N=4; placebo, N=0. No deaths in any group (aripiprazole 2 mg/day, 3%; 5 mg/day, 2%; 10 mg/day, 7%; placebo, 3%) were considered to be treatment-related. Conclusion Aripiprazole 10 mg/day was efficacious and safe for psychosis associated with AD, significantly improving psychotic symptoms, agitation, and clinical global impression. However, clinicians should be aware of the safety considerations of atypical antipsychotic uses in this population.

This study compared the efficacy, safety, and tolerability of aripiprazole, a novel antipsychotic, with placebo in patients with psychosis associated with Alzheimer's Disease (AD). This 10-week, double-blind, multicenter study randomized 208 outpatients (mean age, 81.5 years) with AD-associated psychosis to aripiprazole (n = 106) or placebo (n = 102). The initial aripiprazole dose of 2 mg/d was titrated upwards (5, 10, or 15 mg/d) according to efficacy and tolerability. Evaluations included Neuropsychiatric Inventory (NPI) Psychosis subscale and Brief Psychiatric Rating Scale (BPRS), adverse event (AE) reports, extrapyramidal symptoms (EPS) rating scales, and body weight. Overall, 172 patients (83%) completed the study. Mean aripiprazole dose at end point was 10.0 mg/d. The NPI Psychosis subscale score showed improvements in both groups (aripiprazole, -6.55; placebo, -5.52; P = 0.17 at end point). Aripiprazole-treated patients showed significantly greater improvements from baseline in BPRS Psychosis and BPRS Core subscale scores at end point compared with placebo. AEs were generally mild to moderate in severity and included (aripiprazole vs. placebo): urinary tract infection (8% vs. 12%), accidental injury (8% vs. 5%), somnolence (8% vs. 1%), and bronchitis (6% vs. 3%). Somnolence was mild and not associated with falls or accidental injury. There were no significant differences from placebo in EPS scores, or clinically significant ECG abnormalities, vital signs, or weight. In conclusion, aripiprazole showed similar improvements to placebo in psychotic symptoms as assessed by NPI Psychosis subscale scores, but significantly greater effects on BPRS Core and Psychosis assessments in community-living AD patients with psychosis. Aripiprazole was safe and well tolerated in this patient population.

Homer is a neuronal immediate early gene (IEG) that is enriched at excitatory synapses and binds group 1 metabotropic glutamate receptors (mGluRs). Here, we characterize a family of Homer-related proteins derived from three distinct genes. Like Homer IEG (now termed Homer 1a), all new members bind group 1 mGluRs. In contrast to Homer 1a, new members are constitutively expressed and encode a C-terminal coiled-coil (CC) domain that mediates self-multimerization. CC-Homers form natural complexes that cross-link mGluRs and are enriched at the postsynaptic density. Homer 1a does not multimerize and blocks the association of mGluRs with CC-Homer complexes. These observations support a model in which the dynamic expression of Homer 1a competes with constitutively expressed CC-Homers to modify synaptic mGluR properties.

Eicosanoids are metabolites of arachidonic acid produced by the cyclooxygenase (COX), lipoxygenase (LIPOX), and cytochrome P450 enzymes (for review, see Needleman et al., 1986). Arachidonic acid (AA) and the eicosanoids have been implicated in many brain functions including the control of sleep-wake cycles (Hayaishi, 1991), temperature and fever (Ueno et al., 1982; Stitt, 1991), pituitary hormone production (Ojeda et al., 1982), and even long-term potentiation (LTP; Luo and Vallano, 1995; for review, see Bliss and Collingridge, 1993). Furthermore, these molecules have a well-established role as mediators of inflammation (Goetzl et al., 1995). Thus, any change in content of these eicosanoid-producing enzymes following stimulation might have pro-found effects on brain function. Cyclooxygenase, also known as prostaglandin endoperoxide H synthase (PGHS), has two known isoforms, a constitutive form (COX-1; Smith et al., 1991) and an inducible form (COX-2; Xie et al., 1991). The distribution of these enzymes in the brain has been characterized (Breder et al., 1992, 1995; Breder, 1996; Yamagata et al., 1993). The distribution of the main LIPOX enzymes and their derivatives in the brain has only begun to be characterized (Miyamoto et al., 1987a,b; Simmet and Peskar, 1990; Cluoet et al., 1991; Nishiyama et al., 1992, 1993). Yamagata et al. (1993) have shown that the expression of COX-2 can be rapidly and transiently elevated from seizures. Furthermore, expression was induced by electrical activity that induced LTP and modulated by systemic administration of glutamate receptor blockers and tetrodotoxin treatment of the optic nerve. These results have led to the suggestion that COX-2 may function as an “immediate” or “early” factor following stimulation and that synaptic activity may have a role in its expression. Spreading depression (SD) is a propagating wave of electrical silence and negative interstitial DC potential (Leao, 1944) significantly different from a seizure, as it is a benign phenomenon that is never associated with irreversible injury of brain cells (Nedergaard and Hansen, 1988; Kraig et al., 1991). Seizures induced by chemical (for review, see Nadler et al., 1986) or electrical (Olney et al., 1983a,b) stimulation can cause characteristic patterns of neuronal cell death. Although it is noninjurious, SD stimulation transforms astrocytes (Kraig et al., 1991) and microglia (Gehrmann et al., 1993; Caggiano and Kraig, 1996) into reactive cells. We have previously shown that the eicosanoids alter the induction of microgliosis from SD (Caggiano and Kraig, 1996). Here we investigate how the expression of the eicosanoid-producing enzymes (i.e., COX-2 and LIPOX) are modulated in the cortex following unilateral cortical SD. Previous work (Kraig et al., 1991) has shown that changes in glial fibrillary acidic protein (GFAP) expression are induced by cortical SD in regions anatomically connected to the cortex but not experiencing SD. Because SD does not travel between gray matter areas (Bures et al., 1974), this observation suggests that some effects of SD may be transmitted by a synaptic mechanism. To determine if COX-2 and/or LIPOX expression are sensitive to these transynaptic effects, we examined COX-2 and LIPOX following cortical SD in regions not experiencing SD, namely the hippocampus. Hippocampal circuitry has been well characterized (Swanson and Cowan, 1977) and provides an ideal location to look at events one, two, and three synapses away from events in the cortex (i.e., dentate gyrus, CA3, and CA1, respectively). SD only travels between gray matter areas under extreme circumstances (e.g., see Largo et al., 1996); thus, cortical SD would not be predicted to travel to the hippocampus, and any changes in the expression of enzymes in the hippocampus following neocortical SD would be the result of hippocampal projections from the cortex. We confirmed a lack of SD in the hippocampus and examined COX-2 and LIPOX expression in the cortex, dentate gyrus (DG), CA3, and CA1 following unilateral neocortical SD. Our results show that COX-2 immunoreactivity (IR) was increased rapidly in the hemisphere experiencing SD and remained elevated for 21 days. This change was reduced by Dex (a glucocorticoid), Pe (an adrenergic agonist), and Snp (a nitric oxide donor; NO) with Pe. Mep (a phospholipase A2 inhibitor), Indo (a COX inhibitor), Lnam (a NO synthase antagonist), and Ndga (a LIPOX inhibitor) did not alter the induction of COX-2. The LIPOX IR was unchanged from SD. Recordings confirmed that SD did not occur in the hippocampus; however, COX-2 IR was significantly elevated in the ipsilateral DG, CA3, and CA1, with the extent of change in the order: cortex > DG > CA3 > CA1. LIPOX IR remained unchanged in the hippocampus.

Tumor necrosis factor alpha (TNF-alpha) is a cytokine that is responsible, in part, for several aspects of the acute-phase response to inflammation, including the generation of fever. TNF-alpha has direct effects on central nervous system neurons deep within the hypothalamus that are involved in producing the febrile response, but the blood-brain barrier prevents circulating TNF-alpha from having access to these sites. We therefore have hypothesized that TNF-alpha may be produced in the brain and used as a mediator in the cerebral components of the acute-phase response. We used in situ hybridization to determine the distribution of production of TNF-alpha mRNA in the mouse brain after systemic administration of lipopolysaccharide. During the initial phase of fever, hybridization was observed in perivascular cells and neurons in circumventricular organs, including the vascular organ of the lamina terminalis, median eminence, and area postrema, as well as along the ventral surface of the medulla; hybridization was also prominent over many cell in the meninges. During the late phase of the response, hybridization was observed over neurons in the pericircumventricular nuclei such as the anteroventral periventricular and arcuate nuclei of the hypothalamus and the nucleus of the solitary tract. TNF-alpha produced by a cascade of neurons within the brain may participate in the complex autonomic, neuroendocrine, metabolic, and behavioral responses to infection and inflammation.

The messenger RNAs encoding three somatostatin receptor subtypes, SSTR1, SSTR2 and SSTR3, were detected in rat by RNA blotting and in situ hybridization histochemistry to identify the sites of synthesis and expression of these somatostatin receptor subtypes. RNA blotting revealed that SSTR1 messenger RNA of 3.8 kilobases was highly expressed in cerebral cortex, hippocampus, midbrain and hypothalamus. In situ hybridization histochemistry revealed that SSTR1 messenger RNA was localized to discrete layers of the cerebral cortex, the piriform cortex and the dentate gyrus of the hippocampus. SSTR1 messenger RNA was expressed at low levels in the cerebellum and pituitary and was not detectable in striatum or other peripheral organs. At least two SSTR2 messenger RNAs were detected by RNA blotting of 2.4 and 2.8 kilobases which correspond to the size of the spliced and unspliced forms of this receptor messenger RNA. SSTR2 messenger RNA detected by in situ hybridization is diffusely expressed in cerebral cortex and amygdala but is discretely localized to dentate gyrus in the hippocampus, medial habenula and ventromedial and dorsomedial nuclei and arcuate nucleus of the hypothalamus. The levels of SSTR2 messenger RNA are very low in the cerebellum and were not observed in the striatum or peripheral tissues other than the pituitary or adrenal gland. A single SSTR3 messenger RNA of 4.0 kilobases was seen in hippocampus, cerebral cortex, midbrain, hypothalamus and pituitary. However, the tissue with the highest levels of SSTR3 messenger RNA is the cerebellum with messenger RNA localized to the granule cell layer. The expression of the three different somatostatin receptor messenger RNAs are distinct but overlapping. Such distinct expression may contribute to the selective biological roles of the receptor subtypes.

While trying to identify new members of the somatostatin receptor family of G protein-coupled receptors, we isolated cDNAs from a mouse brain library encoding two related receptor-like proteins, designated msl-1 and msl-2, of 380 and 372 amino acids, respectively. There was 61% identity and 71% similarity between the sequences of msl-1 and msl-2. Among members of the G protein-coupled receptor superfamily, the sequences of both msl-1 and msl-1 were most closely related to those of the somatostatin receptors (SSTRs), having approximately 35% identity with the sequence of SSTR1. Transient expression in COS-1 cells showed that msl-1 and msl-2 did not bind somatostatin. Rather they bound opioids selectively and with high affinity and had the pharmacological properties of kappa and delta opioid receptors, respectively. Indeed, the sequence of msl-2 was identical to that of a delta opioid receptor recently cloned by other workers. Functional characterization of kappa/msl-1 and delta/msl-2 opioid receptors showed that they were coupled to G proteins and mediated opioid receptor class-specific agonist inhibition of forskolin-stimulated cAMP formation. RNA blotting studies and in situ hybridization histochemistry showed that kappa opioid receptor mRNA was expressed at high levels in brain in the neocortex, hippocampus, amygdala, medial habenula, hypothalamus (arcuate and paraventricular nuclei), locus ceruleus, and parabrachial nucleus, suggesting that this receptor may play a role in arousal and regulation of autonomic and neuroendocrine functions.

The febrile reaction is an integrated endocrine, autonomic and behavioral response, coordinated by the hypothalamus, that includes certain components of the stress response, such as elevated corticosteroid secretion. It is produced by the actions of circulating cytokines, such as interleukin-1 (IL-1) and tumor necrosis factor (TNF), on the organum vasculosum of the lamina terminalis (OVLT), resulting in the secretion of prostaglandin E2, which initiates a variety of responses, including elevation of body temperature and corticosteroid secretion. Although circulating cytokines apparently do not enter the brain, injections of IL-1 or TNF well within the blood-brain barrier produce identical effects. We have examined the localization of possible central sources of cytokines and prostaglandins, using immunohistochemistry, immunoblotting and enzyme assay. Our data indicate that in the brain cyclooxygenase, the key enzyme in the synthesis of prostaglandins, is found in neurons in the OVLT, but is also made by neurons in many sensory and visceral regulatory systems. We present evidence also that IL-1 beta in the human brain and TNF alpha in the mouse may be present in the central nervous system as neuromodulators that are important for producing the autonomic, endocrine and behavioral components of the febrile reaction. We propose a sequence of events in the febrile reaction involving: (1) action of circulating cytokines on cyclooxygenase containing neurons within the OVLT to produce local prostaglandin secretion; (2) local diffusion of prostaglandin E2 into the preoptic and anterior hypothalamic areas; (3) action of prostaglandin E2 on cytokine containing neurons in the preoptic and anterior hypothalamic areas; and (4) release of cytokines from neuronal terminals at distal sites involved in producing the autonomic, endocrine and behavioral components of the febrile reaction.

The anatomical distribution of autonomic, particularly cardiovascular, responses originating in the insular cortex was examined by using systematic electrical microstimulation. The localization of these responses to cell bodies in the insular cortex was demonstrated by using microinjection of the excitatory amino acid, D,L-homocysteic acid. The efferents from the cardiovascular responsive sites were traced by iontophoretic injection of the anterograde axonal tracer Phaseoleus vulgaris leucoagglutinin (PHA-L). Two distinct patterns of cardiovascular response were elicited from the insular cortex: an increase in arterial pressure accompanied by tachycardia or a decrease in arterial pressure with bradycardia. The pressor responses were obtained by stimulation of the rostral half of the posterior insular cortex while depressor sites were located in the caudal part of the posterior insular area. Both types of site were primarily located in the dysgranular and agranular insular cortex. Gastric motility changes originated from a separate but adjacent region immediately rostral to the cardiovascular responsive sites in the anterior insular cortex. Tracing of efferents with PHA-L indicated a number of differences in connectivity between the pressor and depressor sites. Pressor sites had substantially more intense connections with other limbic regions including the infralimbic cortex, the amygdala, the bed nucleus of the stria terminalis and the medial dorsal and intralaminar nuclei of the thalamus. Alternatively, the depressor region of the insular cortex more heavily innervated sensory areas of the brain including layer I of the primary somatosensory cortex, a peripheral region of the sensory relay nuclei of the thalamus and the caudal spinal trigeminal nucleus. In addition, there were topographical differences in the projection to the lateral hypothalamic area, the primary site of autonomic outflow for these responses from the insular cortex. These differences in connectivity may provide the anatomic substrate for the specific cardiovascular responses and behaviors integrated in the insular cortex.

Interleukin-1 (IL-1) is a cytokine that mediates the acute phase reaction. Many of the actions of IL-1 involve direct effects on the central nervous system. However, IL-1 has not previously been identified as an intrinsic component within the brain, except in glial cells. An antiserum directed against human IL-1 beta was used to stain the human brain immunohistochemically for IL-1 beta-like immunoreactive neural elements. IL-1 beta-immunoreactive fibers were found innervating the key endocrine and autonomic cell groups that control the central components of the acute phase reaction. These results indicate that IL-1 may be an intrinsic neuromodulator in central nervous system pathways that mediate various metabolic functions of the acute phase reaction, including the body temperature changes that produce the febrile response.