Molnupiravir plus usual care versus usual care alone as early treatment for adults with COVID-19 at increased risk of adverse outcomes (PANORAMIC): an open-label, platform-adaptive randomised controlled trial.

BACKGROUND: The safety, effectiveness, and cost-effectiveness of molnupiravir, an oral antiviral medication for SARS-CoV-2, has not been established in vaccinated patients in the community at increased risk of morbidity and mortality from COVID-19. We aimed to establish whether the addition of molnupiravir to usual care reduced hospital admissions and deaths associated with COVID-19 in this population. METHODS: PANORAMIC was a UK-based, national, multicentre, open-label, multigroup, prospective, platform adaptive randomised controlled trial. Eligible participants were aged 50 years or older-or aged 18 years or older with relevant comorbidities-and had been unwell with confirmed COVID-19 for 5 days or fewer in the community. Participants were randomly assigned (1:1) to receive 800 mg molnupiravir twice daily for 5 days plus usual care or usual care only. A secure, web-based system (Spinnaker) was used for randomisation, which was stratified by age (<50 years vs ≥50 years) and vaccination status (yes vs no). COVID-19 outcomes were tracked via a self-completed online daily diary for 28 days after randomisation. The primary outcome was all-cause hospitalisation or death within 28 days of randomisation, which was analysed using Bayesian models in all eligible participants who were randomly assigned. This trial is registered with ISRCTN, number 30448031. FINDINGS: Between Dec 8, 2021, and April 27, 2022, 26 411 participants were randomly assigned, 12 821 to molnupiravir plus usual care, 12 962 to usual care alone, and 628 to other treatment groups (which will be reported separately). 12 529 participants from the molnupiravir plus usual care group, and 12 525 from the usual care group were included in the primary analysis population. The mean age of the population was 56·6 years (SD 12·6), and 24 290 (94%) of 25 708 participants had had at least three doses of a SARS-CoV-2 vaccine. Hospitalisations or deaths were recorded in 105 (1%) of 12 529 participants in the molnupiravir plus usual care group versus 98 (1%) of 12 525 in the usual care group (adjusted odds ratio 1·06 [95% Bayesian credible interval 0·81-1·41]; probability of superiority 0·33). There was no evidence of treatment interaction between subgroups. Serious adverse events were recorded for 50 (0·4%) of 12 774 participants in the molnupiravir plus usual care group and for 45 (0·3%) of 12 934 in the usual care group. None of these events were judged to be related to molnupiravir. INTERPRETATION: Molnupiravir did not reduce the frequency of COVID-19-associated hospitalisations or death among high-risk vaccinated adults in the community. FUNDING: UK National Institute for Health and Care Research.

Therapeutic Clearance of Amyloid by Antibodies to Serum Amyloid P Component.

BACKGROUND: The amyloid fibril deposits that cause systemic amyloidosis always contain the nonfibrillar normal plasma protein, serum amyloid P component (SAP). The drug (R)-1-[6-[(R)-2-carboxy-pyrrolidin-1-yl]-6-oxo-hexanoyl]pyrrolidine-2-carboxylic acid (CPHPC) efficiently depletes SAP from the plasma but leaves some SAP in amyloid deposits that can be specifically targeted by therapeutic IgG anti-SAP antibodies. In murine amyloid A type amyloidosis, the binding of these antibodies to the residual SAP in amyloid deposits activates complement and triggers the rapid clearance of amyloid by macrophage-derived multinucleated giant cells. METHODS: We conducted an open-label, single-dose-escalation, phase 1 trial involving 15 patients with systemic amyloidosis. After first using CPHPC to deplete circulating SAP, we infused a fully humanized monoclonal IgG1 anti-SAP antibody. Patients with clinical evidence of cardiac involvement were not included for safety reasons. Organ function, inflammatory markers, and amyloid load were monitored. RESULTS: There were no serious adverse events. Infusion reactions occurred in some of the initial recipients of larger doses of antibody; reactions were reduced by slowing the infusion rate for later patients. At 6 weeks, patients who had received a sufficient dose of antibody in relation to their amyloid load had decreased liver stiffness, as measured with the use of transient elastography. These patients also had improvements in liver function in association with a substantial reduction in hepatic amyloid load, as shown by means of SAP scintigraphy and measurement of extracellular volume by magnetic resonance imaging. A reduction in kidney amyloid load and shrinkage of an amyloid-laden lymph node were also observed. CONCLUSIONS: Treatment with CPHPC followed by an anti-SAP antibody safely triggered clearance of amyloid deposits from the liver and some other tissues. (Funded by GlaxoSmithKline; ClinicalTrials.gov number, NCT01777243.).

A randomized, double-blind, placebo-controlled trial of camicinal in Parkinson's disease.

BACKGROUND: Delayed gastric emptying may impair l-dopa absorption, contributing to motor fluctuations. We evaluated the effect of camicinal (GSK962040), a gastroprokinetic, on the absorption of l-dopa and symptoms of PD. METHODS: Phase II, double-blind, placebo-controlled trial. Participants were randomized to receive camicinal 50 mg once-daily (n = 38) or placebo (n = 20) for 7 to 9 days. RESULTS: l-dopa exposure was similar with coadministration of camicinal compared to placebo. Median time to maximum l-dopa concentration was reduced, indicating more rapid absorption of l-dopa. Camicinal resulted in significant reduction in OFF time (-2.31 hours; 95% confidence interval: -3.71, -0.90), significant increase in ON time (+1.88 hours; 95% confidence interval: 0.28, 3.48) per day, and significant decrease in mean total MDS-UPDRS score (-12.5; 95% confidence interval: -19.67, -5.29). Camicinal treatment was generally well tolerated. CONCLUSIONS: PD symptom improvement with camicinal occurred in parallel with more rapid absorption of l-dopa. This study provides evidence of an improvement of the motor response to l-dopa in people with PD treated with camicinal 50 mg once-daily compared with placebo, which will require further evaluation. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

The effect of camicinal (GSK962040), a motilin agonist, on gastric emptying and glucose absorption in feed-intolerant critically ill patients: a randomized, blinded, placebo-controlled, clinical trial.

BACKGROUND: The promotility agents currently available to treat gastroparesis and feed intolerance in the critically ill are limited by adverse effects. The aim of this study was to assess the pharmacodynamic effects and pharmacokinetics of single doses of the novel gastric promotility agent motilin agonist camicinal (GSK962040) in critically ill feed-intolerant patients. METHODS: A prospective, randomized, double-blind, parallel-group, placebo-controlled, study was performed in mechanically ventilated feed-intolerant patients [median age 55 (19-84), 73 % male, APACHE II score 18 (5-37) with a gastric residual volume ≥200 mL]. Gastric emptying and glucose absorption were measured both pre- and post-treatment after intragastric administration of 50 mg (n = 15) camicinal and placebo (n = 8) using the (13)C-octanoic acid breath test (BTt1/2), acetaminophen concentrations, and 3-O-methyl glucose concentrations respectively. RESULTS: Following 50 mg enteral camicinal, there was a trend to accelerated gastric emptying [adjusted geometric means: pre-treatment BTt1/2 117 minutes vs. post- treatment 76 minutes; 95 % confidence intervals (CI; 0.39, 1.08) and increased glucose absorption (AUC240min pre-treatment: 28.63 mmol.min/L vs. post-treatment: 71.63 mmol.min/L; 95 % CI (1.68, 3.72)]. When two patients who did not have detectable plasma concentrations of camicinal were excluded from analysis, camicinal accelerated gastric emptying (adjusted geometric means: pre-treatment BTt1/2 121 minutes vs. post-treatment 65 minutes 95 % CI (0.32, 0.91) and increased glucose absorption (AUC240min pre-treatment: 33.04 mmol.min/L vs. post-treatment: 74.59 mmol.min/L; 95 % CI (1.478, 3.449). In those patients receiving placebo gastric emptying was similar pre- and post-treatment. CONCLUSIONS: When absorbed, a single enteral dose of camicinal (50 mg) accelerates gastric emptying and increases glucose absorption in feed-intolerant critically ill patients. TRIAL REGISTRATION: The study protocol was registered with the US NIH clinicaltrials.gov on 23 December 2009 (Identifier NCT01039805 ).

Current usage of explainer animations in trials: a survey of the UKCRC registered clinical trial units in the UK.

BACKGROUND: Explainer animations are a means to communicate aspects of clinical trials to participants in a more engaging and accessible way. Delivered well these have the potential to enhance recruitment and retention. The range of media technology used to deliver this material is expanding rapidly but is highly fragmented. Usage of explainer animations across the UK is unknown, the aim of this research was to determine current usage across the 52 registered UK Clinical Research Collaboration (UKCRC) Clinical Trials Units (CTUs) to understand the current landscape and any barriers that could be preventing wider uptake of this functionality. METHODS: A survey link was emailed to all UKCRC CTU Directors and Trial Management Leads to ascertain current usage of explainer animations within their CTU. The survey ran between 01 February 2023 and 07 March 2023. RESULTS: Responses were received from 35 CTUs-representing a response rate of 67%. 24 CTUs (69%) reported that they had created/used at least one explainer animation within their unit, although the usage, cost, length and production activities varied among the units. CONCLUSIONS: The survey showed that a high proportion of the UKCRC CTUs have used explainer animations to provide information to participants about clinical studies. For those not using the technology yet, the most common reasons cited were a lack of expertise, lack of resources and costs to produce them. One of the desired outcomes of this project is the creation of a free-to-use library of animations to encourage wider uptake and avoid duplication.

Use of oxygen-loaded nanobubbles to improve tissue oxygenation: Bone-relevant mechanisms of action and effects on osteoclast differentiation.

Gas-loaded nanobubbles have potential as a method of oxygen delivery to increase tumour oxygenation and therapeutically alleviate tumour hypoxia. However, the mechanism(s) whereby oxygen-loaded nanobubbles increase tumour oxygenation are unknown; with their calculated oxygen-carrying capacity being insufficient to explain this effect. Intra-tumoural hypoxia is a prime therapeutic target, at least partly due to hypoxia-dependent stimulation of the formation and function of bone-resorbing osteoclasts which establish metastatic cells in bone. This study aims to investigate potential mechanism(s) of oxygen delivery and in particular the possible use of oxygen-loaded nanobubbles in preventing bone metastasis via effects on osteoclasts. Lecithin-based nanobubbles preferentially interacted with phagocytic cells (monocytes, osteoclasts) via a combination of lipid transfer, clathrin-dependent endocytosis and phagocytosis. This interaction caused general suppression of osteoclast differentiation via inhibition of cell fusion. Additionally, repeat exposure to oxygen-loaded nanobubbles inhibited osteoclast formation to a greater extent than nitrogen-loaded nanobubbles. This gas-dependent effect was driven by differential effects on the fusion of mononuclear precursor cells to form pre-osteoclasts, partly due to elevated potentiation of RANKL-induced ROS by nitrogen-loaded nanobubbles. Our findings suggest that oxygen-loaded nanobubbles could represent a promising therapeutic strategy for cancer therapy; reducing osteoclast formation and therefore bone metastasis via preferential interaction with monocytes/macrophages within the tumour and bone microenvironment, in addition to known effects of directly improving tumour oxygenation.

Cost-utility analysis of molnupiravir for high-risk, community-based adults with COVID-19: an economic evaluation of the PANORAMIC trial.

BACKGROUND: The cost-effectiveness of molnupiravir, an oral antiviral for early treatment of SARS-CoV-2, has not been established in vaccinated populations. AIM: To evaluate the cost-effectiveness of molnupiravir relative to usual care alone among mainly vaccinated community-based people at higher risk of severe outcomes from COVID-19 over 6 months. DESIGN AND SETTING: An economic evaluation of the PANORAMIC trial in the UK. METHOD: A cost-utility analysis that adopted a UK NHS and personal social services perspective and a 6-month time horizon was performed using PANORAMIC trial data. Cost-effectiveness was expressed in terms of incremental cost per quality-adjusted life year (QALY) gained. Sensitivity and subgroup analyses assessed the impacts of uncertainty and heterogeneity. Threshold analysis explored the price for molnupiravir consistent with likely reimbursement. RESULTS: In the base-case analysis, molnupiravir had higher mean costs of £449 (95% confidence interval [CI] = 445 to 453) and higher mean QALYs of 0.0055 (95% CI = 0.0044 to 0.0067) than usual care (mean incremental cost per QALY of £81 190). Sensitivity and subgroup analyses showed similar results, except for those aged ≥75 years, with a 55% probability of being cost-effective at a £30 000 per QALY threshold. Molnupiravir would have to be priced around £147 per course to be cost-effective at a £15 000 per QALY threshold. CONCLUSION: At the current cost of £513 per course, molnupiravir is unlikely to be cost-effective relative to usual care over a 6-month time horizon among mainly vaccinated patients with COVID-19 at increased risk of adverse outcomes, except those aged ≥75 years.

Randomized controlled trial of molnupiravir SARS-CoV-2 viral and antibody response in at-risk adult outpatients.

Viral clearance, antibody response and the mutagenic effect of molnupiravir has not been elucidated in at-risk populations. Non-hospitalised participants within 5 days of SARS-CoV-2 symptoms randomised to receive molnupiravir (n = 253) or Usual Care (n = 324) were recruited to study viral and antibody dynamics and the effect of molnupiravir on viral whole genome sequence from 1437 viral genomes. Molnupiravir accelerates viral load decline, but virus is detectable by Day 5 in most cases. At Day 14 (9 days post-treatment), molnupiravir is associated with significantly higher viral persistence and significantly lower anti-SARS-CoV-2 spike antibody titres compared to Usual Care. Serial sequencing reveals increased mutagenesis with molnupiravir treatment. Persistence of detectable viral RNA at Day 14 in the molnupiravir group is associated with higher transition mutations following treatment cessation. Viral viability at Day 14 is similar in both groups with post-molnupiravir treated samples cultured up to 9 days post cessation of treatment. The current 5-day molnupiravir course is too short. Longer courses should be tested to reduce the risk of potentially transmissible molnupiravir-mutated variants being generated. Trial registration: ISRCTN30448031.

Health outcomes 3 months and 6 months after molnupiravir treatment for COVID-19 for people at higher risk in the community (PANORAMIC): a randomised controlled trial.

BACKGROUND: No randomised controlled trials have yet reported on the effectiveness of molnupiravir on longer term outcomes for COVID-19. The PANORAMIC trial found molnupiravir reduced time to recovery in acute COVID-19 over 28 days. We aimed to report the effect of molnupiravir treatment for COVID-19 on wellbeing, severe and persistent symptoms, new infections, health care and social service use, medication use, and time off work at 3 months and 6 months post-randomisation. METHODS: This study is a follow-up to the main analysis, which was based on the first 28 days of follow-up and has been previously reported. For this multicentre, primary care, open-label, multi-arm, prospective randomised controlled trial conducted in the UK, participants were eligible if aged at least 50 years, or at least 18 years with a comorbidity, and unwell 5 days or less with confirmed COVID-19 in the community. Participants were randomly assigned to the usual care group or molnupiravir group plus usual care (800 mg twice a day for 5 days), which was stratified by age (<50 years or ≥50 years) and vaccination status (at least one dose: yes or no). The primary outcome was hospitalisation or death (or both) at 28 days; all longer term outcomes were considered to be secondary outcomes and included self-reported ratings of wellness (on a scale of 0-10), experiencing any symptom (fever, cough, shortness of breath, fatigue, muscle ache, nausea and vomiting, diarrhoea, loss of smell or taste, headache, dizziness, abdominal pain, and generally feeling unwell) rated as severe (moderately bad or major problem) or persistent, any health and social care use, health-related quality of life (measured by the EQ-5D-5L), time off work or school, new infections, and hospitalisation. FINDINGS: Between Dec 8, 2021, and April 27, 2022, 25 783 participants were randomly assigned to the molnupiravir plus usual care group (n=12 821) or usual care group (n=12 962). Long-term follow-up data were available for 23 008 (89·2%) of 25 784 participants with 11 778 (91·9%) of 12 821 participants in the molnupiravir plus usual care group and 11 230 (86·6%) of 12 963 in the usual care group. 22 806 (99·1%) of 23 008 had at least one previous dose of a SARS-CoV-2 vaccine. Any severe (3 months: adjusted risk difference -1·6% [-2·6% to -0·6%]; probability superiority [p(sup)]>0·99; number needed to treat [NNT] 62·5; 6 months: -1·9% [-2·9% to -0·9%]; p(sup)>0·99, NNT 52·6) or persistent symptoms (3 months: adjusted risk difference -2·1% [-2·9% to -1·5%]; p(sup)>0·99; NNT 47·6; 6 months: -2·5% [-3·3% to -1·6%]; p(sup)>0·99; NNT 40) were reduced in severity, and health-related quality of life (measured by the EQ-5D-5L) improved in the molnupiravir plus usual care group at 3 months and 6 months (3 months: adjusted mean difference 1·08 [0·65 to 1·53]; p(sup)>0·99; 6 months: 1·09 [0·63 to 1·55]; p(sup)>0·99). Ratings of wellness (3 months: adjusted mean difference 0·15 (0·11 to 0·19); p(sup)>0·99; 6 months: 0·12 (0·07 to 0·16); p(sup)>0·99), experiencing any more severe symptom (3 months; adjusted risk difference -1·6% [-2·6% to -0·6%]; p(sup)=0·99; 6 months: -1·9% [-2·9% to -0·9%]; p(sup)>0·99), and health-care use (3 months: adjusted risk difference -1·4% [-2·3% to -0·4%]; p(sup)>0·99; NNT 71·4; 6 months: -0·5% [-1·5% to 0·4%]; p(sup)>0·99; NNT 200) had high probabilities of superiority with molnupiravir treatment. There were significant differences in persistence of any symptom (910 [8·9%] of 10 190 vs 1027 [11%] of 9332, NNT 67) at 6 months, and reported time off work at 3 months (2017 [17·9%] of 11 274 vs 2385 [22·4%] of 10 628) and 6 months (460 [4·4%] of 10 562 vs 527 [5·4%] of 9846; NNT 100). There were no differences in hospitalisations at long-term follow-up. INTERPRETATION: In a vaccinated population, people treated with molnupiravir for acute COVID-19 felt better, experienced fewer and less severe COVID-19 associated symptoms, accessed health care less often, and took less time off work at 6 months. However, the absolute differences in this open-label design are small with high numbers needed to treat. FUNDING: UK Research and Innovation and National Institute for Health and Care Research.

Effect of ketoconazole on the pharmacokinetic profile of ambrisentan.

Ambrisentan is an endothelin type A (ET(A))-selective receptor antagonist that is metabolized primarily by glucuronidation but also undergoes oxidative metabolism by CYP3A4. The potential for ketoconazole, the archetypal strong inhibitor of CYP3A4, to alter the pharmacokinetic profile of ambrisentan and its oxidative metabolite, 4-hydroxymethyl ambrisentan, was assessed in an open-label, nonrandomized, 2-period, single-sequence study in 16 healthy men. Participants received a single dose of ambrisentan 10 mg alone and after 4 days of ketoconazole 400 mg administered once daily. In the presence of multiple doses of ketoconazole, single-dose ambrisentan AUC(0-infinity) estimate was increased by 35.3%, whereas C(max) was increased by 20.0%. For the 4-hydroxymethyl ambrisentan metabolite, AUC(0-infinity) estimate was decreased by 4.0%, whereas C(max) was decreased by 16.5%. Concomitant administration of ambrisentan and ketoconazole was well tolerated. In summary, ketoconazole had no clinically significant effect on the pharmacokinetics or safety profile of ambrisentan; therefore, no changes in ambrisentan dose should be necessary when the drug is administered concomitantly with known CYP3A4 inhibitors.

Repeat doses of antibody to serum amyloid P component clear amyloid deposits in patients with systemic amyloidosis.

Systemic amyloidosis is a fatal disorder caused by pathological extracellular deposits of amyloid fibrils that are always coated with the normal plasma protein, serum amyloid P component (SAP). The small-molecule drug, miridesap, [(R)-1-[6-[(R)-2-carboxy-pyrrolidin-1-yl]-6-oxo-hexanoyl]pyrrolidine-2-carboxylic acid (CPHPC)] depletes circulating SAP but leaves some SAP in amyloid deposits. This residual SAP is a specific target for dezamizumab, a fully humanized monoclonal IgG1 anti-SAP antibody that triggers immunotherapeutic clearance of amyloid. We report the safety, pharmacokinetics, and dose-response effects of up to three cycles of miridesap followed by dezamizumab in 23 adult subjects with systemic amyloidosis (ClinicalTrials.gov identifier: NCT01777243). Amyloid load was measured scintigraphically by amyloid-specific radioligand binding of 123I-labeled SAP or of 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid. Organ extracellular volume was measured by equilibrium magnetic resonance imaging and liver stiffness by transient elastography. The treatment was well tolerated with the main adverse event being self-limiting early onset rashes after higher antibody doses related to whole body amyloid load. Progressive dose-related clearance of hepatic amyloid was associated with improved liver function tests. 123I-SAP scintigraphy confirmed amyloid removal from the spleen and kidneys. No adverse cardiac events attributable to the intervention occurred in the six subjects with cardiac amyloidosis. Amyloid load reduction by miridesap treatment followed by dezamizumab has the potential to improve management and outcome in systemic amyloidosis.

Opioid Antagonists and the A118G Polymorphism in the µ-Opioid Receptor Gene: Effects of GSK1521498 and Naltrexone in Healthy Drinkers Stratified by OPRM1 Genotype.

This corrects the article DOI: 10.1038/npp.2016.60.

The pharmacodynamics, safety and pharmacokinetics of single doses of the motilin agonist, camicinal, in type 1 diabetes mellitus with slow gastric emptying.

BACKGROUND AND PURPOSE: Here we have investigated the pharmacokinetics, pharmacodynamics and safety of single doses of camicinal in type 1 diabetes mellitus (T1DM) patients with a history of slow gastric emptying with symptoms consistent with gastroparesis. EXPERIMENTAL APPROACH: In a randomized, double-blind, placebo-controlled, incomplete block, three-period, two-centre crossover study, patients received oral administration of placebo and two of the three possible doses of camicinal (25, 50 or 125 mg). Gastric emptying ((13) C-octanoic acid breath test), pharmacokinetics and safety were primary outcomes. KEY RESULTS: Nine of the 10 patients enrolled completed the study. Gastric half-emptying time decreased by -95 min (95% CI: -156.8, -34.2) after a single dose of camicinal 125 mg compared with placebo (52 vs. 147 min, P < 0.05), representing a 65% improvement. A decrease of the gastric half-emptying time compared with placebo (approximately 39 min) was observed with camicinal 25 and 50 mg, representing a 27% reduction for both doses (not statistically significant). A positive exposure-response relationship was demonstrated across all doses. The effects of camicinal on gastric half-emptying time were not influenced by fasting glucose levels. Single doses up to 125 mg were well tolerated. Camicinal was well absorbed, exhibiting linear and approximately dose-proportional pharmacokinetic characteristics and a clear exposure-response relationship with gastric emptying. CONCLUSIONS AND IMPLICATIONS: Camicinal significantly accelerated gastric emptying of solids in T1DM patients following administration of a single oral dose. Camicinal was well tolerated and exhibited similar pharmacokinetic characteristics in diabetic patients to those previously reported in healthy volunteers.

Opioid Antagonists and the A118G Polymorphism in the µ-Opioid Receptor Gene: Effects of GSK1521498 and Naltrexone in Healthy Drinkers Stratified by OPRM1 Genotype.

The A118G single-nucleotide polymorphism (SNP rs1799971) in the µ-opioid receptor gene, OPRM1, has been much studied in relation to alcohol use disorders. The reported effects of allelic variation at this SNP on alcohol-related behaviors, and on opioid receptor antagonist treatments, have been inconsistent. We investigated the pharmacogenetic interaction between A118G variation and the effects of two µ-opioid receptor antagonists in a clinical lab setting. Fifty-six overweight and moderate-heavy drinkers were prospectively stratified by genotype (29 AA homozygotes, 27 carriers of at least 1 G allele) in a double-blind placebo-controlled, three-period crossover design with naltrexone (NTX; 25 mg OD for 2 days, then 50 mg OD for 3 days) and GSK1521498 (10 mg OD for 5 days). The primary end point was regional brain activation by the contrast between alcohol and neutral tastes measured using functional magnetic resonance imaging (fMRI). Secondary end points included other fMRI contrasts, subjective responses to intravenous alcohol challenge, and food intake. GSK1521498 (but not NTX) significantly attenuated fMRI activation by appetitive tastes in the midbrain and amygdala. GSK1521498 (and NTX to a lesser extent) significantly affected self-reported responses to alcohol infusion. Both drugs reduced food intake. Across all end points, there was less robust evidence for significant effects of OPRM1 allelic variation, or for pharmacogenetic interactions between genotype and drug treatment. These results do not support strong modulatory effects of OPRM1 genetic variation on opioid receptor antagonist attenuation of alcohol- and food-related behaviors. However, they do support further investigation of GSK1521498 as a potential therapeutic for alcohol use and eating disorders.

The effects of alcohol on the pharmacokinetics and pharmacodynamics of the selective mu-opioid receptor antagonist GSK1521498 in healthy subjects.

The mu-opioid system has a key role in hedonic and motivational processes critical to substance addiction. However, existing mu-opioid antagonists have had limited success as anti-addiction treatments. GSK1521498 is a selective and potent mu-opioid antagonist being developed for the treatment of overeating and substance addictions. In this study, 28 healthy participants were administered single doses of GSK1521498 20 mg, ethanol 0.5 g/kg body weight, or both in combination, in a double blind placebo controlled four-way crossover design. The primary objective was to determine the risk of significant adverse pharmacodynamic and pharmacokinetic (PK) interactions. The effects of GSK1521498 on hedonic and consummatory responses to alcohol and the attentional processing of alcohol-related stimuli, and their modulation by the OPRM1 A118G polymorphism were also explored. GSK1521498 20 mg was well tolerated alone and in combination with ethanol. There were mild transient effects of GSK1521498 on alertness and mood that were greater when it was combined with ethanol. These effects were not of clinical significance. There were no effects of GSK1521498 on reaction time, hedonic or consummatory responses. These findings provide encouraging safety and PK data to support continued development of GSK1521498 for the treatment of alcohol addiction.

Multiple-dose safety, pharmacokinetics, and pharmacodynamics of the µ-opioid receptor inverse agonist GSK1521498.

The endogenous opioid system and µ-opioid receptors in particular have been demonstrated to play a fundamental role in hedonic and motivational behaviors reinforced by rewards. In healthy participants, the authors examined the multiple-dose safety, pharmacokinetic, and secondary pharmacodynamic profile of GSK1521498, a µ-opioid receptor inverse agonist that is being developed for treatment of disorders of compulsive consumption. Clinically relevant doses of GSK1521498 (2, 5, and 10 mg) following once-daily administration for 10 days, were well tolerated with no clinically relevant changes in vital signs, chemistry, or hematologic parameters and with a favorable neuropsychiatric profile. Following oral administration, median first time to reach maximum observed plasma concentration for GSK1521498 occurred 2 to 5 hours after dosing, with individual values ranging from 1 to 8 hours. Systemic exposure to GSK1521498 (area under the curve [0-∞] and maximum observed plasma concentration) increased in a slightly greater-than-dose-proportional manner, and steady-state plasma levels were reached within approximately 7 days. The secondary pharmacodynamic effects of GSK1521498 on cognition and pain threshold and tolerance were dose related, with mild to moderate impairments in measures of attention and reductions of pressure pain threshold and tolerance at the highest dose. These findings provide encouraging safety, tolerability, and pharmacokinetic data in support of the continued clinical development of GSK1521498.

Effects of mu opioid receptor antagonism on cognition in obese binge-eating individuals.

RATIONALE: Translational research implicates the mu opioid neurochemical system in hedonic processing, but its role in dissociable high-level cognitive functions is not well understood. Binge-eating represents a useful model of 'behavioural addiction' for exploring this issue. OBJECTIVE: The aim of this study was to objectively assess the cognitive effects of a mu opioid receptor antagonist in obese individuals with binge-eating symptoms. METHODS: Adults with moderate to severe binge-eating and body mass index ≥30 kg/m² received 4 weeks of treatment with a mu opioid receptor antagonist (GSK1521498) 2 or 5 mg per day, or placebo, in a double-blind randomised parallel design. Neuropsychological assessment was undertaken at baseline and endpoint to quantify processing bias for food stimuli (visual dot probe with 500- and 2,000-ms stimulus presentations and food Stroop tasks) and other distinct cognitive functions (N-back working memory, sustained attention, and power of attention tasks). RESULTS: GSK1521498 5 mg/day significantly reduced attentional bias for food cues on the visual dot probe task versus placebo (p = 0.042), with no effects detected on other cognitive tasks (all p > 0.10). The effect on attentional bias was limited to the longer stimulus duration condition in the higher dose cohort alone. CONCLUSIONS: These findings support a central role for mu opioid receptors in aspects of attentional processing of food cues but militate against the notion of major modulatory influences of mu opioid receptors in working memory and sustained attention. The findings have implications for novel therapeutic directions and suggest that the role of different opioid receptors in cognition merits further research.

Opioid receptor modulation of hedonic taste preference and food intake: a single-dose safety, pharmacokinetic, and pharmacodynamic investigation with GSK1521498, a novel µ-opioid receptor inverse agonist.

Endogenous opioids and µ-opioid receptors have been linked to hedonic and rewarding aspects of palatable food intake. The authors examined the safety, pharmacokinetic, and pharmacodynamic profile of GSK1521498, a µ-opioid receptor inverse agonist that is being investigated primarily for the treatment of overeating behavior in obesity. In healthy participants, GSK1521498 oral solution and capsule formulations were well tolerated up to a dose of 100 mg. After single doses (10-150 mg), the maximum concentration (C(max)) and area under the curve (AUC) in plasma increased in a dose-proportional manner. GSK1521498 selectively reduced sensory hedonic ratings of high-sugar and high-fat dairy products and caloric intake of high-fat/high-sucrose snack foods. These findings provide encouraging data in support of the development of GSK1521498 for the treatment of disorders of maladaptive ingestive behavior or compulsive consumption.

Treatment with a peroxisomal proliferator activated receptor gamma agonist has a modest effect in the allergen challenge model in asthma: a randomised controlled trial.

PURPOSE: A considerable body of non clinical evidence has accumulated to support peroxisomal proliferator-activated receptor gamma agonists as candidate anti-inflammatory drugs in asthma. We utilized rosiglitazone as a tool compound in the inhaled allergen challenge model of asthma. METHODS: A single centre, double-blind, randomised, placebo controlled, two period cross-over study. Subjects received rosiglitazone 4mg and placebo twice daily for 28 days in random order. On day 28, inhaled allergen challenge was performed 1 hour post-dose. A methacholine challenge was performed on day 29 and an adenosine monophosphate challenge on day 14. Exhaled nitric oxide was measured on days 1, 14, 28, 29. Blood was collected pre dose on days 1, 14 and 28 and analysed for markers associated with PPAR activity and systemic markers of inflammation. RESULTS: The late asthmatic reaction (LAR) change from post saline FEV(1) from 4-10 hrs post allergen on day 28 was statistically significant for the weighted mean LAR. The difference in weighted mean was 0.06 L (95% CI 0.01 to 0.11) which equates to a 15% attenuation of the response during placebo treatment. This was accompanied by trends in other markers of efficacy and anti-inflammatory activity but none were considered major effects. DISCUSSION: Treatment with a PPARgamma agonist (rosiglitazone) was associated with a modest (15%) reduction in the late asthmatic reaction in the allergen challenge model of asthma. Based on the results of this study, PPARgamma agonist monotherapy is unlikely to represent a clinically useful intervention in human asthma. Registered with www.clinicaltrials.gov (NCT00318630).