Weight Management Drugs Research Articles

The 'hunger games' - Structural studies of the MC4 receptor reveal mechanism for satiety.

Obesity is a global epidemic causing increased morbidity and impaired quality of life. The melanocortin receptor 4 (MC4R) is at the crux of appetite, energy homeostasis, and body-weight control in the central nervous system and is a prime target for anti-obesity drugs. MC4R is a member of the GPCR superfamily and signals primarily through the heterotrimeric G protein Gs. Through combination of structural, biochemical and cellular studies we determined the cryo-EM structure of the human MC4R-Gs signaling complex, and explored the cellular conduits for signal transduction in health and disease. The work reveals the mechanism of MC4R activation, highlighting a molecular switch that signals satiation. These results fill a major gap in understanding MC4R activation and guide the design of future weight management drugs.

Pharmacological Treatments and Natural Biocompounds in Weight Management.

The obesity pandemic is one of society's most urgent public health concerns. One-third of the global adult population may fall under obese or overweight by 2025, suggesting a rising demand for medical care and an exorbitant cost of healthcare expenditure in the coming years. Generally, the treatment strategy for obese patients is largely patient-centric and needs dietary, behavioral, pharmacological, and sometimes even surgical interventions. Given that obesity cases are rising in adults and children and lifestyle modifications have failed to produce the desired results, the need for medical therapy adjunct to lifestyle modifications is vital for better managing obesity. Most existing or past drugs for obesity treatment target satiety or monoamine pathways and induce a feeling of fullness in patients, while drugs such as orlistat are targeted against intestinal lipases. However, many medications targeted against neurotransmitters showed adverse events in patients, thus being withdrawn from the market. Alternatively, the combination of some drugs has been successfully tested in obesity management. However, the demand for novel, safer, and more efficacious pharmaceutical medicines for weight management does exist. The present review elucidates the current understanding of the available anti-obesity medicines of synthetic and natural origin, their main mechanisms of action, and the shortcomings associated with current weight management drugs.

Efficacy of Liraglutide for Weight Loss Among Patients With Type 2 Diabetes: The SCALE Diabetes Randomized Clinical Trial.

Weight loss of 5% to 10% can improve type 2 diabetes and related comorbidities. Few safe, effective weight-management drugs are currently available. To investigate efficacy and safety of liraglutide vs placebo for weight management in adults with overweight or obesity and type 2 diabetes. Fifty-six-week randomized (2:1:1), double-blind, placebo-controlled, parallel-group trial with 12-week observational off-drug follow-up period. The study was conducted at 126 sites in 9 countries between June 2011 and January 2013. Of 1361 participants assessed for eligibility, 846 were randomized. Inclusion criteria were body mass index of 27.0 or greater, age 18 years or older, taking 0 to 3 oral hypoglycemic agents (metformin, thiazolidinedione, sulfonylurea) with stable body weight, and glycated hemoglobin level 7.0% to 10.0%. Once-daily, subcutaneous liraglutide (3.0 mg) (n = 423), liraglutide (1.8 mg) (n = 211), or placebo (n = 212), all as adjunct to 500 kcal/d dietary deficit and increased physical activity (≥150 min/wk). Three coprimary end points: relative change in weight, proportion of participants losing 5% or more, or more than 10%, of baseline weight at week 56. Baseline weight was 105.7 kg with liraglutide (3.0-mg dose), 105.8 kg with liraglutide (1.8-mg dose), and 106.5 kg with placebo. Weight loss was 6.0% (6.4 kg) with liraglutide (3.0-mg dose), 4.7% (5.0 kg) with liraglutide (1.8-mg dose), and 2.0% (2.2 kg) with placebo (estimated difference for liraglutide [3.0 mg] vs placebo, -4.00% [95% CI, -5.10% to -2.90%]; liraglutide [1.8 mg] vs placebo, -2.71% [95% CI, -4.00% to -1.42%]; P < .001 for both). Weight loss of 5% or greater occurred in 54.3% with liraglutide (3.0 mg) and 40.4% with liraglutide (1.8 mg) vs 21.4% with placebo (estimated difference for liraglutide [3.0 mg] vs placebo, 32.9% [95% CI, 24.6% to 41.2%]; for liraglutide [1.8 mg] vs placebo, 19.0% [95% CI, 9.1% to 28.8%]; P < .001 for both). Weight loss greater than 10% occurred in 25.2% with liraglutide (3.0 mg) and 15.9% with liraglutide (1.8 mg) vs 6.7% with placebo (estimated difference for liraglutide [3.0 mg] vs placebo, 18.5% [95% CI, 12.7% to 24.4%], P < .001; for liraglutide [1.8 mg] vs placebo, 9.3% [95% CI, 2.7% to 15.8%], P = .006). More gastrointestinal disorders were reported with liraglutide (3.0 mg) vs liraglutide (1.8 mg) and placebo. No pancreatitis was reported. Among overweight and obese participants with type 2 diabetes, use of subcutaneous liraglutide (3.0 mg) daily, compared with placebo, resulted in weight loss over 56 weeks. Further studies are needed to evaluate longer-term efficacy and safety. clinicaltrials.gov Identifier:NCT01272232.

The Expected Net Present Value of Developing Weight Management Drugs in the Context of Drug Safety Litigation.

Following withdrawals, failures, and significant litigation settlements, drug product launches in the anti-obesity category slowed despite a large and growing unmet need. Litigation concerns, a more risk-averse regulatory policy, and the difficulty of developing a product with a compelling risk-benefit profile in this category may have limited innovators' expected return on investment and restricted investment in this therapeutic area. The objective of the study was to estimate perceived manufacturer risk associated with product safety litigation and increased development costs vs. revenue expectations on anticipated return on investment and to determine which scenarios might change a manufacturer's investment decision. Expected net present value of a weight-management drug entering pre-clinical trials was calculated for a range of scenarios representing evolving expectations of development costs, revenue, and litigation risk over the past 25years. These three factors were based on published estimates, historical data, and analogs from other therapeutic areas. The main driver in expected net present value calculations is expected revenue, particularly if one assumes that litigation risk and demand are positively correlated. Changes in development costs associated with increased regulatory concern with potential safety issues for the past 25years likely did not impact investment decisions. Regulatory policy and litigation risk both played a role in anti-obesity drug development; however, product revenue-reflecting efficacy at acceptable levels of safety-was by far the most important factor. To date, relatively modest sales associated with recent product introductions suggest that developing a product that is sufficiently efficacious with an acceptable level of safety continues to be the primary challenge in this market.

The Perils of Marketing Weight-Management Remedies and the Role of Health Literacy

This research explores the impact of weight-management remedy marketing on healthy lifestyle behaviors. Three studies demonstrate that exposure to drug (but not supplement) marketing for weight management encourages unhealthy consumer behavior as a result of consumers' reliance on erroneous beliefs about health remedies. The authors explore the possible mitigating role of two dimensions of healthy literacy: nutrition knowledge and remedy knowledge. Whether measured or manipulated, the results show remedy knowledge to be more effective than nutrition knowledge at lessening the effect of weight-management drug marketing on unhealthy behavior. The authors close with a discussion of the theoretical and substantive implications of this research for consumer welfare.

Obesity, adiposity, and dyslipidemia: A consensus statement from the National Lipid Association

The term "fat" may refer to lipids as well as the cells and tissue that store lipid (ie, adipocytes and adipose tissue). "Lipid" is derived from "lipos," which refers to animal fat or vegetable oil. Adiposity refers to body fat and is derived from "adipo," referring to fat. Adipocytes and adipose tissue store the greatest amount of body lipids, including triglycerides and free cholesterol. Adipocytes and adipose tissue are active from an endocrine and immune standpoint. Adipocyte hypertrophy and excessive adipose tissue accumulation can promote pathogenic adipocyte and adipose tissue effects (adiposopathy), resulting in abnormal levels of circulating lipids, with dyslipidemia being a major atherosclerotic coronary heart disease risk factor. It is therefore incumbent upon lipidologists to be among the most knowledgeable in the understanding of the relationship between excessive body fat and dyslipidemia. On September 16, 2012, the National Lipid Association held a Consensus Conference with the goal of better defining the effect of adiposity on lipoproteins, how the pathos of excessive body fat (adiposopathy) contributes to dyslipidemia, and how therapies such as appropriate nutrition, increased physical activity, weight-management drugs, and bariatric surgery might be expected to impact dyslipidemia. It is hoped that the information derived from these proceedings will promote a greater appreciation among clinicians of the impact of excess adiposity and its treatment on dyslipidemia and prompt more research on the effects of interventions for improving dyslipidemia and reducing cardiovascular disease risk in overweight and obese patients.

To Be or Not To Be—Obese

The prevalence of obesity in westernized societies is now considered by epidemiologists to be at an epidemic level. Slightly over a third of adult Americans are considered obese because they have a body mass index of more than 30 kg/m2 (1). Additionally, the percentage of the U.S. population that has a body mass index of more than 25 (considered “overweight”) is almost 70%, which gives even more “food” for thought (1). The consistent failure, for reasons of compliance or adverse actions, of multiple weight-management strategies is a worrying trend. In this issue of Endocrinology, Lockie et al. (2) potentially offer rational modifications to one of these “failed” treatments, rimonabant, that may allow a more positive reception of what was considered an effective, but flawed, weight-management drug.

Evaluating the Power of Food Scale in obese subjects and a general sample of individuals: development and measurement properties

The Power of Food Scale (PFS) was developed to assess the psychological impact of today's food-abundant environments. To evaluate the structure of the PFS in diverse populations of obese and nonobese individuals. Data were obtained from obese adults in a clinical trial for a weight management drug (n=1741), and overweight, obese and normal weight adults in a Web-based survey (n=1275). Exploratory and confirmatory factor analyses were used to investigate the PFS structure using the clinical data. The model developed was then tested using the Web-based data. Relationships between PFS domains and body mass index (BMI) were examined. Logistic regression was used in the Web-based survey to evaluate the association between obesity status and PFS scores. Clinical data indicated that the scale was best represented by a 15-item version with three subscale domains and an aggregate domain (average of three domains); this was confirmed with data from the Web-based survey (Comparative Fit Index: 0.95 and 0.94 for the clinical and Web-based studies, respectively). Cronbach's alpha for both data sets was high, ranging from 0.81 to 0.91. The relationships between BMI and each domain were weak (and approximately linear). A full category increase in PFS domain score (range 1-5) increased the odds of being obese 1.6-2.3 times. The 15-item PFS is best represented by three domains and an aggregate domain. The PFS may provide a useful tool to evaluate the effects of obesity treatments on feelings of being controlled by food in an obesogenic food environment.

Pharmacotherapeutic targeting of the endocannabinoid signaling system: Drugs for obesity and the metabolic syndrome

Endogenous signaling lipids (“endocannabinoids”) functionally related to Δ 9-tetrahydrocannabinol, the psychoactive ingredient of marijuana ( Cannabis), are important biomediators and metabolic regulators critical to mammalian (patho)physiology. The growing family of endocannabinoids, along with endocannabinoid biosynthetic and inactivating enzymes, transporters, and at least two membrane-bound, G-protein coupled receptors, comprise collectively the mammalian endocannabinoid signaling system. The ubiquitous and diverse regulatory actions of the endocannabinoid system in health and disease have supported the regulatory approval of natural products and synthetic agents as drugs that alter endocannabinoid-system activity. More recent data support the concept that the endocananbinoid system may be modulated for therapeutic gain at discrete pharmacological targets with safety and efficacy. Potential medications based on the endocannabinoid system have thus become a central focus of contemporary translational research for varied indications with important unmet medical needs. One such indication, obesity, is a global pandemic whose etiology has a pathogenic component of endocannabinoid-system hyperactivity and for which current pharmacological treatment is severely limited. Application of high-affinity, selective CB1 cannabinoid receptor ligands to attenuate endocannabinoid signaling represents a state-of-the-art approach for improving obesity pharmacotherapy. To this intent, several selective CB1 receptor antagonists with varied chemical structures are currently in advanced preclinical or clinical trials, and one (rimonabant) has been approved as a weight-management drug in some markets. Emerging preclinical data suggest that CB1 receptor neutral antagonists may represent breakthrough medications superior to antagonists/inverse agonists such as rimonabant for therapeutic attenuation of CB1 receptor transmission. Since obesity is a predisposing condition for the cluster of cardiovascular and metabolic derangements collectively known as the metabolic syndrome, effective endocannabinoid-modulatory anti-obesity therapeutics would also help redress other major health problems including type-2 diabetes, atherothrombosis, inflammation, and immune disorders. Pressing worldwide healthcare needs and increasing appreciation of endocannabinoid biology make the rational design and refinement of targeted CB1 receptor modulators a promising route to future medications with significant therapeutic impact against overweight, obesity, obesity-related cardiometabolic dysregulation, and, more generally, maladies having a reward-supported appetitive component.

Panel advises against rimonabant approval

Members of FDA’s Endocrinologic and Metabolic Drugs Advisory Committee in June agreed unanimously that rimonabant, a weight-management drug made by Sanofi Aventis, lacks adequate safety data to merit FDA approval. “I wouldn’t in any way suggest that it be approved at the present time for use

When, for whom and how to use sibutramine?

Sibutramine is the first of a new generation of weight management drugs, and offers long-term control of weight when used as an adjunct to diet and exercise. This paper considers the criteria set down by the European Union's regulatory agency for its use and how this relates to the information now available on its efficacy, side-effect profile and benefits in different patient groups. The data presented relate to 18-65y olds; its use in other age groups has not been established. The EU licence permits continuous treatment for periods of up to 1 y; the STORM study has now led the US Food and Drug Administration to extend clearance to 2 y. The addition of sibutramine to a regimen of diet, exercise and lifestyle modification results in 3-5 times more patients responding to a weight-reduction programme, ie achieving more than 5% weight maintenance. Sibutramine is indicated for use in obese patients (BMI > 30 kg/m2) and also overweight patients with a BMI > 27 kg/m2 who have additional obesity-related risk factors such as type 2 diabetes or dyslipidaemia.

The impact of pharmacotherapy on weight management in type 2 diabetes.

Today, obesity is the most important modifiable risk factor for type 2 diabetes. An excess of body fat is associated with a deterioration of glucose utilisation and promotes the development of type 2 diabetes, particularly in those with a genetic predisposition for the disease. It is also well established that a reduction of excess body fat improves insulin sensitivity and can prevent the conversion to diabetes. In those with overt diabetes, weight loss usually ameliorates glycaemic control and associated metabolic disturbances. Among the pharmacological agents that are used for the treatment of type 2 diabetes only metformin has a weak weight-lowering activity and is considered as the drug of choice for adjunct pharmacotherapy in obese diabetic subjects. A few studies also suggest that acarbose can induce a modest weight reduction in such patients. In contrast, sulphonylurea and insulin treatment is frequently accompanied by substantial weight gain which should be taken into consideration when these drugs are used. Another approach to improve metabolic control in obese type 2 diabetic patients is the use of weight-lowering agents. The new serotonin and noradrenaline reuptake inhibitor sibutramine promotes weight loss which subsequently leads to improved glycaemic control. Orlistat, a lipase inhibitor, is also able to ameliorate metabolic control in such patients due to its weight-lowering potential. As obesity remains a therapeutic challenge in most type 2 diabetic subjects, weight management drugs may represent an alternative or supplement to antidiabetic agents. Moreover, weight management agents have the advantage that they have additional favourable effects on associated cardiovascular risk factors.