Food and Drug Administration's Obesity Drug Guidance Document: a short history

Design and participant characteristics for a randomized effectiveness trial of an intensive lifestyle intervention to reduce cardiovascular risk in adults with type 2 diabetes: The I-D-HEALTH study

Intervening in Diabetes with Healthy Eating, Activity and Linkages To Healthcare (I-D-HEALTH) is a community-based randomized trial evaluating the effectiveness of a group-based adaption of the Look AHEAD intensive lifestyle intervention. Most potentially eligible patients were identified through electronic medical record queries or referral to a diabetes resource hub. Trial enrollees had a usual source of primary care, elevated body mass index (BMI) and type 2 diabetes. I-D-HEALTH participants were randomized to either standard care alone or standard care plus free-of-charge access to a group-based lifestyle intervention (GLI) offered by the YMCA. GLI participation was encouraged, but not required, for the latter group. The primary outcome is percent weight change over 6, 12 and 24months. Secondary outcomes include direct intervention costs and direct medical and non-medical expenditures, as well as changes in systolic blood pressure, hemoglobin A1c and cholesterol. Among 331 I-D-HEALTH participants, 167 were randomized to standard care and 164 to GLI. The mean age (±standard deviation) in each group was 57.1years (±12.2) and 57.6years (±10.5), respectively. Mean BMI was 34.9kg/m(2) (±7.3) among standard care participants and 36.2kg/m(2) (±7.8) among GLI participants. In both groups, approximately one third of participants were non-Hispanic Whites. We detected no significant differences between groups in mean systolic blood pressure, hemoglobin A1c or total cholesterol (P >0.05 for all characteristics above). The I-D-HEALTH study enrolled a diverse sample of adults with diabetes and offers a unique opportunity to evaluate the effectiveness of offering a community-based intensive lifestyle intervention.

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

BACKGROUND

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.

OBJECTIVE

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.

METHODS

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 25 years. These three factors were based on published estimates, historical data, and analogs from other therapeutic areas.

RESULTS

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 25 years likely did not impact investment decisions.

CONCLUSIONS

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.

Effects of Polygonatum sibiricum rhizome ethanol extract in high-fat diet-fed mice

CONTEXT

The rhizome of Polygonatum sibiricum Redoute (Liliaceae) has long been used to treat diabetes-associated complications. However, the pharmacological mechanism of P. sibiricum on metabolic disorders is not clear.

OBJECTIVE

This study investigates the effect of an ethanol extract of P. sibiricum rhizomes (designated ID1216) on obesity conditions including weight loss in high-fat (HF) diet-fed mice and explores the potential underlying mechanisms.

METHODS

To identify the metabolic impact of the P. sibiricum rhizome extract, HF diet-fed mice were administered ID1216 orally at doses of 250 and 1000 mg/kg/d for 10 weeks, and various factors related to metabolic syndrome were analyzed. We also examined the effects of ID1216 on the expression of genes involved in adipogenesis and lipolysis in 3T3-L1 cells, as well as genes associated with energy homeostasis in C2C12 myocytes.

RESULTS

ID1216 administration led to significant decreases in body weight gain (37.5%), lipid accumulation in adipose tissues (52.8%), and the levels of plasma triglycerides (26.4%) and free fatty acids (28.1%) at a dose of 250 mg/kg/d, compared with the vehicle-treated group, as well as improved insulin resistance. In addition, ID1216 was found to regulate the expression of genes related to adipogenesis and fatty acid oxidation in 3T3-L1 cells and enhance the expression of genes that modulate energy homeostasis in C2C12 myocytes.

CONCLUSIONS

ID1216 may be a promising therapeutic agent for improving obesity conditions through the sirtuin-1 and peroxisome proliferator-activated receptor γ coactivator-1α pathway.

The risk of metabolic syndrome after gestational diabetes mellitus - a hospital-based cohort study

BACKGROUND

Women with gestational diabetes mellitus (GDM) are at an increased risk of developing metabolic syndrome (MetS) after delivery. Recently, the prevalence of both GDM and MetS has increased worldwide, in parallel with obesity. We investigated whether the presentation of MetS and its clinical features among women with previous GDM differs from that among those with normal glucose tolerance during pregnancy, and whether excess body weight affects the results.

METHODS

This hospital-based study of two cohorts was performed in Kanta-Häme Central Hospital, Finland. 120 women with a history of GDM and 120 women with a history of normal glucose metabolism during pregnancy, all aged between 25 and 46 were enrolled. They all underwent physical examination and had baseline blood samples taken. All 240 women were also included in subgroup analyses to study the effect of excess body weight on the results.

RESULTS

Although the groups did not differ in body mass index (BMI; p = 0.069), the risk of developing MetS after pregnancy complicated by GDM was significantly higher than after normal pregnancy, 19 vs. 8 cases (p  =  0.039). Fasting glucose (p < 0.001) and triglyceride levels (p < 0.001) were significantly higher in women affected. In subgroup analysis, cardiovascular risk factors were more common in participants with high BMI than in those with previous gestational diabetes.

CONCLUSIONS

The risk of MetS was 2.4-fold higher after GDM than after normal pregnancy. Cardiovascular risk factors were more common in participants with high BMI than in those with previous GDM. Multivariate analysis supported the main findings. Weight control is important in preventing MetS after delivery.

New medications for treatment of obesity: metabolic and cardiovascular effects

The management of obesity remains a major challenge. Dietary therapy often fails, whereas bariatric surgery, although successful, is demanding and applicable to a limited number of patients. Drug therapy has had many setbacks over the past 20 years because of serious adverse effects; however, several new drugs for the treatment of obesity are either licensed in some parts of the world, submitted for registration, or completing phase III trials. These include combinations (at low dose) of existing drugs, e.g., bupropion + naltrexone (Contrave), phentermine + topiramate (Qsymia), higher doses of existing drugs licensed for other indications (liraglutide, 3 mg), and new entities (lorcaserin). We discuss the challenges and opportunities for obesity pharmacotherapy and review in detail the efficacy of the new drugs regarding weight loss and both desirable and potential undesirable cardiovascular (CV) and metabolic risk factors. Substantial barriers remain, even if the drugs are approved, in successfully integrating these agents into weight management practice, largely related to cost, patient acceptability, and clinician willingness to be engaged in obesity treatment. Although hard clinical outcome benefit (at least for CV outcomes) has yet to be established, obesity pharmacotherapy may soon address many of the challenges in the clinical management of obesity, although newer and better drug combinations and more evidence of benefit from appropriately designed outcome trials is needed.

Modern obesity pharmacotherapy: weighing cardiovascular risk and benefit

Obesity is a major correlate of cardiovascular disease. Weight loss improves cardiovascular risk factors and has the potential to improve outcomes. Two drugs, phentermine plus topiramate and lorcaserin, have recently been approved by the US Food and Drug Administration for the indication of obesity; a third, bupropion plus naltrexone, is under consideration for approval. In clinical trials, these drugs cause weight loss and improve glucose tolerance, lipid profile, and, with the exception of bupropion plus naltrexone, blood pressure. However, their effect on cardiovascular outcomes is unknown. In defining appropriate roles for these drugs in preventive cardiology, it is important to remember the checkered history of drugs for obesity. New weight-loss drugs share the serotonergic and sympathomimetic mechanisms that proved harmful in the cases of Fen-Phen and sibutramine, respectively, albeit with significant differences. Given these risks, randomized cardiovascular outcomes trials are needed to establish the safety, and potential benefit, of these drugs. This review will discuss the history of pharmacotherapy for obesity, existing efficacy and safety data for the novel weight-loss drugs, and issues in the design of postapproval clinical trials.

Long-term drug treatment for obesity: a systematic and clinical review

IMPORTANCE

Thirty-six percent of US adults are obese, and many cannot lose sufficient weight to improve health with lifestyle interventions alone.

OBJECTIVE

To conduct a systematic review of medications currently approved in the United States for obesity treatment in adults. We also discuss off-label use of medications studied for obesity and provide considerations for obesity medication use in clinical practice.

EVIDENCE REVIEW

A PubMed search from inception through September 2013 was performed to find meta-analyses, systematic reviews, and randomized, placebo-controlled trials for currently approved obesity medications lasting at least 1 year that had a primary or secondary outcome of body weight change, included at least 50 participants per group, reported at least 50% retention, and reported results on an intention-to-treat basis. Studies of medications approved for other purposes but tested for obesity treatment were also reviewed.

FINDINGS

Obesity medications approved for long-term use, when prescribed with lifestyle interventions, produce additional weight loss relative to placebo ranging from approximately 3% of initial weight for orlistat and lorcaserin to 9% for top-dose (15/92 mg) phentermine plus topiramate-extended release at 1 year. The proportion of patients achieving clinically meaningful (at least 5%) weight loss ranges from 37% to 47% for lorcaserin, 35% to 73% for orlistat, and 67% to 70% for top-dose phentermine plus topiramate-extended release. All 3 medications produce greater improvements in many cardiometabolic risk factors than placebo, but no obesity medication has been shown to reduce cardiovascular morbidity or mortality. Most prescriptions are for noradrenergic medications, despite their approval only for short-term use and limited data for their long-term safety and efficacy.

CONCLUSIONS AND RELEVANCE

Medications approved for long-term obesity treatment, when used as an adjunct to lifestyle intervention, lead to greater mean weight loss and an increased likelihood of achieving clinically meaningful 1-year weight loss relative to placebo. By discontinuing medication in patients who do not respond with weight loss of at least 5%, clinicians can decrease their patients' exposure to the risks and costs of drug treatment when there is little prospect of long-term benefit.

A case of dilated cardiomyopathy with massive left ventricular thrombus after use of a sibutramine-containing slimming product

Sibutramine, which acts as an anti-obesity drug by inhibiting reuptake of serotonin and norepinephrine, has now been banned due to cardiovascular adverse effects. However, despite being banned, it is not uncommon for people to purchase products with sibutramine or its analogues used as adulterants in non-prescription slimming products or health foods available on the internet. Sibutramine has been associated with rare but serious adverse reactions such as cardiac arrhythmia including QT interval prolongation, myocardial infarction, and cardiomyopathy, as well as increases in blood pressure and pulse rate. Here, we report a case of a 32-year-old male who presented with dilated cardiomyopathy with massive left ventricular thrombus after taking unauthorized sibutramine-containing slimming pills sold over the internet.

Reducing the risk of obesity: defining the role of weight loss drugs

The prevalence of obesity has increased dramatically in the past 20 years. As a public health concern, obesity is associated with a health care resource burden that is quickly approaching that associated with tobacco use. Although lifestyle intervention (diet and exercise) remains the mainstay of treatment of obesity, its effectiveness is limited by poor long-term adherence. Drug therapy has historically been unsuccessful in producing sustained weight loss. Many older weight loss drugs have adverse benefit-to-risk profiles. This review provides an overview of nonpharmacologic interventions for weight loss. The safety and efficacy of older weight loss drugs, as well as current data related to lorcaserin, phentermine/topiramate, and naltrexone-bupropion, are evaluated. Although associated with modest weight loss and some improvement in adverse obesity-related metabolic effects, none of these drugs has been demonstrated to reduce mortality. In addition, the long-term safety of these drugs remains largely unknown. Bariatric surgery is an option for patients with morbid obesity who have failed conventional treatment.

It is important research, but why is it necessary?

The findings regarding cardiovascular actions of dietary supplements labeled as "ephedra free" reported by Foster et al. in the March issue reaffirm decades of research that began in the 1920s with K.K. Chen's study of naturally occurring adrenergic chemicals. Although the study by Foster et al. provides scientifically sound data needed by the US Food and Drug Administration (FDA) as it evaluates the safety of these products, we should ask, "Why was it necessary that these chemicals be studied again for their cardiovascular actions in humans?"

Why do we need drugs to treat the patient with obesity?

OBJECTIVE

Obesity is a public health problem, which increases the risk of chronic diseases and mortality. Weight loss can reduce mortality and improve most of the detrimental health consequences of obesity.

DESIGN AND METHODS

This paper was developed from two presentations to the US Food and Drug Administration (FDA), which has responsibility for reviewing and approving drugs to treat obesity.

RESULTS

A weight loss of 5% or more is sufficient to significantly reduce health risks in individuals with impaired glucose tolerance, hypertension, or nonalcoholic fatty liver disease. Slightly more weight loss (16% on average, achieved by surgery) reduces mortality. The goal of medicating for obesity is to help more patients achieve more weight loss. A barrier to drug approval has been the concern that weight loss medications might be used by individuals with little or no health risks, thus mandating a low side effect profile for approval of any drug. This limits the options for patients who have obesity-related health problems that could improve with weight loss. Recently the FDA signaled interest in identifying health benefits in higher risk patients that might justify medications with higher risk; however, the potential impact on a large segment of the population has led the FDA to consider requiring a cardiovascular outcome trial for all obesity medications, either prior to or after approval.

CONCLUSION

This review argues that drugs are needed for obesity because they enhance behaviorally induced weight loss and that new medications for obesity are needed in the approval process.

Obesity and the Cardiorenal Metabolic Syndrome: Therapeutic Modalities and Their Efficacy in Improving Cardiovascular and Renal Risk Factors

The prevalence of obesity has increased rapidly in the United States. Obesity affects about one third of the adult population and, even though it is attributed to excess calorie intake and inadequate physical activity, its etiopathogenesis is much more complex and is an area of active study. Lifestyle modifications (with a focus on increased activity and decreased calorie intake) have modest efficacy in the treatment of obesity. There is a dearth of safe and effective therapeutic modalities to treat obesity. In this review, we discuss the role of different treatment options in the management of obesity and its comorbidities, with a focus on recently approved drugs and the emerging role of bariatric surgery.