Effect of pramlintide on A1C and body weight in insulin-treated African Americans and Hispanics with type 2 diabetes: a pooled post hoc analysis

Amylin analogs for the treatment of obesity without diabetes: present and future

INTRODUCTION

Obesity is a pandemic, linked with increased morbidity including diabetes mellitus (DM) and certain cancer types. Amylin is a major regulatory hormone for satiation and food intake perception in humans. Amylin analogs (pramlintide and cagrilintide) are emerging as promising anti-obesity agents in non-DM subjects.

AREAS COVERED

Pramlintide, the first amylin analog, initially used for the treatment of both type 1 and type 2 DM, has demonstrated weight-lowering action. Clinical trials confirmed a weight loss exceeding 3% in the study period without major untoward effects, which was maintained beyond the follow-up period. Recently, cagrilintide, a long-lasting synthetic amylin analog has been introduced. Cagrilintide has achieved adequate weight loss, reaching even more than 10% of the total weight in early clinical trials. However, adverse gastrointestinal effects, particularly nausea, were more frequent compared with pramlintide. Clinical trials have also confirmed the effectiveness of cagrilintide in comparison with glucagon-like peptide 1 receptor agonists.

EXPERT OPINION

Amylin analogs will certainly enrich the growing therapeutic armamentarium aimed at tackling obesity. The most exciting future research venue could be the development of their combinations with other weight-lowering drugs, especially dual and triple incretin-based co-agonists, thus potentially providing massive weight-loss effects.

Recent trends and advances in type 1 diabetes therapeutics: A comprehensive review

Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by the destruction of pancreatic β-cells, leading to insulin deficiency. Insulin replacement therapy is the current standard of care for T1D, but it has significant limitations. However, stem cell-based replacement therapy has the potential to restore β-cell function and achieve glycaemic control eradicating the necessity for drugs or injecting insulin externally. While significant progress has been made in preclinical studies, the clinical translation of stem cell therapy for T1D is still in its early stages. In continuation, further research is essentially required to determine the safety and efficacy of stem cell therapies and to develop strategies to prevent immune rejection of stem cell-derived β-cells. The current review highlights the current state of cellular therapies for T1D including, different types of stem cell therapies, gene therapy, immunotherapy, artificial pancreas, and cell encapsulation being investigated, and their potential for clinical translation.

Pharmacotherapy of type 2 diabetes: An update and future directions

Type 2 diabetes (T2D) is a widely prevalent disease with substantial economic and social impact for which multiple conventional and novel pharmacotherapies are currently available; however, the landscape of T2D treatment is constantly changing as new therapies emerge and the understanding of currently available agents deepens. This review aims to provide an updated summary of the pharmacotherapeutic approach to T2D. Each class of agents is presented by mechanism of action, details of administration, side effect profile, cost, and use in certain populations including heart failure, non-alcoholic fatty liver disease, obesity, chronic kidney disease, and older individuals. We also review targets of novel therapeutic T2D agent development. Finally, we outline an up-to-date treatment approach that starts with identification of an individualized goal for glycemic control then selection, initiation, and further intensification of a personalized therapeutic plan for T2D.

Amylin and Calcitonin: Potential Therapeutic Strategies to Reduce Body Weight and Liver Fat

The hormones amylin and calcitonin interact with receptors within the same family to exert their effects on the human organism. Calcitonin, derived from thyroid C cells, is known for its inhibitory effect on osteoclasts. Calcitonin of mammalian origin promotes insulin sensitivity, while the more potent calcitonin extracted from salmon additionally inhibits gastric emptying, promotes gallbladder relaxation, increases energy expenditure and induces satiety as well as weight loss. Amylin, derived from pancreatic beta cells, regulates plasma glucose by delaying gastric emptying after meal ingestion, and modulates glucagon secretion and central satiety signals in the brain. Thus, both hormones seem to have metabolic effects of relevance in the context of non-alcoholic fatty liver disease (NAFLD) and other metabolic diseases. In rats, studies with dual amylin and calcitonin receptor agonists have demonstrated robust body weight loss, improved glucose tolerance and a decreased deposition of fat in liver tissue beyond what is observed after a body weight loss. The translational aspects of these preclinical data currently remain unknown. Here, we describe the physiology, pathophysiology, and pharmacological effects of amylin and calcitonin and review preclinical and clinical findings alluding to the future potential of amylin and calcitonin-based drugs for the treatment of obesity and NAFLD.

Pharmacotherapy of type 2 diabetes: An update

Type 2 diabetes (T2DM) is a leading cause of morbidity and mortality worldwide and a major economic burden. The prevalence of T2DM is rising, suggesting more effective prevention and treatment strategies are necessary. The aim of this narrative review is to summarize the pharmacologic treatment options available for patients with T2DM. Each therapeutic class is presented in detail, outlining medication effects, side effects, glycemic control, effect on weight, indications and contraindications, and use in selected populations (heart failure, renal insufficiency, obesity and the elderly). We also present representative cost for each antidiabetic category. Then, we provide an individualized guide for initiation and intensification of treatment and discuss the considerations and rationale for an individualized glycemic goal.

Efficacy and safety of pramlintide injection adjunct to insulin therapy in patients with type 1 diabetes mellitus: a systematic review and meta-analysis

AIMS

We aim to assess the efficacy and safety of pramlintide plus insulin therapy in patients with type 1 diabetes.

METHODS

We included clinical studies comparing pramlintide plus insulin to placebo plus insulin. Efficacy was reflected by glycemic control and reduction in body weight and insulin use. Safety concerns were hypoglycemia and other adverse events. Subgroup analysis was performed for different doses (30, 60, 90 µg/meal) and durations (≤4, 26, 29, >29 weeks) of the treatment.

RESULTS

A total of 10 randomized placebo-controlled studies were included for this meta-analysis (pramlintide, n=1978; placebo, n=1319). Compared with controls, patients given pramlintide had significantly lower HbA1c (p < 0.001), total daily insulin dose (p = 0.024), mean mealtime insulin dose (p < 0.001), body weight (p < 0.001) and postprandial glucose level (p = 0.002). The addition of pramlintide increased the incidence of nausea (p < 0.001), vomiting (p < 0.001), anorexia (p < 0.001) and hypoglycemia (p < 0.05) at the initiation of the treatment. The efficacy and adverse reactions of pramlintide were largely significant for the different doses and durations of the treatment.

CONCLUSIONS

The addition of pramlintide to insulin therapy in patients with type 1 diabetes improves glycemic control and reduces insulin requirement and body weight while bringing transient hypoglycemia and digestive disorders.

The impact of diabetes and diabetes medications on bone health

Patients with type 2 diabetes mellitus (T2DM) have an increased risk of fragility fractures despite increased body weight and normal or higher bone mineral density. The mechanisms by which T2DM increases skeletal fragility are unclear. It is likely that a combination of factors, including a greater risk of falling, regional osteopenia, and impaired bone quality, contributes to the increased fracture risk. Drugs for the treatment of T2DM may also impact on the risk for fractures. For example, thiazolidinediones accelerate bone loss and increase the risk of fractures, particularly in older women. In contrast, metformin and sulfonylureas do not appear to have a negative effect on bone health and may, in fact, protect against fragility fracture. Animal models indicate a potential role for incretin hormones in bone metabolism, but there are only limited data on the impact of dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 agonists on bone health in humans. Animal models also have demonstrated a role for amylin in bone metabolism, but clinical trials in patients with type 1 diabetes with an amylin analog (pramlintide) have not shown a significant impact on bone metabolism. The effects of insulin treatment on fracture risk are inconsistent with some studies showing an increased risk and others showing no effect. Finally, although there is limited information on the latest class of medications for the treatment of T2DM, the sodium-glucose co-transporter-2 inhibitors, these drugs do not seem to increase fracture risk. Because diabetes is an increasingly common chronic condition that can affect patients for many decades, further research into the effects of agents for the treatment of T2DM on bone metabolism is warranted. In this review, the physiological mechanisms and clinical impact of diabetes treatments on bone health and fracture risk in patients with T2DM are described.

Gut-Brain Endocrine Axes in Weight Regulation and Obesity Pharmacotherapy

In recent years, the obesity epidemic has developed into a major health crisis both in the United States as well as throughout the developed world. With current treatments limited to expensive, high-risk surgery and minimally efficacious pharmacotherapy, new therapeutic options are urgently needed to combat this alarming trend. This review focuses on the endogenous gut-brain signaling axes that regulate appetite under physiological conditions, and discusses their clinical relevance by summarizing the clinical and preclinical studies that have investigated manipulation of these pathways to treat obesity.

Antiobesity pharmacotherapy: new drugs and emerging targets

Obesity is a growing pandemic, and related health and economic costs are staggering. Pharmacotherapy, partnered with lifestyle modifications, forms the core of current strategies to reduce the burden of this disease and its sequelae. However, therapies targeting weight loss have a significant history of safety risks, including cardiovascular and psychiatric events. Here, evolving strategies for developing antiobesity therapies, including targets, mechanisms, and developmental status, are highlighted. Progress in this field is underscored by Belviq (lorcaserin) and Qsymia (phentermine/topiramate), the first agents in more than 10 years to achieve regulatory approval for chronic weight management in obese patients. On the horizon, novel insights into metabolism and energy homeostasis reveal guanosine 3',5'-cyclic monophosphate (cGMP) signaling circuits as emerging targets for antiobesity pharmacotherapy. These innovations in molecular discovery may elegantly align with practical off-the-shelf approaches, leveraging existing approved drugs that modulate cGMP levels for the management of obesity.

Non-insulin treatments for diabetes

Aimed to review newer therapeutic agents for the treatment of diabetes that are related to hormones responsible for glucose metabolism other than insulin. Data from several new therapeutic agents were reviewed to provide an overview of the efficacy and tolerability of these agents. With a greater understanding of the physiology of glucose homeostasis and the pathophysiology of diabetes, new therapeutic agents have been developed to address other hormonal deficiencies/defects that are seen in the disease. These new agents fall under the categories of incretin-related therapies, such as glucagon-like peptide-1 mimetics, glucagon-like peptide-1 analogs, dipeptidyl peptidase-4 inhibitors, and amylin analogs. A1c reductions with these agents range from 0.4% to 1.6% (depending on each agent), with added benefits such as weight neutrality/loss and low risk for hypoglycemia.

New advances in models and strategies for developing anti-obesity drugs

INTRODUCTION

Obesity is a worldwide pandemic. Obesity-related health and economic costs are staggering. Existing strategies to combat obesity through lifestyle improvements and medical intervention have had limited success. Pharmacotherapy, in combination with lifestyle modification, may play a vital role in reversing the disease burden. However, past and current weight-loss medications have had serious safety risks, notably cardiovascular and psychiatric events.

AREAS COVERED

The authors review the strategies for designing new anti-obesity drugs by describing those currently in development. They describe their target, mechanism of action and developmental or regulatory status. Furthermore, they discuss the problem of weight regain following weight loss, and its relevance to the long-term success of anti-obesity pharmacotherapy.

EXPERT OPINION

For weight management drugs to achieve the safety and efficacy required to be impactful, current studies are uncovering and characterizing new targets, including new signaling circuits and hormones regulating appetite and metabolism, and re-evaluating the role of pharmacotherapy in weight management. To avoid the safety failures of many past weight-loss drugs, the models and strategies covered in this article incorporate recent advances in knowledge and technology. We discuss the emergence of cGMP signaling as a potentially transformative target in weight management. Modulating cGMP signaling may represent an ideal goal for an anti-obesity pharmacotherapy, reflecting some of the major themes described in the present review: targeting pathways that are newly realized as relevant for weight management; promoting safety by re-purposing drugs that are safe, proven, and approved for clinical use; and having a synergistic effect on multiple, reinforcing pathways.

Pharmacotherapy for childhood obesity: present and future prospects

Pediatric obesity is a serious medical condition associated with significant comorbidities during childhood and adulthood. Lifestyle modifications are essential for treating children with obesity, yet many have insufficient response to improve health with behavioral approaches alone. This review summarizes the relatively sparse data on pharmacotherapy for pediatric obesity and presents information on obesity medications in development. Most previously studied medications demonstrated, at best, modest effects on body weight and obesity-related conditions. It is to be hoped that the future will bring new drugs targeting specific obesity phenotypes that will allow clinicians to use etiology-specific, and therefore more effective, anti-obesity therapies.

Obesity pharmacotherapy: what is next?

The increase in obesity in the Unites States and around the world in the last decade is overwhelming. The number of overweight adults in the world surpassed 1 billion in 2008. Health hazards associated with obesity are serious and include heart disease, sleep apnea, diabetes, and cancer. Although lifestyle modifications are the most straightforward way to control weight, a large portion of the population may not be able to rely on this modality alone. Thus, the development of anti-obesity therapeutics represents a major unmet medical need. Historically, anti-obesity pharmacotherapies have been unsafe and minimally efficacious. A better understanding of the biology of appetite and metabolism provides an opportunity to develop drugs that may offer safer and more effective alternatives for weight management. This review discusses drugs that are currently on the market and in development as anti-obesity therapeutics based on their target and mechanism of action. It should serve as a roadmap to establish expectations for the near future for anti-obesity drug development.

Efficacy and safety of biphasic insulin aspart 70/30 in type 2 diabetes patients of different race or ethnicity (INITIATEplus trial)

OBJECTIVE

To determine if self-titration using biphasic insulin aspart 70/30 (BIAsp 30) had a different impact on efficacy and safety across different racial/ethnic subgroups.

RESEARCH DESIGN/METHODS

This was an exploratory, post hoc analysis by race (White vs. Black/African-American) and ethnicity (Hispanic/Latino vs. non-Hispanic/Latino) of data from the INITIATEplus trial. Participants were treated twice-daily with BIAsp 30 over 24 weeks.

TRIAL REGISTRATION

NCT00101751.

MAIN OUTCOME MEASURES

Efficacy endpoints included reductions in mean glycated hemoglobin (A1C) and fasting plasma glucose (FPG). Safety endpoints included hypoglycemia rates (events/patient-year) and adverse events. Body weight changes were also measured.

RESULTS

Glycemic control improved by a similar extent for all demographic groups. Observed mean decreases in A1C ranged from 2.4% to 2.6% after 24 weeks' treatment. Baseline-adjusted mean A1C decreases for White vs. Black/African-American subjects were 2.56% and 2.13% (p < 0.0001), and for Hispanic/Latino vs. non-Hispanic/Latino subjects were 2.45% and 2.42% (p = 0.677), respectively. Final FPG values were similar among all groups (141-146 mg/dL [7.83-8.10 m mol/L]), and baseline-adjusted FPG decreases were not significantly different (p > 0.025) between groups. Hypoglycemia was low for White, Black/African-American, Hispanic/Latino, and non-Hispanic/Latino subjects (0.08, 0.04, 0.03, and 0.07 major events/patient-year, with 0.60, 0.30, 0.37, and 0.52 minor events/patient-year, respectively). Body weight increases were 3.17 and 3.06 kg (White vs. African-American) and 2.69 and 3.19 kg (Hispanic/Latino vs. non-Hispanic/Latino). Final weight-adjusted total daily insulin doses were 0.60 U/kg for Black/African-American subjects vs. 0.78 U/kg for White subjects (p < 0.0001), and 0.71 U/kg for Hispanic/Latino subjects vs. 0.74 U/kg for non-Hispanic/Latino subjects (p = 0.42).

LIMITATIONS

The trial was not designed or powered for comparisons across racial or ethnic groups, subjects were not stratified for pre-baseline medication regimens between each race and ethnic group, and unequal subject numbers and baseline A1C disparities existed between the pairs of groups being compared.

CONCLUSIONS

Diabetes self-management with BIAsp 30 using an easily followed self-titration algorithm produced low hypoglycemia rates. All subgroups achieved A1C reductions >2.1% and FPG declines >82 mg/dL that were similar across groups, demonstrating that self-titration of BIAsp 30 can successfully be pursued in a primary care setting by patients who had previously failed to meet ADA A1C targets under oral antidiabetes therapy, with race or ethnicity not an obstacle to achieving better glycemic control.

Medications for weight reduction

Comparatively few drugs are available for the treatment of overweight patients, and their effectiveness is limited to palliation of the chronic disease of obesity. Nevertheless, drug development that is now underway is more rapid than in the past, and we anticipate the discovery of safe and effective pharmacologic strategies for the management of obesity and its serious complications.

Regulation of appetite to treat obesity

Obesity has escalated into a pandemic over the past few decades. In turn, research efforts have sought to elucidate the molecular mechanisms underlying the regulation of energy balance. A host of endogenous mediators regulate appetite and metabolism, and thereby control both short- and long-term energy balance. These mediators, which include gut, pancreatic and adipose neuropeptides, have been targeted in the development of anti-obesity pharmacotherapy, with the goal of amplifying anorexigenic and lipolytic signaling or blocking orexigenic and lipogenic signaling. This article presents the efficacy and safety of these anti-obesity drugs.

Efficacy and harms of the hypoglycemic agent pramlintide in diabetes mellitus

PURPOSE

We conducted a study to examine the efficacy, effectiveness, and harms of pramlintide as adjunct therapy in adults and children with type 1 or type 2 diabetes.

METHODS

We searched multiple bibliographic databases to January 2010, the US Food and Drug Administration Web site, and other sources to identify randomized controlled trials (RCTs) fulfilling inclusion criteria. Syntheses were qualitative because data were too heterogeneous for meta-analysis.

RESULTS

Three published RCTs in type 1 diabetes and 4 in type 2 disease fulfilled inclusion criteria. All trials were conducted with adults, and none was longer than 52 weeks. In type 1 diabetes with intensive insulin therapy, pramlintide was as effective as placebo in lowering glycated hemoglobin (HbA(1c)) levels in one trial. Pramlintide was somewhat more effective than placebo in patients using conventional insulin therapy, with a between-group difference in HbA(1c) levels of 0.2% to 0.3% (2 studies). In patients with type 2 diabetes, pramlintide was more effective at reducing HbA(1c) levels than placebo when added to flexibly dosed glargine (without prandial insulin) and when added to fixed-dose insulin therapies, with or without oral hypoglycemic agents (between-group differences in HbA(1c) were approximately 0.4%). Weight loss was observed with pramlintide in both type 1 and type 2 diabetes, whereas placebo-treated patients tended to gain weight. Pramlintide-treated patients experienced more frequent nausea and severe hypoglycemia compared with patients treated with placebo.

CONCLUSIONS

Pramlintide was somewhat more effective than placebo as adjunct therapy for improving HbA(1c) levels and weight in adults with type 1 diabetes on conventional insulin therapy, or type 2 diabetes and inadequate glycemic control with their current therapies, with between-group differences in HbA(1c) levels in the range of 0.2% to 0.4%. Further research is needed to determine pramlintide's durability of hypoglycemic effect, as well as effects on patient-reported outcomes, morbidity, mortality, and long-term harms.

Current trends in targeting the hormonal regulation of appetite and energy balance to treat obesity

With the eruption of the obesity pandemic over the past few decades, much research has been devoted to understanding the molecular mechanisms by which the human body regulates energy balance. These studies have revealed several mediators, including gut/pancreatic/adipose hormones and neuropeptides that control both short- and long-term energy balance by regulating appetite and/or metabolism. These endogenous mediators of energy balance have been the focus of many anti-obesity drug-development programs aimed at either amplifying endogenous anorexigenic/lipolytic signaling or blocking endogenous orexigenic/lipogenic signaling. Here, we discuss the efficacy and safety of targeting these pathways for the pharmacologic treatment of obesity.

Central and peripheral molecular targets for antiobesity pharmacotherapy

Obesity has emerged as one of the principal worldwide health concerns of the modern era, and there exists a tremendous unmet clinical need for safe and effective therapies to combat this global pandemic. The prevalence of obesity and its associated comorbidities, including cardiovascular and metabolic diseases, has focused the attention of those in drug discovery and development on generating effective modalities for the treatment and prevention of obesity. Early efforts in the field of obesity pharmacotherapy centered on the development of agents with indeterminate mechanisms of action. This led to treatment paradigms characterized by significant off-target effects. In the past two decades, new insights have been made into the physiologic regulation of energy balance and the subordinate central and peripheral circuits coordinating appetite, metabolism, and lipogenesis. These studies have revealed previously unrecognized molecular targets for controlling appetite and managing weight from which has emerged a new wave of targeted pharmacotherapies to prevent and control obesity.

The Role of Pramlintide for Weight Loss

Objective:

To evaluate the weight-loss effects of pramlintide.

Data Sources:

A literature search was conducted in MEDLINE (1950–October week 4, 2009), International Pharmaceutical Abstracts (1970–October 2009), and Evidence Based Medicine Database (1991–2009 week 44) to identify relevant publications. Key words searched included pramlintide, weight loss, obesity, and overweight. Additional data sources were obtained through a bibliographic review of selected articles.

Study Selection/Data Extraction:

All studies conducted on humans and published in English that examined the effects of pramlintide on body weight as a primary or secondary endpoint were selected for analysis.

Data Synthesis:

Pramlintide is a human amylin analog approved by the Food and Drug Administration for use in conjunction with insulin therapy in patients with type 1 or 2 diabetes. In addition to its glucoregulatory actions, pramlintide has been shown to increase satiety and, therefore, decrease calorie Intake via a central mechanism. Several studies show that this translates into statistically significant weight loss in overweight or obese patients with type 1 or 2 diabetes; patients with type 1 diabetes lost up to 1.7 kg over 1 year with pramlintide 60 μg 3 times daily, while patients with type 2 diabetes experienced a placebo-subtracted weight loss of up to 3.7 kg after 16 weeks of pramlintide 120–240 μg administered 3 times daily. Preliminary trials assessing the use of pramlintide for weight loss in obese patients without diabetes have demonstrated weight loss of up to 8 kg after 1 year. In all studies, the drug was generally well tolerated, with nausea being the most commonly reported adverse effect.

Conclusions:

Based on preliminary evidence, pramlintide facilitates modest weight loss in obese or overweight patients with and without diabetes. However, current trials were limited by inconsistent study design, dosing, and patient population.

Present and Prospective Pharmacotherapy for the Management of Patients with Type 2 Diabetes

Diabetes Mellitus is a chronic condition prevalent worldwide. Type 2 diabetes is the most common form of diabetes, comprising 90% to 95% of all cases. Over the last few decades, the importance of glycemic control and its impact on prevention of diabetes-related complications has been documented in multiple clinical trials. As most patients with type 2 diabetes will require pharmacologic intervention to achieve and maintain appropriate glycemic control, new medications targeting different aspects of the pathophysiology of type 2 diabetes have been a significant focus of research and development. During the last decade, multiple new medications for diabetes management have become available: these medications have novel mechanisms of action, differences in effectiveness, and varying side effect profiles which will be reviewed in this article. Some of these newer medications, such as the GLP-1 analogues and DPP-4 inhibitors, have become widely accepted as therapeutic options for the management of type 2 diabetes.Additional classes of glucose-lowering medications are expected to become available in the near future. This manuscript will summarize available data regarding these newer and prospective medications for the management of type 2 diabetes.

Review of pramlintide as adjunctive therapy in treatment of type 1 and type 2 diabetes

Pramlintide (Symlin^®), a synthetic analog of a neurohormone amylin, was approved by the US Food and Drug Administration for use along with premeal insulin in patients with type 1. In patients with type 2 diabetes, pramlintide is approved for addition to premeal insulin in those patients who are either only on premeal insulin or those receiving the combination of insulin and metformin and/or a sulfonylurea. This article reviews the pharmacology, pharmacokinetics, dosing, clinical trials, safety, contraindications, and drug interactions of pramlintide therapy. A search for published clinical trials and therapeutic reviews in the English language was done in the following databases: Iowa Drug Information Service (1966 to July 2008), MEDLINE (1966 to July 2008), and International Pharmaceutical Abstracts (1970 to July 2008). Pramlintide and amylin were used as keywords and title words. References of key articles were also reviewed to identify additional publications. Amylin is a 37 amino acid peptide neurohormone cosecreted from the beta cells of the pancreas, along with insulin, in response to meals. Amylin lowers serum glucose by decreasing glucagon release, slowing gastric emptying and decreasing food intake. Pramlintide, a synthetic analog of amylin, reduces 2-hour postprandial blood glucose between 3.4 and 5 mmol/L, reduces A1C by 0.2% to 0.7% and has no effect on fasting glucose levels. The use of pramlintide was associated with up to a 1.6 kg weight loss. Nausea was the most commonly reported adverse event. Pramlintide is an amylin analog that was FDA approved for the treatment of type 1 and type 2 diabetes. Its use results in modest reduction of A1C and the most frequent side effects are hypoglycemia and nausea.

Medications for weight reduction

Only two drugs are currently approved for long-term use in the treatment of obesity and four others for short-term use. Evaluating the risk-benefit profile is an essential first step. For individuals who have a low body mass index for whom the risk is small, the risk profile must make the drug acceptable for almost everyone. For higher-risk patients, such as those planning intestinal bypass or who have sleep apnea, a wider range of drugs may be considered. Obesity is a chronic disease that has many causes. Treatment is aimed at palliation-that is, producing and maintaining weight loss. Regardless of the primary site of action, the net effect must be a reduction in food intake or increase in energy expenditure.

Management of type 2 diabetes in the obese patient: current concerns and emerging therapies

OBJECTIVES

The aims of this review are (1) to examine the pathophysiologic relationship between type 2 diabetes and obesity, (2) to provide an overview of current and emerging treatments for type 2 diabetes and their effects on body weight.

METHODS

A MEDLINE search was performed for literature published in the English language from 1966 to 2006. Abstracts and presentations from the American Diabetes Association Scientific Sessions (2002-2006) and the European Association for the Study of Diabetes Annual Meetings (1998-2006) were also searched for relevant studies. Preclinical and clinical data were selected for inclusion based on novelty and pertinence to treatment of the obese patient.

FINDINGS

Recent guidelines suggest that all patients with type 2 diabetes should initially receive metformin as well as lifestyle intervention, followed by rapid administration of other oral anti-diabetic agents or insulin if glycemic goals are not met or maintained. Many oral anti-diabetic drugs, and insulin, are associated with weight gain. New agents with anti-diabetic activity that may be advantageous in obese patients with type 2 diabetes have recently become available. These include injectable incretin mimetics, which reduce blood glucose while reducing body weight but commonly cause nausea and vomiting. A new class of oral agents, the dipeptidyl peptidase-4 inhibitors, is weight-neutral and largely devoid of gastrointestinal side-effects. The cannabinoid receptor antagonist rimonabant is the first of a new class of anti-obesity agents that reduces central obesity and improves multiple aspects of vascular risk.

CONCLUSION

New agents offer the prospect of improved glycemic control without weight gain. However, the ultimate roles of these agents in the treatment of obese patients with type 2 diabetes remain to be established.

Cost effectiveness of duloxetine in the treatment of diabetic peripheral neuropathic pain in the UK

OBJECTIVE

The objective of this analysis was to evaluate the cost-effectiveness of duloxetine when considered as an additional treatment option for UK-based patients suffering from diabetic peripheral neuropathic pain.

RESEARCH DESIGN AND METHODS

A decision-analytic model was used to represent the sequential management of patients with diabetic peripheral neuropathic pain. The standard UK treatment strategy was defined as first-line tricyclic antidepressants (amitriptyline), second-line anticonvulsants (gabapentin) and lastly an opioid-related treatment. The cost-effectiveness of duloxetine was evaluated as an additional first, second, third or fourth-line therapy over a 6-month treatment period for a cohort of 1000 patients. Treatment response was modelled based on changes from baseline pain severity using a standard 11-point pain scale (0-10); full response (>or= 50% change), partial response (30-49%) and no response (< 30%). The model was populated with efficacy and discontinuation data using indirect comparisons of treatment efficacy based on relative effects to a common placebo comparator.

RESULTS

The second-line use of duloxetine resulted in cost savings of pound 77,071 for every 1000 treated patients, with an additional 29 patients achieving a full pain response when compared to standard UK treatment. Additional quality-adjusted life years (QALYs) were achieved at 1.88 QALYs per 1000 patients.

CONCLUSIONS

This UK-based economic model suggests that second-line use of duloxetine is a beneficial and cost-effective treatment strategy for diabetic peripheral neuropathic pain.

Medical therapy for obesity--current status and future hopes

In accepting any new drug for the treatment of obesity, the safety profile must make it acceptable for almost everyone. Criteria for selecting treatments involve evaluating the risks to the individual from obesity and balancing that against any possible problems with the treatment. Obesity is a chronic disease that has many causes. Cure is rare and treatment is thus aimed at palliation, that is, producing and maintaining weight loss. Wherever the primary site of action may be, however, the net effect must be a reduction in food intake or an increase in energy expenditure.

New Therapeutic Options for the Management of Diabetes

Objective: To review new hypoglycemic and antihyperglycemic agents recently approved for the treatment of type 1 and type 2 diabetes mellitus.Data Sources: A MEDLINE search of articles published from 1966 to March 2006 was conducted to identify English-language literature available on the newer therapies approved for the treatment of diabetes. Search terms used were: Byetta, exenatide, insulin detemir, NN304, Exubera inhaled insulin, Levemir, pramlintide, Symlin, AC137, AC0137, and Tripro-Amylin. These articles, abstracts, and data provided by the pharmaceutical manufacturers were reviewed to identify pertinent data. Additional references were obtained from the bibliographies of these publications.Study Selection: Randomized, English-language studies investigating safety or efficacy data on these newer agents with a focus on human studies.Data Extraction: These hypoglycemic and antihyperglycemic agents were reviewed with regard to background information, pharmacokinetic and pharmacodynamic data, relevant clinical studies, U.S. Food and Drug Administration-approved indications, dosing and administration, contraindications, drug interactions, adverse effects, storage, cost, availability, and role in therapy.Data Synthesis: Over the last decade, management options for the treatment of diabetes have exploded. Among these are the incretin mimetics, amylin analogs, insulin analogs, and inhaled insulin. Short-term studies demonstrate that each of these therapies may offer specific advantages such as improved glycemia, convenience, and/or weight loss. Continued study of the incretin mimetics, amylin analogs, and inhaled insulin will be needed to verify long-term safety and efficacy of these agents.Conclusions: These agents with novel mechanisms of action and a new insulin-delivery device offer patients and clinicians additional options that improve glycemic and nonglycemic factors while addressing some of the concerns of older agents. Longerterm studies will help providers weigh the benefits, adverse effects, cost, and unknown long-term risks of these medications.

Pramlintide acetate injection for the treatment of type 1 and type 2 diabetes mellitus

BACKGROUND

Amylin is a hormone cosecreted with insulin by the beta cells of the pancreas. It suppresses postprandial glucagon secretion and slows gastric emptying. Pramlintide acetate is an amylin analogue that was approved by the US Food and Drug Administration in March 2005.

OBJECTIVE

This article reviews the current primary literature on the clinical efficacy and tolerability of pramlintide injection in the treatment of type 1 and type 2 diabetes mellitus (DM). Among other topics covered are the pharmacokinetics, pharmacodynamics, and dosing and administration of pramlintide.

METHODS

Pertinent English-language articles were identified through a search of MEDLINE (1966-January 2007), International Pharmaceutical Abstracts (1970-present), Database of Abstracts of Reviews of Effectiveness (1995-January 2007), Cochrane Database of Systematic Reviews (1995-January 2007), and EMBASE Drugs & Pharmacology (1991-1st quarter 2007). The search terms included pramlintide, amylin, gastric emptying, pharmacokinetic, pharmacoeconomic, postprandial hyperglycemia, and glucagon. Articles were selected for review if they described studies having a randomized, double-blind, controlled design and included glycosylated hemoglobin (HbA(1c)) as an end point.

RESULTS

Pramlintide is administered subcutaneously in the abdominal area or thigh immediately before each main meal to achieve maximal reductions in post-prandial glucose excursions. Its C(max) is reached within 20 minutes, and its t(1/2) is 48 minutes. Metabolism is primarily via the kidneys. Pramlintide therapy was associated with inhibition of postprandial glucagon secretion in 24 patients with type 2 DM; prolonged gastric emptying in 11 patients with type 1 DM; a 23% reduction in total energy intake in 11 patients with type 2 DM; and a reduction in markers of oxidative stress in 18 patients with type 1 DM (all, P <- 0.05 vs placebo). In two 52-week studies in patients with type 1 DM, the groups that received pramlintide 30 to 60 microg QID (n = 243), 60 microg TID (n = 164), and 60 microg QID (n = 161) had respective 0.39%, 0.29%, and 0.34% reductions in HbA(1c) and 0.5-, 0.3-, and 0.6-kg reductions in body weight, respectively (all, P < 0.05 vs placebo). In two 52-week studies in patients with type 2 DM, the groups that received pramlintide 120 microg BID (n = 166) and 150 microg TID (n = 144) had respective 0.62% and 0.6% reductions in HbA(1c) and 1.4- and 1.3-kg reductions in body weight (all, P < 0.05 vs placebo). Hypoglycemia, nausea, vomiting, and anorexia were the most frequently reported (>/=10% occurrence) adverse events in patients receiving pramlintide compared with placebo. These events were mild to moderate and occurred more frequently during the first month of therapy.

CONCLUSIONS

Pramlintide therapy was associated with reductions in HbA(1c) and body weight in four 52-week studies in patients with type 1 DM and type 2 DM. Hypoglycemia, nausea, vomiting, and anorexia were the most frequently occurring adverse events, particularly during the first month of therapy. Pramlintide was associated with reductions in measures of oxidative stress, but studies are needed to evaluate the effects of this agent on DM-related complications.

Adjunctive Therapy with Pramlintide in Patients with Type 1 or Type 2 Diabetes Mellitus

Uncontrolled diabetes mellitus is associated with both microvascular and macrovascular complications. Despite an array of treatment options available, achievement of euglycemia in most patients with diabetes is still lacking. Pramlintide acetate, a synthetic analog of the human hormone amylin and belonging to a new class of agents, was approved in March 2005 as adjunctive treatment in patients with type 1 or 2 diabetes mellitus. To evaluate the data available on the efficacy and safety of pramlintide, we conducted a search of MEDLINE (January 1966-May 2006) and International Pharmaceutical Abstracts (January 1970-May 2006). Bibliographies of clinical trials were reviewed for additional references. The literature reviewed demonstrated that pramlintide is effective in reducing levels of glycosylated hemoglobin and potentially preventing weight gain. The most commonly reported adverse effects associated with pramlintide were nausea, anorexia, and hypoglycemia. These adverse effects occurred more often during the initiation of therapy and were usually mild to moderate in nature. Whether this therapy is a cost-effective option for patients with type 1 or type 2 diabetes mellitus is yet to be determined.

Disparities in HbA1c levels between African-American and non-Hispanic white adults with diabetes: a meta-analysis

OBJECTIVE

Among individuals with diabetes, a comparison of HbA(1c) (A1C) levels between African Americans and non-Hispanic whites was evaluated. Data sources included PubMed, Web of Science, the Cumulative Index to Nursing and Allied Health, the Cochrane Library, the Combined Health Information Database, and the Education Resources Information Center.

RESEARCH DESIGN AND METHODS

We executed a search for articles published between 1993 and 2005. Data on sample size, age, sex, A1C, geographical location, and study design were extracted. Cross-sectional data and baseline data from clinical trials and cohort studies for African Americans and non-Hispanic whites with diabetes were included. Diabetic subjects aged <18 years and those with pre-diabetes or gestational diabetes were excluded. We conducted a meta-analysis to estimate the difference in the mean values of A1C for African Americans and non-Hispanic whites.

RESULTS

A total of 391 studies were reviewed, of which 78 contained A1C data. Eleven had data on A1C for African Americans and non-Hispanic whites and met selection criteria. A meta-analysis revealed the standard effect to be 0.31 (95% CI 0.39-0.25). This standard effect correlates to an A1C difference between groups of approximately 0.65%, indicating a higher A1C across studies for African Americans. Grouping studies by study type (cross-sectional or cohort), method of data collection for A1C (chart review or blood draw), and insurance status (managed care or nonmanaged care) showed similar results.

CONCLUSIONS

The higher A1C observed in this meta-analysis among African Americans compared with non-Hispanic whites may contribute to disparity in diabetes morbidity and mortality in this population.

Current and novel approaches to the drug therapy of obesity

INTRODUCTION

Obesity has been described as the greatest current threat to human health. Although diet and lifestyle changes remain the cornerstones of therapy for obesity, weight losses are often small, and long-term success is disappointing.

DISCUSSION

When these lifestyle-modifying attempts fail, the use of anti-obesity drugs is warranted. Drug treatment is often indicated, but is somewhat limited by the minimal number of well-tolerated drugs that have proven to have long-term efficacy in maintaining body weight loss. The currently available drugs, sibutramine and orlistat, appear modestly effective in promoting weight loss. However, pharmacological therapy for obesity is in transition; expanding knowledge of the physiological mechanisms of body weight regulation has revealed new molecular targets, and more than 150 novel agents are under active development.

CONCLUSIONS

Because weight regulation is complex, and redundant systems protect against perceived starvation, optimal treatment of obesity will likely require combinations of therapies. In addition, a better comprehension of the problem prior to its treatment would be preferable before targeting homeostatic pathways which could be irrelevant.

Diabetes in African Americans

African Americans have a high risk for type 2 diabetes. Genetic traits, the prevalence of obesity, and insulin resistance all contribute to the risk of diabetes in the African American community. African Americans have a high rate of diabetic complications, because of poor glycaemic control and racial disparities in health care in the USA. African Americans with diabetes may have an atypical presentation that simulates type 1 diabetes, but then their subsequent clinical course is typical of type 2 diabetes. Culturally sensitive strategies, structured disease management protocols, and the assistance of nurses, diabetic educators, and other health care professionals are effective in improving the outcome of diabetes in the African American community.

Obesity drugs and their targets: correlation of mouse knockout phenotypes with drug effects in vivo

Sequencing of the human genome has yielded thousands of potential drug targets. The difficulty now is in determining which targets have real therapeutic value and should be the focus of a drug discovery effort. The available evidence suggests that knockout technology can be used prospectively to identify targets that are amenable to drug development for the treatment of a variety of diseases. This review compares the knockout phenotypes of 21 potential obesity targets with the effects of therapeutics designed for those targets on rodents and, when data were available, on humans. The phenotypes of obesity target knockouts model the effects seen when therapeutics designed for those obesity targets are delivered to rodents; of the 21 obesity targets reviewed, 16 showed a correspondence between knockout phenotype and drug effect in mice and/or rats. This suggests that, at least in terms of evaluating obesity targets, it is rare for compensatory developmental changes caused by the gene knockout to prevent detection of the relevant phenotype. In the majority of cases, the knockout phenotypes also modelled the effects seen when the relevant therapeutics were delivered to humans. Thus, it seems rational to use mouse knockout technology prospectively to identify genes that regulate body fat in vivo, and then to develop anti-obesity therapeutics by targeting the human protein products of these genes. Ultimately, the value of using this approach to identify novel targets for human anti-obesity therapies will be judged by future studies examining the anti-obesity effect, in humans, of the therapeutics that result from this approach.

Pramlintide in the treatment of type 1 and type 2 diabetes mellitus

BACKGROUND

Amylin is a 37-amino acid peptide neurohormone that is cosecreted with insulin from the pancreatic beta cells in response to meals. It lowers serum glucose by decreasing glucagon release, slowing gastric emptying, and decreasing food intake. Pramlintide, a synthetic amylin analogue, is approved by the US Food and Drug Administration for use with mealtime insulin in patients with type 1 diabetes and patients with type 2 diabetes who are using mealtime insulin only or the combination of insulin and metformin and/or a sulfonylurea.

OBJECTIVE

This article reviews the available literature on pramlintide with respect to its mechanism of action, pharmacokinetics and pharmacodynamics, clinical efficacy in type 1 and type 2 diabetes, safety and tolerability, dosing, contraindications, and drug interactions.

METHODS

MEDLINE (1966-April 2005), Iowa Drug Information Service (1966-April 2005), and International Pharmaceutical Abstracts (1970-April 2005) were searched for clinical trials and therapeutic reviews published in the English language. The search terms were pramlintide and amylin. The bibliographies of identified articles were reviewed for additional references. All relevant studies were included in the review.

RESULTS

Six studies, ranging in duration from 4 to 52 weeks, examined the effect of administering pramlintide with premeal insulin in patients with type 1 diabetes. In these trials, pramlintide 120 to 270 microg/d reduced glycosylated hemoglobin (HbA(1c)) by 0.1 % to 0.67%, 1-hour postprandial glucose (PPG) by 4.4 to 7 mmol/L, and 2-hour PPG by 3.6 to 4.8 mmol/L. Five studies, also ranging from 4 to 52 weeks' duration, examined the effect of administering premeal pramlintide in patients with type 2 diabetes. In these trials, pramlintide 90 to 450 microg/d reduced HbA(1c) by 0.3% to 0.62%, 1-hour PPG by 4.8 mmol/L, and 2-hour PPG by 3.4 mmol/L. The principal adverse events reported in clinical trials were nausea and hypoglycemia. The incidence of hypoglycemia in the first 4 weeks of therapy was 2 to 4 times greater with pramlintide compared with placebo; thus, the manufacturer recommends reducing the dose of premeal insulin by 50% when starting pramlintide. Close monitoring of blood glucose levels is recommended when initiating pramlintide therapy.

CONCLUSIONS

Use of pramlintide in addition to insulin in patients with type 1 and type 2 diabetes was associated with modest reductions in HbA(1c). The primary adverse effects of pramlintide therapy were nausea and hypoglycemia.

Pramlintide Acetate

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Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. If you would like information about The Formulary Monograph Service or The F.I.X., call The Formulary at 800-322-4349. The July 2005 monograph topics are exenatide injection, inhaled insulin, fluocinolone acetonide intravitreal implant, tigecycline, and medroxyprogesterone acetate injectable suspension. The DUE is on exenatide injection.

Novel pharmacologic agents for type 2 diabetes

After many decades of relative therapeutic stagnation since the initial discovery of insulin, followed by some modifications on its structure and only having sulfonylureas and biguanides for many years, the last decade has seen a surge in new therapeutic options for the management of diabetes. The results of the United Kingdom Prospective Diabetes Study and Kumamoto study indicate the need for aggressive glycemic control and the slow inexorable clinical deterioration associated with type 2 diabetes overtime. The propensity for weight gain and hypoglycemia are the two major limitations that subcutaneous insulin and sulfonylureas have been particularly prone to. The newer antidiabetic medications and those on the horizon attempt to address these limitations. GLP-1 agonists and the DPP-IV inhibitors exploit the innate incretin system to improve glycemia while promoting satiety and weight management. Like GLP-1 related compounds, pramlintide offers the potential to address postprandial hyperglucagonemia associated with type 2 diabetes only limited by the multiple injections and gastrointestinal side effects. The glitazars offer the hope ofa new approach to diabetes care addressing not just glycemia, but dyslipidemia and other components of the metabolic syndrome, though the side effect profile remains a major unknown. The INGAP peptide represents the holy grail of diabetes care as it offers the potential of a new paradigm: that of islet regeneration and potential for a cure. But at this stage, with no human data available, it remains highly speculative. Beyond these and other novel agents being developed to meet the challenge of the worldwide epidemic of diabetes, the central place of insulin in diabetes care cannot be forgotten. In view of this the continued efforts of improvement in insulin delivery, kinetics and action have spurred such innovations as the various inhaled insulins and new insulin analogues. There is cause for guarded optimism and excitement about the years ahead. There is reason to expect that despite the growing burden of diabetes worldwide, we will be better equipped to manage it and its comorbidities and prevent its onset and possibly even cure it.

Clinical studies

Recognizing that type 1 diabetes was characterized not only by insulin deficiency, but also by amylin deficiency, Cooper (Cooper, 1991) predicted that certain features of the disease could be related thereto, and he proposed amylin/insulin co-replacement therapy. Although the early physiological rationale was flawed, the idea that glucose control could be improved over that attainable with insulin alone without invoking the ravages of worsening insulin-induced hypoglycemia was vindicated. The proposal spawned a first-in-class drug development program that ultimately led to marketing approval by the U.S. Food and Drug Administration of the amylinomimetic pramlintide acetate in March 2005. The prescribers' package insert (Amylin Pharmaceuticals Inc., 2005), which includes a synopsis of safety and efficacy of pramlintide, is included as Appendix 1. Pramlintide exhibited a terminal t1/2, in humans of 25-49 min and, like amylin, was cleared mainly by the kidney. The dose-limiting side effect was nausea and, at some doses, vomiting. These side effects usually subsided within the first days to weeks of administration. The principal risk of pramlintide co-therapy was an increased probability of insulin-induced hypoglycemia, especially at the initiation of therapy. This risk could be mitigated by pre-emptive reduction in insulin dose. Pramlintide dosed at 30-60 microg three to four times daily in patients with type 1 diabetes, and at doses of 120 microg twice daily in patients with type 2 diabetes, invoked a glycemic improvement, typically a decrease in HbA1c of 0.4-0.5% relative to placebo, that was sustained for at least 1 year. This change relative to control subjects treated with insulin alone typically was associated with a reduction in body weight and insulin use, and was not associated with an increase in rate of severe hypoglycemia other than at the initiation of therapy. Effects observed in animals, such as slowing of gastric emptying, inhibition of nutrient-stimulated glucagon secretion, and inhibition of food intake, generally have been replicated in humans. A notable exception appears to be induction of muscle glycogenolysis and increase in plasma lactate.

Current and investigational antiobesity agents and obesity therapeutic treatment targets

Public health efforts and current antiobesity agents have not controlled the increasing epidemic of obesity. Investigational antiobesity agents consist of 1) central nervous system agents that affect neurotransmitters or neural ion channels, including antidepressants (bupropion), selective serotonin 2c receptor agonists, antiseizure agents (topiramate, zonisamide), some dopamine antagonists, and cannabinoid-1 receptor antagonists (rimonabant); 2) leptin/insulin/central nervous system pathway agents, including leptin analogues, leptin transport and/or leptin receptor promoters, ciliary neurotrophic factor (Axokine), neuropeptide Y and agouti-related peptide antagonists, proopiomelanocortin and cocaine and amphetamine regulated transcript promoters, alpha-melanocyte-stimulating hormone analogues, melanocortin-4 receptor agonists, and agents that affect insulin metabolism/activity, which include protein-tyrosine phosphatase-1B inhibitors, peroxisome proliferator activated receptor-gamma receptor antagonists, short-acting bromocriptine (ergoset), somatostatin agonists (octreotide), and adiponectin; 3) gastrointestinal-neural pathway agents, including those that increase cholecystokinin activity, increase glucagon-like peptide-1 activity (extendin 4, liraglutide, dipeptidyl peptidase IV inhibitors), and increase protein YY3-36 activity and those that decrease ghrelin activity, as well as amylin analogues (pramlintide); 4) agents that may increase resting metabolic rate ("selective" beta-3 stimulators/agonist, uncoupling protein homologues, and thyroid receptor agonists); and 5) other more diverse agents, including melanin concentrating hormone antagonists, phytostanol analogues, functional oils, P57, amylase inhibitors, growth hormone fragments, synthetic analogues of dehydroepiandrosterone sulfate, antagonists of adipocyte 11B-hydroxysteroid dehydrogenase type 1 activity, corticotropin-releasing hormone agonists, inhibitors of fatty acid synthesis, carboxypeptidase inhibitors, indanones/indanols, aminosterols, and other gastrointestinal lipase inhibitors (ATL962). Finally, an emerging concept is that the development of antiobesity agents must not only reduce fat mass (adiposity) but must also correct fat dysfunction (adiposopathy).