Effect on body weight and safety of RC-1291, a novel, orally available ghrelin mimetic and growth hormone secretagogue: results of a phase I, randomized, placebo-controlled, multiple-dose study in healthy volunteers

Anamorelin for the Treatment of Cancer Anorexia-Cachexia Syndrome

PURPOSE OF REVIEW

The following review will highlight the development of anamorelin to treat cancer anorexia-cachexia syndrome (CACS) including the potential benefits, limitations, and future directions.

RECENT FINDINGS

Ghrelin, a 28-amino acid peptide hormone, is secreted by the stomach mucosa and regulates appetite, promotes lipogenesis, increases body weight, improves gastric motility, reduces catabolic wasting and inflammation. Several randomized, double-blind, placebo-controlled clinical trials evaluating anamorelin, a ghrelin agonist, for the treatment of CACS have reported improvement in appetite and body composition including both lean body and fat mass; however, most studies noted no improvement in physical function as assessed by measuring non-dominant hand-grip strength. Common adverse effects of anamorelin include the development of diabetes mellitus, hyperglycemia, and less frequently, hepatic abnormalities and cardiovascular events including conduction abnormalities, hypertension, and ischemic cardiomyopathy. Anamorelin has the potential to stimulate appetite, improve gastric movement, and may have anti-inflammatory effects on patients with CACS. In patients with cancer, studies involving anamorelin combined with other multimodal treatments including nutrition counseling (branched chain amino acids, omega 3 fatty acids, and other nutrients), exercise, treatment of hormonal abnormalities including hypogonadism and hypovitaminosis D, and anti-inflammatory agents are needed. Compliance with multimodality treatment has been a barrier and future studies may need to incorporate motivational counseling to promote adherence.

Emerging drugs for the treatment of sarcopenia in cirrhosis of the liver

INTRODUCTION

Malnutrition and sarcopenia are common and impact the prognosis in patients with liver cirrhosis. The etiology is multifactorial and includes periods of reduced caloric intake, increased catabolism and direct molecular mechanisms that inhibit muscle synthesis. Although these conditions are widely acknowledged, and there is a growing interest in their diagnosis, robust evidence regarding the treatment and reversibility of these conditions is still lacking.

AREAS COVERED

We have explored the current evidence on the pharmacological treatment of sarcopenia in patients with cirrhosis. Additionally, we have searched for drugs already in use and ongoing trials for other chronic diseases.

EXPERT OPINION

The current guidelines recommend the use of a protein-adequate diet and moderate physical activity for treating sarcopenia in patients with cirrhosis. Currently, robust evidence is derived only from the supplementation of Branched-Chain Amino Acids, capable of increasing muscle mass and function. There are many drugs targeting various pathways that contribute to sarcopenia. However, evidence is sporadic and insufficient to suggest their use in clinical practice.Novel drugs specifically designed to enhance muscle mass and function should be developed. Finally, gender significantly influences the type of muscle alteration and therapeutic mechanisms; therefore, future studies should be designed taking gender differences into consideration.

IUPHAR ECR review: Cancer-related anorexia-cachexia in cancer patients: Pathophysiology and treatment

Cancer-related anorexia-cachexia (CRAC) comprises one of the most common syndromes of advanced cancer patients. The prevalence of CRAC increases from 50% to 80% before death. CRAC is associated not only with impaired quality of life in patients and family members but also with shorter survival. The management of CRAC is a great challenge in clinical practice. There are no definite practice guidelines yet for the prevention and treatment of CRAC. A multimodal strategy is the most effective way to treat anorexia-cachexia. Numerous medications have been suggested and used in clinical trials, while others are still being studied on experimental animals. These medications include branched-chain amino acids, eicosapentaenoic acid, thalidomide, cytokine inhibitors, steroids, antiserotoninergic medications, and appetite stimulants. The benefits of supportive care interventions and the advancement of exciting new pharmacological medicines for anorexia-cachexia are becoming more widely recognized. Health care professionals need to be aware of the psychosocial and biological effects of anorexia-cachexia, even though knowledge of the underlying molecular causes of the disorder has advanced significantly.

Predictors of efficacy of anamorelin in patients with non‑small cell lung cancer and cachexia: A retrospective study

Anamorelin, a ghrelin receptor agonist, is approved in Japan for the treatment of cachexia in patients with lung and gastrointestinal cancer. However, there is limited research on the usefulness of anamorelin in clinical settings, therefore, the present study evaluated its efficacy using patient characteristics. A total of 40 patients with non-small cell lung cancer and cachexia who were prescribed anamorelin in the Department of Respiratory Medicine, Hirosaki University Graduate School of Medicine (Aomori, Japan) between July 2021 and November 2022, were retrospectively assessed. Anamorelin was prescribed at a dose of 100 mg once daily to patients who had lost >5% of their body weight within 6 months. All patients were weighed before treatment and those who continued anamorelin treatment for 12 weeks were also weighed at 12 weeks. A logistic regression analysis was used to analyze the association between background characteristics and early discontinuation of treatment with anamorelin (within 4 weeks). The median age was 67 years (range, 36-88), and 65% of the patients were male. There were 24 patients (60.0%) with an Eastern Cooperative Oncology Group Performance Status (ECOG-PS) score 1, 11 patients (27.5%) with an ECOG-PS score 2 and five patients (12.5%) with an ECOG-PS score 3. The early discontinuation group included 11 patients (27.5%). An ECOG-PS score ≥2 (odds ratio, 7.85; 95% confidence interval, 1.43-43.21; P=0.018) was associated with early discontinuation. A total of 18/40 patients (45.0%) were able to continue anamorelin treatment for 12 weeks, and the mean change in body weight was +2.31 kg, which was a significant change from the weight recorded at baseline (P=0.027). The mean changes in lean body mass and soft lean mass between baseline and 12 weeks were +1.97 kg (P=0.14) and +1.26 kg (P=0.15), respectively. The results from the present study indicate that anamorelin is unlikely to be useful for patients with a poor general condition (ECOG-PS score ≥2).

EXT418, a novel long-acting ghrelin, mitigates Lewis lung carcinoma induced cachexia in mice

BACKGROUND

Ghrelin is a potential therapy for cachexia due to its orexigenic properties and anabolic effects on muscle and fat. However, its clinical use is limited by the short half-life of active (acylated) ghrelin (~11 min in humans). EXT418 is a novel long-acting, constitutively active ghrelin analog created by covalently linking it to a vitamin D derivative. Here, we evaluated the effects and mechanisms of action of EXT418 on Lewis lung carcinoma (LLC)-induced cachexia in mice.

METHODS

Male C57BL/6J mice (5- to 7-month-old) were implanted with 1 × 106 heat-killed (HK) or live LLC cells. When the tumour was palpable, mice were injected with vehicle (T + V) or EXT418 daily (T + 418 Daily, 0.25 mg/kg/day) or every other day (T + 418 EOD, 0.5 mg/kg/EOD) for up to 14 days, whereas HK-treated mice were given vehicle (HK + V). Subsets of T + 418 Daily or EOD-treated mice were pair-fed to the T + V group. Body composition and grip strength were evaluated before tumour implantation and at the end of the experiment. Molecular markers were probed in muscles upon termination.

RESULTS

In tumour-bearing mice, administration of EXT418 daily or EOD partially prevented weight loss (T + V vs. T + 418 Daily, P = 0.030; and vs. T + 418 EOD, P = 0.020). Similar effects were observed in whole body fat and lean body mass. Grip strength in tumour-bearing mice was improved by EXT418 daily (P = 0.010) or EOD (P = 0.008) administration compared with vehicle-treated mice. These effects of EXT418 on weight and grip strength were partially independent of food intake. EXT418 daily administration also improved type IIA (P = 0.015), IIB (P = 0.037) and IIX (P = 0.050) fibre cross-sectional area (CSA) in tibialis anterior (TA) and EXT418 EOD improved CSA of IIB fibres in red gastrocnemius (GAS; P = 0.005). In skeletal muscles, tumour-induced increases in atrogenes Fbxo32 and Trim63 were ameliorated by EXT418 treatments (TA and GAS/plantaris, PL), which were independent of food intake. EXT418 administration decreased expression of the mitophagy marker Bnip3 (GAS/PL; P ≤ 0.010). Similar effects of EXT418 EOD were observed in p62 (GAS/PL; P = 0.039). In addition, EXT418 treatments ameliorated the tumour-induced elevation in muscle Il6 transcript levels (TA and GAS/PL), independently of food intake. Il-6 transcript levels in adipose tissue and circulating IL-10 were elevated in response to the tumour but these increases were not significant with EXT418 administration. Tumour mass was not altered by EXT418.

CONCLUSIONS

EXT418 mitigates LLC-induced cachexia by attenuating skeletal muscle inflammation, proteolysis, and mitophagy, without affecting tumour mass and partially independent of food intake.

Pilot clinical trial of macimorelin to assess safety and efficacy in patients with cancer cachexia

BACKGROUND

Cancer cachexia is associated with reduced body weight, appetite and quality of life (QOL) with no approved treatments. Growth hormone secretagogues like macimorelin have potential to mitigate these effects.

METHODS

This pilot study assessed the safety and efficacy of macimorelin for 1 week. Efficacy was defined a priori as 1-week change in body weight (≥0.8 kg), plasma insulin-like growth factor (IGF)-1 (≥50 ng/mL) or QOL (≥15%). Secondary outcomes included food intake, appetite, functional performance, energy expenditure and safety laboratory parameters. Patients with cancer cachexia were randomized to 0.5 or 1.0 mg/kg macimorelin or placebo; outcomes were assessed non-parametrically.

RESULTS

Participants receiving at least one of either macimorelin dose were combined (N = 10; 100% male; median age = 65.50 ± 2.12) and compared with placebo (N = 5; 80% male; median age = 68.00 ± 6.19). Efficacy criteria achieved: body weight (macimorelin N = 2; placebo N = 0; P = 0.92); IGF-1 (macimorelin N = 0; placebo N = 0); QOL by Anderson Symptom Assessment Scale (macimorelin N = 4; placebo N = 1; P = 1.00) or Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F; macimorelin N = 3; placebo N = 0; P = 0.50). No related serious or non-serious adverse events were reported. In macimorelin recipients, change in FACIT-F was directly associated with change in body weight (r = 0.92, P = 0.001), IGF-1 (r = 0.80, P = 0.01), and caloric intake (r = 0.83, P = 0.005), and inversely associated with change in energy expenditure (r = -0.67, P = 0.05).

CONCLUSIONS

Daily oral macimorelin for 1 week was safe and numerically improved body weight and QOL in patients with cancer cachexia compared with placebo. Longer term administration should be evaluated for mitigation of cancer-induced reductions in body weight, appetite and QOL in larger studies.

Efficacy and safety of anamorelin in patients with cancer cachexia: Post-hoc subgroup analyses of a placebo-controlled study

BACKGROUND

Cachexia, a disorder associated with anorexia, inflammation, and muscle wasting, is frequent in cancer patients. We performed post-hoc analyses of the ONO-7643-04 study to investigate the efficacy and safety of anamorelin in subgroups of Japanese patients with non-small cell lung cancer (NSCLC).

METHODS

The patients were divided into subgroups by baseline characteristics, including sex, age, body mass index, prior weight loss, performance status (PS), concomitant anticancer therapy, and number of previous chemotherapy regimens. The changes from baseline through to 12 weeks for lean body mass (LBM), body weight, and appetite were calculated. Appetite was evaluated using the quality of life questionnaire for cancer patients treated with anticancer drugs (QOL-ACD) item 8 score. Responder rates were defined as the maintenance/improvement of LBM (≥0 kg), body weight (≥0 kg), or QOL-ACD item 8 score (≥0) from baseline to all evaluation time points. Safety was evaluated in patients subgrouped by age and PS.

RESULTS

Anamorelin resulted in greater improvements versus placebo in LBM, body weight, and appetite in most subgroups. Anamorelin was also associated with greater LBM, body weight, and appetite responder rates than placebo in nearly all subgroups. Among anamorelin-treated patients, adverse drug reactions (ADRs) tended to be more frequent with increasing age (<65 years, 19.2%; ≥65 to <75 years, 45.9%; ≥75 years, 60.0%) and PS score (PS 0-1, 38.4%; PS 2, 60.0%). The frequency of serious ADRs was 2.7% and 0% in the PS 0-1 and PS 2 subgroups, respectively.

CONCLUSION

This study of NSCLC patients with cancer cachexia revealed consistent improvements in LBM, body weight, and appetite across most subgroups of anamorelin-treated patients. This study also demonstrated the tolerability of anamorelin regardless of age and PS, with a low incidence of serious ADRs in each subgroup.

Appetite loss at discharge from acute decompensated heart failure: Observation from KCHF registry

Objective

The complex link between nutritional status, protein and lipid synthesis, and immunity plays an important prognostic role in patients with heart failure. However, the association between appetite loss at discharge and long-term outcome remains unclear.

Methods

The Kyoto Congestive Heart Failure registry is a prospective cohort study that enrolled consecutive patients hospitalized for acute decompensated heart failure (ADHF) in Japan. We assessed 3528 patients alive at discharge, and for whom appetite and follow-up data were available. We compared one-year clinical outcomes in patients with and without appetite loss at discharge.

Results

In the multivariable logistic regression analysis using 19 clinical and laboratory factors with P value < 0.1 by univariate analysis, BMI < 22 kg/m² (odds ratio (OR): 1.57, 95% confidence interval (CI): 1.11–2.24, P = 0.01), CRP >1.0mg/dL (OR: 1.49, 95%CI: 1.04–2.14, P = 0.03), and presence of edema at discharge (OR: 4.30, 95%CI: 2.99–6.22, P<0.001) were associated with an increased risk of appetite loss at discharge, whereas ambulatory status (OR: 0.57, 95%CI: 0.39–0.83, P = 0.004) and the use of ACE-I/ARB (OR: 0.70, 95% CI: 0.50–0.98, P = 0.04) were related to a decreased risk in the presence of appetite loss. The cumulative 1-year incidence of all-cause death (primary outcome measure) was significantly higher in patients with appetite loss than in those without appetite loss (31.0% vs. 15.0%, P<0.001). The excess adjusted risk of appetite loss relative to no appetite loss remained significant for all-cause death (hazard ratio (HR): 1.63, 95%CI: 1.29–2.07, P<0.001).

Conclusions

Loss of appetite at discharge was associated with worse 1-year mortality in patients with ADHF. Appetite is a simple, reliable, and useful subjective marker for risk stratification of patients with ADHF.

Revisiting Cancer Cachexia: Pathogenesis, Diagnosis, and Current Treatment Approaches

The objective of this article is to group together various management strategies and to highlight the recent treatment modifications that attempt to target the multimodal etiological factors involved in cancer cachexia. The contemporary role of nursing fraternity in psychosocial and nutritional assessment of cancer patients is briefly discussed. Cachexia is a syndrome of metabolic disturbance, characterized by the inflammation and loss of muscle with or without loss of adipose tissue. In cancer cachexia, a multifaceted condition, patients suffer from loss of body weight that leads to a negative impact on the quality of life and survival of the patients. The main cancers associated with cachexia are that of pancreas, stomach, lung, esophagus, liver, and that of bowel. The changes include increased proteolysis, lipolysis, insulin resistance, high energy expenditure, and reduced intake of food, all leading to impaired response to different treatments. There is no standardized treatment for cancer cachexia that can stabilize or reverse this complex metabolic disorder at present. The mainstay of cancer cachexia therapy remains to be sufficient nutritional supplements with on-going efforts to explore the drugs that target heightened catabolic processes and complex inflammation. There is a need to develop a multimodal treatment approach combining pharmacology, exercise program, and nutritional support to target anorexia and the severe metabolic changes encountered in cancer cachexia.

Cancer-Mediated Muscle Cachexia: Etiology and Clinical Management

Muscle cachexia has a major detrimental impact on cancer patients, being responsible for 30% of all cancer deaths. It is characterized by a debilitating loss in muscle mass and function, which ultimately deteriorates patients' quality of life and dampens therapeutic treatment efficacy. Muscle cachexia stems from widespread alterations in whole-body metabolism as well as immunity and neuroendocrine functions and these global defects often culminate in aberrant signaling within skeletal muscle, causing muscle protein breakdown and attendant muscle atrophy. This review summarizes recent landmark discoveries that significantly enhance our understanding of the molecular etiology of cancer-driven muscle cachexia and further discuss emerging therapeutic approaches seeking to simultaneously target those newly discovered mechanisms to efficiently curb this lethal syndrome.

An overview of anamorelin as a treatment option for cancer-associated anorexia and cachexia

INTRODUCTION

Cancer cachexia is a complex multifaceted syndrome involving functional impairment, changes in body composition, and nutritional disorders. The treatment of cancer cachexia can be based on these three domains of the syndrome. Phase II and III trials of anamorelin, a ghrelin mimetic agent, have been shown to increase body weight in patients with cancer cachexia, mainly by increasing muscle and fat mass. Anamorelin has been shown to improve anorexia scores.

AREAS COVERED

This review aims to outline the effect of anamorelin on body composition and functional parameters as well as to discuss the clinical importance of these alterations in patients with cancer cachexia.

EXPERT OPINION

To date, there is no treatment approved to enhance body composition and functional parameters in patients with cancer cachexia. Anamorelin, the most advanced therapy to treat cachexia, has not yielded convincing results in all aspects of the syndrome. In particular, no effect has been noted on physical function and long-term survival. Along with these essential improvements for future interventions with anamorelin, subsequent studies must address other etiologies of cancer, rather than non-small cell lung cancer, and add complementary therapies, such as exercise training and nutritional interventions, in an attempt to overcome cancer cachexia.

Ghrelin ameliorates tumor-induced adipose tissue atrophy and inflammation via Ghrelin receptor-dependent and -independent pathways

Adipose tissue (AT) atrophy is a hallmark of cancer cachexia contributing to increased morbidity/mortality. Ghrelin has been proposed as a treatment for cancer cachexia partly by preventing AT atrophy. However, the mechanisms mediating ghrelin's effects are incompletely understood, including the extent to which its only known receptor, GHSR-1a, is required for these effects. This study characterizes the pathways involved in AT atrophy in the Lewis Lung Carcinoma (LLC)-induced cachexia model and those mediating the effects of ghrelin in Ghsr ^+/+ and Ghsr ^-/- mice. We show that LLC causes AT atrophy by inducing anorexia, and increasing lipolysis, AT inflammation, thermogenesis and energy expenditure. These changes were greater in Ghsr ^-/-. Ghrelin administration prevented LLC-induced anorexia only in Ghsr ^+/+, but prevented WAT lipolysis, inflammation and atrophy in both genotypes, although its effects were greater in Ghsr ^+/+. LLC-induced increases in BAT inflammation, WAT and BAT thermogenesis, and energy expenditure were not affected by ghrelin. In conclusion, ghrelin ameliorates WAT inflammation, fat atrophy and anorexia in LLC-induced cachexia. GHSR-1a is required for ghrelin's orexigenic effect but not for its anti-inflammatory or fat-sparing effects.

Management of Cancer Cachexia: Attempting to Develop New Pharmacological Agents for New Effective Therapeutic Options

Cancer cachexia (CC) is a multifactorial syndrome characterized by systemic inflammation, uncontrolled weight loss and dramatic metabolic alterations. This includes myofibrillar protein breakdown, increased lipolysis, insulin resistance, elevated energy expediture, and reduced food intake, hence impairing the patient's response to anti-cancer therapies and quality of life. While a decade ago the syndrome was considered incurable, over the most recent years much efforts have been put into the study of such disease, leading to the development of potential therapeutic strategies. Several important improvements have been reached in the management of CC from both the diagnostic-prognostic and the pharmacological viewpoint. However, given the heterogeneity of the disease, it is impossible to rely only on single variables to properly treat patients presenting this metabolic syndrome. Moreover, the cachexia symptoms are strictly dependent on the type of tumor, stage and the specific patient's response to cancer therapy. Thus, the attempt to translate experimentally effective therapies into the clinical practice results in a great challenge. For this reason, it is of crucial importance to further improve our understanding on the interplay of molecular mechanisms implicated in the onset and progression of CC, giving the opportunity to develop new effective, safe pharmacological treatments. In this review we outline the recent knowledge regarding cachexia mediators and pathways involved in skeletal muscle (SM) and adipose tissue (AT) loss, mainly from the experimental cachexia standpoint, then retracing the unimodal treatment options that have been developed to the present day.

Emerging Treatment Options For Cancer-Associated Cachexia: A Literature Review

Cachexia is a disease that has been recognized since antiquity; however, research in this area has recently increased. Promising new agents, including anamorelin hydrochloride, have been tested in large randomized controlled studies, and multidrug as well as multimodal approaches have been proposed as having the potential to improve outcomes in patients with cancer cachexia. However, standard treatment remains elusive. This review summarizes the current literature on treatment of cancer-associated cachexia, showing that there are challenges associated with conducting clinical trials in such patients. First, poor recruitment, retention, and compliance among cachectic patients cause research delays. Second, the lack of consensus regarding clinically meaningful endpoints impedes standardization of study designs and results. Further consideration is needed to identify the most suitable study design and endpoints, which can lead to the development of pharmacological and nonpharmacological interventions that improve patients’ prognosis and outcomes.

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Appetite and food intake results from phase I studies of anamorelin

BACKGROUND

Loss of appetite and body weight are potentially devastating, highly prevalent cancer complications. The ghrelin receptor is a mediator of appetite and metabolism, and anamorelin is a novel, orally administered ghrelin receptor agonist. Effects on appetite and food intake may influence body-weight gain but can be difficult to measure in multi-site studies. Here, we summarize two single-centre trials.

METHODS

Both trials were phase I, randomized, double-blind, placebo-controlled, partly/wholly crossover studies of healthy young adults. Study 102 tested single anamorelin doses of 1-20 mg. Assessments included post-dose self-ratings on 100 mm visual analogue scales for hunger, anticipated eating pleasure, and anticipated quantity of food consumption. Study 101 tested single 10, 25, and 50 mg doses. Assessments included the same scales plus caloric intake beginning 4 h post-dose.

RESULTS

Study 102 treated 16 male subjects (mean age, 26.3 years). Mean hunger scores generally increased after all treatments, with significant differences from placebo (P < 0.05) in the 5 mg anamorelin group at 0.5 and 1 h post-dose (+8.2 and +13.2 mm). Results for other scales were similar. Study 101 treated nine male subjects (mean age, 26.3 years). Pooled findings for anamorelin 25 and 50 mg vs. placebo showed significant mean increases in hunger scores at all but 1 pre-prandial time point, including the first assessment, 0.5 h post-dose (+10.9 vs. +0.7 mm, P = 0.0077), and the last assessment, 4 h post-dose (+32.7 vs. +7.0 mm, P = 0.0170), with a significant mean 18.4% increase vs. placebo in caloric intake (P = 0.0148).

CONCLUSIONS

In single-centre studies of healthy adults, single anamorelin doses of 1-20 mg elicited modest increases in hunger, and single doses of 25 and 50 mg achieved significant increases in hunger and caloric intake. The findings are consistent with dose-related weight gain reported in a prior phase I study as well as multi-centre findings in cachectic cancer patients and expand the evidence supporting anamorelin as a potential intervention.

Pharmacological Modulation of Ghrelin to Induce Weight Loss: Successes and Challenges

PURPOSE OF REVIEW

Obesity is affecting over 600 million adults worldwide and has numerous negative effects on health. Since ghrelin positively regulates food intake and body weight, targeting its signaling to induce weight loss under conditions of obesity seems promising. Thus, the present work reviews and discusses different possibilities to alter ghrelin signaling.

RECENT FINDINGS

Ghrelin signaling can be altered by RNA Spiegelmers, GHSR/Fc, ghrelin-O-acyltransferase inhibitors as well as antagonists, and inverse agonists of the ghrelin receptor. PF-05190457 is the first inverse agonist of the ghrelin receptor tested in humans shown to inhibit growth hormone secretion, gastric emptying, and reduce postprandial glucose levels. Effects on body weight were not examined. Although various highly promising agents targeting ghrelin signaling exist, so far, they were mostly only tested in vitro or in animal models. Further research in humans is thus needed to further assess the effects of ghrelin antagonism on body weight especially under conditions of obesity.

A multicenter, open-label, single-arm study of anamorelin (ONO-7643) in advanced gastrointestinal cancer patients with cancer cachexia

Background

Cancer cachexia is characterized by weight loss and is associated with increased morbidity and mortality in patients with cancer. Anamorelin (ONO‐7643; ANAM) is a novel and selective ghrelin receptor agonist that improves appetite, lean body mass (LBM), body weight, and anorexia.

Methods

This multicenter, open‐label, single‐arm study investigated the efficacy and safety of 100 mg anamorelin in 50 Japanese patients with advanced and unresectable gastrointestinal (colorectal, gastric, or pancreatic) cancer. ANAM was administered once daily over 12 weeks. The primary endpoint was the proportion of patients that maintained or gained LBM over the course of the study. Secondary endpoints included changes in LBM, body weight, quality of life (QoL), and nutritional status biomarkers.

Results

The proportion of patients who responded to treatment was 63.3% (95% CI, 48.3%‐76.6%), with a least square mean ± SE change in LBM and body weight from baseline of 1.89 ± 0.36 kg and 1.41 ± 0.61 kg, respectively. Appetite‐related questions on the QoL questionnaire showed that ANAM improved appetite. Adverse events occurred in 79.6% of patients, and the most common treatment‐related adverse events were increased γ‐glutamyl transpeptidase (8.2%), diabetes mellitus (6.1%), hyperglycemia (6.1%), and prolonged QRS complex (6.1%).

Conclusions

ANAM improved anorexia and patients' nutritional status, resulting in rapid increases in LBM and body weight in patients with advanced gastrointestinal cancer who had cancer cachexia. ANAM treatment was well tolerated over 12 weeks. ANAM is a potential clinically beneficial pharmacotherapeutic option for patients with advanced gastrointestinal cancer who have cancer cachexia.

The receipt of 100 mg anamorelin increases lean body mass and improves symptoms of anorexia and nutritional status in patients with advanced gastrointestinal cancer who have cancer cachexia. Anamorelin is well tolerated in these patients.

GHRELIN LEVEL IN PATIENTS WITH LIVER CIRRHOSIS

BACKGROUND

Ghrelin is a gastro-duodenal hormone which plays a major role in the regulation of food intake, energy balance and gastrokinesis. Ghrelin represents a novel biological marker for assessment of the presence as well as the severity of liver cirrhosis. We aimed to measure the level of plasma ghrelin in patients with liver cirrhosis (compensated and decompensated) and to correlate its level with different studied clinical and laboratory parameters.

SUBJECTS AND METHODS

40 cirrhotic patients were included in a cross-sectional study and divided equally according to the Child-Pugh classification into Group I: patients with compensated liver cirrhosis (Child A), and Group II: patients with decompensated liver cirrhosis (Child B|C). Also, 20 age and sex matched healthy subjects were included as a control group (Group III). All patients were subjected to: full history taking, full clinical examination, routine biochemical studies together with estimation of plasma ghrelin level, assessment of the severity of liver disease according to Child-Pugh classification, also, abdominal ultrasonography was done.

RESULTS

Plasma ghrelin level was low among cirrhotic patients (both compensated and decompensated) in comparison to normal control subjects.

CONCLUSION

Ghrelin can be used as a serum biomarker for detection and assessment of the severity of liver cirrhosis.

Sarcopenic obesity in older adults: aetiology, epidemiology and treatment strategies

The prevalence of obesity in combination with sarcopenia (the age-related loss of muscle mass and strength or physical function) is increasing in adults aged 65 years and older. A major subset of adults over the age of 65 is now classified as having sarcopenic obesity, a high-risk geriatric syndrome predominantly observed in an ageing population that is at risk of synergistic complications from both sarcopenia and obesity. This Review discusses pathways and mechanisms leading to muscle impairment in older adults with obesity. We explore sex-specific hormonal changes, inflammatory pathways and myocellular mechanisms leading to the development of sarcopenic obesity. We discuss the evolution, controversies and challenges in defining sarcopenic obesity and present current body composition modalities used to assess this condition. Epidemiological surveys form the basis of defining its prevalence and consequences beyond comorbidity and mortality. Current treatment strategies, and the evidence supporting them, are outlined, with a focus on calorie restriction, protein supplementation and aerobic and resistance exercises. We also describe weight loss-induced complications in patients with sarcopenic obesity that are relevant to clinical management. Finally, we review novel and potential future therapies including testosterone, selective androgen receptor modulators, myostatin inhibitors, ghrelin analogues, vitamin K and mesenchymal stem cell therapy.

Anamorelin (ONO-7643) for the treatment of patients with non-small cell lung cancer and cachexia: Results from a randomized, double-blind, placebo-controlled, multicenter study of Japanese patients (ONO-7643-04)

BACKGROUND

Cachexia, described as weight loss (mainly in lean body mass [LBM]) and anorexia, is common in patients with advanced cancer. This study examined the efficacy and safety of anamorelin (ONO-7643), a novel selective ghrelin receptor agonist, in Japanese cancer patients with cachexia.

METHODS

This double-blind clinical trial (ONO-7643-04) enrolled 174 patients with unresectable stage III/IV non-small cell lung cancer (NSCLC) and cachexia in Japan. Patients were randomized to daily oral anamorelin (100 mg) or a placebo for 12 weeks. The primary endpoint was the change from the baseline LBM (measured with dual-energy x-ray absorptiometry) over 12 weeks. The secondary endpoints were changes in appetite, body weight, quality of life, handgrip strength (HGS), and 6-minute walk test (6MWT) results.

RESULTS

The least squares mean change (plus or minus the standard error) in LBM from the baseline over 12 weeks was 1.38 ± 0.18 and -0.17 ± 0.17 kg in the anamorelin and placebo groups, respectively (P < .0001). Changes from the baseline in LBM, body weight, and anorexia symptoms showed significant differences between the 2 treatment groups at all time points. Anamorelin increased prealbumin at weeks 3 and 9. No changes in HGS or 6MWT were detected between the groups. Twelve weeks' treatment with anamorelin was safe and well tolerated in NSCLC patients.

CONCLUSIONS

Anamorelin significantly increased LBM and improved anorexia symptoms and the nutritional state, but not motor function, in Japanese patients with advanced NSCLC. Because no effective treatment for cancer cachexia is currently available, anamorelin can be a beneficial treatment option. Cancer 2018;124:606-16. © 2017 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

What is next after anamorelin?

PURPOSE OF REVIEW

In spite of its relevance, treatments for the cancer anorexia and cachexia syndrome (CACS) are not available. One of the agents that recently reached phase III clinical trials is anamorelin. Its development, along with that of other agents for this indication, will be reviewed here, with a focus on the gaps in the current knowledge and future directions.

RECENT FINDINGS

In spite of several targets showing promising results in early development, their difficulties obtaining regulatory approval underscore the need to reconsider the current strategies in drug development and the challenges in the field of CACS.

SUMMARY

Further research is needed in order to meet the challenges of developing treatments for CACS. Preclinical studies should expand our understanding about key regulators of appetite, muscle, and energy metabolism in this setting using models that can be translated reliably to humans. Clinical research efforts should focus on validating the entry criteria, endpoints, outcomes, and the potential synergistic effects and interaction between different targets, nutrition, and exercise interventions. Clinical meaningfulness and significance should be taken into account in the design of clinical trials. It is essential that all key stakeholders are included in the design of future strategies.

Oncology Update: Anamorelin

Background:

Cancer cachexia is a catabolic syndrome associated with uncontrolled muscle breakdown. There may be associated fat loss. Occurring in high frequency in advanced cancer, it is an indicator of poor prognosis. Besides weight loss, patients experience a cluster of symptoms including anorexia, early satiety, and weakness. The 3 stages of cachexia include stages of precachexia, cachexia, and refractory cachexia. Refractory cachexia is associated with active catabolism or the presence of factors that make active management of weight loss no longer possible. Patients with refractory cachexia often receive glucocorticoids or megasterol acetate. Glucocorticoid effect is short and responses to megasterol are variable. Anamorelin is a new agent for cancer anorexia-cachexia, with trials completed in advanced lung cancer. Acting as an oral mimetic of ghrelin, it improves appetite and muscle mass. This article reviews the pharmacology, pharmacodynamics, and effect on cancer cachexia.

Methods:

A PubMed search was done using the Medical Subject Headings term anamorelin. Articles were selected to provide a pharmacologic characterization of anamorelin.

Results:

Anamorelin increases muscle mass in patients with advanced cancer in 2-phase 3 trials.

Conclusions:

Anamorelin improves anorexia-cachexia symptoms in patients with advanced non–small-cell lung cancer.

Anamorelin hydrochloride in the treatment of cancer anorexia-cachexia syndrome: design, development, and potential place in therapy

Cancer anorexia–cachexia syndrome (CACS) is a complex and largely untreatable paraneoplastic complication common in advanced cancer. It is associated with profoundly deleterious effects on quality of life and survival. Since its discovery over a decade ago, anamorelin hydrochloride (anamorelin), a mimetic of the growth hormone secretagogue ghrelin, has shown considerable promise in ameliorating components of CACS when administered to patients with advanced cancer, including loss of lean body mass and reversal of anorexia. This review summarizes the development of anamorelin and its safety and efficacy in clinical investigations. The potential future role of anamorelin in treating CACS is also discussed.

Deletion of ghrelin prevents aging-associated obesity and muscle dysfunction without affecting longevity

During aging, decreases in energy expenditure and locomotor activity lead to body weight and fat gain. Aging is also associated with decreases in muscle strength and endurance leading to functional decline. Here, we show that lifelong deletion of ghrelin prevents development of obesity associated with aging by modulating food intake and energy expenditure. Ghrelin deletion also attenuated the decrease in phosphorylated adenosine monophosphate‐activated protein kinase (pAMPK) and downstream mediators in muscle, and increased the number of type IIa (fatigue resistant, oxidative) muscle fibers, preventing the decline in muscle strength and endurance seen with aging. Longevity was not affected by ghrelin deletion. Treatment of old mice with pharmacologic doses of ghrelin increased food intake, body weight, and muscle strength in both ghrelin wild‐type and knockout mice. These findings highlight the relevance of ghrelin during aging and identify a novel AMPK‐dependent mechanism for ghrelin action in muscle.

From Belly to Brain: Targeting the Ghrelin Receptor in Appetite and Food Intake Regulation

Ghrelin is the only known peripherally-derived orexigenic hormone, increasing appetite and subsequent food intake. The ghrelinergic system has therefore received considerable attention as a therapeutic target to reduce appetite in obesity as well as to stimulate food intake in conditions of anorexia, malnutrition and cachexia. As the therapeutic potential of targeting this hormone becomes clearer, it is apparent that its pleiotropic actions span both the central nervous system and peripheral organs. Despite a wealth of research, a therapeutic compound specifically targeting the ghrelin system for appetite modulation remains elusive although some promising effects on metabolic function are emerging. This is due to many factors, ranging from the complexity of the ghrelin receptor (Growth Hormone Secretagogue Receptor, GHSR-1a) internalisation and heterodimerization, to biased ligand interactions and compensatory neuroendocrine outputs. Not least is the ubiquitous expression of the GHSR-1a, which makes it impossible to modulate centrally-mediated appetite regulation without encroaching on the various peripheral functions attributable to ghrelin. It is becoming clear that ghrelin’s central signalling is critical for its effects on appetite, body weight regulation and incentive salience of food. Improving the ability of ghrelin ligands to penetrate the blood brain barrier would enhance central delivery to GHSR-1a expressing brain regions, particularly within the mesolimbic reward circuitry.

Two ghrelin receptor agonists for adults with malnutrition: a systematic review and meta-analysis

Background

Ghrelin receptor agonists have been established to be important in ameliorating the nutritional conditions in patients with malnutrition. However, some studies have reported inconsistent results. We aimed to coalesce the available evidence on the efficacy of ghrelin receptor agonists for the treatment of malnutrition.

Methods

We searched PubMed, the Cochrane Central Register of Controlled Trials, and EMBASE for relevant articles published through March 2016. Studies comparing the efficacy of ghrelin receptor agonists versus placebo in malnourished patients were eligible for inclusion.

Results

A total of 12 studies involving 1377 patients were included. Compared with placebo, ghrelin receptor agonists could increase the energy intake (standard mean difference [SMD] 2.67, 95% confidence interval [CI] 1.48 to 3.85, P < 0.001), lean body mass (weighted mean difference [WMD] 0.25 kg, 95% CI 0.07 to 0.42, P = 0.006), fat mass (WMD 0.92 kg, 95% CI 0.05 to 1.8, P = 0.038), and grip strength (WMD 0.31 kg, 95% CI 0.207 to 0.414, P < 0.001) of patients with malnutrition.

Conclusion

Our analysis indicated that ghrelin receptor agonists could improve the poor nutritional state of malnourished patients by increasing their energy intake, ameliorating their irregular body composition and improving their grip strength. However, these results might be less conclusive due to the limited sample sizes and one potential publication that has not been released.

Anamorelin (ONO-7643) in Japanese patients with non-small cell lung cancer and cachexia: results of a randomized phase 2 trial

Purpose

Cancer cachexia is characterized by decreased body weight (mainly lean body mass [LBM]) and negatively impacts quality of life (QOL) and prognosis. Anamorelin (ONO-7643) is a novel selective ghrelin receptor agonist under development for treating cancer cachexia.

Methods

In this double-blind, exploratory phase 2 trial, we examined the efficacy and safety of anamorelin in Japanese patients (n = 181) with non-small cell lung cancer (NSCLC) and cancer cachexia (≥5 % weight loss within the previous 6 months). The participants were randomized into three groups and were administered 50 or 100 mg anamorelin, or placebo, orally every day for 12 weeks. The co-primary endpoints were the changes from baseline over 12 weeks in LBM and handgrip strength (HGS). Secondary endpoints included body weight, QOL, Karnofsky Performance Scale (KPS), and serum biomarkers.

Results

The change in LBM over 12 weeks was 0.55 and 1.15 kg in the placebo and 100-mg anamorelin groups, respectively, but the efficacy of anamorelin in HGS was not detected. The changes in body weight were −0.93, 0.54, and 1.77 kg in the placebo, 50-mg anamorelin, and 100-mg anamorelin groups, respectively. Anamorelin (100 mg) significantly improved KPS and QOL-ACD compared with placebo. Administration of anamorelin for 12 weeks was well tolerated.

Conclusions

This phase 2 study showed that 100 mg anamorelin has promising results in improving lean body mass, performance status, and especially, QOL in patients with cancer cachexia.

Electronic supplementary material

The online version of this article (doi:10.1007/s00520-016-3144-z) contains supplementary material, which is available to authorized users.

Ghrelin Actions on Somatotropic and Gonadotropic Function in Humans

Ghrelin, a 28 amino-acid octanoylated peptide predominantly produced by the stomach, was discovered to be the natural ligand of the type 1a GH secretagogue receptor (GHS-R1a). It was thus considered as a natural GHS additional to GHRH, although later on ghrelin has mostly been considered a major orexigenic factor. The GH-releasing action of ghrelin takes place both directly on pituitary cells and through modulation of GHRH from the hypothalamus; some functional antisomatostatin action has also been shown. However, ghrelin is much more than a natural GH secretagogue. In fact, it also modulates lactotroph and corticotroph secretion in humans as well as in animals and plays a relevant role in the modulation of the hypothalamic-pituitary-gonadal function. Several studies have indicated that ghrelin plays an inhibitory effect on gonadotropin pulsatility, is involved in the regulation of puberty onset in animals, and may regulate spermatogenesis, follicular development and ovarian cell functions in humans. In this chapter ghrelin actions on the GH/IGF-I and the gonadal axes will be revised. The potential therapeutic role of ghrelin as a treatment of catabolic conditions will also be discussed.

Nonmuscle Tissues Contribution to Cancer Cachexia

Cachexia is a syndrome associated with cancer, characterized by body weight loss, muscle and adipose tissue wasting, and inflammation, being often associated with anorexia. In spite of the fact that muscle tissue represents more than 40% of body weight and seems to be the main tissue involved in the wasting that occurs during cachexia, recent developments suggest that tissues/organs such as adipose (both brown and white), brain, liver, gut, and heart are directly involved in the cachectic process and may be responsible for muscle wasting. This suggests that cachexia is indeed a multiorgan syndrome. Bearing all this in mind, the aim of the present review is to examine the impact of nonmuscle tissues in cancer cachexia.

A hypothesis for a possible synergy between ghrelin and exercise in patients with cachexia: Biochemical and physiological bases

This article reviews the biochemical and physiological observations underpinning the synergism between ghrelin and ghrelin agonists with exercise, especially progressive resistance training that has been shown to increase muscle mass. The synergy of ghrelin agonists and physical exercise could be beneficial in conditions where muscle wasting is present, such as that found in patients with advanced cancer. The principal mechanism that controls muscle anabolism following the activation of the ghrelin receptor in the central nervous system involves the release of growth hormone/insulin-like growth factor-1 (GH/IGF-1). GH/IGF-1 axis has a dual pathway of action on muscle growth: (a) a direct action on muscle, bone and fat tissue and (b) an indirect action via the production of both muscle-restricted mIGF-1 and anti-cachectic cytokines. Progressive resistance training is a potent inducer of the secretion the muscle-restricted IGF-1 (mIGF-1) that enhances protein synthesis, increases lean body mass and eventually leads to the improvement of muscle strength. Thus, the combination of ghrelin administration with progressive resistance training may serve to circumvent ghrelin resistance and further reduce muscle wasting, which are commonly associated with cachexia.

Mechanisms of anorexia-cachexia syndrome and rational for treatment with selective ghrelin receptor agonist

Cancer cachexia is a multi-organ, multifactorial and often irreversible syndrome affecting many patients with cancer. Cancer cachexia is invariably associated with weight loss, mainly from loss of skeletal muscle and body fat, conditioning a reduced quality of life due to asthenia, anorexia, anaemia and fatigue. Treatment options for treating cancer cachexia are limited. The approach is multimodal and may include: treatment of secondary gastrointestinal symptoms, nutritional treatments, drug, and non-drug treatments. Nutritional counselling and physical training may be beneficial in delaying or preventing the development of anorexia-cachexia. However, these interventions are limited in their effect, and no definitive pharmacological treatment is available to address the relevant components of the syndrome. Anamorelin is a first-in-class, orally active ghrelin receptor agonist that binds and stimulates the growth hormone secretagogue receptor centrally, thereby mimicking the appetite-enhancing and anabolic effects of ghrelin. It represents a new class of drug and an additional treatment option for this patient group, whose therapeutic options are currently limited. In this review we examine the mechanisms of anamorelin by which it contrasts catabolic states, its role in regulation of metabolism and energy homeostasis, the data of recent trials in the setting of cancer cachexia and its safety profile.

Relationship between Plasma Ghrelin Levels and Sarcopenia in Elderly Subjects: A Cross-Sectional Study

OBJECTIVE

The aim of this study was to investigate the relationship between plasma ghrelin levels and sarcopenia in elderly people.

DESIGN

Cross-sectional study.

SETTING

Health consortium medical centers in the Maresme region, Barcelona (Spain).

PARTICIPANTS

Two groups of subjects: persons ≥70 years (elderly group) and persons 25-65 years (young adults).

MEASUREMENTS

Sarcopenia, diagnosed according to the EWGSOP definition, fasting and postprandial plasma ghrelin levels, body composition, hand grip, Barthel score, and frailty using Fried criteria.

RESULTS

Fifty-five elderly subjects and 33 young adults were recruited. In both age groups, mean ghrelin levels were significantly higher in women than in men. However, mean ghrelin levels were similar in elderly and young men (716 vs. 752 pg mL-1, P = 0.763) as well as in elderly and young women (859 vs. 995 pg mL-1, P = 0.190). In the elderly group, subjects with sarcopenia showed significantly lower ghrelin levels than those without sarcopenia (650 vs. 899 pg mL-1, P = 0.036), but these differences disappeared when stratifying by gender. Elderly subjects without sarcopenia had the same ghrelin levels as young adults (899.3 vs. 899.6 pg mL-1). In young women, ghrelin levels correlated with fat free mass (rs = 0.58, P = 0.007) and muscular mass (rs = 0.54, P = 0.015) but these correlations were not observed in men nor in elderly women.

CONCLUSION

This cross-sectional study does not allow a definitive conclusion about the relationship between ghrelin levels and sarcopenia. Further large prospective studies are needed to test this hypothesis.

Impact of synthetic ghrelin administration for patients with severe body weight reduction more than 1 year after gastrectomy: a phase II clinical trial

PURPOSE

Ghrelin is mainly secreted from the stomach and plays a role in appetite, weight gain, and the promotion of a positive energy balance. The levels of ghrelin decrease immediately after gastrectomy. We herein investigated the effect of the administration of synthetic ghrelin to treat postoperative severe weight loss in a prospective, one-arm clinical trial to develop new strategies for weight gain.

METHODS

Ten patients (four distal gastrectomy and six total gastrectomy) received ghrelin treatment. Eligibility criteria included patients who underwent gastrectomy more than 1 year previously and 15 % body weight loss from the preoperative weight or a body mass index under 19. Synthetic human ghrelin (3 μg/kg) was administered to the patients twice a day for 1 week. Oral intake of calories, appetite [evaluated using the visual analog scale (VAS)], and body weight before and during administration of ghrelin were compared.

RESULTS

There was a significant difference in the oral food intake before and during treatment (before treatment: 1236 ± 409 kcal vs. during treatment: 1398 ± 365 kcal, p = 0.039), and the VAS for appetite significantly improved with each day of ghrelin administration (p < 0.05). Significant amounts of body weight were gained (39.5 ± 6.8 vs. 40.1 ± 6.9, p = 0.037).

CONCLUSIONS

The administration of synthetic ghrelin improved the food intake and was effective for treating appetite loss and body weight loss. Synthetic ghrelin may be a promising new therapy for severe body weight loss following gastrectomy.

Anamorelin hydrochloride for the treatment of cancer-anorexia-cachexia in NSCLC

INTRODUCTION

Cancer anorexia-cachexia syndrome (CACS) is associated with increased morbidity and mortality. Anamorelin is a novel, orally active ghrelin receptor agonist in clinical development for the treatment of CACS in NSCLC. The aim of this review is to summarize preclinical and clinical studies evaluating anamorelin as a potential promising treatment for CACS in NSCLC.

AREAS COVERED

Pharmacodynamics, pharmacokinetics and metabolism, clinical efficacy, safety and tolerability of anamorelin for the treatment of CACS in NSCLC were reviewed. Anamorelin administration may lead to increases in food intake, body weight and lean body mass, and a stimulatory effect on growth hormone secretion in NSCLC patients. Anamorelin is well tolerated with no dose-limiting toxicities identified to date.

EXPERT OPINION

Targeting ghrelin receptors presents the advantage of potentially addressing multiple mechanisms of CACS simultaneously including appetite, muscle protein balance, adipose tissue metabolism, energy expenditure and inflammation. Clinical data suggest that anamorelin is well tolerated and it effectively increases appetite, body weight and lean mass in patients with advanced NSCLC. Long-term safety remains unknown at this time. The potential synergistic effects of anamorelin with nutritional support or exercise as well as its efficacy/safety in other tumor types are also unknown.

Cancer cachexia update in head and neck cancer: Pathophysiology and treatment

The pathophysiology of cancer cachexia remains complex. A comprehensive literature search was performed up to April 2013 using PubMed, the Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, and the Google search engine. In this review, we focus on the different mediators of impaired anabolism and upregulated catabolism that alter the skeletal muscle homeostasis resulting in the wasting of cancer cachexia. We present recent evidence of targeted treatment modalities from clinical trials along with their potential mechanisms of action. We also report on the most current evidence from randomized clinical trials using multimodal treatments in patients with cancer cachexia, but also the evidence from head and neck cancer-specific trials. A more complete understanding of the pathophysiology of the syndrome may lead to more effective targeted therapies and improved outcomes for patients.

An open-label clinical trial of the effects of age and gender on the pharmacodynamics, pharmacokinetics and safety of the ghrelin receptor agonist anamorelin

PURPOSE

To assess the effect of age and gender on the pharmacokinetics (PK) of the ghrelin receptor agonist anamorelin.

METHODS

Three demographic cohorts of healthy subjects were enrolled in this single-center, open-label study. Subjects received a single oral dose (25 mg) of anamorelin HCl. Serial blood samples were collected over 24 hours to assess anamorelin PK and circulating growth hormone (GH) levels. Data were compared with a reference cohort.

RESULTS

Anamorelin was rapidly absorbed in all cohorts; peak concentrations were observed 30-45 minutes and 2-4 hours post-dose, which declined biexponentially with mean terminal half-lives of 6-7 hours. An age effect on C_max and AUC_∞ was not apparent; however, mean AUC_∞ values were approximately 1.8-1.9-fold higher in the female cohorts than in the reference male cohort. GH increase was rapid and virtually identical in both sexes, though attenuated in elderly subjects. No clinically significant safety or tolerability findings were observed.

CONCLUSIONS

While PK parameters do suggest higher exposure in females, this effect is considered to be modest given the variability of the 6-8 subjects per cohort. Moreover, no such effect was observed in the pharmacodynamic responses, thus, dose adjustment for age and gender is considered unnecessary.

The Pentapeptide RM-131 Promotes Food Intake and Adiposity in Wildtype Mice but Not in Mice Lacking the Ghrelin Receptor

The gastrointestinal peptide hormone ghrelin is the endogenous ligand of the growth hormone secretagogue receptor (a.k.a. ghrelin receptor, GHR). Currently, ghrelin is the only circulating peripheral hormone with the ability to promote a positive energy balance by stimulating food intake while decreasing energy expenditure and body fat utilization, as defined in rodents. Based on these and additional, beneficial effects on metabolism, the endogenous ghrelin system is considered an attractive target to treat diverse pathological conditions including those associated with eating/wasting disorders and cachexia. As the pharmacological potential of ghrelin is hampered by its relatively short half-life, ghrelin analogs with enhanced pharmacokinetics offer the potential to sustainably improve metabolism. One of these ghrelin analogs is the pentapeptide RM-131, which promotes food intake and adiposity with higher potency as compared to native ghrelin in rodents. Whereas, the effect of RM-131 on energy metabolism is solidly confirmed in rodents, it remains elusive whether RM-131 exerts its effect solely via the ghrelin receptor. Accordingly, we assessed the receptor specificity of RM-131 to promote food intake and adiposity in mice lacking the GHR. Our data show that in wildtype mice RM-131 potently promotes weight gain and adiposity through stimulation of food intake. However, RM-131 fails to affect food intake and body weight in mice lacking the GHR, underlining that the anabolic effects of RM-131 are mediated via the ghrelin receptor in mice.

Anamorelin for patients with cancer cachexia: an integrated analysis of two phase 2, randomised, placebo-controlled, double-blind trials

BACKGROUND

Cancer anorexia-cachexia syndrome is associated with increased morbidity and mortality. Anamorelin is an oral ghrelin-receptor agonist with appetite-enhancing and anabolic activity. We assessed the effects of anamorelin on body composition, strength, quality of life, biochemical markers, and safety in patients with cancer anorexia-cachexia.

METHODS

Data were pooled, a priori, from two completed phase 2, multicentre, placebo-controlled, double-blind trials in patients with advanced or incurable cancer and weight loss of 5% or more. Patients were stratified by weight loss severity (5-15%, >15%) and randomly allocated (1:1) with a computer-generated randomisation schedule to anamorelin hydrochloride 50 mg or placebo once-daily for 12 weeks. Primary outcome was lean body mass by dual-energy x-ray absorptiometry over the 12 week treatment period in eligible patients who had at least one dose of study drug and post-treatment efficacy assessment. We assessed safety in all patients who received at least one dose of study drug. The trials are registered with ClinicalTrials.gov, numbers NCT00219817 and NCT00267358.

FINDINGS

Between June 29, 2005, and Oct 26, 2006, we enrolled 44 patients in the anamorelin group and 38 patients in the placebo group. 74 patients were eligible for the efficacy analyses. Over 12 weeks, lean body mass increased in 38 patients in the anamorelin group by a least-squares mean of 1.89 kg (95% CI 0.84 to 2.95) compared with a decrease of a least-squares mean of -0.20 kg (-1.23 to 0.83) for 36 patients in the placebo group (difference 2.09 kg [0.94-3.25]; p=0.0006). 42 (95%) of 44 patients treated with anamorelin and 33 (87%) of 38 patients treated with placebo had adverse events. The most common grade 3-4 adverse events (treatment-related or not) in the anamorelin group were fatigue, asthenia, atrial fibrillation, and dyspnoea (two [5%] each); in the placebo group, such events were pneumonia (three [8%]) and anaemia, thrombocytopenia, abdominal pain, anxiety, and dyspnoea (two [5%] each).

INTERPRETATION

Anamorelin treatment for 12 weeks had a favourable clinical response profile in patients with cancer anorexia-cachexia syndrome. These findings support further investigation in this setting.

FUNDING

Helsinn Therapeutics (US), Helsinn Healthcare SA.

Anamorelin HCl (ONO-7643), a novel ghrelin receptor agonist, for the treatment of cancer anorexia-cachexia syndrome: preclinical profile

BACKGROUND

Anamorelin HCl (ANAM) is a novel, orally active, ghrelin receptor agonist in clinical development for the treatment of cancer cachexia. We report in vitro and in vivo studies evaluating the preclinical pharmacologic profile of ANAM.

METHODS

Fluorescent imaging plate reader and binding assays in HEK293 and baby hamster kidney cells determined the agonist and antagonist activity of ANAM, and its affinity for the ghrelin receptor. Rat pituitary cells were incubated with ANAM to evaluate its effect on growth hormone (GH) release. In vivo, rats were treated with ANAM 3, 10, or 30 mg/kg, or control orally, once daily for 6 days to evaluate the effect on food intake (FI) and body weight (BW), and once to assess GH response. In pigs, single (3.5 mg/kg) or continuous (1 mg/kg/day) ANAM doses were administered to assess GH and insulin-like growth factor (IGF-1) response.

RESULTS

ANAM showed significant agonist and binding activity on the ghrelin receptor, and stimulated GH release in vitro. In rats, ANAM significantly and dose-dependently increased FI and BW at all dose levels compared with control, and significantly increased GH levels at 10 or 30 mg/kg doses. Increases in GH and IGF-1 levels were observed following ANAM administration in pigs.

CONCLUSION

ANAM is a potent and highly specific ghrelin receptor agonist with significant appetite-enhancing activity, leading to increases in FI and BW, and a stimulatory effect on GH secretion. These results support the continued investigation of ANAM as a potential treatment of cancer anorexia-cachexia syndrome.

Possible synergism of physical exercise and ghrelin-agonists in patients with cachexia associated with chronic heart failure

The occurrence of cachexia of multifactorial etiology in chronic heart failure (CHF) is a common and underestimated condition that usually leads to poor outcome and low survival rates, with high direct and indirect costs for the Health Care System. Recently, a consensus definition on cachexia has been reached, leading to a growing interest by the scientific community in this condition, which characterizes the last phase of many chronic diseases (i.e., cancer, acquired immunodeficiency syndrome). The etiology of cachexia is multifactorial and the underlying pathophysiological mechanisms are essentially the following: anorexia and malnourishment; immune overactivity and systemic inflammation; and endocrine disorders (anabolic/catabolic imbalance and resistance to growth hormone). In this paper, we review the main pathophysiological mechanisms underlying CHF cachexia, focusing also on the broad spectrum of actions of ghrelin and ghrelin agonists, and their possible use in combination with physical exercise to contrast CHF cachexia.

Cachexia and pancreatic cancer: Are there treatment options?

Cachexia is frequently described in patients with pancreatic ductal adenocarcinoma (PDAC) and is associated with reduced survival and quality of life. Unfortunately, the therapeutic options of this multi-factorial and complex syndrome are limited. This is due to the fact that, despite extensive preclinical and clinical research, the underlying pathological mechanisms leading to PDAC-associated cachexia are still not fully understood. Furthermore, there is still a lack of consensus on the definition of cachexia, which complicates the standardization of diagnosis and treatment as well as the analysis of the current literature. In order to provide an efficient therapy for cachexia, an early and reliable diagnosis and consistent monitoring is required, which can be challenging especially in obese patients. Although many substances have been tested in clinical and preclinical settings, so far none of them have been proven to have a long-term effect in ameliorating cancer-associated cachexia. However, recent studies have demonstrated that multidimensional therapeutic modalities are able to alleviate pancreatic cancer-associated cachexia and ultimately improve patients’ outcome. In this current review, we propose a stepwise and pragmatic approach to facilitate and standardize the treatment of cachexia in pancreatic cancer patients. This strategy consists of nutritional, dietary, pharmacological, physical and psychological methods.

Clinical development of ghrelin axis-derived molecules for cancer cachexia treatment

PURPOSE OF REVIEW

Cachexia is a devastating complication of cancer for which there is no approved treatment. Here we review the clinical development of ghrelin and ghrelin mimetics (also known as growth hormone secretagogues or GHS) for cancer cachexia treatment.

RECENT FINDINGS

Ghrelin, a novel hormone known to increase appetite, lean and fat mass, and growth hormone secretion, is being developed as a therapeutic option for cancer anorexia-cachexia syndrome (CACS). Recent animal studies suggest that it may also decrease inflammation and that some of its effects may be independent of its only known receptor, the GHS receptor-1a.Clinical studies recently have shown that administration of ghrelin or GHS improves appetite and quality of life as assessed by questionnaires. Weight gain, increased food intake and better tolerance to chemotherapy have also been reported. This treatment appears to be safe and well tolerated.

SUMMARY

Ghrelin and GHS have the potential to effectively prevent or reverse CACS. Preliminary studies show improvements in weight stabilization and appetite with short-term usage. Further studies are required to fully characterize the role of ghrelin and GHS for the treatment of CACS and to establish the safety of this approach.

Anamorelin hydrochloride in the treatment of cancer anorexia-cachexia syndrome

Anamorelin hydrochloride is an orally active ghrelin receptor agonist in development by Helsinn, for the treatment of non-small-cell lung cancer (NSCLC) cachexia. In preclinical and clinical studies, the potent affinity of anamorelin for the ghrelin receptor is associated with significant appetite-enhancing activity and resultant improvements in body weight, lean body mass, and handgrip strength compared with placebo. The accompanying stimulatory effects on growth hormone and IGF-1 are not associated with tumor growth, and overall survival in patients with cancer is not compromised. Anamorelin is well tolerated with no dose-limiting toxicities identified to date. The findings of ongoing Phase III studies are needed to confirm the significant potential of anamorelin to treat NSCLC cachexia.

Mechanisms and treatment of cancer cachexia

According to a recent consensus, cachexia is a complex metabolic syndrome associated with underlying illness and characterised by loss of muscle with or without loss of fat mass. The prominent clinical feature of cachexia is weight loss. Cachexia occurs in the majority of terminal cancer patients and it is responsible for the deaths of 22% of cancer patients. Although body weight is, indeed, an important factor to be taken into consideration in any cachexia treatment, body composition, physical performance and quality of life should be monitored. From the results presented here, one can speculate that a single therapy may not be completely successful in the treatment of cachexia. From this point of view, treatments involving different combinations are more likely to be successful. The objectives of any therapeutical combination are two: an anticatabolic aim directed towards both fat and muscle catabolism and an anabolic objective leading to the synthesis of macromolecules such as contractile proteins.

Macimorelin (AEZS-130)-stimulated growth hormone (GH) test: validation of a novel oral stimulation test for the diagnosis of adult GH deficiency

CONTEXT

In the absence of panhypopituitarism and low serum IGF-I levels, the diagnosis of adult GH deficiency (AGHD) requires confirmation with a GH stimulation test. Macimorelin is a novel, orally active ghrelin mimetic that stimulates GH secretion.

OBJECTIVE

The objective of the study was to determine the diagnostic efficacy and safety of macimorelin in AGHD.

DESIGN

This was a multicenter open-label study comparing the diagnostic accuracy of oral macimorelin with that of arginine+GHRH in AGHD patients and healthy, matched controls. After 43 AGHD patients and 10 controls were tested, the GHRH analog Geref Diagnostic [GHRH(1-29)NH2] became unavailable in the United States. The study was completed by testing 10 additional AGHD patients and 38 controls with macimorelin alone.

MAIN OUTCOME MEASURE

Peak GH area under the receiver operating characteristic curve after macimorelin was measured.

RESULTS

Fifty AGHD subjects and 48 controls were evaluated. Peak GH levels in AGHD patients and controls after macimorelin were 2.36 ± 5.69 and 17.71 ± 19.11 ng/mL, respectively (P < .0001). With macimorelin, the receiver operating characteristic analysis yielded an optimal GH cut point of 2.7 ng/mL, with 82% sensitivity, 92% specificity, and 13% misclassification rate. For subjects receiving both tests, macimorelin showed discrimination comparable with arginine+GHRH (area under the receiver operating characteristic curve 0.99 vs 0.94, respectively, P = .29). Obesity (body mass index > 30 kg/m(2)) was present in 58% of subjects, and peak GH levels were inversely associated with body mass index in controls (r = -0.37, P = .01). Using the separate cut points of 6.8 ng/mL for nonobese and 2.7 for obese subjects reduced the misclassification rate to 11%. Only 1 drug-related serious adverse event, an asymptomatic QT interval prolongation on the electrocardiogram, was reported.

CONCLUSION

Oral macimorelin is safe, convenient, and effective in diagnosing AGHD with accuracy comparable with the arginine+GHRH test.

Effect of ghrelin and anamorelin (ONO-7643), a selective ghrelin receptor agonist, on tumor growth in a lung cancer mouse xenograft model

Purpose

Anamorelin (ONO-7643) is an orally active ghrelin receptor agonist in development for non-small cell lung cancer (NSCLC)-related anorexia/cachexia. It displays both orexigenic and anabolic properties via ghrelin mimetic activity and transient increases in growth hormone (GH). However, increasing GH and insulin-like growth factor-1 in cancer patients raises concerns of potentially stimulating tumor growth. Therefore, we investigated the effect of ghrelin and anamorelin on tumor growth in a murine NSCLC xenograft model.

Methods

Female nude mice (15–21/group) with established A549 tumors were administered ghrelin (2 mg/kg i.p.), anamorelin (3, 10, or 30 mg/kg p.o.), or vehicle controls daily for 28 days. Tumor growth, food consumption, and body weight were monitored. Murine growth hormone (mGH) and murine insulin-like growth factor-1 (mIGF-1) were measured in plasma.

Results

Tumor growth progressed throughout the study, with no significant differences between treatment groups. Daily food consumption was also relatively unchanged, while the percentage of mean body weight gain at the end of treatment was significantly increased in animals administered 10 and 30 mg/kg compared with controls (p < 0.01). Peak mGH levels were significantly higher in ghrelin- and anamorelin-treated animals than in controls, while peak mIGF-1 levels were slightly elevated but not statistically significant. All regimens were well tolerated.

Conclusions

These findings demonstrate that neither anamorelin nor ghrelin promoted tumor growth in this model, despite increased levels of mGH and a trend of increased mIGF-1. Together with anamorelin’s ability to increase body weight, these results support the clinical development of ghrelin receptor agonist treatments for managing NSCLC-related anorexia/cachexia.