Safety and efficacy of pasireotide in dumping syndrome-results from a phase 2, multicentre study

Dumping syndrome: Update on pathophysiology, diagnosis, and management

BACKGROUND

Dumping syndrome is a complex of gastrointestinal symptoms originally studied in peptic ulcer surgery patients. At present, it is most prevalent in patients who underwent bariatric, upper gastrointestinal cancer or anti-reflux surgery. The symptom pattern comprises early and late dumping symptoms. Several management options have been reported including nutritional, pharmacological and surgical approaches.

AIMS AND METHODS

In this study, we aimed to review the current evidence on dumping syndrome definition, diagnosis and treatment, including preliminary data from newer pharmacological studies.

RESULTS

Current pathophysiological concepts and analyses of provocative tests has led to a clear definition of dumping syndrome, including both early and late dumping symptoms. The term postbariatric hypoglycemia represents a limited focus on late dumping only. The diagnosis relies on recognition of symptoms and signs in a patient with appropriate surgical history; and can be confirmed by provocative testing or registration of spontaneous hypoglycemia. The initial treatment focuses on dietary intervention, to which meal viscosity enhancers and/or the glycosidase inhibitor acarbose can be added. The most effective therapy is the use of short- or long-acting somatostatin analogues, which is however expensive and entails side effect issues. In case of refractory hypoglycemia, diazoxide or SGLT2 inhibitors can be considered, based on limited evidence. In refractory patients, continuous enteral feeding or (rarely) surgical reinterventions have been advocated, although not supported by solid evidence. Therapies under current evaluation include the broad-spectrum somatostatin analogue pasireotide, GLP-1 receptor antagonists, GLP-1 receptor agonists and administration of stable forms of glucagon are currently under study.

CONCLUSIONS

Dumping syndrome is a well-defined but probably under-diagnosed complication of upper gastrointestinal, especially bariatric, and surgeries. Diagnosis is confirmed by a provocative test and incremental therapies starting with diet, adding meal viscosity enhancers or glycosidase inhibitors and adding somatostatin analogues in refractory cases. A number of emerging therapies targeting intestinal propulsion, peptide hormone effects and hypoglycemic events are under evaluation.

Managing gastrointestinal manifestations in systemic sclerosis, a mechanistic approach

INTRODUCTION

Systemic sclerosis (SSc) is a connective tissue disease with heterogeneous presentation. Gastrointestinal (GI) complications of SSc are characterized by esophageal reflux, abnormal motility, and microbiome dysbiosis, which impact patient quality of life and mortality. Preventative therapeutics are lacking, with management primarily aimed at symptomatic control.

AREAS COVERED

A broad literature review was conducted through electronic databases and references from key articles. We summarize the physiology of gastric acid production and GI motility to provide context for existing therapies, detail the current understanding of SSc-GI disease, and review GI medications studied in SSc. Finally, we explore new therapeutic options. We propose a management strategy that integrates data on drug efficacy with knowledge of disease pathophysiology, aiming to optimize future therapeutic targets.

EXPERT OPINION

SSc-GI complications remain a challenge for patients, clinicians, and investigators alike. Management presently focuses on treating symptoms and minimizing mucosal damage. Little evidence exists to suggest immunosuppressive therapy halts progression of GI involvement or reverses damage, leaving many unanswered questions about the optimal clinical approach. Further research focused on identifying patients at risk for GI progression, and the underlying mechanism(s) that drive disease will provide opportunities to prevent long-term damage, and significantly improve patient quality of life.

Postbariatric surgery hypoglycemia: Nutritional, pharmacological and surgical perspectives

Post-bariatric hypoglycaemia (PBH) is a metabolic complication of bariatric surgery (BS), consisting of low post-prandial glucose levels in patients having undergone bariatric procedures. While BS is currently the most effective and relatively safe treatment for obesity and its complications, the development of PBH can significantly impact patients' quality of life and mental health. The diagnosis of PBH is still challenging, considering the lack of definitive and reliable diagnostic tools, and the fact that this condition is frequently asymptomatic. However, PBH's prevalence is alarming, involving up to 88% of the post-bariatric population, depending on the diagnostic tool, and this may be underestimated. Given the prevalence of obesity soaring, and an increasing number of bariatric procedures being performed, it is crucial that physicians are skilled to diagnose PBH and promptly treat patients suffering from it. While the milestone of managing this condition is nutritional therapy, growing evidence suggests that old and new pharmacological approaches may be adopted as adjunct therapies for managing this complex condition.

Dumping Syndrome: Pragmatic Treatment Options and Experimental Approaches for Improving Clinical Outcomes

Dumping syndrome is a common complication after esophageal, gastric and bariatric surgery and has a significant negative impact on the quality of life of patients. This narrative review describes the clinical syndrome, pathophysiology, diagnosis and reports on standard and pragmatic therapeutical treatment options in order to improve the clinical outcome of patients with dumping syndrome. Dumping syndrome consists of early and late dumping symptoms and can be diagnosed using clinical parameters with the help of the Sigstad's score, questionnaires or by provocative testing. The prevalence of dumping syndrome varies depending on the employed definition of dumping syndrome. Overall, dumping syndrome is more frequent nowadays due to increasing numbers of upper gastrointestinal and bariatric surgeries being performed. First treatment step includes dietary adjustment and dietary supplements, which are often sufficient to manage symptoms for the majority of patients. Next step of therapy includes acarbose, which is effective for late dumping symptoms, but the use is limited due to side effects. Somatostatin analogues are indicated after these two steps have failed. Somatostatin analogues are very effective for controlling early and late dumping, also in the long term. Glucagon like peptide-1 receptor agonists, endoscopic and surgical (re)interventions are reported as treatment options for refractory dumping syndrome; however, their use is not recommended in clinical practice due to the limited evidence on and uncertainty of outcomes. These alternatives should be considered only as last resort options in patients with otherwise refractory and invalidating dumping syndrome.

Dumping Syndrome in Children: A Narrative Review

Dumping syndrome (DS) is a typical side effect of stomach surgery, which includes cancer, non-cancer esophageal and gastric surgery, and bariatric surgery. It is marked by the fast evacuation of undigested food from the stomach into the small intestine, which causes a variety of symptoms. Early dumping symptoms include gastrointestinal symptoms such as stomach discomfort, diarrhea, and nausea, as well as vasomotor symptoms such as drowsiness and face flushing, and occur within the first hour following a meal. Late dumping symptoms appear one to three hours after a meal and are related to reactive hypoglycemia, resulting in hypoglycemia, sweating, palpitations, and confusion. Early dumping pathophysiology involves abnormalities in stomach structure and function, which result in rapid transit of stomach contents to the duodenum, insufficient digestion, and fluid transfers from the vascular compartment to the intestine. Late dumping occurs as a result of hyperinsulinemia caused by the fast passage of undigested foods to the gut. Symptom-based questionnaires and diagnostic testing such as plasma glucose measurement and stomach emptying studies can be used to confirm a diagnosis of DS. The primary approach to managing DS is dietary modifications, including eating smaller, more frequent meals and avoiding high glycemic index carbohydrates. Dietary supplements and medications may be used to slow down gastric emptying or control blood glucose levels. Pharmacological options include alpha-glycosidase inhibitors, somatostatin analogs, glucagon-like peptide-1 analogs, and sodium-glucose cotransporter inhibitors. In severe cases, refractory to conservative measures, surgical interventions may be considered. DS can arise in children following gastric surgery for obesity or corrective surgery for congenital abnormalities. It is frequently misdiagnosed and can have serious implications, such as hypoglycemia-related cognition deficits. Screening and early identification using glucose tolerance testing and continuous glucose monitoring (CGM) are critical in at-risk youngsters. Children's treatment techniques are similar to those used in adults, with dietary changes and medication therapies serving as the cornerstone of care. Overall, DS is a complex condition that requires a multidisciplinary approach to diagnosis and management. Further research is needed to improve understanding of its pathophysiology and optimize treatment strategies, particularly in children. This review aims to provide a well-rounded informative summary of the most recent literature on the under-recognized clinical and scientific aspects of DS among the children age group. It incorporates the quality of life, pathophysiology, diagnosis, prevalence, and treatment.

Medical and surgical treatment of postbariatric hypoglycaemia: Retrospective data from daily practice

AIM

To evaluate medical and surgical treatment of postbariatric hypoglycaemia (PBH) in daily practice.

MATERIALS AND METHODS

Retrospective data were extracted from medical records from four hospitals. PBH was defined by neuroglycopenic symptoms together with a documented glucose <3.0 mmol/L in the postprandial setting after previous bariatric surgery. Data were scored semiquantitatively on efficacy and side effects by two reviewers independently. Duration of efficacy and of use were calculated.

RESULTS

In total, 120 patients were included with a median follow-up of 27 months with a mean baseline age of 41 years, total weight loss of 33% and glucose nadir 2.3 mmol/L. Pharmacotherapy consisted of acarbose, diazoxide, short- and long-acting octreotide and glucagon-like peptide-1 receptor agonist analogues (liraglutide and semaglutide) with an overall efficacy in 45%-75% of patients. Combination therapy with two drugs was used by 30 (25%) patients. The addition of a second drug was successful in over half of the patients. Long-acting octreotide and the glucagon-like peptide-1 receptor agonist analogues scored best in terms of efficacy and side effects with a median duration of use of 35 months for octreotide. Finally, 23 (19%) patients were referred for surgical intervention. Efficacy of the surgical procedures, pouch banding, G-tube placement in remnant stomach and Roux-en-Y gastric bypass reversal, pooled together, was 79% with a median duration of initial effect of 13 months.

CONCLUSIONS

In daily practice, pharmacotherapy for PBH was successful in half to three quarters of patients. Combination therapy was often of value. One in five patients finally needed a surgical procedure, with overall good results.

Discovery of 4-(3-aminopyrrolidinyl)-3-aryl-5-(benzimidazol-2-yl)-pyridines as potent and selective SST5 agonists for the treatment of congenital hyperinsulinism

SST5 receptor activation potently inhibits insulin secretion from pancreatic β-cells, and an orally available nonpeptide selective SST5 agonist may be used to effectively manage the blood glucose levels of congenital HI patients to avoid severe hypoglycemia. Our medicinal chemistry efforts have led to the discovery of 4-(3-aminopyrrolidinyl)-3-aryl-5-(benzimidazol-2-yl)-pyridine analogs as potent SST5 agonists. This class of molecules exhibits excellent human SST5 potency and selectivity against SST1, SST2, SST3 and SST4 receptors. Leading compound 3-{4-[(3S)-3-aminopyrrolidin-1-yl]-5-(4-methyl-1H-1,3-benzodiazol-2-yl)pyridin-3-yl-5-fluorobenzonitrile (28, CRN02481) showed limited off-target activity and good pharmacokinetic profiles in both male Sprague Dawley rats and Beagle dogs to advance into further preclinical evaluations.

Gastrointestinal hormones and regulation of gastric emptying

PURPOSE OF REVIEW

In this review, we evaluate recent findings related to the association between gastrointestinal hormones and regulation of gastric emptying.

RECENT FINDINGS

Motilin and ghrelin, which act during fasting, promote gastric motility, whereas most of the hormones secreted after a meal inhibit gastric motility. Serotonin has different progastric or antigastric motility effects depending on the receptor subtype. Serotonin receptor agonists have been used clinically to treat dyspepsia symptoms but other hormone receptor agonists or antagonists are still under development. Glucagon-like peptide 1 agonists, which have gastric motility and appetite-suppressing effects are used as a treatment for obesity and diabetes.

SUMMARY

Gastrointestinal hormones play an important role in the regulation of gastric motility. Various drugs have been developed to treat delayed gastric emptying by targeting gastrointestinal hormones or their receptors but few have been commercialized.

Patient involvement to inform the design of a clinical trial in postbariatric hypoglycaemia

Background

Bariatric surgery may lead to symptomatic postprandial hypoglycaemia as a major side effect without established therapy so far. We aimed to develop an evidence-based study design of a clinical trial that tests treatment options and can provide useful patient-relevant evidence.

Methods

We searched systematically for guidance of core outcome sets to determine the most relevant types of outcomes and duration of such a trial. Our search comprised literature databases, a database of core outcome sets and self-help organizations. We then developed a simple online questionnaire based on interviews with German-speaking patients with postprandial hypoglycaemia after bariatric surgery. We recruited participants by reaching out to all German speaking endocrinologists in Switzerland and large Swiss bariatric centres. We asked for preferences regarding outcome types and acceptable duration of being included in a corresponding clinical trial.

Results

The literature search did not identify evidence-based guidance for informing our study design. Experience of clinical and research routine as well as patient interviews helped in identifying potential outcomes and the design of an online questionnaire. Therein, a total of 29 persons started the questionnaire and 22 answered questions related to the primary outcome. Of these, 17 (77.3%) deemed quality of life more relevant as primary outcome than the rate of hypoglycaemic episodes. A trial length of four weeks or longer was regarded as acceptable for 19 of 21 respondents to this question (91.4%) and of six months or longer for 12 respondents (56%).

Conclusions

In situations with no other guidance, a simple questionnaire may help to inform trial design decisions. This study identifies a patient preference for “quality of life” as a primary outcome and supports the evidence-based conception of a patient-centred clinical trial in postbariatric hypoglycaemia.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s12874-020-01171-z.

Counterregulatory responses to postprandial hypoglycemia after Roux-en-Y gastric bypass

BACKGROUND

Postbariatric hypoglycemia (PBH) is a potentially serious complication after Roux-en-Y gastric bypass (RYGB), and impaired counterregulatory hormone responses have been suggested to contribute to the condition.

OBJECTIVES

We evaluated counterregulatory responses during postprandial hypoglycemia in individuals with PBH who underwent RYGB.

SETTING

University hospital.

METHODS

Eleven women with documented PBH who had RYGB underwent a baseline liquid mixed meal test (MMT) followed by 5 MMTs preceded by treatment with (1) acarbose 50 mg, (2) sitagliptin 100 mg, (3) verapamil 120 mg, (4) liraglutide 1.2 mg, and (5) pasireotide 300 μg. Blood was collected at fixed time intervals. Plasma and serum were analyzed for glucose, insulin, glucagon, epinephrine, norepinephrine, pancreatic polypeptide (PP), and cortisol.

RESULTS

During the baseline MMT, participants had nadir blood glucose concentrations of 3.3 ± .2 mmol/L. At the time of nadir glucose, there was a small but significant increase in plasma glucagon. Plasma epinephrine concentrations were not increased at nadir glucose but were significantly elevated by the end of the MMT. There were no changes in norepinephrine, PP, and cortisol concentrations in response to hypoglycemia. After treatment with sitagliptin, 8 individuals had glucose nadirs <3.2 mmol/L (versus 4 individuals at baseline), and significant increases in glucagon, PP, and cortisol responses were observed.

CONCLUSIONS

In response to postprandial hypoglycemia, individuals with PBH who underwent RYGB only had minor increases in counterregulatory hormones, while larger hormone responses occurred when glucose levels were lowered during treatment with sitagliptin. The glycemic threshold for counterregulatory activation could be altered in individuals with PBH, possibly explained by recurrent hypoglycemia.

Postfundoplication retching: Strategies for management

BACKGROUND

Retching is a common symptom in children following antireflux surgery, particularly in those with neurodisability. There is now a strong body of evidence that implicates retching as a major cause of wrap breakdown. Retching is not a symptom of gastroesophageal reflux disease; it is a component of the emetic reflex. In addition to causing wrap breakdown, it is indicative of the presence of nausea. It is a highly aversive experience and warrants treatment in its own right.

METHODS

A framework was constructed for the management of postoperative retching, with strategies targeting different components of the emetic reflex. The impact of differing antireflux procedures upon retching was also considered.

CONCLUSIONS

Once treatable underlying causes have been excluded, the approach includes modifications to feeds and feeding regimens, antiemetics and motility agents. Neuromodulation and other, novel, therapies may prove beneficial in future. Children at risk of postoperative retching may be identified before any antireflux surgery is performed. Fundoplication is inappropriate in these children because it does not treat their symptoms, which are not because of gastroesophageal reflux, and may make them worse. They are also at risk of wrap disruption. Alternative strategies for symptom management should be employed, and fundoplication should be avoided.

LEVEL OF EVIDENCE

II-V.

International consensus on the diagnosis and management of dumping syndrome

Dumping syndrome is a common but underdiagnosed complication of gastric and oesophageal surgery. We initiated a Delphi consensus process with international multidisciplinary experts. We defined the scope, proposed statements and searched electronic databases to survey the literature. Eighteen experts participated in the literature summary and voting process evaluating 62 statements. We evaluated the quality of evidence using grading of recommendations assessment, development and evaluation (GRADE) criteria. Consensus (defined as >80% agreement) was reached for 33 of 62 statements, including the definition and symptom profile of dumping syndrome and its effect on quality of life. The panel agreed on the pathophysiological relevance of rapid passage of nutrients to the small bowel, on the role of decreased gastric volume capacity and release of glucagon-like peptide 1. Symptom recognition is crucial, and the modified oral glucose tolerance test, but not gastric emptying testing, is useful for diagnosis. An increase in haematocrit >3% or in pulse rate >10 bpm 30 min after the start of the glucose intake are diagnostic of early dumping syndrome, and a nadir hypoglycaemia level <50 mg/dl is diagnostic of late dumping syndrome. Dietary adjustment is the agreed first treatment step; acarbose is effective for late dumping syndrome symptoms and somatostatin analogues are preferred for patients who do not respond to diet adjustments and acarbose.

Somatostatin Analogs in Clinical Practice: a Review

Somatostatin analogs are an invaluable therapeutic option in the diagnosis and treatment of somatotropinomas, thyrotropinomas, and functioning and non-functioning gastroenteropancreatic neuroendocrine tumors. They should also be considered an effective and safe therapeutic alternative to corticotropinomas, gonadotropinomas, and prolactinomas resistant to dopamine agonists. Somatostatin analogs have also shown to be useful in the treatment of other endocrine diseases (congenital hyperinsulinism, Graves’ orbitopathy, diabetic retinopathy, diabetic macular edema), non-endocrine tumors (breast, colon, prostate, lung, and hepatocellular), and digestive diseases (chronic refractory diarrhea, hepatorenal polycystosis, gastrointestinal hemorrhage, dumping syndrome, and intestinal fistula).

Postprandial hypoglycaemia after Roux-en-Y gastric bypass and the effects of acarbose, sitagliptin, verapamil, liraglutide and pasireotide

AIM

To investigate the effects of acarbose, sitagliptin, verapamil, liraglutide and pasireotide on post-bariatric hypoglycaemia (PBH) after Roux-en-Y gastric bypass.

MATERIALS AND METHODS

In a randomized crossover study, 11 women who had undergone Roux-en-Y gastric bypass and had documented hypoglycaemia were each evaluated during a baseline period without treatment and during five treatment periods with the following interventions: acarbose 50 mg for 1 week, sitagliptin 100 mg for 1 week, verapamil 120 mg for 1 week, liraglutide 1.2 mg for 3 weeks and pasireotide 300 μg as a single dose. Treatment effects were evaluated by a mixed-meal tolerance test (MMTT) and, for all treatment periods except pasireotide, by 6 days of continuous glucose monitoring (CGM).

RESULTS

Treatment with acarbose and treatment with pasireotide both significantly lifted nadir glucose levels (mean ± SEM 3.9 ± 0.2 and 7.9 ± 0.4 vs 3.4 ± 0.2; P < .03) and reduced time in hypoglycaemia during the MMTTs. Acarbose reduced peak glucose levels and time in hyperglycaemia, whereas pasireotide greatly increased both variables. Acarbose and pasireotide reduced insulin and C-peptide levels, and pasireotide also diminished glucagon-like peptide-1 levels. Sitagliptin lowered nadir glucose values, while verapamil and liraglutide had no effect on hypoglycaemia. During the CGM periods, the treatments had no impact on hypoglycaemia, whereas acarbose and liraglutide reduced hyperglycaemia and glycaemic variability.

CONCLUSIONS

In an experimental setting, treatment with acarbose and pasireotide reduced PBH. Acarbose appears to have an overall glucose-stabilizing effect, whereas pasireotide leads to increased and sustained hyperglycaemia.

Efficacy and safety of lanreotide in postoperative dumping syndrome: A Phase II randomised and placebo-controlled study

Background

Data on the efficacy and safety of the long-acting somatostatin analogue lanreotide (LAN) for postoperative dumping syndrome are lacking.

Objective

We performed a double-blind, randomised and placebo-controlled crossover study of LAN Autogel® 90 mg in postoperative dumping.

Methods

Adults with a positive prolonged oral glucose tolerance test or spontaneous hypoglycaemia and total dumping score (DS) ≥ 10 despite dietary measures were treated with three monthly injections of LAN or placebo in a randomised crossover fashion with an eight-week wash-out period. Primary outcome was the effect of LAN on total DS versus placebo. Secondary outcomes were the effect on early and late DS, treatment assessment, quality of life and safety.

Results

Of 24 included patients (66.7% female; age 49.1 ± 2.1 years), 12 were randomised to LAN first. Pooled DS after three injections were lower compared to baseline after LAN (median=14 (interquartile range (IQR) 11.5-23) vs. median = 22 (IQR 16-27); p = 0.03) but not placebo (median = 20 (IQR 15-27) vs. median = 23 (IQR 13-29); p = 0.15). Improvement of early (median = 7.5 (IQR 4.5-13) vs. median = 12 (IQR 9-16); p = 0.03) but not late (median = 7 (IQR 6-10.3) vs. median = 9 (IQR 6-13); p = 0.26) DS was seen. Overall treatment assessment correlated with change in DS (r = -0.69, p = 0.004). Symptom improvement was not associated with changes in quality of life. Of the 81 reported adverse events, 44 occurred on LAN compared to 37 on placebo (p > 0.05), with seven serious adverse events on LAN.

Conclusions

LAN is effective for treating early postoperative dumping symptoms, although side effects are common and quality of life is not significantly affected.