Applications of peptide hormone ligands for the treatment of dumping and short bowel syndrome

Dumping syndrome after bariatric surgery: prevalence, pathophysiology and role in weight reduction - a systematic review

Background

Dumping syndrome is a frequent and wellknown adverse event after bariatric surgery and covers a dynamic spectrum of early and late dumping. Accelerated gastric emptying is generally considered to be the cause of gastrointestinal and vasomotor complaints. However, there is much uncertainty regarding the exact pathophysiology of dumping. It has been speculated that the syndrome is a desired consequence of bariatric surgery and contributes to more efficient weight loss, but supporting data are scarce.

Methods

A systematic search was conducted in PubMed in July-August 2021. The prevalence of dumping after the most frequently performed bariatric procedures was analyzed, as well as underlying pathophysiology and its role in weight reduction.

Results

Roux-en-Y gastric bypass (RYGB) is associated with the highest postoperative prevalence of dumping. The fast transit induces neurohumoral changes which contribute to an imbalance between postprandial glucose and insulin levels, resulting in hypoglycemia which is the hallmark of late dumping. Early dumping can, when received in a positive way, become a tool to maintain a strict dietary pattern, but no significant relationship to the degree of weight loss has been shown. However, late dumping is detrimental and promotes overall higher caloric intake.

Conclusion

Dumping syndrome is common after bariatric surgery, especially after RYGB. The pathophysiology is complex and ambiguous. Currently available data do not support dumping as a necessary condition to induce weight loss after bariatric surgery.

Treatment of short bowel syndrome: Breaking the therapeutic ceiling?

Short bowel syndrome (SBS) is the most common cause of chronic intestinal failure, requiring home parenteral support (intravenous fluid, parenteral nutrition, or parenteral nutrition with intravenous fluid) to compensate for severe malabsorption. The loss of mucosal absorptive area after extensive intestinal resection is accompanied by an accelerated transit and hypersecretion. Changes in physiology and clinical outcomes differ between patients with SBS with or without the distal ileum and/or colon-in-continuity. This narrative review summarizes the treatments used in SBS, with a focus on novel approaches with intestinotrophic agents. During the early postoperative years, spontaneous adaptation occurs and can be induced or accelerated with conventional therapies, which include dietary and fluid modifications and antidiarrheal and antisecretory drugs. Based on the proadaptive role of enterohormones (eg, glucagon-like peptide [GLP]-2), analogues have been developed to allow enhanced or hyperadaptation after a period of stabilization. Teduglutide is the first GLP-2 analogue developed and commercialized with proadaptive effects resulting in reduced parenteral support needs; however, the potential for weaning of parenteral support is variable. Whether early treatment with enterohormones or accelerated hyperadaptation would further improve absorption and outcomes remains to be shown. Longer-acting GLP-2 analogues are currently being investigated. Encouraging reports with GLP-1 agonists require confirmation in randomized trials, and dual GLP-1 and GLP-2 analogues have yet to be clinically investigated. Future studies will prove whether the timing and/or combinations of different enterohormones will be able to break the ceiling of intestinal rehabilitation in SBS.

Therapeutic Potential of GLP-2 Analogs in Gastrointestinal Disorders: Current Knowledge, Nutritional Aspects, and Future Perspectives

PURPOSE OF REVIEW

Although Glucagon-like peptide (GLP)-1 receptor agonists have been used for almost two decades in the treatment of diabetes mellitus type 2 and, lately, in obesity, recent years have seen an increasing interest in the pharmacological agonism of other proglucagon-derived peptides, including GLP-2. Herein, we aimed to review the available evidence on the effects of GLP-2 agonism from animal and clinical studies. Furthermore, we summarize the current clinical applications of GLP-2 agonists among patients with intestinal failure associated with short bowel syndrome (SBS-IF) as well as potential future expansion of their indications to other intestinal disorders.

RECENT FINDINGS

Evidence from preclinical studies has highlighted the cellular trophic and functional beneficial actions of GLP-2 on small intestinal and colonic mucosa. Subsequently, pharmacologic agonism of GLP-2 has gathered interest for the treatment of patients with conditions pertaining to the loss of intestinal anatomical and/or functional integrity to a degree requiring parenteral support, collectively referred to as intestinal failure. GLP-2 analogs positively influence nutrient absorption in animal models and humans, although continued therapy is likely needed for sustained effects. The degradation-resistant GLP-2-analog teduglutide has received approval for the treatment of SBS-IF, in which it may decisively reduce patient dependency on parenteral support and improve quality of life. Another two longer-acting analogs, glepaglutide and apraglutide, are currently undergoing phase III clinical trials. The use of GLP-2 analogs is effective in the management of SBS-IF and may show promise in the treatment of other severe gastrointestinal disorders associated with loss of effective intestinal resorptive surface area.

Effectiveness of beinaglutide in a patient with late dumping syndrome after gastrectomy: A case report

RATIONALE

Dumping syndrome is a frequent and potentially severe complication after gastric surgery. Beinaglutide, a recombinant human glucagon-like peptide-1 (GLP-1) which shares 100% homology with human GLP-1(7-36), has never been reported in the treatment of dumping syndrome before.

PATIENT CONCERNS

The patient had undergone distal gastrectomy for gastric signet ring cell carcinoma 16 months ago. He presented with symptoms of paroxysmal palpitation, sweating, and dizziness for 4 months.

DIAGNOSIS

He was diagnosed with late dumping syndrome.

INTERVENTIONS AND OUTCOMES

The patient was treated with dietary changes and acarbose for 4 months before admitted to our hospital. The treatment with dietary changes and acarbose did not prevent postprandial hyperinsulinemia and hypoglycemia according to the 75 g oral glucose tolerance test (OGTT) and continuous glucose monitoring (CGM) on admission.Therefore, the patient was treated with beinaglutide 0.1 mg before breakfast and lunch instead of acarbose. After the treatment of beinaglutide for 1 month, OGTT showed a reduction in postprandial hyperinsulinemia compared with before starting treatment, and the time in the range of 3.9 to 10 mmol/L became 100% in CGM. No side effect was observed in this patient during beinaglutide treatment.

LESSONS

These findings suggest that beinaglutide may be effective for treating post-gastrectomy late dumping syndrome.

Impact of gastrointestinal tract variability on oral drug absorption and pharmacokinetics: An UNGAP review

The absorption of oral drugs is frequently plagued by significant variability with potentially serious therapeutic consequences. The source of variability can be traced back to interindividual variability in physiology, differences in special populations (age- and disease-dependent), drug and formulation properties, or food-drug interactions. Clinical evidence for the impact of some of these factors on drug pharmacokinetic variability is mounting: e.g. gastric pH and emptying time, small intestinal fluid properties, differences in pediatrics and the elderly, and surgical changes in gastrointestinal anatomy. However, the link of colonic factors variability (transit time, fluid composition, microbiome), sex differences (male vs. female) and gut-related diseases (chronic constipation, anorexia and cachexia) to drug absorption variability has not been firmly established yet. At the same time, a way to decrease oral drug pharmacokinetic variability is provided by the pharmaceutical industry: clinical evidence suggests that formulation approaches employed during drug development can decrease the variability in oral exposure. This review outlines the main drivers of oral drug exposure variability and potential approaches to overcome them, while highlighting existing knowledge gaps and guiding future studies in this area.

Citrulline correlations in short bowel syndrome-intestinal failure by patient stratification: Analysis of 24 weeks of teduglutide treatment from a randomized controlled study

BACKGROUND & AIMS

Disease-associated factors influence parenteral support (PS) reduction in response to teduglutide in patients with intestinal failure associated-short bowel syndrome (SBS-IF). We sought to determine correlative relationships between plasma citrulline levels, small bowel length, and PS volume.

METHODS

A post hoc analysis of plasma citrulline levels from patients in the STEPS 24-week study of teduglutide in patients with SBS-IF. Plasma citrulline was assessed in all patients; patients were stratified 3 times into subgroups based on bowel anatomy, cause of SBS-IF, and baseline PS volumes. Correlation analyses used simple linear regression models. Statistical comparisons between study groups were conducted using 2-sided t tests for 2 independent mean differences.

RESULTS

Baseline plasma citrulline correlated with remnant small bowel length (r = 0.355, P = 0.002), but not with baseline PS volume (r = -0.167, P = 0.14), in the overall population. There was a robust correlation between the baseline and Week 24 citrulline (r = 0.705, P < 0.0001), and an inverse correlation between change from baseline in citrulline and PS volume from baseline to Week 24 (r = -0.359, P = 0.001). In all subgroups, patients treated with teduglutide showed numerically greater increases in plasma citrulline at Week 24 compared with placebo.

CONCLUSION

Baseline plasma citrulline showed significant correlations with small bowel length in patients with ≥50% colon remaining/no stoma/colon-in-continuity, and patients with SBS-IF causes other than IBD/vascular disease. Citrulline levels may correlate with PS changes in response to teduglutide and more research may reveal a relationship between citrulline levels within the heterogeneous population of patients with SBS-IF. ClinicalTrials.gov NCT00798967, ClinicalTrialsRegister.eu 2008-006193-15.

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.

A Practical and Total Synthesis of Pasireotide: Synthesis of Cyclic Hexapeptide via a Three-Component Condensation

Pasireotide is a multi-receptor ligand somatostatin analogue approved for medical treatment of Cushing’s disease and acromegaly. The liquid-phase total synthesis of pasireotide-a 18-membered cyclic hexapeptide-was achieved by the 3 + 2 + 1 strategy, and the Pro¹-Phe⁶ peptide bond was selected as the final cyclization position. Two key fragments were simply synthesized using N,O-bis(trimethylsilyl)acetamide/N-hydroxysuccinimide ester (BSA/NHS) as coupling agents, and processes of the two key fragments were simple without any chromatographic purification. The current synthesis method is easily scalable and produces the target peptide with an overall yield of 15%.