A randomized, double-blind, placebo-controlled, phase 2b study of the efficacy and safety of velusetrag in subjects with diabetic or idiopathic gastroparesis

Postoperative delayed gastric emptying: may gut microbiota play a role?

Postoperative delayed gastric emptying is a prevalent complication following surgical procedures, imposing heavy physical and financial burdens on patients. However, current treatment options remain suboptimal. In recent years, an increasing number of studies have highlighted that the gut microbiota and its metabolites are closely associated with postoperative complications. Various factors can disrupt the gut microbiome after surgery. This review discusses the potential mechanisms by which the gut microbiota and their metabolites may contribute to the pathogenesis of postoperative delayed gastric emptying. However, the current knowledge base is limited in terms of fully understanding the exact mechanisms involved. It is therefore evident that further research is required to fully elucidate the role of the gut microbiome in postoperative delayed gastric emptying, with the aim of uncovering new possibilities for preventive measures and therapeutic treatments.

The 5HT4R agonist velusetrag efficacy on neuropathic chronic intestinal pseudo-obstruction in PrP-SCA7-92Q transgenic mice

Background

Chronic intestinal pseudo-obstruction (CIPO) is a type of intestinal dysfunction with symptoms of intestinal blockage but without the actual mechanical obstruction. Currently, there are no drugs available to treat this disease. Herein, we report the characterization of the PrP-SCA7-92Q transgenic (Tg) line as a valuable CIPO mouse model and investigated the tolerability and efficacy of the 5-hydroxytryptamine type-4 receptor (5HT4R) agonist velusetrag as a promising pharmacological treatment for CIPO.

Methods

To test the pharmacodynamics of velusetrag, 8-week-old SCA7 Tg mice, which express human mutated Ataxin-7 gene containing 92 CAG repeats under the mouse prion protein promoter, were treated for 5 weeks by oral route with velusetrag at 1 and 3 mg/kg doses or vehicle. Body weight was monitored throughout the treatment. After sacrifice, the small intestine and proximal colon were collected for whole-mount immunostaining. Untreated, age-matched, C57BL/6J mice were also used as controls in comparison with the other experimental groups.

Results

Analysis of SCA7 Tg mice showed tissue damage and alterations, mucosal abnormalities, and ulcers in the distal small intestine and proximal colon. Morphological changes were associated with significant neuronal loss, as shown by decreased staining of pan-neuronal markers, and with accumulation of ataxin-7-positive inclusions in cholinergic neurons. Administration of velusetrag reversed intestinal abnormalities, by normalizing tissue damage and re-establishing the normal level of glia/neuron's count in both the small and large intestines.

Conclusion

We demonstrated that the PrP-SCA7-92Q Tg line, a model originally developed to mimic spinocerebellar ataxia, is suitable to study CIPO pathology and can be useful in establishing new therapeutic strategies, such as in the case of velusetrag. Our results suggest that velusetrag is a promising compound to treat patients affected by CIPO or intestinal dysmotility disease.

The goals for successful development of treatment in gastroparesis

BACKGROUND

Gastroparesis is a motility disorder of the stomach characterized by cardinal symptoms and delayed gastric emptying of solid food in the absence of mechanical obstruction. There is significant unmet need in its management, and essentially there are no medications approved for its treatment over four decades.

PURPOSE

The objectives of this review are to develop an understanding of the goals of treatment, the evidence-based criteria for treatment success based on the current scientific understanding of gastroparesis as well as patient response outcomes, and to propose evidence-based principles for the successful development of treatments for gastroparesis. Specifically, we discuss the pathophysiologic targets in gastroparesis, eligibility criteria for clinical trial participation based on validated gastric emptying studies, and the patient response outcome measures that have been validated to appraise effects of treatment on clinically relevant outcomes. These considerations lead to recommendations regarding eligibility, design, and duration of proof-of-efficacy studies, and to endorsing the American Neurogastroenterology and Motility Society Gastroparesis Cardinal Symptom Index Daily Diary as a validated patient response outcome and to justification of the shortening of proof-of-efficacy, placebo-controlled clinical trials to 4 weeks treatment duration after a baseline period. We believe that such approaches will increase the likelihood of successful assessment of efficacy of novel approaches to treating patients with gastroparesis.

Safety and Efficacy of Highly Selective 5-Hydroxytryptamine Receptor 4 Agonists for Diabetic and Idiopathic Gastroparesis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Gastroparesis significantly affects quality of life and healthcare expenditure. Effective treatment options are limited, and the utility of current prokinetic agents is inhibited by serious adverse effects. There exists an unmet need for prokinetic agents demonstrating both efficacy and an acceptable adverse effect profile. Highly selective 5-Hydroxytryptamine receptor 4 (5-HT4) agonists have exhibited clinical efficacy and safety in randomized controlled trials (RCTs). Consequently, we conducted a meta-analysis to comprehensively assess the safety and efficacy of these highly selective agents. Multiple databases, including PubMed, Scopus, and Embase, were systematically screened from inception until September 2023. Only RCTs evaluating the efficacy and safety of highly selective 5-HT4 agonists for gastroparesis were included. Key outcomes of interest included the pooled rates of Gastroparesis Cardinal Symptom Index (GCSI) scores, gastric emptying time (GET), and adverse event rates in each group. We adhered to standard meta-analysis methodology utilizing the random-effects model, with heterogeneity assessed by I2 statistics. Our analysis identified six RCTs, comprising 570 patients with diabetic (48%) or idiopathic (51%) gastroparesis, with mean ages of 46 and 45.9 years in the intervention and placebo groups, respectively. In the meta-analysis, highly selective 5-HT4 agonists demonstrated significantly superior pooled GCSI scores compared to placebo (mean difference: 4.283, (1.380, 7.186), p<0.05). Pooled GET was also significantly improved with 5-HT4 agonists compared to placebo (mean difference: 2.534, (1.695, 3.373), p<0.05). Although pooled rates of total adverse events were higher with 5-HT4 agonists (mean difference: 6.975, (1.042, 46.684), p<0.05), rates of specific adverse events such as diarrhea, abdominal pain, and headaches were comparable. In conclusion, this meta-analysis underscores a statistically significant improvement in GET and GCSI scores among patients receiving highly selective 5-HT4 agonists (Velusetrag, Felcisetrag, Prucalopride) for both diabetic and idiopathic gastroparesis. While the overall adverse effect profile is deemed acceptable, larger studies with extended follow-up periods are needed to investigate rare and/or serious adverse events. Moreover, future high-quality RCTs comparing the efficacy and safety of these novel agents with currently available agents are essential to further validate these findings.

Velusetrag rescues GI dysfunction, gut inflammation and dysbiosis in a mouse model of Parkinson's disease

In patients with Parkinson's disease (PD), constipation is common, and it appears in a prodromal stage before the hallmark motor symptoms. The present study aimed to investigate whether Velusetrag, a selective 5‑HT4 receptor agonist, may be a suitable candidate to improve intestinal motility in a mouse model of PD. Five months old PrP human A53T alpha-synuclein transgenic (Tg) mice, which display severe constipation along with decreased colonic cholinergic transmission already at 3 months, were treated daily with the drug for 4 weeks. Velusetrag treatment reduced constipation by significantly stimulating both the longitudinal and circular-driven contractions and improved inflammation by reducing the level of serum and colonic IL1β and TNF-α and by decreasing the number of GFAP-positive glia cells in the colon of treated mice. No significant downregulation of the 5-HT4 receptor was observed but instead Velusetrag seemed to improve axonal degeneration in Tgs as shown by an increase in NF-H and VAChT staining. Ultimately, Velusetrag restored a well-balanced intestinal microbial composition comparable to non-Tg mice. Based on these promising data, we are confident that Velusetrag is potentially eligible for clinical studies to treat constipation in PD patients.