Profile of plecanatide in the treatment of chronic idiopathic constipation: design, development, and place in therapy

Pharmacological potential of cyclic nucleotide signaling in immunity

Cyclic nucleotides are important signaling molecules that play many critical physiological roles including controlling cell fate and development, regulation of metabolic processes, and responding to changes in the environment. Cyclic nucleotides are also pivotal regulators in immune signaling, orchestrating intricate processes that maintain homeostasis and defend against pathogenic threats. This review provides a comprehensive examination of the pharmacological potential of cyclic nucleotide signaling pathways within the realm of immunity. Beginning with an overview of the fundamental roles of cAMP and cGMP as ubiquitous second messengers, this review delves into the complexities of their involvement in immune responses. Special attention is given to the challenges associated with modulating these signaling pathways for therapeutic purposes, emphasizing the necessity for achieving cell-type specificity to avert unintended consequences. A major focus of the review is on the recent paradigm-shifting discoveries regarding specialized cyclic nucleotide signals in the innate immune system, notably the cGAS-STING pathway. The significance of cyclic dinucleotides, exemplified by 2'3'-cGAMP, in controlling immune responses against pathogens and cancer, is explored. The evolutionarily conserved nature of cyclic dinucleotides as antiviral agents, spanning across diverse organisms, underscores their potential as targets for innovative immunotherapies. Findings from the last several years have revealed a striking diversity of novel bacterial cyclic nucleotide second messengers which are involved in antiviral responses. Knowledge of the existence and precise identity of these molecules coupled with accurate descriptions of their associated immune defense pathways will be essential to the future development of novel antibacterial therapeutic strategies. The insights presented herein may help researchers navigate the evolving landscape of immunopharmacology as it pertains to cyclic nucleotides and point toward new avenues or lines of thinking about development of therapeutics against the pathways they regulate.

Plecanatide Improves Abdominal Bloating and Bowel Symptoms of Irritable Bowel Syndrome with Constipation

BACKGROUND

Bloating is a bothersome symptom in irritable bowel syndrome with constipation (IBS-C).

AIM

To evaluate plecanatide efficacy in patients with IBS-C stratified by bloating intensity.

METHODS

Pooled phase 3 data (2 randomized, controlled IBS-C trials) from adults treated with plecanatide 3 mg or placebo for 12 weeks were analyzed. Patients were stratified post-hoc by baseline bloating severity (11-point scale: mild [≤ 5] and moderate-to-severe [> 5]). Assessments included change from baseline in bloating, abdominal pain, and complete spontaneous bowel movement (CSBM) frequency. Abdominal pain and bloating composite responders were defined as patients with ≥ 30% improvement from baseline in both bloating and abdominal pain at Week 12.

RESULTS

At baseline, 1104/1436 patients with IBS-C (76.9%) reported moderate-to-severe bloating. In the moderate-to-severe bloating subgroup, plecanatide significantly reduced bloating severity versus placebo (least-squares mean change [LSMC]: - 1.7 vs - 1.3; P = 0.002), reduced abdominal pain (- 1.7 vs - 1.3; P = 0.006), and increased CSBM frequency (1.4 vs 0.8; P < 0.0001). In the mild bloating subgroup, significant improvements were observed with plecanatide versus placebo for abdominal pain (LSMC: - 1.3 vs - 1.0; P = 0.046) and CSBM frequency (2.0 vs 1.2; P = 0.003) but not bloating (- 0.9 vs - 0.8; P = 0.28). A significantly greater percentage of patients were abdominal pain and bloating composite responders with plecanatide versus placebo (moderate-to-severe bloating: 33.6% vs 26.8% [P = 0.02]; mild bloating: 38.4% vs 27.2% [P = 0.03]).

CONCLUSION

Plecanatide treatment improved IBS-C abdominal and bowel symptoms, including in those who present with moderate-to-severe bloating.

Therapeutic proteins: developments, progress, challenges, and future perspectives

Proteins are considered magic molecules due to their enormous applications in the health sector. Over the past few decades, therapeutic proteins have emerged as a promising treatment option for various diseases, particularly cancer, cardiovascular disease, diabetes, and others. The formulation of protein-based therapies is a major area of research, however, a few factors still hinder the large-scale production of these therapeutic products, such as stability, heterogenicity, immunogenicity, high cost of production, etc. This review provides comprehensive information on various sources and production of therapeutic proteins. The review also summarizes the challenges currently faced by scientists while developing protein-based therapeutics, along with possible solutions. It can be concluded that these proteins can be used in combination with small molecular drugs to give synergistic benefits in the future.

Plecanatide for the treatment of chronic idiopathic constipation and irritable bowel syndrome with constipation: Post hoc analyses of placebo-controlled trials in adults with severe constipation

BACKGROUND

Patients with chronic idiopathic constipation (CIC) and irritable bowel syndrome with constipation (IBS-C) often experience severe symptoms. The current aim was to evaluate plecanatide in adults with CIC or IBS-C with severe constipation.

METHODS

Data were analyzed post hoc from randomized, placebo-controlled trials (CIC [n = 2], IBS-C [n = 2]) of plecanatide 3 mg, 6 mg, or placebo administered for 12 weeks. Severe constipation was defined as no complete spontaneous bowel movements (CSBMs) and an average straining score ≥3.0 (CIC; 5-point scale) or ≥8.0 (IBS-C; 11-point scale) during a 2-week screening. Primary efficacy endpoints were durable overall CSBM responders (CIC: ≥3 CSBMs/week, plus increase from baseline of ≥1 CSBM/week, for ≥9 of 12 weeks, including ≥3 of the last 4 weeks) and overall responders (IBS-C: ≥30% reduction from baseline in abdominal pain and ≥1 CSBM/week increase for ≥6 of 12 weeks).

KEY RESULTS

Severe constipation was observed in 24.5% (646/2639) and 24.2% (527/2176) of CIC and IBS-C populations, respectively. The CIC durable overall CSBM response rate (plecanatide 3 mg, 20.9%; plecanatide 6 mg, 20.2%; placebo, 11.3%) and IBS-C overall response rate (plecanatide 3 mg, 33.0%; plecanatide 6 mg, 31.0%; placebo, 19.0%) were significantly greater with plecanatide versus placebo (p ≤ 0.01 for all). Median time to first CSBM in CIC and IBS-C populations were significantly shorter with plecanatide 3 mg versus placebo (p = 0.01 for both).

CONCLUSIONS AND INFERENCES

Plecanatide was effective in the treatment of severe constipation in adults with CIC or IBS-C.

Receptor Guanylyl Cyclase C and Cyclic GMP in Health and Disease: Perspectives and Therapeutic Opportunities

Receptor Guanylyl Cyclase C (GC-C) was initially characterized as an important regulator of intestinal fluid and ion homeostasis. Recent findings demonstrate that GC-C is also causally linked to intestinal inflammation, dysbiosis, and tumorigenesis. These advances have been fueled in part by identifying mutations or changes in gene expression in GC-C or its ligands, that disrupt the delicate balance of intracellular cGMP levels and are associated with a wide range of clinical phenotypes. In this review, we highlight aspects of the current knowledge of the GC-C signaling pathway in homeostasis and disease, emphasizing recent advances in the field. The review summarizes extra gastrointestinal functions for GC-C signaling, such as appetite control, energy expenditure, visceral nociception, and behavioral processes. Recent research has expanded the homeostatic role of GC-C and implicated it in regulating the ion-microbiome-immune axis, which acts as a mechanistic driver in inflammatory bowel disease. The development of transgenic and knockout mouse models allowed for in-depth studies of GC-C and its relationship to whole-animal physiology. A deeper understanding of the various aspects of GC-C biology and their relationships with pathologies such as inflammatory bowel disease, colorectal cancer, and obesity can be leveraged to devise novel therapeutics.

Evaluation and Treatment of Constipation in the Geriatric Population

Chronic constipation affects one-third of the US population and occurs disproportionately in the elderly and female individuals, increasing in older individuals who are institutionalized. This condition has a significant impact on health care costs and quality of life. Clinicians need to consider primary as well as secondary causes of constipation in elderly individuals because the cause is often multifactorial. Diagnostic algorithms should eliminate red-flag symptoms that may indicate a malignancy but also consider pelvic floor dysfunction, which is more common in this age group. An appropriate treatment plan is tailored to the severity of the patient's symptoms.

Cyclic nucleotides, gut physiology and inflammation

Misregulation of gut function and homeostasis impinges on the overall well-being of the entire organism. Diarrheal disease is the second leading cause of death in children under 5 years of age, and globally, 1.7 billion cases of childhood diarrhea are reported every year. Accompanying diarrheal episodes are a number of secondary effects in gut physiology and structure, such as erosion of the mucosal barrier that lines the gut, facilitating further inflammation of the gut in response to the normal microbiome. Here, we focus on pathogenic bacteria-mediated diarrhea, emphasizing the role of cyclic adenosine 3',5'-monophosphate and cyclic guanosine 3',5'-monophosphate in driving signaling outputs that result in the secretion of water and ions from the epithelial cells of the gut. We also speculate on how this aberrant efflux and influx of ions could modulate inflammasome signaling, and therefore cell survival and maintenance of gut architecture and function.

Recent advances in the pharmacological management of constipation predominant irritable bowel syndrome

Introduction: Irritable bowel syndrome (IBS) is a complex functional gut disorder that typically manifests in early adult years. More than a third of IBS patients are diagnosed with predominant constipation subtype (IBS-C). This syndrome has a distressing impact on the quality of life and is challenging both for patients and physicians.Areas covered: This review focuses on the pathophysiology of constipation in IBS and presents current management options. It also covers the latest findings that may lead to novel pharmacological options in IBS-C management. The authors intend to highlight the results of published research including abstracts, records from the clinicaltrials.gov database (second and third phases of the study) and information from original FDA documents.Expert opinion: Current therapeutic options for IBS-C treatment are based on linaclotide, lubiprostone, plecanatide, and the reintroduced tegaserod. Drugs present on the market as well as those in pre-clinical development should increase the lower esophageal sphincter pressure, promote gastric motility, accelerate gastric emptying and improve gastro-duodenal coordination. Most significantly, they shall not induce severe side effects.

Plecanatide for the treatment of chronic idiopathic constipation in adult patients

Introduction. Chronic idiopathic constipation (CIC) is a functional gastrointestinal disorder that is associated with an increased healthcare cost and an abnormally poor quality of life. Plecanatide is a natural analog to the peptide agonist of the guanylate cyclase-C (GC-C) receptor, uroguanylin. The conversion of guanosine 5-triphosphate to cyclic guanosine monophosphate results in an increased bowel fluid secretion. Plecanatide is a promising new agent for CIC unresponsive to current therapeutic regimes.Areas covered. A comprehensive online search of Medline and the Science Citation Index was made using the keywords 'plecanatide', 'guanylate cyclase-C agonists', and 'constipation', in various combinations. We reviewed the pharmacodynamics, pharmacokinetics, and metabolism of this agent, and the most significant studies regarding the clinical efficacy and safety of plecanatide in CIC therapy.Expert opinion. Experimental studies showed that plecanatide was significantly better than placebo in reducing CIC severity, straining, stool consistency, bowel movements and quality of life. Apart from limited cases of diarrhea, no serious adverse events were reported. However, few data are available on its long-term safety. Furthermore, patients' affordability of plecanatide can be limited by its costs. Finally, this new agent with a different way of action can be proposed in patients refractory to common therapy.