Effect of Various Dosing Conditions on the Pharmacokinetics of Oral Semaglutide, a Human Glucagon-Like Peptide-1 Analogue in a Tablet Formulation

Head-to-Head Comparison of Caco-2 Transwell and Gut-on-a-Chip Models for Assessing Oral Peptide Formulations

Oral delivery of potent peptide drugs provides key formulation challenges in the pharmaceutical industry: stability, solubility, and permeability. Intestinal permeation enhancers (PEs) can overcome the low oral bioavailability by improving the drug permeability. Conventional in vitro and ex vivo models for assessing PEs fail to predict efficacy in vivo. Here, we compared Caco-2 cells cultured in the conventional static Transwell model to a commercially available continuous flow microfluidic Gut-on-a-Chip model. We determined baseline permeability of FITC-Dextan 3 kDa (FD3) in Transwell (5.3 ± 0.8 × 10-8 cm/s) vs Chip (3.2 ± 1.8 × 10-7 cm/s). We screened the concentration impact of two established PEs sodium caprate and sucrose monolaurate and indicated a requirement for higher enhancer concentration in the Chip model to elicit equivalent efficacy e.g., 10 mM sodium caprate in Transwells vs 25 mM in Chips. Fasted and fed state simulated intestinal fluids (FaSSIF/FeSSIF) were introduced into the Chip and increased basal FD3 permeability by 3-fold and 20-fold, respectively, compared to 4-fold and 4000-fold in Transwells. We assessed the utility of this model to peptides (Insulin and Octreotide) with PEs and observed much more modest permeability enhancement in the Chip model in line with observations in ex vivo and in vivo preclinical models. These data indicate that microfluidic Chip models are well suited to bridge the gap between conventional in vitro and in vivo models.

A phase 1, randomized, double-blind, placebo-controlled trial investigating the pharmacokinetics, pharmacodynamics, safety and tolerability of oral semaglutide in healthy Chinese subjects

AIM

The trial (NCT04016974) investigated the pharmacokinetics, pharmacodynamics, safety and tolerability of oral semaglutide, the first orally administered glucagon-like peptide-1 analogue for type 2 diabetes, in healthy Chinese subjects.

MATERIALS AND METHODS

This single-centre, multiple-dose, placebo-controlled trial randomized 32 healthy Chinese adults to once-daily oral semaglutide (3 mg escalating to 14 mg) or placebo for 12 weeks. Blood samples were collected regularly during treatment and follow-up. The primary endpoint was the area under the semaglutide concentration-time curve over a dosing interval (0-24 h) at steady state (AUC0-24h,sema,SS). Secondary pharmacokinetic endpoints included the maximum observed semaglutide plasma concentration at steady state (Cmax,sema,SS). Supportive secondary pharmacodynamics endpoints included changes in body weight and fasting plasma glucose.

RESULTS

Treatment with all oral semaglutide doses showed dose-dependent increases in semaglutide exposure in healthy Chinese subjects at steady state, determined by AUC0-24h,sema,SS (233, 552 and 1288 h·nmol/L for 3, 7 and 14 mg of oral semaglutide, respectively) and Cmax,sema,SS. Oral semaglutide treatment was associated with significant reductions in body weight (p = .0001) and fasting plasma glucose (p = .0011) versus placebo at the end of treatment. The safety and tolerability of oral semaglutide were consistent with the known profile of glucagon-like peptide-1 receptor agonists, with no severe or blood-glucose-confirmed symptomatic hypoglycaemic events, serious adverse events or deaths. The most frequent adverse events were gastrointestinal disorders.

CONCLUSIONS

At steady state, oral semaglutide exposure was dose dependent and close to dose proportionality in healthy Chinese subjects. This is consistent with previous clinical pharmacology results for oral semaglutide.

Clinical Pharmacokinetics of Semaglutide: A Systematic Review

Purpose

The aim of this review was to provide all the pharmacokinetic data for semaglutide in humans concerning its pharmacokinetics after subcutaneously and oral applications in healthy and diseased populations, to provide recommendations for clinical use.

Methodology

The PubMed and Embase databases were searched to screen studies associated with the pharmacokinetics of semaglutide. The pharmacokinetic parameters included area under the curve plasma concentrations (AUC), maximal plasma concentration (Cmax), time to Cmax, half-life (t1/2), and clearance. The systematic literature search retrieved 17 articles including data on pharmacokinetic profiles after subcutaneously and oral applications of semaglutide, and at least one of the above pharmacokinetic parameter was reported in all included studies.

Results

Semaglutide has a predictable pharmacokinetic profile with a long t1/2 that allows for once-weekly subcutaneous administration. The AUC and Cmax of both oral and subcutaneous semaglutide increased with dose. Food and various dosing conditions including water volume and dosing schedules can affect the oral semaglutide exposure. There are limited drug-drug interactions and no dosing adjustments in patients with upper gastrointestinal disease, renal impairment or hepatic impairment. Body weight may affect semaglutide exposure, but further studies are needed to confirm this.

Conclusion

This review encompasses all the pharmacokinetic data for subcutaneous and oral semaglutide in both healthy and diseased participants. The existing pharmacokinetic data can assist in developing and evaluating pharmacokinetic models of semaglutide and will help clinicians predict semaglutide dosages. In addition, it can also help optimize future clinical trials.

The microbial metabolite agmatine acts as an FXR agonist to promote polycystic ovary syndrome in female mice

Polycystic ovary syndrome (PCOS), an endocrine disorder afflicting 6-20% of women of reproductive age globally, has been linked to alterations in the gut microbiome. We previously showed that in PCOS, elevation of Bacteroides vulgatus in the gut microbiome was associated with altered bile acid metabolism. Here we show that B. vulgatus also induces a PCOS-like phenotype in female mice via an alternate mechanism independent of bile acids. We find that B. vulgatus contributes to PCOS-like symptoms through its metabolite agmatine, which is derived from arginine by arginine decarboxylase. Mechanistically, agmatine activates the farnesoid X receptor (FXR) pathway to subsequently inhibit glucagon-like peptide-1 (GLP-1) secretion by L cells, which leads to insulin resistance and ovarian dysfunction. Critically, the GLP-1 receptor agonist liraglutide and the arginine decarboxylase inhibitor difluoromethylarginine ameliorate ovarian dysfunction in a PCOS-like mouse model. These findings reveal that agmatine-FXR-GLP-1 signalling contributes to ovarian dysfunction, presenting a potential therapeutic target for PCOS management.

Effect of Food Consumption on the Pharmacokinetics, Safety, and Tolerability of Once-Daily Orally Administered Orforglipron (LY3502970), a Non-peptide GLP-1 Receptor Agonist

INTRODUCTION

We assessed the effect of the prandial state on the pharmacokinetics, safety, and tolerability of single and multiple doses of orforglipron (LY3502970), an oral, non-peptide glucagon-like peptide 1 receptor agonist (GLP-1 RA), in two studies (A and B).

METHODS

Study A and study B were phase 1, randomized, crossover studies in healthy adults aged 18-65 years and 21-70 years, respectively. Participants received single (3 mg, study A) or multiple (16 mg, study B) oral doses of orforglipron under fasted and fed conditions. Blood samples were collected pre- and postdose to assess area under the concentration-time curve (AUC), maximum observed drug concentration (Cmax), time of Cmax (tmax), and half-life (t1/2) associated with terminal rate constant. AUC and Cmax were analyzed using a linear mixed-effects model. Treatment differences were presented as ratios of geometric least squares means (GLSM). Treatment-emergent adverse events (TEAEs), adverse events of special interest, and serious adverse events were assessed.

RESULTS

Study A included 12 participants (mean age 45.0 years; male 66.7%); study B included 34 participants (mean age 42.8 years; male 88.2%). GLSM AUC and Cmax were lower by 23.7% and 23.2% in study A, and 17.6% and 20.9% in study B, in the fed versus fasted states, respectively. In both studies, t1/2 and median tmax were comparable between fed and fasted states. The majority of TEAEs in both studies were gastrointestinal tract-related conditions. No serious adverse events or deaths were reported in either study.

CONCLUSION

The observed pharmacokinetic differences due to the prandial state are unlikely to contribute to clinically meaningful differences in the efficacy of orforglipron. The safety profile was consistent with the known profiles of other GLP-1 RAs. Given the absence of prandial restrictions, orforglipron may emerge as a convenient oral treatment option for patients with type 2 diabetes or obesity.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers, NCT03929744 and NCT05110794.

G protein-coupled receptors driven intestinal glucagon-like peptide-1 reprogramming for obesity: Hope or hype?

'Globesity' is a foremost challenge to the healthcare system. The limited efficacy and adverse effects of available oral pharmacotherapies pose a significant obstacle in the fight against obesity. The biology of the leading incretin hormone glucagon-like-peptide-1 (GLP-1) has been highly captivated during the last decade owing to its multisystemic pleiotropic clinical outcomes beyond inherent glucoregulatory action. That fostered a pharmaceutical interest in synthetic GLP-1 analogues to tackle type-2 diabetes (T2D), obesity and related complications. Besides, mechanistic insights on metabolic surgeries allude to an incretin-based hormonal combination strategy for weight loss that emerged as a forerunner for the discovery of injectable 'unimolecular poly-incretin-agonist' therapies. Physiologically, intestinal enteroendocrine L-cells (EECs) are the prominent endogenous source of GLP-1 peptide. Despite comprehending the potential of various G protein-coupled receptors (GPCRs) to stimulate endogenous GLP-1 secretion, decades of translational GPCR research have failed to yield regulatory-approved endogenous GLP-1 secretagogue oral therapy. Lately, a dual/poly-GPCR agonism strategy has emerged as an alternative approach to the traditional mono-GPCR concept. This review aims to gain a comprehensive understanding by revisiting the pharmacology of a few potential GPCR-based complementary avenues that have drawn attention to the design of orally active poly-GPCR agonist therapy. The merits, challenges and recent developments that may aid future poly-GPCR drug discovery are critically discussed. Subsequently, we project the mechanism-based therapeutic potential and limitations of oral poly-GPCR agonism strategy to augment intestinal GLP-1 for weight loss. We further extend our discussion to compare the poly-GPCR agonism approach over invasive surgical and injectable GLP-1-based regimens currently in clinical practice for obesity.

Daily Glucose Profiles after Switching from Injectable to Oral Semaglutide in Patients with Type 2 Diabetes Mellitus

Objective This prospective observational study explored the changes in the daily glycemic profile after switching from injectable to oral semaglutide in patients with type 2 diabetes mellitus. Methods Patients with type 2 diabetes mellitus who were treated with once-weekly 0.5 mg injectable semaglutide and wished to switch to once-daily oral semaglutide participated in this study. Oral semaglutide was initiated at 3 mg and increased to 7 mg a month later, according to the package insert. Before and two months after the switch, participants wore a sensor for continuous glucose monitoring for up to 14 days. We also evaluated the questionnaire-based treatment satisfaction and the preference between the two formulations. Patients Twenty-three patients participated. Results Mean glucose levels significantly increased by 9 mg/dL on average, from 132±20 to 141±27 mg/dL (p=0.047), which was equivalent to a change of 0.2% in the estimated hemoglobin A1c (6.5±0.5% to 6.7±0.7%). The inter-individual variability assessed with standard deviation also significantly increased (p=0.004). The change in treatment satisfaction varied considerably among patients, with no specific trend in the overall population. After trying oral semaglutide, 48% of patients responded that they preferred the oral formulation, while 35% preferred the injectable formulation, and 17% had no preference. Conclusion The mean glucose levels increased by 9 mg/dL on average after switching from once-weekly 0.5 mg injectable semaglutide to once-daily 7 mg oral semaglutide, with an increased inter-individual variability. The change in treatment satisfaction considerably varied among patients.

Oral semaglutide improves body composition and preserves lean mass in patients with type 2 diabetes: a 26-week prospective real-life study

Background

Oral semaglutide is the first glucagon-like peptide-1 receptor agonist (GLP-1RA) designed for oral administration; it offers a promising opportunity to facilitate an early approach to Type 2 Diabetes (T2D). The study aimed to evaluate, in a real-life setting, the effects of oral semaglutide on the body composition of patients with T2D after 26 weeks of therapy.

Methods

Thirty-two patients with T2D were evaluated at baseline (T0) and after three (T3) and six (T6) months of therapy with oral semaglutide. At each time point, body composition was assessed using a phase sensitive bioimpedance analyzer. Clinical, anthropometric and laboratory parameters, and the main biometric surrogates of liver steatosis and fibrosis, were also analyzed and compared.

Results

A significant and early reduction in anthropometric and glucometabolic parameters, alanine aminotransferase, Fatty Liver Index, and Fat Mass was observed. Visceral Adipose Tissue (VAT) decreased, while Fat Free Mass and Skeletal Muscle Mass (SMM) were preserved during therapy, resulting in a beneficial increase in the SMM/VAT ratio. Finally, an overall improvement in body fluid distribution was observed.

Conclusion

Our real-world data confirm the clinical efficacy of oral semaglutide and highlight its ability to improve the nutritional status of patients with T2D.

Current Understanding of Sodium N-(8-[2-Hydroxylbenzoyl] Amino) Caprylate (SNAC) as an Absorption Enhancer: The Oral Semaglutide Experience

Oral administration of peptide therapeutics faces challenges because of the distinct environment of the gastrointestinal tract. An oral formulation of semaglutide, a glucagon-like peptide 1 receptor agonist, was approved by the U.S. Food and Drug Administration in 2019 as a peptide therapy for the treatment of type 2 diabetes. Oral semaglutide uses sodium N-(8-[2-hydroxybenzoyl] amino) caprylate (SNAC) technology to enhance the absorption of semaglutide in the stomach and protect it from degradation by gastric enzymes. This article presents a summary of studies investigating SNAC technology as an absorption enhancer for a number of molecules and, in particular, explores how SNAC, once coformulated with oral semaglutide, facilitates increased absorption and bioavailability. Practical advice and dispensing information for pharmacists is also provided.

Effect of Various Dosing Schedules on the Pharmacokinetics of Oral Semaglutide: A Randomised Trial in Healthy Subjects

BACKGROUND

Prescribing information instructs taking oral semaglutide (a glucagon-like peptide-1 analogue) in the fasting state, followed by a post-dose fasting period of ≥ 30 min. This trial compared the recommended dosing schedule with alternative schedules.

METHODS

This was a randomised, single-centre, multiple-dose, open-label, five-armed, parallel-group trial in healthy subjects who received once-daily oral semaglutide (3 mg for 5 days followed by 7 mg for 5 days). Subjects (n = 156) were randomised to five dosing schedules: 2-, 4-, or 6-h pre-dose fast followed by a 30-min post-dose fast (treatment arms: 2 h-30 min, 4-30 min, 6 h-30 min); 2-h pre-dose fast followed by an overnight post-dose fast (treatment arm: 2 h-night); or overnight pre-dose fast followed by a 30-min post-dose fast (reference arm: night-30 min). Semaglutide plasma concentration was measured regularly until 24 h after the 10th dose. Endpoints included area under the semaglutide plasma concentration-time curve during a 24-h interval after the 10th dose (AUC_0-24h) (primary endpoint) and maximum observed semaglutide plasma concentration after the 10th dose (C_max) (secondary endpoint).

RESULTS

Compared with an overnight pre-dose fast (reference arm: night-30 min), shorter pre-dose fasting times in the 2 h-night, 2 h-30 min, 4 h-30 min, and 6 h-30 min treatment arms resulted in significantly lower semaglutide AUC_0-24h and C_max after the 10th dose (estimated treatment ratio ranges: 0.12-0.43 and 0.11-0.44, respectively; p < 0.0001 for all comparisons). Semaglutide AUC_0-24h and C_max after the 10th dose were similar for the 2 h-30 min and 2 h-night treatment arms.

CONCLUSION

This trial supports dosing oral semaglutide in accordance with prescribing information, which requires dosing in the fasting state.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT04513704); registered August 14, 2020.

Delivering on the promise of protein degraders

Over the past 3 years, the first bivalent protein degraders intentionally designed for targeted protein degradation (TPD) have advanced to clinical trials, with an initial focus on established targets. Most of these clinical candidates are designed for oral administration, and many discovery efforts appear to be similarly focused. As we look towards the future, we propose that an oral-centric discovery paradigm will overly constrain the chemical designs that are considered and limit the potential to drug novel targets. In this Perspective, we summarize the current state of the bivalent degrader modality and propose three categories of degrader designs, based on their likely route of administration and requirement for drug delivery technologies. We then describe a vision for how parenteral drug delivery, implemented early in research and supported by pharmacokinetic-pharmacodynamic modelling, can enable exploration of a broader drug design space, expand the scope of accessible targets and deliver on the promise of protein degraders as a therapeutic modality.

Evaluation in pig of an intestinal administration device for oral peptide delivery

The bioavailability of peptides co-delivered with permeation enhancers following oral administration remains low and highly variable. Two factors that may contribute to this are the dilution of the permeation enhancer in the intestinal fluid, as well as spreading of the released permeation enhancer and peptide in the lumen by intestinal motility. In this work we evaluated an Intestinal Administration Device (IAD) designed to reduce the luminal dilution of drug and permeation enhancer, and to minimize movement of the dosage form in the intestinal lumen. To achieve this, the IAD utilizes an expanding design that holds immediate release mini tablets and places these in contact with the intestinal epithelium, where unidirectional drug release can occur. The expanding conformation limits movement of the IAD in the intestinal tract, thereby enabling drug release at a single focal point in the intestine. A pig model was selected to study the ability of the IAD to promote intestinal absorption of the peptide MEDI7219 formulated together with the permeation enhancer sodium caprate. We compared the IAD to intestinally administered enteric coated capsules and an intestinally administered solution. The IAD restricted movement of the immediate release tablets in the small intestine and histological evaluation of the mucosa indicated that high concentrations of sodium caprate were achieved. Despite significant effect of the permeation enhancer on the integrity of the intestinal epithelium, the bioavailability of MEDI7219 was of the same order of magnitude as that achieved with the solution and enteric coated capsule formulations (2.5-3.8%). The variability in plasma concentrations of MEDI7219 were however lower when delivered using the IAD as compared to the solution and enteric coated capsule formulations. This suggests that dosage forms that can limit intestinal dilution and control the position of drug release can be a way to reduce the absorptive variability of peptides delivered with permeation enhancers but do not offer significant benefits in terms of increasing bioavailability.

A new era for oral peptides: SNAC and the development of oral semaglutide for the treatment of type 2 diabetes

Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs) were first introduced for the treatment of type 2 diabetes (T2D) in 2005. Despite the high efficacy and other benefits of GLP-1RAs, their uptake was initially limited by the fact that they could only be administered by injection. Semaglutide is a human GLP-1 analog that has been shown to significantly improve glycemic control and reduce body weight, in addition to improving cardiovascular outcomes, in patients with T2D. First approved as a once-weekly subcutaneous injection, semaglutide was considered an ideal peptide candidate for oral delivery with a permeation enhancer on account of its low molecular weight, long half-life, and high potency. An oral formulation of semaglutide was therefore developed by co-formulating semaglutide with sodium N-(8-[2-hydroxybenzoyl]amino)caprylate, a well-characterized transcellular permeation enhancer, to produce the first orally administered GLP-1RA. Pharmacokinetic analysis showed that stable steady-state concentrations could be achieved with once-daily dosing owing to the long half-life of oral semaglutide. Upper gastrointestinal disease and renal and hepatic impairment did not affect the pharmacokinetic profile. In the phase III PIONEER clinical trial program, oral semaglutide was shown to reduce glycated hemoglobin and body weight compared with placebo and active comparators in patients with T2D, with no new safety signals reported. Cardiovascular efficacy and safety are currently being assessed in a dedicated outcomes trial. The development of an oral GLP-1RA represents a significant milestone in the management of T2D, providing an additional efficacious treatment option for patients.

Progress and limitations of oral peptide delivery as a potentially transformative therapy

INTRODUCTION

The oral delivery of peptides offers advantages over the injectable route of administration due to patient convenience. However, oral delivery remains challenging due to physiological barriers. Numerous formulation technologies have been developed to overcome these challenges, and understanding the advantages and limitations of each technology is important for the development of new delivery systems to enable oral delivery of peptides designed for parenteral administration.

AREAS COVERED

This review summarizes key learnings from the use of permeation enhancers (PEs) for oral peptide delivery associated with solid dosage form optimization to maximize the PE effect. Furthermore, we will highlight the most recent emerging delivery strategies to improve oral peptide bioavailability such as nanoparticles, self-emulsifying drug delivery systems, gut shuttles, and ingestible devices. In addition, advantages and limitations of these technologies will be compared with the permeation enhancer technology.

EXPERT OPINION

Despite the success of permeation enhancer technology in the FDA approved oral peptide products for gastric and intestinal delivery, oral peptide delivery is still facing the immense challenge of low-to-single digit oral bioavailability and the impact of food and water intake on oral absorption. Optimization of drug product attributes such as dissolution kinetics is critical to overcome spreading and dilution effects in vivo to improve permeation enhancer efficacy. The next frontiers to substantially increase oral bioavailability and transform injectable peptides to oral deliverables may be ingestible devices and gut shuttles. In addition, ingestible devices may have potential to overcome the impact of food on oral bioavailability. However, clinical studies are necessary to inform the safety and efficacy of these emerging technologies.

Machine learning predicts the effect of food on orally administered medicines

Food-mediated changes to drug absorption, termed the food effect, are hard to predict and can have significant implications for the safety and efficacy of oral drug products in patients. Mimicking the prandial states of the human gastrointestinal tract in preclinical studies is challenging, poorly predictive and can produce difficult to interpret datasets. Machine learning (ML) has emerged from the computer science field and shows promise in interpreting complex datasets present in the pharmaceutical field. A ML-based approach aimed to predict the food effect based on an extensive dataset of over 311 drugs with more than 20 drug physicochemical properties, referred to as features. Machine learning techniques were tested; including logistic regression, support vector machine, k-Nearest neighbours and random forest. First a standard ML pipeline using a 80:20 split for training and testing was tried to predict no food effect, negative food effect and positive food effect, however this lead to specificities of less than 40%. To overcome this, a strategic ML pipeline was devised and three tasks were developed. Random forest achieved the strongest performance overall. High accuracies and sensitivities of 70%, 80% and 70% and specificities of 71%, 76% and 71% were achieved for classifying; (i) no food effect vs food effect, (ii) negative food vs positive food effect and (iii) no food effect vs negative food effect vs positive food effect, respectively. Feature importance using random forest ranked the features by importance for building the predictive tasks. The calculated dose number was the most important feature. Here, ML has provided an effective screening tool for predicting the food effect, with the potential to select lead compounds with no food effect, reduce the number of animal studies, and accelerate oral drug development studies.

Oral Semaglutide, the First Ingestible Glucagon-Like Peptide-1 Receptor Agonist: Could It Be a Magic Bullet for Type 2 Diabetes?

The gastrointestinal tract secretes gut hormones in response to food consumption, and some of these stimulate insulin secretion. Glucagon-like peptide-1 (GLP-1) is an incretin peptide hormone released from the lower digestive tract that stimulates insulin secretion, suppresses glucagon secretion, and decreases hunger. GLP-1 receptor agonist (GLP-1RA) mimics the action of endogenous GLP-1, consequently reversing hyperglycemia and causing weight reduction, demonstrating its efficacy as an antidiabetic and antiobesity agent. Previously restricted to injection only, the invention of the absorption enhancer sodium N-(8-[2-hydroxybenzoyl]amino) caprylate resulted in the development of oral semaglutide, the first ingestible GLP-1RA. Oral semaglutide demonstrated its efficacy in glycemic management and body weight loss with a low risk of hypoglycemia as a monotherapy and in combination with other hypoglycemic medications in its clinical trial programs named Peptide Innovation for Early Diabetes Treatment. Consistent with other injectable GLP-1RAs, gastrointestinal side effects were often reported. Additionally, cardiovascular safety was established by demonstrating that oral semaglutide was not inferior to a placebo in terms of cardiovascular outcomes. Thus, oral semaglutide represents a novel treatment option that is particularly well-suited for patients with type 2 diabetes and/or obesity.