Dorzagliatin monotherapy in Chinese patients with type 2 diabetes: a dose-ranging, randomised, double-blind, placebo-controlled, phase 2 study

The efficacy and safety of glucokinase activators for the treatment of type-2 diabetes mellitus: A protocol for systematic review and meta-analysis

BACKGROUND

Glucokinase activators are a novel family of glucose-lowering agents used for the treatment of type-2 diabetes mellitus (T2DM). Glucokinase activators blind to GK activate the enzyme allosterically. Treatment with different GKAs has been shown to reduce fasting and postprandial glucose in patients with type 2 diabetes. We compared the efficacy/safety of glucokinase activators in T2DM patients through a meta-analysis.

METHODS

We searched PubMed, Excerpt Medica Database, and Cochrane Central Register of Controlled Trials databases for articles published before December 30, 2020. Two independent reviewers extracted the information from article. The quality of articles were assessed by 2 independent reviewers using the 5 items of scale proposed by Jadad. We computed the weighted mean difference and 95% confidence interval (CI) for a change from baseline to the study endpoint for glucokinase activators vs placebo. Egger test and Begg test were used to assess the possible publication bias caused by the tendency of published studies to be positive.

RESULTS

The present meta-analysis will compare the efficacy and safety of glucokinase activators and placebo for the treatment of T2DM.

CONCLUSIONS

This meta-analysis will provide advanced evidence on the efficacy and safety of glucokinase activators for the treatment of T2DM.

ETHICS AND DISSEMINATION

Ethical approval and patient consent are not required because this study is a literature-based study. This systematic review and meta-analysis will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42021220364.

Determination of unbound fraction of dorzagliatin in human plasma by equilibrium dialysis and LC-MS/MS and its application to a clinical pharmacokinetic study

Dorzagliatin, a novel glucokinase (GK) activator targeting both pancreatic and hepatic GK, is currently in late-stage clinical development for treatment of type 2 diabetes (T2D). For the optimization of dosing regimens to ensure adequate safety and efficacy, it is critical to have a deep understanding of pharmacokinetic (PK) and pharmacodynamic (PD) profiles of the drug in various targeting patient populations, considering the fact that T2D adversely affects a vast patient population who often times also suffer from a wide range of comorbidities including severe liver and/or kidney damage. Since drug efficacy seems to be closely related to unbound drug concentrations at the site of action, therefore, the determination of plasma unbound concentrations/fractions of dorzagliatin is of crucial importance, especially when performing the PK/PD assessment in those special populations. In the current study, a method was developed and validated for determining the unbound fraction (f_u) of dorzagliatin in human plasma by using equilibrium dialysis for the separation of the bound and unbound drug, and LC-MS/MS for subsequent quantification. We have successfully addressed two widely recognized challenges for determination of the f_u, i.e., the lack of knowledge on the "true f_u" and the difficulty in assessing the accuracy and reproducibility of the measurement. Using this method, a 0.2 mL aliquot of human plasma samples were first dialyzed against 0.35 mL of phosphate buffered saline buffer at 37 °C for 5 h in the equilibrium dialysis device to separate the unbound dorzagliatin. Afterwards, post-dialysis samples were extracted by protein precipitation using acetonitrile. Separation of dorzagliatin and potential interferences were achieved using a Gemini C18 column coupled with gradient elution. Subsequent detection was carried out on tandem mass spectrometer operated by multiple reaction monitoring in positive mode using electrospray ionization. The standard curve over the concentration range of 0.125-250 ng/mL exhibits good linearity. The method was fully validated meeting the requirements in current bioanalytical guidance and was successfully applied in a clinical PK study of dorzagliatin in healthy volunteers and patients with renal function impairment. Method reproducibility was demonstrated in incurred sample reanalysis. With demonstrated accuracy, stability and reproducibility, reliable analytical results were obtained from clinical samples for PK/PD interpretation, providing valuable insight for the development of dorzagliatin.

Pharmacogenomic Studies of Current Antidiabetic Agents and Potential New Drug Targets for Precision Medicine of Diabetes

Diabetes is a major threat to people's health and has become a burden worldwide. Current drugs for diabetes have limitations, such as different drug responses among individuals, failure to achieve glycemic control, and adverse effects. Exploring more effective therapeutic strategies for patients with diabetes is crucial. Currently pharmacogenomics has provided potential for individualized drug therapy based on genetic and genomic information of patients, and has made precision medicine possible. Responses and adverse effects to antidiabetic drugs are significantly associated with gene polymorphisms in patients. Many new targets for diabetes also have been discovered and developed, and even entered clinical trial phases. This review summarizes pharmacogenomic evidence of some current antidiabetic agents applied in clinical settings, and highlights potential drugs with new targets for diabetes, which represent a more effective treatment in the future.

Safety, Pharmacokinetics, and Pharmacodynamics of Globalagliatin, a Glucokinase Activator, in Chinese Patients with Type 2 Diabetes Mellitus: A Randomized, Phase Ib, 28-day Ascending Dose Study

BACKGROUND AND OBJECTIVES

Globalagliatin, a glucokinase activator, plays a vital role in glucose homeostasis. The aim of this study was to assess the safety, pharmacokinetics, and pharmacodynamics of globalagliatin in Chinese patients with type 2 diabetes.

METHODS

In this dose-titration study, 24 patients were randomized (3:1 ratio) to receive globalagliatin or placebo. The 28-day titration was divided into two stages, each comprising 12 subjects. In stage I (low-dose), globalagliatin or placebo was administered at ascending doses of 20, 40, 80, and 120 mg once daily, increased at weekly intervals. As the treatment was well tolerated, stage II (high-dose) was initiated, with ascending doses of 80, 160, 240, and 320 mg. Safety, pharmacokinetic and pharmacodynamic analysis were conducted.

RESULTS

Following once-daily titration with ascending doses of globalagliatin of 20-120 mg (stage I) and 80-320 mg (stage II) for 7 days, globalagliatin caused mildly high incidences of hypoglycemia and hypertriglyceridemia. The mean maximum plasma concentration (C_max) of globalagliatin increased from 7.76 to 138.13 ng/mL (stage I), and 29.36 to 471.50 ng/mL (stage II), which occurred at 3-5 h post-dose. A steady state was achieved after 7 days of once-daily dosing in stage I and stage II, respectively. Mean area under the plasma-concentration curve for steady-state 24-h interval (AUC_0-24) increased from 106.13 to 2461.95 ng·h/mL (stage I) and 369.71 to 9218.38 ng·h/mL (stage II). Fasting plasma glucose (FPG) decreased continuously during the titration period. Compared with the placebo, high-dose globalagliatin significantly increased the reductions in FPG, the area under the curve of 24-h glucose levels, and glycated albumin, with least-squares mean changes (relative to baseline) of - 4.08 mmol/L (95% CI - 5.05 to - 3.12) (P < 0.01), - 103.93 mmol/L (95% CI - 135.80 to - 72.06) (P < 0.01), and - 4.71% (95% CI - 6.91 to - 2.51) (P < 0.01)), respectively. High-dose globalagliatin significantly increased the Matsuda index, indicating improved insulin resistance.

CONCLUSIONS

Globalagliatin was well tolerated and showed favorable pharmacokinetic profiles in Chinese patients with type 2 diabetes. High-dose globalagliatin reduced plasma glucose, and improved insulin resistance.

TRIAL REGISTRATION

Clinicaltrials.gov indentifier, NCT03414892.

Insights into the binding of dorzagliatin with glucokinase: A molecular dynamics simulation

Human glucokinase (GK) is a potentially attractive target for diabetes, playing a prominent role in the control of glucose homeostasis. Dorzagliatin is the first GK activator (GKA) to enter phase III clinical trial. In this study, the possible binding mode of dorzagliatin with GK was investigated via the molecular simulation method. Two other systems in the absence of dorzagliatin and glucose were also studied to disclose the roles of dorzagliatin and glucose. The outcomes revealed that dorzagliatin can create the characteristic hydrogen bonds of GKA with Arg63, and Arg63 can form hydrogen bonds with nearby residues, making a tight binding hydrogen bond network around dorzagliatin. The presence of dorzagliatin can stabilize glucokinase for a period of time, and the binding of glucose may prevent the GK conformational change to a certain extent. Our results may be beneficial to mechanism understanding of GKA, and will be useful in design of novel GKAs for treating metabolic diseases.

Non-alcoholic fatty liver disease and cardiovascular disease: assessing the evidence for causality

Non-alcoholic fatty liver disease (NAFLD) is highly prevalent among individuals with type 2 diabetes. Although epidemiological studies have shown that NAFLD is associated with cardiovascular disease (CVD), it remains unknown whether NAFLD is an active contributor or an innocent bystander. Plasma lipids, low-grade inflammation, impaired fibrinolysis and hepatokines are potential mediators of the relationship between NAFLD and CVD. The Mendelian randomisation approach can help to make causal inferences. Studies that used common variants in PNPLA3, TM6SF2 and GCKR as instruments to investigate the relationship between NAFLD and coronary artery disease (CAD) have reported contrasting results. Variants in PNPLA3 and TM6SF2 were found to protect against CAD, whereas variants in GCKR were positively associated with CAD. Since all three genes have been associated with non-alcoholic steatohepatitis, the second stage of NAFLD, the question of whether low-grade inflammation is an important mediator of the relationship between NAFLD and CAD arises. In contrast, the differential effects of these genes on plasma lipids (i.e. lipid-lowering for PNPLA3 and TM6SF2, and lipid-raising for GCKR) strongly suggest that plasma lipids account for their differential effects on CAD risk. This concept has recently been confirmed in an extended set of 12 NAFLD susceptibility genes. From these studies it appears that plasma lipids are an important mediator between NAFLD and CVD risk. These findings have important clinical implications, particularly for the design of anti-NAFLD drugs that also affect lipid metabolism.

The Central Role of Glucokinase in Glucose Homeostasis: A Perspective 50 Years After Demonstrating the Presence of the Enzyme in Islets of Langerhans

It is hypothesized that glucokinase (GCK) is the glucose sensor not only for regulation of insulin release by pancreatic β-cells, but also for the rest of the cells that contribute to glucose homeostasis in mammals. This includes other cells in endocrine pancreas (α- and δ-cells), adrenal gland, glucose sensitive neurons, entero-endocrine cells, and cells in the anterior pituitary. Glucose transport is by facilitated diffusion and is not rate limiting. Once inside, glucose is phosphorylated to glucose-6-phosphate by GCK in a reaction that is dependent on glucose throughout the physiological range of concentrations, is irreversible, and not product inhibited. High glycerol phosphate shuttle, pyruvate dehydrogenase, and pyruvate carboxylase activities, combined with low pentose-P shunt, lactate dehydrogenase, plasma membrane monocarboxylate transport, and glycogen synthase activities constrain glucose-6-phosphate to being metabolized through glycolysis. Under these conditions, glycolysis produces mostly pyruvate and little lactate. Pyruvate either enters the citric acid cycle through pyruvate dehydrogenase or is carboxylated by pyruvate carboxylase. Reducing equivalents from glycolysis enter oxidative phosphorylation through both the glycerol phosphate shuttle and citric acid cycle. Raising glucose concentration increases intramitochondrial [NADH]/[NAD⁺] and thereby the energy state ([ATP]/[ADP][Pi]), decreasing [Mg²⁺ADP] and [AMP]. [Mg²⁺ADP] acts through control of K_ATP channel conductance, whereas [AMP] acts through regulation of AMP-dependent protein kinase. Specific roles of different cell types are determined by the diverse molecular mechanisms used to couple energy state to cell specific responses. Having a common glucose sensor couples complementary regulatory mechanisms into a tightly regulated and stable glucose homeostatic network.

Dorzagliatin (HMS5552), a novel dual-acting glucokinase activator, improves glycaemic control and pancreatic β-cell function in patients with type 2 diabetes: A 28-day treatment study using biomarker-guided patient selection

AIMS

To investigate the pharmacokinetics and pharmacodynamics of a dual-acting glucokinase activator, dorzagliatin, and its safety, tolerability and effect on pancreatic β-cell function in Chinese patients with type 2 diabetes (T2D).

MATERIALS AND METHODS

A total of 24 T2D patients were selected, utilizing a set of predefined clinical biomarkers, and were randomized to receive dorzagliatin 75 mg twice or once daily (BID, QD respectively) for 28 days. Changes in HbA1c and glycaemic parameters from baseline to Day 28 were assessed. In addition, changes in β-cell function from baseline to Day 32 were evaluated.

RESULTS

Significant reductions in HbA1c were observed in both regimens on Day 28 (-0.79%, 75 mg BID; -1.22%, 75 mg QD). Similar trends were found in the following parameters, including reductions from baseline in fasting plasma glucose by 1.20 mmol/L and 1.51 mmol/L, in 2-hour postprandial glucose by 2.48 mmol/L and 5.03 mmol/L, and in glucose AUC_0-24 by 18.59% and 20.98%, for the BID and QD groups, respectively. Both regimens resulted in improvement in β-cell function as measured by steady state HOMA 2 parameter, %B, which increased by 36.31% and 40.59%, and by dynamic state parameter, ΔC₃₀ /ΔG₃₀ , which increased by 24.66% and 167.67%, for the BID and QD groups, respectively. Dorzagliatin was well tolerated in both regimens, with good pharmacokinetic profiles.

CONCLUSIONS

Dorzagliatin treatment for 28 days in Chinese T2D patients, selected according to predefined biomarkers, resulted in significant improvement in β-cell function and glycaemic control. The safety and pharmacokinetic profile of dorzagliatin supports a subsequent Phase II trial design and continued clinical development.