Diabetes is a significant risk factor for sudden cardiac death, with the QTc interval on electrocardiograms (ECGs) often prolonged in diabetic patients due to factors such as hyperglycaemia and insulin resistance. Drugs like moxifloxacin can further exacerbate this effect, especially in those with diabetes. A previous trial on Type 1 diabetes suggested that hyperglycaemia and moxifloxacin have additive effects, prompting an investigation into whether similar effects occur in Type 2 diabetes (T2DM), particularly in individuals with high insulin resistance. This study aims to evaluate whether moxifloxacin-induced QT-prolongation is amplified by elevated blood glucose levels or insulin deficiency in T2DM patients, considering potential differences between sexes. Blood biomarkers will be analysed to understand the underlying molecular mechanisms. The trial will involve at least 24 male and female participants with insulin-resistant T2DM, aged 18 to 64 years, conducted at Richmond Pharmacology Ltd. Participants will receive treatments with glucose, moxifloxacin, and placebos while closely monitored for side effects during an inpatient stay, followed by outpatient appointments.
Diabetes has been established as a key independent risk factor for sudden cardiac death, a common cause of death from cardiovascular disease. The underlying mechanisms for this seem to be complex and multifactorial, but a change in the electrocardiogram (ECG)(which measures the electrical activity of the heart) parameter called QTc interval has been identified as potentially having a significant role. In patients with diabetes, QT interval prolongation is frequently reported. High blood glucose levels (hyperglycaemia) and insulin resistance (the condition where the body does not respond well to insulin) are thought to be important causes. The investigators also know that some drugs e.g., moxifloxacin (a common antibiotic) can prolong the QT interval and this effect can be more pronounced in patients with diabetes. The investigators have previously conducted a trial on Type 1 diabetes showing that the effects of hyperglycaemia and moxifloxacin were additive. This led to our hypothesis that similar effects might be observed in type 2 diabetes (T2DM), specifically in those with high insulin resistance. Understanding whether the well-established QT-prolongation caused by moxifloxacin is exaggerated by elevated levels of blood glucose alone or by an insulin deficiency is important for evaluating the risk to patients with T2DM and the potential prevention of cardiac complications. The investigators would also like to determine if the effect varies between sexes and gain a comprehensive understanding of the molecular factors driving these differences by analysing blood biomarkers. This trial will be conducted at Richmond Pharmacology Ltd. involving a minimum of 24 male and female participants with insulin-resistant T2DM, aged 18 to 64 years. The participants will stay in the clinical trials unit, receive treatments with glucose, moxifloxacin, and placebos and will be monitored closely for any side effects. Following the inpatient stay, participants will return to the unit for an outpatient appointment.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
SINGLE
Enrollment
24
Participants will receive treatments with glucose or matching placebo (please see study design section).
Participants will receive moxifloxacin or matching placebo (please see study design section).
Richmond Pharmacology Ltd.
London, United Kingdom
RECRUITINGClinically significant ECG morphology and interval changes from baseline
ECG Analysis Mean QT/QTc values will be calculated for each time point (triplicate ECG) for subsequent analyses. Telemetry data gathered during the study may be used in the optional exploratory analysis of drug related QT/QTc interval changes. The primary baseline corrections will be calculated using averaged QTc pre-dose baseline values (three pre-dose time points). This single value will be used to calculate ΔQTc. A supplementary analysis to calculate ΔΔQTc may be performed using pooled placebo data. The effect on QTc will be calculated using concentration-effect analysis based on the placebo-corrected change from average baseline.
Time frame: Specified timepoints for 4 days and at follow up visit on Day10-D17
Cardiac intervals/subintervals calculated using concentration-effect analysis on Days 1, 2, and 3.
The primary baseline corrections will be calculated using averaged QTc pre-dose baseline values (three pre-dose time points). This single value will be used to calculate ΔQTc. A supplementary analysis to calculate ΔΔQTc may be performed using pooled placebo data. The effect on QTc will be calculated using concentration-effect analysis based on the placebo-corrected change from average baseline.
Time frame: Specified timepoints for 3 days
The paired PK of blood glucose and moxifloxacin (Cmax)
PK parameter: Maximum observed plasma concentration (Cmax) * Glucose * Day 1: Cmax * Day 2: Cmax * Day 3: Cmax * Day 4: Cmax * Moxifloxacin * Day 3: Cmax * Day 4: Cmax
Time frame: 4 Days
The paired PK of blood glucose and moxifloxacin (Tmax)
PK parameter: time to reach maximum plasma concentration (Tmax) * Glucose * Day 1: Tmax * Day 2: Tmax * Day 3: Tmax * Day 4: Tmax * Moxifloxacin * Day 3: Tmax * Day 4: Tmax
Time frame: 4 days
The paired PK of blood glucose and moxifloxacin (AUC)
PK parameter: Area under the plasma concentration-time curve (AUC). * Glucose * Day 1: AUC * Day 2: AUC * Day 3: AUC * Day 4: AUC * Moxifloxacin * Day 3: AUC * Day 4: AUC
Time frame: 4 days
Cardiac interval/subinterval parameters
Cardiac interval/subinterval parameters (QTcF, JTpc, TpTe) prior to glucose administration compared to post-administration
Time frame: 4 days
Comparison of the PK of blood glucose and moxifloxacin with cardiac interval/subinterval parameters and ECG morphology between sexes on Days 1, 2, 3 and 4
Comparison between males and females of the paired PK blood glucose and moxifloxacin, and cardiac interval/subinterval parameters (QTcF, JTpc, TpTe) prior to glucose administration compared to post-administration. PK parameters include maximum observed plasma concentration (Cmax), time to reach maximum plasma concentration (tmax), area under the plasma concentration-time curve (AUC). * Glucose * Day 1: Cmax, tmax, AUC * Day 2: Cmax, tmax, AUC * Day 3: Cmax, tmax, AUC * Day 4: Cmax, tmax, AUC * Moxifloxacin * Day 3: Cmax, tmax, AUC * Day 4: Cmax, tmax, AUC * QTcF, JTpc, TpTe o Days 1, 2, and 3.
Time frame: Specified time points over 4 days
• Concentration effect analysis between male and female volunteers on Days 1, 2, 3 and 4
Comparison of males vs females of the primary baseline corrections calculated using averaged QTc pre-dose baseline values (three pre-dose time points). This single value will be used to calculate ΔQTc. A supplementary analysis to calculate ΔΔQTc may be performed using pooled placebo data. The effect on QTc will be calculated using concentration-effect analysis based on the placebo-corrected change from average baseline.
Time frame: specified timepoints over 4 days
The incidence of treatment-emergent adverse events (TEAEs)
Proportion of participants with clinically significant changes in laboratory safety tests (haematology, chemistry, coagulation and urinalysis), proportion of participants with morphological and/or rhythm abnormalities on ECG, proportion of participants with clinically significant changes in ECG time intervals (PR, QRS, QT and QTc intervals) and proportion of participants with clinically significant changes in vital signs (systolic blood pressure, diastolic blood pressure, pulse rate, respiratory rate and tympanic temperature).
Time frame: From screening to follow up approximately 75 days
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