Urinary glucose excretion after dapagliflozin treatment: An exposure-response modelling comparison between Japanese and non-Japanese patients diagnosed with type 1 diabetes mellitus

Utilization of Pharmacokinetic/Pharmacodynamic Modeling in Pharmacoepidemiological Studies: A Systematic Review on Antiarrhythmic and Glucose-Lowering Medicines

Introduction: In human pharmacology, there are two important scientific branches: clinical pharmacology and pharmacoepidemiology. Pharmacokinetic/pharmacodynamic (PK/PD) modeling is important in preclinical studies and randomized control trials. However, it is rarely used in pharmacoepidemiological studies on the effectiveness and medication safety where the target population is heterogeneous and followed for longer periods. The objective of this literature review was to investigate how far PK/PD modeling is utilized in observational studies on glucose-lowering and antiarrhythmic drugs.

Method: A systematic literature search of MEDLINE, Embase, and Web of Science was conducted from January 2010 to 21 February 2020. To calculate the utilization of PK/PD modeling in observational studies, we followed two search strategies. In the first strategy, we screened a 1% random set from 95,672 studies on glucose-lowering and antiarrhythmic drugs on inclusion criteria. In the second strategy, we evaluated the percentage of studies in which PK/PD modeling techniques were utilized. Subsequently, we divided the total number of included studies in the second search strategy by the total number of eligible studies in the first search strategy.

Results: The comprehensive search of databases and the manual search of included references yielded a total of 29 studies included in the qualitative synthesis of our systematic review. Nearly all 29 studies had utilized a PK model, whereas only two studies developed a PD model to evaluate the effectiveness of medications. In total, 16 out of 29 studies (55.1%) used a PK/PD model in the observational setting to study effect modification. The utilization of PK/PD modeling in observational studies was calculated as 0.42%.

Conclusion: PK/PD modeling techniques were substantially underutilized in observational studies of antiarrhythmic and glucose-lowering drugs during the past decade.

Long-term (52-week) efficacy and safety of dapagliflozin as an adjunct to insulin therapy in Japanese patients with type 1 diabetes: Subgroup analysis of the DEPICT-2 study

AIM

To examine the long-term efficacy and safety of dapagliflozin, a sodium-glucose co-transporter-2 (SGLT2) inhibitor used to treat type 1 diabetes, in the Japanese subpopulation of the DEPICT-2 study.

MATERIALS AND METHODS

Patients with type 1 diabetes were randomized to dapagliflozin 5 mg (n = 55), dapagliflozin 10 mg (n = 41) or placebo (n = 58) plus insulin for a 24-week, double-blind period followed by a 28-week, single-blind extension phase.

RESULTS

From baseline to 24 weeks, dapagliflozin reduced HbA1c compared with placebo (mean change of -0.58% and -0.80% for 5 and 10 mg, respectively), and an HbA1c reduction was observed up to 52 weeks. Compared with placebo, dapagliflozin 5 and 10 mg increased the proportion of patients achieving HbA1c reductions of 0.5% or more without severe hypoglycaemia events and reduced glycaemic variability assessed via continuous glucose monitoring. Both dapagliflozin doses decreased body weight and total daily insulin dose at 24 weeks compared with placebo; these reductions were maintained up to 52 weeks. Diabetic ketoacidosis occurred in both dapagliflozin groups (one and two cases, respectively) but not with placebo.

CONCLUSIONS

Efficacy and safety results from the Japanese subpopulation of the DEPICT-2 study were generally consistent with those from the overall population, indicating that long-term dapagliflozin adjunct to insulin therapy improves glycaemic control without an increased risk of hypoglycaemia but with a risk of diabetic ketoacidosis in Japanese patients with type 1 diabetes.

Sodium-glucose cotransporter 2 inhibitors as an add-on therapy to insulin for type 1 diabetes mellitus: Meta-analysis of randomized controlled trials

AIMS

The aim was to systematically review the efficacy and safety of sodium-glucose cotransporter inhibitor (SGLT2i) as an adjunct to insulin at different follow-up durations in randomized, double-blind clinical trials in patients with type 1 diabetes.

METHODS

We conducted a search on Medline, Embase, and the Cochrane Library for relevant studies published before May 2020. According to the duration of follow-up, the subgroup analysis included four periods: 1-4, 12-18, 24-26, and 52 weeks. In the five trials included both 24-26 and 52 weeks of follow-up, we compared the efficacy by the placebo-subtracted difference and changes in SGLT2i groups.

RESULTS

Fifteen trials including 7109 participants were analyzed. The combination of SGLT2i and insulin improved hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), daily insulin dose, body weight, and blood pressure, which varied greatly by different follow-ups. Compared with %HbA1c at 24-26 weeks, placebo-subtracted differences and changes in the SGLT2i groups slightly increased. SGLT2i plus insulin treatment showed no difference in the occurrence of urinary tract infections (UTIs), hypoglycemia, or severe hypoglycemia but increased the risk of genital tract infections (GTIs) in a duration-dependent manner. SGLT2i treatment was associated with a significantly higher rate of ketone-related SAEs and diabetic ketoacidosis (DKA) at 52 weeks.

CONCLUSION

SGLT2i as an add-on therapy to insulin improved glycemic control and body weight and decreased the required dose of insulin without increasing the risk of hypoglycemia. However, after 6 months the benefits of SGLT2is on glycemic control may weaken and the risks of GTIs and DKA increased.

Comparison of pharmacokinetics and the exposure-response relationship of dapagliflozin between adolescent/young adult and adult patients with type 1 diabetes mellitus

AIMS

To quantitatively compare pharmacokinetics (PK) and the exposure-response (ER) relationship of the sodium-glucose cotransporter-2 inhibitor, dapagliflozin, between adolescents/young adults and adults with type 1 diabetes mellitus (T1DM).

METHODS

Data from 2 clinical studies for dapagliflozin were analysed using a non-linear mixed-effects approach. The PK and the relationship between dapagliflozin exposure and response (24-hour urinary glucose excretion) were characterized. PK was evaluated using a 2-compartment model with first-order absorption while the exposure response-relationship was analysed using a sigmoidal maximal-effect model. The 24-hour median blood glucose, estimated glomerular filtration rate (eGFR), sex, age and body weight were evaluated as covariates.

RESULTS

A 2-compartment model with first order absorption provided a reasonable fit to the dapagliflozin PK data. Body weight was found to be a significant covariate on dapagliflozin exposure. The ER relationship was best described by a sigmoidal maximal effect model with 24-hour median blood glucose and eGFR as significant covariates on maximal effect. In accordance with the observed data, model-predicted urinary glucose excretion response following 10 mg dapagliflozin dose was higher in the study in adolescents/young adults (138.0 g/24 h) compared to adults (70.5 g/24 h) with T1DM. This is linked to higher eGFR and 24-hour median blood glucose in this trial.

CONCLUSIONS

Dapagliflozin PK and ER relationship were similar in the 2 analysed studies after accounting for covariate effects. These results suggest that no dose adjustment is required for adolescent patients with T1DM.

Model-based characterization of the relationship between dapagliflozin systemic exposure and HbA1c response in patients with type 1 diabetes mellitus

AIMS

To quantitatively describe the relationship between dapagliflozin systemic exposure and HbA1c response among patients with type 1 diabetes mellitus (T1DM) and assess the potential impact of covariate effects.

MATERIALS AND METHODS

Individual longitudinal HbA1c data from two phase 3 studies in patients with T1DM (24-week treatment with once-daily dapagliflozin 5 or 10 mg or placebo, with adjustable insulin) were analyzed using a non-linear mixed effect modeling approach. Area under the concentration curve was used to measure dapagliflozin systemic exposure. Baseline HbA1c, estimated glomerular filtration rate, reduction in total insulin dose, baseline glucose concentrations, age, sex, race (Asian vs. non-Asian), and insulin administration method (multiple daily injections vs. insulin pump) were assessed as covariates.

RESULTS

A maximum effect (Emax ) model identified a positive exposure-response relationship. Model-predicted placebo-corrected HbA1c reductions after 24 weeks for dapagliflozin 5- and 10-mg doses were - 0.42% [95% confidence interval (CI) -0.47 to -0.36) and - 0.45% (95% CI -0.50 to -0.40), respectively; baseline HbA1c was ~8.4%. This was in good agreement with actual observations from both studies. Baseline HbA1c was a significant covariate: patients with higher baseline HbA1c were predicted to have greater HbA1c reductions.

CONCLUSIONS

The relationship between dapagliflozin systemic exposure and HbA1c response was successfully described in patients with T1DM. None of the tested covariates affected the efficacy of dapagliflozin to a clinically relevant extent. Therefore, no dose adjustment of dapagliflozin is required in patients with T1DM based on the tested covariates. ClinicalTrials.gov, NCT02268214; NCT02460978.

Urinary glucose excretion after dapagliflozin treatment: An exposure-response modelling comparison between Japanese and non-Japanese patients diagnosed with type 1 diabetes mellitus

AIMS

To assess the dapagliflozin exposure-response relationship in Japanese and non-Japanese patients with type 1 diabetes mellitus (T1DM) and investigate if a dose adjustment is required in Japanese patients.

MATERIALS AND METHODS

Data from two clinical studies were used to develop a non-linear mixed effects model describing the relationship between dapagliflozin exposure (area under the concentration curve) and response (24-hour urinary glucose excretion [UGE]) in Japanese and non-Japanese patients with T1DM. The effects of patient-level characteristics (covariates; identified using a stepwise procedure) on response was also assessed. Simulations were performed using median-normalized covariate values.

RESULTS

Data from 84 patients were included. Average self-monitored blood glucose (SMBG) at day 7, change from baseline in total insulin dose at day 7, and baseline estimated glomerular filtration rate (eGFR) all had a significant effect on 24-hours UGE, with SMBG being the most influential. Dapagliflozin systemic exposure for matching doses and baseline eGFR was similar between Japanese and non-Japanese patients; however, higher SMBG and a greater reduction in total insulin dose was observed in the Japanese population. When the significant covariates were included, the model fit the data well for both populations, and accurately predicted exposure-response in the Japanese and non-Japanese populations, in agreement with the observed data.

CONCLUSIONS

There was no difference in dapagliflozin exposure-response in Japanese and non-Japanese patients with T1DM once differences in renal function, glycaemic control and insulin dose reductions between studies were considered. Therefore, no dose adjustment is recommended in Japanese patients with T1DM.