Treatment Compliance with Fixed-Dose Combination of Vildagliptin/Metformin in Patients with Type 2 Diabetes Mellitus Inadequately Controlled with Metformin Monotherapy: A 24-Week Observational Study

Effectiveness of Single-Tablet Combination Therapy in Improving Adherence and Persistence and the Relation to Clinical and Economic Outcomes

Background: Single-tablet combination therapies (STCTs) combine multiple drugs into one formulation, making drug administration more convenient for patients. STCTs were developed to address concerns with treatment adherence and persistence, but the impact of STCT use is not fully understood across indications. Objectives: We conducted a systematic literature review (SLR) to examine STCT-associated outcomes across 4 evidence domains: clinical trials, real-world evidence (RWE), health-related quality of life (HRQoL) studies, and economic evaluations. Methods: Four SLRs were conducted across the aforementioned domains. Included studies compared STCTs as well as fixed-dose combinations ([FDCs] of non-tablet formulations) with the equivalent active compounds and doses in loose-dose combinations (LDCs). Original research articles were included; case reports, case series, and non-English-language sources were excluded. Databases searched included EconLit, Embase, and Ovid MEDLINE® ALL. Two independent reviewers assessed relevant studies and extracted data. Conflicts were resolved with a third reviewer or consensus-based discussion. Results: In all, 109 studies were identified; 27 studies were identified in more than one SLR. Treatment adherence was significantly higher in patients receiving FDCs vs LDCs in 12 of 13 RWE studies and 3 of 13 clinical trials. All 18 RWE studies reported higher persistence with FDCs. In RWE studies examining clinical outcomes (n = 17), 14 reported positive findings with FDCs, including a reduced need for add-on medication, blood pressure control, and improved hemoglobin A1C. HRQoL studies generally reported numerical improvements with STCTs or similarities between STCTs and LDCs. Economic outcomes favored STCT use. All 6 cost-effectiveness or cost-utility analyses found FDCs were less expensive and more efficacious than LDCs. Four budget impact models found that STCTs were associated with cost savings. Medical costs and healthcare resource use were generally lower with FDCs than with LDCs. Discussion: Evidence from RWE and economic studies strongly favored STCT use, while clinical trials and HRQoL studies primarily reported similarity between STCTs and LDCs. This may be due to clinical trial procedures aimed at maximizing adherence and HRQoL measures that are not designed to evaluate drug administration. Conclusions: Our findings highlight the value of STCTs for improving patient adherence, persistence, and clinical outcomes while also offering economic advantages.

Long-term clinical outcomes of oral antidiabetic drugs as fixed-dose combinations: A nationwide retrospective cohort study

AIM

To compare treatment patterns and clinical outcomes of single-pill fixed-dose combination (FDC) and two-pill combination (TPC) therapies using real-world data.

METHODS

We conducted a nationwide retrospective cohort study using South Korea's healthcare database (2002-2015). We identified two cohorts of incident patients with type 2 diabetes who initiated FDC or TPC therapy within 4 months of their first prescription for metformin or sulphonylurea. We examined persistence and adherence patterns and the clinical outcome of a composite endpoint of death or hospitalization for acute myocardial infarction, heart failure or stroke and compared the differences in treatment patterns and clinical outcomes using Cox models.

RESULTS

Of 5143 and 10 973 patients who initiated FDC and TPC therapy, respectively, we identified 5143 patient pairs after propensity score matching. The FDC group exhibited greater median time to treatment discontinuation (163 vs. 146 days), and proportion of days covered at 12 months (mean 0.60 vs. 0.57, P < .0001) and at 24 months (0.53 vs. 0.51, P = .014) than the TPC group. The FDC group, compared with the TPC group, had reduced risks of the composite clinical outcome (hazard ratio 0.86, 95% confidence intervals 0.77-0.97) and hospitalization for stroke (0.80, 0.67-0.96).

CONCLUSION

FDC therapy may provide favourable cardiovascular benefits, especially reducing the risk of hospitalization for stroke, and has better medication adherence among patients with type 2 diabetes.

Bioequivalence Studies of New Generic Formulations of Vildagliptin and Fixed-Drug Combination of Vildagliptin and Metformin Versus Respective Originator Products in Healthy Volunteers

INTRODUCTION

Vildagliptin and metformin are two well-established oral antidiabetics with a complementary mechanism of action. Two new generic products, vildagliptin and its fixed-drug combination (FDC) with metformin, were tested for bioequivalence versus the approved originator reference products (Galvus® and Eucreas®).

METHODS

Three randomized studies with two-treatment, two-period, two-sequence crossover design were conducted in healthy adults. One study evaluated vildagliptin 50 mg tablets as single dose under fasting conditions. Vildagliptin-metformin FDC tablet strengths of 50/850 mg and 50/1000 mg were evaluated in separate studies as single dose under fed conditions, given 30 min after a standardized high-fat, high-calorie breakfast following 10 h overnight fasting. Blood samples for analysis were collected until 24 h after dosing in each study period. Bioequivalence between test (T) and reference (R) products required 90% confidence interval (CIs) for the geometric least square (LS) mean T/R ratio to be within 80-125% for the pharmacokinetic parameters, maximum plasma concentration (C_max), and area under the curve (AUC_0-t).

RESULTS

The 90% CIs of geometric LS means of T/R ratio for C_max and AUC_0-t with vildagliptin tablets of 50 mg were 92.22-103.94% and 99.00-102.66%, respectively; corresponding results with FDC tablets for 50/850 mg tablets were 94.81-115.41% and 95.28-106.00% for vildagliptin and 90.87-101.18% and 90.56-100.09% for metformin; for 50/1000 mg tablets C_max and AUC_0-t were 105.56-122.30% and 98.30-107.55%, respectively, for vildagliptin and 92.14-103.73% and 94.60-101.81%, respectively, for metformin. Other parameters such as AUC_0-∞, time to maximum concentration (T_max), and terminal half-life (t_1/2) were comparable between test and reference products. Adverse events (AEs), mainly vomiting, were reported without relevant difference between test and reference products in each study. AEs were generally mild and transient. No severe or serious AEs occurred.

CONCLUSIONS

The new generic drug products of vildagliptin and the FDCs of vildagliptin and metformin demonstrated bioequivalence to the approved originator products and are therefore expected to provide similar therapeutic effects.

Regimen simplification and medication adherence: Fixed-dose versus loose-dose combination therapy for type 2 diabetes

BACKGROUND

Suboptimal patient adherence to pharmacological therapy of type 2 diabetes may be due in part to pill burden. One way to reduce pill burden in patients who need multiple medications is to use fixed-dose combinations. Our study aimed to compare the effects of fixed-dose combination versus loose-dose combination therapy on medication adherence and persistence, health care utilization, therapeutic safety, morbidities, and treatment modification in patients with type 2 diabetes over three years.

METHODS

Using administrative data, we conducted a retrospective controlled cohort study comparing type 2 diabetes patients who switched from monotherapy to either a fixed-dose combination or a loose-dose combination. Adherence was assessed as the primary endpoint and calculated as the proportion of days covered with medication. After using entropy balancing to eliminate differences in observable baseline characteristics between the two groups, we applied difference-in-difference estimators for each outcome to account for time-invariant unobservable heterogeneity.

RESULTS

Of the 990 type 2 diabetes patients included in our analysis, 756 were taking a fixed-dose combination and 234 were taking a loose-dose combination. We observed a statistically significantly higher change in adherence (year one: 0.22, p<0.001, year two: 0.25, p<0.001, and year three: 0.29, p<0.001) as well as higher persistence and a smaller change in the number of drug prescriptions in each of the three years in the fixed-dose combination group compared to the loose-dose combination group. The differences were most pronounced in patients who were poorly adherent, had a high pill burden, or did not have a severe concomitant disease.

CONCLUSION

Our results indicate that taking a fixed-dose combination can lead to a significant improvement in adherence to pharmacological therapy of type 2 diabetes compared to a loose-dose combination. In particular, these findings suggest that reducing pill burden may improve disease management among patients with more complex medication demand and patients who have demonstrated poor medication adherence.

[Early intensification of glucose-lowering therapy: VERIFY lessons and real clinical practice on the example of the Moscow region diabetes register data]

BACKGROUND

The prevalence of T2DM is steadily increasing not only among the elderly, but also at a young age. T2DM is preceded by a long period of significant metabolic changes with the development of insulin resistance and в-cell dysfunction. To reduce the prevalence of complications, treatment is needed which affects several pathophysiological mechanisms underlying the disease. Monotherapy with metformin at the onset of T2DM is often insufficient. The VERIFY study demonstrated the advantage of early administration of a combination of vildagliptin and metformin in relation to the glycemic durability compared to the sequential intensification of metformin with vildagliptin in patients with type 2 diabetes.

AIMS

To assess the current situation in terms of the incidence of T2DM complications and the structure of the prescribing glucose lowering drugs based on the data from the Diabetes Register (DR) of the Moscow Region. To demonstrate the advantages of early combination therapy in patients with newly diagnosed T2DM using clinical cases.

MATERIALS AND METHODS

The data from the DR of the Moscow region, which is part of the National Diabetes Register of the Russian Federation, were used for the analysis. The data of 6,096 patients with T2DM who died in 2019 were evaluated for building the structure of the causes of death of patients with T2DM. The pattern of glucose-lowering therapy was analyzed based on data of 226,327 patients with T2DM (for 2020), as well as separately of 14,379 patients with newly diagnosed T2DM in 2019. Clinical cases are described based on the data of two patients with T2DM, available in the DR database and outpatient records.

RESULTS

In patients with young onset T2DM (&lt;40 years), the prevalence of severe complications is higher than in the general population of patients with T2DM: blindness is in 5.9 times, end-stage chronic renal failure in 2.9 times, lower limb amputations in 6.4 times more. When prescribing glucose lowering drugs, monotherapy is prevalent, mostly metformin. In double combination, metformin is used in 96.22% of cases. In the structure of glucose lowering drugs, with newly diagnosed T2DM, combination therapy is used less frequently than in patients with T2DM in general. Of the drugs of the IDP-4 group, vildagliptin is most often prescribed - 46.25% (including of a fixed combination with metformin - 12.22%). Clinical cases reflect a rapid clinical outcome: a decrease in HbA1c to the target in 6 months, the absence of hypoglycemia or other side effects, and positive weight dynamics.

CONCLUSIONS

A fairly large propotion of patients with T2DM are on monotherapy with glucouse lowering drugs. Early prescription of the combination of metformin plus vildagliptin provides a longer maintenance of glycemic control without increasing the risk of hypoglycemia and weight gain for patients with newly diagnosed T2DM.

Does the Polypill Improve Patient Adherence Compared to Its Individual Formulations? A Systematic Review

Many patients, especially those with a high pill burden and multiple chronic illnesses, are less adherent to medication. In medication treatments utilizing polypills, this problem might be diminished since multiple drugs are fused into one formulation and, therefore, the therapy regimen is simplified. This systematic review summarized evidence to assess the effect of polypills on medication adherence. The following databases were searched for articles published between 1 January 2000, and 14 May 2019: PubMed, Web of Science, Cochrane Library, and Scopus. Medication adherence was the only outcome assessed, regardless of the method of measuring it. Sixty-seven original peer-reviewed articles were selected. Adherence to polypill regimens was significantly higher in 56 articles (84%) compared to multiple pill regimens. This finding was also supported by the results of 13 out of 17 selected previously published systematic reviews and meta-analyses dealing with this topic. Adherence can be improved through the formulation of polypills, which is probably why the interest in researching them is growing. There are many polypills on the market, but the adherence studies so far focused mainly on a small range of medical conditions.

Glycemic Improvement with a Fixed-dose combination of DPP-4 inhibitor + metformin in patients with Type 2 diabetes (GIFT study)

This study investigates changes in A1C following a switch from dual therapy of metformin and DPP-4 inhibitor to a fixed-dose combination (FDC) of metformin + DPP-4 inhibitor following the introduction of the FDC in the provincial formulary. The LMC Diabetes Registry was queried retrospectively for patients with type 2 diabetes, aged between 18 and 80 years with at least one A1C recorded prior and ≥3 months post-switch. Five hundred and sixty-eight subjects with mean age 64 ± 12 years and mean A1C 7.7% ± 1.2% met study criteria. Overall, A1C was 0.3% lower post-switch to FDC (P < .01). In stratified analysis, subjects with baseline A1C between 7% and 10% had 0.4% lower A1C (P < .01), with 31% of these subjects reaching target A1C ≤7%, post-switch. A1C reduction was greater among patients with a higher baseline pill burden: 0.4% among those using ≥10 pills/day vs. 0.1% for those with <10 pills/day (P = .02). In this real-world study, switching to FDC of metformin + DPP-4 inhibitor was associated with a significant improvement in A1C. Switching to FDC, especially in patients with high pill burden, can improve A1C goal achievement in clinical practice.

Safety, Efficacy, and Bioavailability of Fixed-Dose Combinations in Type 2 Diabetes Mellitus: A Systematic Updated Review

Purpose

Type 2 diabetes mellitus (T2DM) is a multifactorial disease characterized by insulin resistance. As time progresses, monotherapy often does not provide effective glycemic control, generating the need for an add-on therapy. Hence, multiple oral hypoglycemic agents formulated as a single-dose form called fixed-dose combinations (FDCs) play an essential role in glycemic control. The purpose of this systematic review is to appraise the recently published evidence on the safety, efficacy, and bioavailability of FDCs.

Methods

A comprehensive literature search of PUBMED, Scopus, ScienceDirect.com, ProQuest, SpringerLink, clintrials.gov, Embase, and EBSCO using the key words FDCs, combination therapy, T2DM management, and add-on therapy was conducted. Studies on the safety profile/tolerability, efficacy, and bioavailability of various FDCs of oral hypoglycemic agents were preferred.

Findings

The systematic review of all the publications suggests that FDCs of oral hypoglycemic agents (OHAs) significantly reduce HbA_1c and fasting plasma glucose values, thereby efficiently reducing hyperglycemia in patients in whom monotherapy fails. FDCs are the bioequivalent of the concomitant drugs administered as individual components. Improved adherence to FDCs and the absence of serious adverse drug reactions compared with dual therapy play an important role in decreasing the incidence of hyperglycemia in patients with T2DM.

Implications

From this updated review, it was found that metformin was the most widely used component of FDCs with other OHAs. Studies on the safety and efficacy of newly approved OHAs such as sodium glucose cotransporter inhibitors were limited. An increasing number of randomized trials on the safety and efficacy of newly emerging FDCs suggests that they would be better treatment options for T2DM patients.

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Comprehensive analysis of current fixed-dose combinations used in the treatment of type 2 diabetes mellitus

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Most widely used component of fixed-dose combinations is metformin with other oral hypoglycemic agents (eg, like glimepiride, pioglitazone, rosiglitazone, acarbose, and sitagliptin.

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Fixed-dose combinations help to reduce hyperglycemia efficiently; the long-term complication of diabetes could be minimized in these patients, thereby improving the quality of life of patients.

Changes in Type 2 Diabetes Mellitus Patients in German Primary Care Prior to (2006) and After (2010, 2014) Launch of New Drugs

AIMS

The aim was to analyze the changes in a German type 2 diabetes population prior to (2006) and after (2010, 2014) launch of new drugs.

METHODS

Patients with T2DM in 2006, 2010, and 2014 were recruited for the study. Demographic data included age, gender, and health insurance type (private/statutory). Drug prescription, mean costs per patient, HbA1c levels, macrovascular complications, and time before first insulin prescription were analyzed.

RESULTS

In all, 64 098, 77 219, and 85 004 T2DM patients were included for 2006, 2010, and 2014, respectively. The mean age (65.9-66.9 years), proportion of men (50.8%-53.8%), and proportion of patients with private health insurance (6.6%-7.2%) differed significantly for each of the 3 years. There was a 1.25-fold increase in the total costs per patient, linked with an increase in the costs associated with the use of new drugs and a decrease in those associated with the use of old drugs, respectively. HbA1c levels were slightly better regulated in 2014 than in 2006 and 2010. The share of macrovascular complications decreased significantly over time, dropping from 27.4% in 2006 to 24.6% in 2014. The mean duration before first insulin treatment increased from 1225 days in 2006 to 1406 days in 2014.

CONCLUSIONS

The new drugs analyzed in this study had positive effects on HbA1c levels, macrovascular complications, and mean time before first insulin treatment.