Glycemic Control Outcomes After Canagliflozin Initiation: Observations in a Medicare and Commercial Managed Care Population in Clinical Practice

Use of prescription drug samples in the US and implications for pharmacoepidemiologic research: a systematic search of the literature

INTRODUCTION

Free drug samples are not captured in the pharmacy claims databases used in many pharmacoepidemiologic studies, which could lead to misclassification of drug exposure status and thus bias study results.

AREAS COVERED

We systematically searched the literature in PubMed/MEDLINE, Embase, and Scopus from database inception to August 2020 for studies assessing the magnitude of exposure misclassification in pharmacy claims data associated with uncaptured drug sample utilization. Our review identified five US-based studies with substantially different characteristics, contexts, methods, and results. Taken together, these studies suggest that the risk of sample-related bias may be higher for (1) studies of newly approved, patented brand-only drugs in specific classes and contexts; (2) studies of populations where sample use is common and the unexposed cohort is small; and (3) studies where the outcomes of interest are expected to be early-onset or acute, with non-constant hazards.

EXPERT OPINION

In light of declining overall trends in sample use, future research on sample-related exposure misclassification should focus on delineating bias across those modern contexts where sample use remains high and optimizing bias quantification methods to create a more standardized approach. Additionally, further assessment is warranted for other sources of misclassified exposure status in claims-based pharmacoepidemiology research.

Canagliflozin: metabolic, cardiovascular and renal protection

Patients with Type 2 Diabetes (T2D) are at risk of developing macrovascular (cardiac, cerebrovascular, peripheral arterial disease) and microvascular (nephropathy, neuropathy, retinopathy) complications. Glycemic control improves only microvascular outcomes. However, some SGLT-2 inhibitors and GLP1-R agonists have proven beneficial in macrovascular conditions. Canagliflozin is an SGLT2 inhibitor that provides sustained reductions in HbA1c, blood pressure and weight. Remarkably, as CANVAS program and CREDENCE trial demonstrated, canagliflozin promotes significant reductions in the frequency of atherosclerotic cardiovascular events, hospitalizations for heart failure and renal outcomes. In addition, real-world studies have confirmed the results of clinical trials in clinical practice. Therefore, canagliflozin should be considered a first-line therapy in the management of T2D patients in order to reduce both micro- and macrovascular complications.

Canagliflozin: A Review in Type 2 Diabetes

Canagliflozin (Invokana^®) is a sodium-glucose co-transporter-2 (SGLT2) inhibitor indicated in various countries worldwide for the once-daily oral treatment of type 2 diabetes (T2D). Canagliflozin lowers blood glucose levels independently of insulin, with the inhibition of SGLT2 reducing renal reabsorption of glucose and increasing excretion of glucose in the urine. In well-designed clinical trials, canagliflozin (as first-line monotherapy or add-on therapy to other antihyperglycaemic agents) improved glycaemic control in adults with T2D, including those of older age and/or at high cardiovascular (CV) risk, and also had beneficial effects on their bodyweight and blood pressure (BP). CV risk reduction, as well as possible renal benefits, were also seen with canagliflozin in T2D patients at high CV risk in the CANVAS Program, an integrated analysis of two large CV outcomes studies. Canagliflozin was generally well tolerated, had a low risk of hypoglycaemia and was most commonly associated with adverse events such as genital and urinary tract infections and increased urination, consistent with its mechanism of action. Although the amputation and fracture risk observed among recipients of the drug require further investigation, canagliflozin is an important option for T2D management in adults.

An investigation into the durability of glycemic control in patients with type II diabetes initiated on canagliflozin or sitagliptin: A real-world analysis of electronic medical records

AIMS

The aims of this study were to assess glycemic control, weight loss, and durability of glycemic control in patients initiated on canagliflozin (CANA) versus sitagliptin (SITA).

METHODS

Adults with type II diabetes mellitus initiated on CANA or SITA (index date) were identified from IQVIA™ Real-World Data Electronic Medical Records - US database (03/29/2012-04/30/2016). Inverse probability of treatment weighting accounted for baseline differences between cohorts. Outcomes were compared using weighted Cox regression and Kaplan-Meier curves and included time to reaching HbA1c thresholds (<7%[53 mmol/mol], <8%[64 mmol/mol], <9%[75 mmol/mol]), weight loss ≥5%, failure to maintain HbA1c below threshold, new antihyperglycemic (AHA) prescription, and failure to maintain HbA1c/new AHA prescription.

RESULTS

Weighted cohorts were well balanced (N_CANA = 14,542; N_SITA = 15,151). CANA patients were 12-15% more likely to reach the HbA1c thresholds, 47% more likely to lose ≥5% of body weight, 31% less likely to have a new AHA prescription, 10-15% less likely to fail to maintain HbA1c, and 13-26% less likely to fail to maintain HbA1c or have a new AHA, versus SITA patients.

CONCLUSIONS

CANA patients were more likely to reach HbA1c and weight loss thresholds and maintain HbA1c below threshold versus SITA patients, while being less likely to have a prescription for a new AHA, suggesting more durable glycemic control with CANA.