A Systematic Review of Economic Evaluations of Insulin for the Management of Type 2 Diabetes

Diabetes is a chronic, metabolic disease characterized by hyperglycemia, which occurs as a result of inadequate production or utilization of insulin. Type 2 diabetes (T2D) is the most common type of diabetes with estimates projecting a prevalence of more than 1 billion people living with T2DM by 2050. Hence, it was decided to conduct a systematic literature review of health economic evaluations of insulin, the most common medication used for the treatment of the disease, to inform policy. Pharmacoeconomic analyses, written in English and published after 2016, were considered for inclusion. PubMed/Medline, Global Health, Embase and Health Management Consortium were searched separately between 5 July 2023 and 17 July 2023. Grey literature articles were searched on ISPOR and the Cost-Effectiveness Analysis Registry during the same period. After the exclusion criteria were applied, 21 studies were included. Using the BMJ checklist, a quality appraisal was performed on all included studies. Data extraction was performed manually. Regarding evidence synthesis, data were heterogenous and are presented based on study type. The results showed a variety of treatment combinations being available for the treatment of diabetes, with insulin degludec/DegLira and semaglutide being cost-effective despite their high cost, due to the effectiveness of managing the disease. Research around the cost-effectiveness or cost-utility of insulin has potential to progress further, to ensure informed policy-making in the future.

Cost-Effectiveness of Insulin Degludec vs. Insulin Glargine U100 in Type 1 and Type 2 Diabetes Mellitus in a UK Setting

BACKGROUND

Understanding which therapeutic innovations in diabetes represent the best value requires rigorous economic evaluation. Data from randomised controlled trials and observational studies indicate that insulin degludec has a hypoglycemia advantage versus insulin glargine 100 units/mL (glargine U100), the most widely prescribed basal insulin analogue in the UK. This analysis was done to more rigorously assess cost-effectiveness in a UK setting.

METHODS

Data from two double-blinded, randomised, two-period crossover trials in type 1 (SWITCH 1) and type 2 (SWITCH 2) diabetes mellitus were used to assess the cost-effectiveness of degludec vs. glargine U100 with an economic model. Cost-effectiveness was analysed over a 1-year time horizon based on the different rates of hypoglycaemia and actual doses of insulin used, rather than glycaemic control due to the treat-to-target trial design.

RESULTS

In type 1 diabetes mellitus, degludec was highly cost-effective compared with glargine U100, with an incremental cost-effectiveness ratio of £984 (increased costs of only £23/year and improvement in participant health of 0.0232 quality-adjusted life-years (QALYs)). In type 2 diabetes mellitus, it was estimated that quality of life was improved (0.0065 QALYs gain) with degludec compared with glargine U100 at an increased annual cost of £117 (incremental cost-effectiveness ratio, £17,939). One-way sensitivity analyses showed that the results were robust to changes in parameters in both type 1 and type 2 diabetes mellitus.

CONCLUSIONS

The rigorous design of the SWITCH trials, coupled with a representative patient population and a definition of hypoglycaemia that is relevant for real-world patients, makes the results of these trials highly generalisable. The within-trial analysis has the added value of being able to include doses and event rates directly from the trials. This short-term economic analysis estimated that IDeg would be cost-effective relative to IGlar U100 in both type 1 and type 2 diabetes mellitus in the UK.

TRIAL REGISTRATION

SWITCH 1 (NCT02034513); SWITCH 2 (NCT02030600).

FUNDING

Novo Nordisk, Søborg, Denmark.

Systematic Review of the Cost Effectiveness of Insulin Analogues in Type 1 and Type 2 Diabetes Mellitus

BACKGROUND

Insulin analogues have a pharmacokinetic advantage over human insulin and are increasingly used to treat diabetes mellitus. A summary of their cost effectiveness versus other available treatments was required.

OBJECTIVE

Our objective was to systematically review the published cost-effectiveness studies of insulin analogues for the treatment of patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM).

METHODS

We searched major databases and health technology assessment agency reports for economic evaluation studies published up until 30 September 2015. Two reviewers performed data extraction and assessed the quality of the data using the CHEERS (Consolidated Health Economic Evaluation Reporting Standards) guidelines.

RESULTS

Seven of the included studies assessed short-acting insulin analogues, 12 assessed biphasic insulin analogues, 30 assessed long-acting insulin analogues and one assessed a combination of short- and long-acting insulin analogues. Only 17 studies involved patients with T1DM, all were modelling studies and 12 were conducted in Canada. The incremental cost-effectiveness ratios (ICERs) for short-acting insulin analogues ranged from dominant to $US435,913 per quality-adjusted life-year (QALY) gained, the ICERs for biphasic insulin analogues ranged from dominant to $US57,636 per QALY gained and the ICERs for long-acting insulin analogues ranged from dominant to $US599,863 per QALY gained. A total of 15 studies met all the CHEERS guidelines reporting quality criteria. Only 26 % of the studies assessed heterogeneity in their analyses.

CONCLUSION

Current evidence indicates that insulin analogues are cost effective for T1DM; however, evidence for their use in T2DM is not convincing. Additional evidence regarding compliance and efficacy is required to support the broader use of long-acting and biphasic insulin analogues in T2DM. The value of insulin analogues depends strongly on reductions in hypoglycaemia event rates and its efficacy in lowering glycated haemoglobin (HbA_1c).

PEGylated insulin Lispro (LY2605541): clinical overview of a new long-acting basal insulin analog in the treatment of Type 2 diabetes mellitus

Neutral Protamine Hagedorn insulin with an intermediate action profile has been in use for many years for the treatment of Type 1 diabetes and as an option for Type 2 diabetes. It is efficacious in reducing blood sugars, but shows substantial variability and risk of hypoglycemia. Basal insulin analogs have been developed in recent years to overcome these issues. Three basal insulin analogs are currently in the market in Europe. PEGylated insulin lispro is a new second-generation basal insulin analog which most likely will undergo review in 2016 by the US FDA and EMA in Europe for possible approval for marketing. Phase III trials are finalized, but not yet published. Phase II studies suggest antiglycemic efficacy, possible with a preferential hepato-specific action, a low rate of hypoglycemia, minor weight loss and acceptable tolerability. The benefit-risk profile needs, however, to be established.

Old and new basal insulin formulations: understanding pharmacodynamics is still relevant in clinical practice

Long-acting insulin analogues have been developed to mimic the physiology of basal insulin secretion more closely than human insulin formulations (Neutral Protamine Hagedorn, NPH). However, the clinical evidence in favour of analogues is still controversial. Although their major benefit as compared with NPH is a reduction in the hypoglycaemia risk, some cost/effectiveness analyses have not been favourable to analogues, largely because of their higher price. Nevertheless, these new formulations have conquered the insulin market. Human insulin represents currently no more than 20% of market share. Despite (in fact because of) the widespread use of insulin analogues it remains critical to analyse the pharmacodynamics (PD) of basal insulin formulations appropriately to interpret the results of clinical trials correctly. Importantly, these data may help physicians in tailoring insulin therapy to patients' individual needs and, additionally, when clinical evidence is not available, to optimize insulin treatment. For patients at low risk for/from hypoglycaemia, it might be acceptable and also cost-effective not to use long-acting insulin analogues as basal insulin replacement. Conversely, in patients with a higher degree of insulin deficiency and increased risk for hypoglycaemia, analogues are the best option due to their more physiological profile, as has been shown in PD and clinical studies. From this perspective optimizing basal insulin treatment, especially in type 2 diabetes patients who are less prone to hypoglycaemia, would be suitable making significant resources available for other relevant aspects of diabetes care.

Basal insulin analogues in the management of diabetes mellitus: What progress have we made?

Insulin remains the most effective and consistent means of controlling blood glucose levels in diabetes. Since 1946, neutral protamine Hagedorn (NPH) has been the predominant basal insulin in clinical use. However, absorption is variable due to the need for resuspension and the time-action profile (peak activity 4-6 h after subcutaneous administration) confers an increased propensity for between-meal and nocturnal hypoglycaemia. In the 1980s, recombinant DNA technology enabled modifications to the insulin molecule resulting in the soluble long-acting insulin analogues, glargine and detemir. Both exhibit a lower risk of hypoglycaemia compared with neutral protamine Hagedorn due to improved time-action profiles and reduced day-to-day glucose variability. Glargine is indicated for administration once daily and detemir once or twice daily. Degludec is the latest prolonged-acting insulin which forms long subcutaneous multi-hexamers that delay absorption. Recent phase III trials in type 1 and type 2 diabetes show that degludec was non-inferior to comparators (predominantly glargine) with a minimal although inconsistent reduction in overall hypoglycaemia and a small absolute difference in nocturnal hypoglycaemia. Newer developmental agents include LY2605541 and glargine U300. LY2605541 comprises insulin lispro combined with polyethylene glycol, thereby increasing its hydrodynamic size and retarding absorption from the subcutaneous tissue. Glargine U300 is a new formulation of glargine resulting in a flatter and more prolonged time-action profile than its predecessor. This article reviews recent advances in basal insulin analogues, including a critical appraisal of the degludec trials.

Fatty acids as therapeutic auxiliaries for oral and parenteral formulations

Many drugs have decreased therapeutic activity due to issues with absorption, distribution, metabolism and excretion. The co-formulation or covalent attachment of drugs with fatty acids has demonstrated some capacity to overcome these issues by improving intestinal permeability, slowing clearance and binding serum proteins for selective tissue uptake and metabolism. For orally administered drugs, albeit at low level of availability, the presence of fatty acids and triglycerides in the intestinal lumen may promote intestinal uptake of small hydrophilic molecules. Small lipophilic drugs or acylated hydrophilic drugs also show increased lymphatic uptake and enhanced passive diffusional uptake. Fatty acid conjugation of small and large proteins or peptides has exhibited protracted plasma half-lives, site-specific delivery and sustained release upon parenteral administration. These improvements are most likely due to associations with lipid-binding serum proteins, namely albumin, LDL and HDL. These molecular interactions, although not fully characterized, could provide the ability of using the endogenous carrier systems for improving therapeutic outcomes.