Cost-Effectiveness of Saxagliptin versus Acarbose as Second-Line Therapy in Type 2 Diabetes in China

Sponsorship bias in published pharmacoeconomic evaluations of national reimbursement negotiation drugs in China: a systematic review

BACKGROUND

China's National Reimbursement Drug List (NRDL) has become the primary route for drug reimbursement in China. More recently, the authority has made pharmacoeconomic evaluation an integral part of the application for NRDL inclusion. The underlying financial conflict of interests (FCOI) of pharmacoeconomic evaluations, however, has the potential to influence evidence generated and thus subsequent decision-making yet remains poorly understood.

METHODS

We searched for studies published between January 2012 and January 2022 on the 174 drugs added to the 2017-2020 NRDLs after successful negotiation. We categorised the study's FCOI status into no funding, industry funding, non-profit funding and multiple fundings based on authors' disclosure and assessed the reporting quality of included studies using the Consolidated Health Economic Evaluation Reporting Standards 2022 checklist. We compiled descriptive statistics of funding types and study outcomes using t-tests and χ2 tests and conducted multivariate regression analysis.

RESULTS

We identified 378 records and our final sample included 92 pharmacoeconomic evaluations, among which 69.6% were conducted with at least one funding source. More than half (57.6%) of the evaluations reached favourable conclusions towards the intervention drug and 12.6% reached a dominant result of the intervention drug over the comparison from model simulation. The reporting quality of included studies ranged from 19 to 25 (on a scale of 28), with an average of 22.3. The statistical tests indicated that industry-funded studies were significantly more likely to conclude that the intervention therapy was economical (p<0.01) and had a significantly higher proportion of resulting target drug economically dominated the comparison drug (p<0.05).

CONCLUSION

The study revealed that FCOI bias is common in published pharmacoeconomic evaluations conducted in Chinese settings and could significantly influence the study's economical results and conclusions through various mechanisms. Multifaceted efforts are needed to improve transparency, comparability and reporting standardisation.

Cost-Effectiveness of Newer Antidiabetic Drugs as Second-Line Treatment for Type 2 Diabetes: A Systematic Review

INTRODUCTION

Evidence from cardiovascular outcome trials (CVOTs) for newer antidiabetic drugs is increasingly influencing revised recommendations for second-line therapy in type 2 diabetes (T2D). This systematic review aimed to compare the cost-effectiveness of newer antidiabetic drugs specified as sodium-glucose cotransporter 2 inhibitor (SGLT2i), glucagon-like peptide 1 receptor agonist (GLP-1RA), and dipeptidyl peptidase 4 inhibitor (DPP-4i) for T2D in a second-line setting.

METHODS

A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines, and all relevant published studies were searched comprehensively in electronic databases, including PubMed, Embase, Web of Science, and International Health Technology Assessment database published from April 2023. The quality of the included studies was evaluated using Consolidated Health Economic Evaluation Reporting Standards (CHEERS) 2022 reporting checklists.

RESULTS

We included 28 studies that met the inclusion criteria. Overall reporting of the identified studies largely met CHEERS 2022 recommendations. The CORE and Cardiff models were the most frequently utilized for pharmacoeconomic evaluation in T2D. Four studies consistently discovered that SGLT2i was more cost-effective than GLP-1RA in T2D who were not adequately controlled by metformin monotherapy. Four studies compared GLP-1RA with DPP-4i, sufonylurea (SU), or insulin. Except for one that demonstrated SU was cost-effective, all were GLP-1RA. Five studies revealed that SGLT2i was more cost-effective than DPP-4i or SU. Eleven studies indicated that DPP-4i was more cost-effective than traditional antidiabetic drugs. Four additional studies explored the cost-effectiveness of various antidiabetic drugs as second-line options, indicating that SU, SGLT2i, or meglitinides were more economically advantageous. The most common driven factors were the cost of new antidiabetic drugs.

CONCLUSION

Newer antidiabetic drugs as second line are the cost-effective option for T2D from the cost-effectiveness perspective, especially SGLT2i.

Pharmacoeconomic evaluation of dipeptidyl peptidase-4 inhibitors for the treatment of type 2 diabetes mellitus: a systematic literature review

INTRODUCTION

Dipeptidyl peptidase-4 inhibitors (DPP-4i) are widely used oral antidiabetic agents that exert antihyperglycemic effects in type 2 diabetes mellitus (T2DM) without increased risk of weight gain or hypoglycemic events. The objective of this paper was to systematically review the latest evidence that was associated with the pharmacoeconomic evaluation of DPP-4i for the treatment of patients with T2DM.

AREAS COVERED

We conducted a systematic literature search of eligible articles published since inception up to March 2021 in Web of Science, MEDLINE (via PubMed), and ECONLIT. Fifty-four eligible articles were included in our review, in which DPP-4i were compared to metformin (4 studies), sulphonylurea (SU) (16 studies), alpha-glucosidase inhibitors (AGI) (3 studies), thiazolidinediones (TZD) (4 studies), other DPP-4i (3 studies), sodium-glucose co-transporter-2 inhibitors (SGLT-2i) (10 studies), glucagon-like peptide 1 receptor agonist (GLP-1RA) (18 studies), insulin (5 studies), and other antidiabetic therapies (5 studies).

EXPERT OPINION

This study provided the updated evidence of systematic pharmacoeconomic evaluation associated with DPP-4i for the treatment of patients with T2DM. The evidence from the literature suggested that DPP-4i may be more cost-effective compared to SU and insulin as second-line therapy after metformin but not a cost-effective alternative compared to SGLPT-2i and GLP-1RA.

The validity of cost-effectiveness analyses of tight glycemic control. A systematic survey of economic evaluations of pharmacological interventions in patients with type 2 diabetes

PURPOSE

Currently available randomized trial evidence has shown no reductions in type 2 diabetes (T2D) complications important to patients with tight glycemic control. Yet, economic analyses consistently find tight glycemic control to be cost-effective. To understand this apparent paradox, we systematically identified and appraised economic analyses of tight glycemic control for T2D.

METHODS

We searched multiple databases from January 2016 to January 2018 for cost-effectiveness or cost-utility analyses of any glucose-lowering treatments for adults with T2D using simulations with long-40 years to lifetime-time horizons. Reviewers selected and appraised each study independently and in duplicate with good reproducibility.

RESULTS

We found 30 analyses, most comparing the glycemic impact of glucose-lowering drugs and applying their impact on HbA1c to model (most commonly IMS CORE or Cardiff T2DM) their impact on the incidence of diabetes-related complication. Models drew from observational evidence of the correlation of HbA1c levels and diabetes-related complication rates; none used estimates of the effect of lowering HbA1c on these outcomes from systematic reviews of randomized trials. Sensitivity analyses, when conducted, demonstrate substantial loss of cost-effectiveness as simulations approach the results seen in these trials.

CONCLUSIONS

Reliance on the association between glycemic control and diabetes-related complications evident in observational studies but not apparent in randomized trial bias the estimates of the cost-effectiveness of interventions to improve glycemic control.

Cost-Utility Analysis of Dapagliflozin Versus Saxagliptin Treatment as Monotherapy or Combination Therapy as Add-on to Metformin for Treating Type 2 Diabetes Mellitus

OBJECTIVE

To assess the long-term cost effectiveness of dapagliflozin (DAPA) and saxagliptin (SAXA) separately or together in patients with type 2 diabetes mellitus (T2DM) inadequately controlled by metformin (MET).

METHODS

Five head-to-head randomised controlled trials of the efficacy of DAPA and SAXA in type 2 diabetes mellitus (T2DM) patients were found by searching PubMed, Embase and Cochrane from inception to October 2019. The lifetime disease progression and long-term effectiveness of therapy in patients were projected by the United Kingdom Prospective Diabetes Study Outcome Model 2 (UKPDS OM2) in three T2DM therapeutic groups: DAPA + SAXA, DAPA and SAXA. Each group used DAPA and/or SAXA as an add-on therapy to MET. The study took the perspective of Chinese healthcare service providers. Univariate, scenario and probabilistic sensitivity analyses were performed.

RESULTS

The quality-adjusted life-years (QALYs) value of the DAPA + SAXA, SAXA and DAPA groups were 11.28, 11.26 and 11.45 years, respectively. The total costs were US$27,954.84, US$23,254.46 and US$25,608.49, respectively. DAPA was dominant over DAPA + SAXA. The DAPA + SAXA group presented an estimated QALY gain of 0.02 and a total cost increase of US$4700.39 over the SAXA group, with an incremental cost of US$217,530.10 per QALY. Compared with the SAXA group, the DAPA group had a QALY gain of 0.19 years and a total cost increase of US$2354.04, for an incremental cost of US$12,191.97 per QALY. The pharmacoeconomic results were robust to univariate, scenario and probabilistic sensitivity analyses.

CONCLUSIONS

Compared with DAPA + SAXA or SAXA, DAPA appears to be a cost-effective therapy as add-on to MET for Chinese patients whose T2DM is insufficiently controlled by MET.

Choice across 10 pharmacologic combination strategies for type 2 diabetes: a cost-effectiveness analysis

BACKGROUND

Clinical guidelines recommend a stepped-escalation treatment strategy for type 2 diabetes (T2DM). Across multiple treatment strategies varying in efficacy and costs, no clinical or economic studies directly compared them. This study aims to estimate and compare the cost-effectiveness of 10 commonly used pharmacologic combination strategies for T2DM.

METHODS

Based on Chinese guideline and practice, 10 three-stepwise add-on strategies were identified, which start with metformin, then switch to metformin plus one oral drug (i.e., sulfonylurea, thiazolidinedione, α-glucosidase inhibitor, glinide, or DPP-4 inhibitor) as second line, and finally switch to metformin plus one injection (i.e., insulin or GLP-1 receptor agonist) as third line. A cohort of 10,000 Chinese patients with newly diagnosed T2DM was established. From a healthcare system perspective, the Cardiff model was used to estimate the cost-effectiveness of the strategies, with clinical data sourced from a systematic review and indirect treatment comparison of 324 trials, costs from claims data of 1164 T2DM patients, and utilities from an EQ-5D study. Outcome measures include costs, quality-adjusted life-years (QALYs), incremental cost-effectiveness ratios (ICERs), and net monetary benefits (NMBs).

RESULTS

Over 40-year simulation, the costs accumulated for a patient ranged from $7661 with strategy 1 to $14,273 with strategy 10, while the QALY gains ranged from 13.965 with strategy 1 to 14.117 with strategy 8. Strategy 7 was dominant over seven strategies (strategies 2~6, 9~10) with higher QALYs but lower costs. Additionally, at a willingness-to-pay threshold of $30,787/QALY (i.e., 3 times GDP/capita for China), strategy 7 was cost-effective compared with strategy 1 (ICER of strategy 7 vs. 1, $3371/QALY) and strategy 8 (ICER of strategy 8 vs. 7, $132,790/QALY). Ranking the strategies by ICERs and NMBs, strategy 7 provided the best value for money when compared to all other strategies, followed by strategies 5, 9, 8, 1, 3, 6, 10, 2, and 4. Scenario analyses showed that patients insist on pharmacologic treatments increased their QALYs (0.456~0.653) at an acceptable range of cost increase (ICERs, $1450/QALY~$12,360/QALY) or even at cost saving compared with those not receive treatments.

CONCLUSIONS

This study provides evidence-based references for diabetes management. Our findings can be used to design the essential drug formulary, infer clinical practice, and help the decision-maker design reimbursement policy.

Cost-utility analysis of second-line anti-diabetic therapy in patients with type 2 diabetes mellitus inadequately controlled on metformin

BACKGROUND

There are significant differences in costs and effectiveness among the second-line treatment options for type 2 diabetes (T2DM). We aimed to evaluate the cost-effectiveness of the second-line anti-diabetic therapy in T2DM patients inadequately controlled on metformin (MET) in Taiwan from the perspective of the National Health Insurance (NHI).

METHODS

The Cardiff T2DM model was used to predict the occurrence of mortality, diabetes-related complications, and drug adverse events. Five second-line treatments were selected for the analysis: sodium-glucose cotransporter 2 inhibitors (SGLT-2-i), glucagon-like peptide-1 receptor agonists (GLP-1-RA), dipeptidyl peptidase-4 inhibitor (DPP-4-i), sulfonylurea (SU), and insulin (INS). Treatment efficacy data were obtained from meta-analyses and randomized clinical trials, whereas cost data were derived from the NHI databases.

RESULTS

The analysis found that SU + MET (DPP-4-i as triple therapy) had the lowest cost, and SU + MET (SGLT-2-i as triple therapy) was associated with a mean incremental benefit of 0.47 quality-adjusted life years (QALYs) at an incremental cost of NT$2769, resulting in an incremental cost-effectiveness ratio (ICER) of NT$5840/QALY. Compared to their next less costly strategies, SGLT-2-i + MET (SU as triple therapy) and SGLT-2-i + MET (DPP-4-i as triple therapy) had ICER values of NT$63,170/QALY and NT$64,090/QALY, respectively. These results were fairly robust to extensive sensitivity analyses, but were relatively sensitive to baseline HbA1c, HbA1c threshold, and utilities.

CONCLUSION

The addition of either SU or SGLT-2-i to MET was found to be cost-effective, using the 2019 forecast for GDP per capita of Taiwan (NT$770,770) as the willingness to pay (WTP) threshold.

Cost Effectiveness of Sodium-Glucose Cotransporter-2 (SGLT2) Inhibitors, Glucagon-Like Peptide-1 (GLP-1) Receptor Agonists, and Dipeptidyl Peptidase-4 (DPP-4) Inhibitors: A Systematic Review

OBJECTIVE

This study aimed to systematically review cost-effectiveness studies of newer antidiabetic medications.

METHODS

The PubMed/MEDLINE, EMBASE, CINAHL Plus, Cochrane Library-NHS Economic Evaluation Database (Wiley), Cochrane Library-Health Technology Assessment Database (Wiley), Cochrane Library-Database of Abstracts of Reviews of Effects (Wiley), and the Cost-Effectiveness Analysis Registry databases (from 1 January 2000 to 1 June 2018) were searched. The search strategies included the Medical Subject Heading (MeSH) term 'economics', and the MeSH entry terms 'cost', 'cost effectiveness', 'value', and 'cost utility', as well as all names for GLP-1 receptor agonists, DPP-4 inhibitors, and SGLT2 inhibitors. Inclusion criteria included (1) cost-effectiveness studies of the newer antidiabetic medications, including sodium-glucose cotransporter-2 (SGLT2) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, and dipeptidyl peptidase-4 (DPP-4) inhibitors; and (2) full-text publications in English. Two reviewers independently screened the titles, abstracts, and full-text articles to select studies for data extraction. Discrepancies were resolved by discussion and consensus. The quality of reporting cost-effectiveness analyses was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) guideline.

RESULTS

Among 85 studies selected, 82 clearly stated the types of diabetes model used (e.g. CORE model), and 70 studied used validated diabetes models. Seventy-four (87%) studies were funded by pharmaceutical companies, and 72 (85%) studies were conducted from a payer's perspective. Seventy-six (89%) studies presented were of good quality (20-24 CHEERS items), and nine were of moderate quality (14-19 items). Thirty studies compared newer antidiabetic medications with insulin, 3 studies compared newer antidiabetic medications with thiazolidinediones (TZDs), 15 studies compared newer antidiabetic medications with sulfonylureas, 40 studies compared new antidiabetic medications with alternative newer antidiabetic medication, and 9 studies compared other antidiabetic agents that were not included above. Newer antidiabetic medications were reported to be cost-effective in 26 of 30 (87%) studies compared with insulin, and 13 of 15 (87%) studies compared with sulfonylureas.

CONCLUSIONS

Most economic evaluations of antidiabetic medications have good reporting quality and use validated diabetes models. The newer antidiabetic medications in most of the reviewed studies were found to be cost effective, compared with insulin, TZDs, and sulfonylureas.

Therapeutic Experience of Saxagliptin as First Add-on after Metformin in Indian Type 2 Diabetes Patients: A Non-interventional, Prospective, Observational Study (ONTARGET-INDIA)

INTRODUCTION

Dipeptidyl peptidase 4 (DPP4) inhibitors are widely used in type 2 diabetes mellitus (T2DM) patients but the data available in existing clinical trial programmes on DPP4 inhibitors include limited number of patients from India. Hence, this study attempted to understand usage, efficacy and safety of saxagliptin as first add-on after metformin in Indians with T2DM.

METHODOLOGY

It was a multicenter, prospective, non-interventional and observational study planned to enrol T2DM patients who were inadequately controlled with metformin alone and had been recently (i.e., within past 15 days) prescribed saxagliptin as an add-on to metformin. Type 1 diabetes mellitus, use of glucose lowering drugs apart from metformin or saxagliptin, pregnancy, lactation, and medical condition, which could interfere with safe completion of the study were excluded.

RESULTS

A total of 1109 participants (658 men and 451 women) with mean ± SD age of 51.17 ± 11.85 years were enrolled from 50 centres throughout India. Significant reduction was observed in mean ± SD change of HbA1c as - 0.86% ± 1.76 from baseline to after 3 months of therapy (P < 0.0001). The quality of life assessed by World Health Organization Quality of Life-BREF (WHOQOL-BREF) questionnaire was reported to be "good" or "neither good nor bad" by majority of the participants at baseline and after 3 months of treatment. A total of 15 adverse events (AEs) were reported in the study, however, no serious adverse event (SAE) occurred during the study. All AEs were of mild intensity and did not require any intervention.

CONCLUSION

Overall, saxagliptin in combination with metformin was generally well tolerated in Indian T2DM patients and new safety event identified is an increased risk of hospitalisation in heart failure patients. This study is also registered on Clinicaltrials.gov (NCT02588859).

Mechanistic Insight and Management of Diabetic Nephropathy: Recent Progress and Future Perspective

Diabetic nephropathy (DN) is the most serious microvascular complication of diabetes and the largest single cause of end-stage renal disease (ESRD) in many developed countries. DN is also associated with an increased cardiovascular mortality. It occurs as a result of interaction between both genetic and environmental factors. Hyperglycemia, hypertension, and genetic predisposition are the major risk factors. However, the exact mechanisms of DN are unclear. Despite the benefits derived from strict control of glucose and blood pressure, as well as inhibition of renin-angiotensin-aldosterone system, many patients continue to enter into ESRD. Thus, there is urgent need for improving mechanistic understanding of DN and then developing new and effective therapeutic approaches to delay the progression of DN. This review focuses on recent progress and future perspective about mechanistic insight and management of DN. Some preclinical relevant studies are highlighted and new perspectives of traditional Chinese medicine (TCM) for delaying DN progression are discussed in detail. These findings strengthen the therapeutic rationale for TCM in the treatment of DN and also provide new insights into the development of novel drugs for the prevention of DN. However, feasibility and safety of these therapeutic approaches and the clinical applicability of TCM in human DN need to be further investigated.