A cost-effectiveness analysis of pioglitazone plus metformin compared with rosiglitazone plus metformin from a third-party payer perspective in the US^*

ABSTRACT

Objective: The long-term cost-effectiveness of using pioglitazone plus metformin (Actoplusmet^†) compared with rosiglitazone plus metformin (Avandamet^‡) in treating type 2 diabetes (T2DM) was assessed from a US third-party payer perspective.

† Actoplusmet is a trade name of Takeda Pharmaceuticals North America, Inc., Deerfield, IL, USA

‡ Avandamet is a trade name of GlaxoSmithKline, Research Triangle, NC, USA

Research design and methods: Clinical efficacy (change in HbA_1c and lipids) and baseline cohort parameters were extracted from a 12-month, randomized clinical trial (Derosa et al., 2006) evaluating the efficacy and tolerability of pioglitazone versus rosiglitazone, both in addition to metformin, in adult T2DM patients with insufficient glucose control (n = 96). A Markov-based model was used to project clinical and economic outcomes over 35 years, discounted at 3% per annum. Costs for complications were taken from published sources. Base-case assumptions were assessed through several sensitivity analyses.

Main outcome measures: Outcomes included incremental life-years, quality-adjusted life-years (QALYs), total direct medical costs, cumulative incidence of complications and associated costs, and incremental cost–effectiveness ratios (ICERs).

Results: Compared to rosiglitazone plus metformin, pioglitazone plus metformin was projected to result in a modest improvement in 0.187 quality-adjusted life-years. Over patients’ lifetimes, total direct medical costs were projected to be marginally lower with pioglitazone plus metformin (difference –$526.), largely due to reduced CVD complication costs. While costs were higher among renal, ulcer/amputation/neuropathy, and eye complications in the pioglitazone plus metformin group, the cost savings for CVD complications outweighed their economic impact. Pioglitazone plus metformin was found to be a dominant long-term treatment strategy in the US compared to rosiglitazone plus metformin. Sensitivity analyses showed findings to be robust under almost all scenarios, including short-term time horizons, 6% discounting, removal of individual lipid parameters, and modifications of patient cohort to more closely represent a US T2DM population. Pioglitazone plus metformin was no longer dominant with 0% discounting, with 25% reduction in its HbA_1c effects, or with a 15% increase in its acquisition price.

Conclusions: Under a range of assumptions and study limitations around cohorts, clinical effects, and treatment patterns, this long-term analysis showed that pioglitazone plus metformin, when compared to rosiglitazone plus metformin, was a dominant treatment strategy within the US payer setting. Results were driven by the combination of modest differences in QALYs and modest savings in total complication costs over 35 years.

Key words: :

• Economic modeling
• Metformin
• Pioglitazone
• Rosiglitazone
• Type 2 diabetes mellitus

Transparency

Declaration of funding

This study was supported by Takeda Pharmaceutical North America, Inc, which funded IMS Health Consulting Service's expenses in carrying out the analyses and producing the manuscript through a consulting services contract. The research agreement did not specify what kind of results should come from the analysis and thus did not specify what type of results would be acceptable to the sponsors.

Declaration of financial/other relationships

B.P. has disclosed that he is an employee of Takeda. R.B. has disclosed that he was an employee of Takeda at the time the study was conducted. S.T. has disclosed that she has received grant/research funding from Takeda and is an employee of IMS Health. M.M. and M.S. have disclosed that they were employees of IMS Health at the time the study was conducted.

All peer reviewers receive honoraria from CMRO for their review work. Peer Reviewer 1 has disclosed that he/she is the recipient of grant/research funding from Novartis; has applied for grant/research funding from Aventis; and is a member of the speakers bureau of Roche. Peer Reviewer 2 has disclosed that he/she has no relevant financial relationships.

Acknowledgments

IMS Health Consulting Service assisted in the preparation of this manuscript under the consulting services contract with Takeda.

Erratum

[Early Online citation]

The Early Online version of this article published online ahead of print on 6 May 2009 contained an error on page 1350. The first sentence in the Discussion section has been corrected and the corrected version is shown in this issue (and as reposted on 27 May 2009).

Notes

* Some of the data in this paper were presented in poster format at the ISPOR 10th European Congress, Dublin, Ireland, October 22–25, 2007

† Actoplusmet is a trade name of Takeda Pharmaceuticals North America, Inc., Deerfield, IL, USA

‡ Avandamet is a trade name of GlaxoSmithKline, Research Triangle, NC, USA

* Actos is a trade name of Takeda Pharmaceuticals North America, Inc., Deerfield, IL, USA

† Avandia is a trade name of GlaxoSmithKline, Research Triangle, NC, USA

‡ Actoplusmet is a trade name of Takeda Pharmaceuticals North America, Inc., Deerfield, IL, USA

§ Avandamet is a trade name of GlaxoSmithKline, Research Triangle, NC, USA