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 HbA1c 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 HbA1c 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 patt