OBJECTIVES : Agents that inhibit the dipeptidylpeptidase-4 (DPP-4) enzyme, including linagliptin, alogliptin, saxagliptin, sitagliptin and vildagliptin, become available for the treatment of Chinese patients with type 2 diabetes mellitus (T2DM). This study assessed the economic outcomes of different DPP-4 inhibitors in patients with T2DM inadequately controlled with metformin in the Chinese context.

METHODS : Economic outcomes were projected by using the validated Chinese Outcomes Model for T2DM (COMT). Efficacy, safety, medical expenditure, and utility data were derived from the literature, which were assigned as model variables for estimating the quality-adjusted life-years (QALYs) and costs as well as incremental cost-effectiveness ratios (ICERs). The analysis was conducted from the perspective of Chinese healthcare service providers. One-way and probabilistic sensitivity analyses were performed. Health outcomes and costs were discounted at 5%.

RESULTS : Of the five competing treatments, alogliptin 25 mg yielded the most significant health outcome, which was associated with improvements in discounted QALYs of 0.008, 0.009, 0.004 and 0.017 versus linagliptin 5 mg, saxagliptin 5 mg, sitagliptin 100 mg and vildagliptin 50 mg, respectively. The sitagliptin 100 mg strategy was the cheapest option. The ICER of alogliptin 25 mg against sitagliptin 100 mg strategy was $7,323 per additional QALY gained, showing that alogliptin 25 mg is a cost-effective alternative under the threshold of one time the gross domestic product (GDP) per capita in China. The rest of treatments were dominated or extended dominated by sitagliptin 100 mg. Sensitivity analyses showed that the most influential parameters were the cost of DPP-4 inhibitors and their treatment efficacy.

CONCLUSIONS : These results suggested that alogliptin was a preferred treatment option compared with other DPP-4 inhibitors for Chinese patients with T2DM inadequately controlled on metformin monotherapy.