Cost‐effectiveness of dapagliflozin as an adjunct to insulin for the treatment of type 1 diabetes mellitus in the United Kingdom

Aims To assess the cost‐effectiveness of dapagliflozin, a sodium‐glucose co‐transporter‐2 (SGLT2) inhibitor, as an adjunct to insulin in adults with type 1 diabetes mellitus (T1DM) inadequately controlled by insulin alone in the UK setting. Methods A cost–utility analysis was conducted to compare dapagliflozin (5 mg or 10 mg) added to insulin versus insulin monotherapy (standard of care) over a lifetime horizon. Treatment efficacy and safety data were obtained from 52‐week results of the DEPICT‐1 and DEPICT‐2 trials and a network meta‐analysis of SGLT2 inhibitors in T1DM. Direct healthcare costs, life‐years, and quality‐adjusted life‐years (QALYs) were estimated from a UK payer perspective and discounted at 3.5% annually, using the Cardiff T1DM Model. Sensitivity analyses assessed uncertainty in estimated incremental cost‐effectiveness ratios (ICERs). Results Dapagliflozin 5 mg was associated with gains of 0.23 life‐years and 0.42 QALYs, at an additional cost of £4240 per person; corresponding to an ICER of £10 143 versus standard of care. For dapagliflozin 10 mg, incremental life‐years, QALYs and costs were 0.24, 0.49 and £2964, respectively; corresponding to an ICER of £6103 versus standard of care. In probabilistic sensitivity analysis, ICER estimates fell below £20 000/QALY in 78% to 90% of simulations. Cost‐effectiveness results were sensitive to changes in baseline patient characteristics and treatment effects on glycated haemoglobin; however, ICERs remained below £20 000. Conclusions At cost‐effectiveness thresholds conventionally applied in the UK, dapagliflozin as an adjunct to insulin appears to be a cost‐effective treatment option for people with T1DM inadequately controlled by insulin alone.