Patients with psoriasis often undergo treatment with a sequence of biologic agents because of poor/loss of response to initial therapy. With the availability of newer agents like ixekizumab and secukinumab, there is a need for cost-effectiveness analyses to better reflect current clinical practice. This study aimed to assess the cost-effectiveness of a sequence of biologic therapies containing first-line ixekizumab vs first-line secukinumab in patients with moderate-to-severe plaque psoriasis in the UK.
A Markov model with a lifetime horizon was developed to compare the cost-effectiveness of ixekizumab and secukinumab treatment sequences: ixekizumab → ustekinumab → infliximab → best supportive care (BSC) vs secukinumab → ustekinumab → infliximab → BSC. The model used monthly cycles, and included four health states: trial period, treatment maintenance, BSC, and death. At the end of the trial period, responders transitioned to maintenance therapy; non-responders transitioned to the next biologic in the sequence. An annual discontinuation rate of 20% was assumed for maintenance therapy.
The ixekizumab sequence provided cost savings of £898 (£176,203 vs 177,101) [year 2015 values] and gained 0.03 more quality-adjusted life-years (QALYs: 1.45 vs 1.42) vs the secukinumab sequence over the lifetime horizon. Probabilistic sensitivity analysis showed an 89.8% likelihood that the ixekizumab sequence would be cost-effective at a threshold of £20,000 per QALY gained.
The analysis used list prices for drugs rather than confidential, preferentially priced Patient Access Scheme costs. In addition, efficacy input data were based on a network meta-analysis, as there were no head-to-head trials comparing ixekizumab and secukinumab.
First-line treatment with ixekizumab as part of a specific sequential biologic therapy for moderate-to-severe plaque psoriasis in the UK provided slight advantages in cost savings and QALYs gained over a similar treatment sequence initiated with secukinumab. In view of the small magnitude of these differences, factors such as patient preferences (e.g. for number of injections) and long-term safety (e.g. related to time on the market) may also be important for clinical decision-making.