Cost-effectiveness analysis of sequential biologic therapy with ixekizumab versus secukinumab as first-line treatment of moderate-to-severe psoriasis in the UK

Aims: 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.

Materials and methods: 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.

Results: 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.

Limitations: 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.

Conclusion: 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.     

Cost per additional responder for ixekizumab and other FDA-approved biologics in moderate-to-severe plaque psoriasis

Background: Evidence of the cost-efficacy of ixekizumab for the treatment of moderate-to-severe plaque psoriasis (PsO) in the US is limited.

Objective: To estimate the number needed to treat (NNT) and monthly cost of achieving one additional Psoriasis Area and Severity Index (PASI) 75, 90, and 100 responder for ixekizumab and other Food and Drug Administration (FDA)-approved biologics in PsO.

Methods: A network meta-analysis estimated the probability of achieving PASI 75, 90, or 100 response during induction for each biologic. NNTs were calculated using response difference of each respective biologic vs placebo at the end of induction. Monthly costs per additional PASI responder were based on FDA-approved doses, wholesale acquisition costs, and induction NNTs.

Results: Induction NNTs for ixekizumab 80?mg once every 2 weeks (Q2W) relative to placebo were consistently lower across all levels of clearance compared with the other biologics. Monthly cost per additional responder was lowest for ustekinumab 45?mg at PASI 75 and for secukinumab 300?mg and ixekizumab 80?mg Q2W at PASI 90. Ixekizumab 80?mg Q2W had the lowest cost for PASI 100.

Conclusion: In this analysis, ixekizumab is the most cost-efficient biologic in the US when targeting complete resolution, as measured by PASI 100 in PsO.