Cost-Effectiveness Analysis of Sequential Biologic Therapy with Ixekizumab Versus Secukinumab in the Treatment of Active Psoriatic Arthritis with Concomitant Moderate-to-Severe Psoriasis in the UK.

Interleukin-17A (IL-17A) antagonists are a recent innovation for treating psoriatic arthritis (PsA). There are currently no cost-effectiveness analyses (CEAs) comparing the IL-17A antagonists ixekizumab and secukinumab in PsA from a UK perspective. We conducted a CEA from the UK National Health Service perspective to compare ixekizumab versus secukinumab in patients with PsA and concomitant moderate-to-severe plaque psoriasis. A Markov model was developed based on the widely accepted York model. In biologic disease-modifying antirheumatic drug (bDMARD)-naive patients, ixekizumab → ustekinumab → best supportive care (BSC) was compared with secukinumab → ustekinumab → BSC. For bDMARD-experienced patients, ixekizumab → BSC was compared with secukinumab → BSC. At the end of the bDMARD trial period, Psoriatic Arthritis Response Criteria (PsARC) responders continued to receive the bDMARD in the continuous treatment period. PsARC nonresponders and patients who ceased continuous treatment transitioned to the trial period of the next treatment. Ixekizumab was less costly and provided more quality-adjusted life-years (QALYs) than secukinumab in bDMARD-naive and -experienced patients based on list prices, although cost savings and QALY gains were small to modest. In bDMARD-naive patients, total costs were £155,455 compared with £155,530 for secukinumab (year 2017 values). Total QALYs were 8.127 versus 7.989. In bDMARD-experienced patients, the corresponding values were £140,051 versus £140,264 for total costs and 3.996 versus 3.875 for total QALYs. Ixekizumab provided more QALYs at a marginally lower cost than secukinumab, and the results were most sensitive to changes in drug costs. Other factors, such as patient preferences for the number of injections and confidential price discounts, may be important considerations in clinical decision-making.