Economic Evaluation of Selected Interleukin Inhibitors Versus Methotrexate for Moderate-to-Severe Plaque Psoriasis From the Philippine Payer Perspective

We conducted an economic evaluation of interleukin inhibitors (ILIs) guselkumab, ixekizumab (IXE), secukinumab (SEC), and ustekinumab to a methotrexate (MTX) comparator for biologic-naive adult Filipino patients with moderate-to-severe chronic plaque psoriasis.A 1-year decision tree and 5-year Markov model were used to estimate incremental cost-effectiveness ratios (ICERs) in Philippine pesos (PHP) per Psoriasis Area Severity Index improvement of at least 75%. For health technology assessment purposes, we also estimated the budget impact of subsidies for SEC to a Government of the Philippines (GoP) payer. Deterministic and probabilistic sensitivity analyses were performed. Data sources included global literature and local intervention prices.All ILIs were more effective but also more expensive than MTX. In the base case, only IXE and SEC were cost-effective treatments at a gross domestic product-benchmarked threshold, yielding ICERs of PHP468 098.01 and PHP483 525.32 per PASI responder, respectively. GUS and UST were less likely to be cost-effective throughout a range of simulated thresholds. ICERs were most responsive to discontinuation rates and drug prices. Full subsidy of SEC for 5 years would cost the GoP PHP1.83 billion more than a similar subsidy for MTX.ILIs were clearly more effective than MTX, but only IXE and SEC were potentially cost-effective for a GoP payer. Any case in which SEC is fully subsidized is more expensive to the GoP than the base case. This study was limited by a lack of country-specific effectiveness data, underestimation of comparator costs, exclusion of noncutaneous and quality-of-life effects, and indirect costs.