Background/Purpose:

For patients with psoriatic arthritis (PsA) failing the first TNF-inhibitor, switching to biologic DMARDs [bDMARDs] with different mechanism of actions (swapping strategy) may be superior than switching to another anti-TNF (cycling strategy) ^[1,2].

The aims of the study were to evaluate the cost-effectiveness of 1) swapping strategy for established PsA and 2) immediate versus standard swapping strategy for early PsA from the Hong Kong (HK) societal perspective

Methods:

A swapping York model with life time horizon was developed for two hypothetical subpopulations:1) established PsA (age=47, HAQ=1.22, Figure A) received five swapping strategies and 2) early PsA (age=40, HAQ=0.71, Figure B) received immediate (start bDMARDs after diagnosis) or standard (initially given BSC and then start bDMARDs when HAQ increase to 1.22) use of the most cost-effective swapping strategy. Both subpopulations were further classified into mild to moderate psoriasis (MMP, PASI=0.73) and moderate to severe psoriasis (MSP, PASI=12.5). All five swapping strategies started with an anti-TNF, followed by secukinumab 300mg and then ustekinumab 45mg. The cost-effectiveness of each strategy was determined using a willingness-to-pay (WTP) threshold of £32,356/ quality-adjusted life-year (QALY) (HK Gross Domestic Product per capita).

Results:

For the base-case scenario, all five swapping strategies are cost-effective versus BSC strategy for established PsA, which are associated with greater QALY gain and lower treatment related direct costs, psoriasis cost and productivity loss. In established PsA with MMP and MSP, etanercept swapping strategy is likely to be the most cost-effective strategy with an incremental cost £9,518.93 and £9,084.58 per QALY gained over BSC strategy respectively. For early PsA with MMP and MSP, the base-case results indicated that standard etanercept swapping strategy was cost-saving (£-50,635.74 and £-67,843.32) and more effective (1.20 and 1.32 QALYs); while immediate etanercept swapping strategy was costlier (£13294.95 and £8986.16), more effective (3.82 and 3.27 QALY), and had relative low ICER (£3482.36 and £2745.35 per QALY gained) relative to BSC strategy.

Conclusion:

Swapping strategy showed favorable cost-effectiveness for established PsA as well as early PsA. The increased costs of biologic agents are offset by the gain in benefits from long-term HAQ reduction.

Reference

^[1] Merola JF, et al. Semin Arthritis Rheum 2017;47:29-37

^[2] Cantini F, et al. Semin Arthritis Rheum 2017;47:183-192

^[3] Kane D, et al. Rheumatology (Oxford) 2003; 42:1460-8

Disclosures: This study has been partly presented at EULAR2018.