Background Antibodies to cyclic citrullinated peptide-2 (CCP-2) are highly specific to RA and a high level of CCP-2 is associated with radiographic progression and progression of disability in RA patients (pts). High-quartile CCP-2+ pts treated with abatacept (ABA) showed better DAS28 (CRP) and HAQ response vs pts treated with adalimumab (ADA) in the Abatacept versus Adalimumab Comparison in Biologic-Naïve RA Subjects with Background Methotrexate (AMPLE) study.1
Objectives To evaluate costs and benefits of treating CCP-2+ RA pts with ABA compared with ADA, on background MTX.
Methods An economic model was developed that estimated lifetime HAQ progression, quality-adjusted life years (QALYs) and direct costs for RA pts treated with ABA or ADA, from a UK NHS perspective. QALYs are a measure of a life lived, adjusted to reflect quality of life. The population modelled reflected baseline characteristics of CCP-2+ pts by quartile (Q) from AMPLE. HAQ changes by CCP-2+ Q due to treatment were modelled based on responses to ABA and ADA in AMPLE. CCP-2+ Q were defined by dividing the range of CCP-2 values into 4 equal parts. Mean long-term survival on treatment with ABA or ADA was derived from AMPLE and published literature.2 In the base case, pts discontinuing ABA or ADA moved to etanercept, followed by palliative care (conventional DMARDs). Direct medical costs and quality-of-life scores were correlated to HAQ score.2 Costs included hospitalization, joint replacement and treatment. Estimates of differences in costs and QALYs between ADA and ABA were used to calculate an incremental cost-effectiveness ratio (cost per QALY gained). A sensitivity analysis examined the effect of varying the input parameters of efficacy, cost and utilities on costs and benefits.
Results Based on the range of CCP-2 values there were no pts in Q4 and only a few pts in Q3 (n=7). Hence, only Q1 (n=316) and Q2 (n=63) pts were considered in this analysis. For Q1 pts, the total estimated QALYs for ABA and ADA were 5.53 and 5.07, respectively. Total lifetime costs were £122,585 and £110,670, respectively. For Q2 pts, the total estimated QALYs for ABA and ADA were 5.29 and 4.71, respectively; total lifetime costs were £126,599 and £116,299. The lifetime cost for ABA pts was higher compared with ADA pts in both CCP-2+ Qs owing to the longer duration of ABA therapy. The cost per QALY for ABA (vs ADA) in Q1 was £25,941/QALY and in Q2 was £17,907/QALY. An intervention with a cost per QALY gain of less than £30,000 is generally considered to be cost effective in the UK. In a sensitivity analysis, in which mean long-term time on treatment was assumed to be the same for ABA and ADA (4.06 years), for Q2 pts, ABA achieved a QALY gain of 0.10 with an incremental cost of £211 (cost per QALY of £2110).
Conclusions Abatacept is projected to be a cost-effective alternative to adalimumab in CCP-2+ pts. The increased treatment costs of ABA were accompanied by a gain in benefits (QALYs) owing to higher HAQ reduction and lower hospitalization costs.The cost per QALY for abatacept (vs adalimumab) is lower in CCP-2+ pts with higher CCP-2 levels.
Schiff M, et al. Ann Rheum Dis 2014;73:86–94.
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Disclosure of Interest E. Alemao Shareholder of: Bristol-Myers Squibb, Employee of: Bristol-Myers Squibb, M. Schiff Grant/research support from: UCB, Consultant for: AbbVie, Amgen, Antares, Bristol-Myers Squibb, Eli Lilly, Horizon, Johnson and Johnson, Novartis, Novo Nordisk, Pfizer, Roche, UCB, Speakers bureau: AbbVie, S. Johal Consultant for: Bristol-Myers Squibb, M. Al: None declared, M. Rutten-van Molken Grant/research support from: BMS has paid Erasmus University Rotterdam a grant to support the PhD thesis of Evo Alemao