Tofacitinib in the treatment of moderate-to-severe rheumatoid arthritis: a cost-effectiveness analysis compared with adalimumab in Taiwan

Abstract

Aims: Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). This analysis investigated the cost-effectiveness of the second-line treatment with tofacitinib, compared with adalimumab, both plus methotrexate (MTX), in patients with moderate-to-severe RA and an inadequate response to the first-line MTX, from a Taiwan National Health Insurance Administration perspective. Materials and methods: A patient-level simulation model was used to project lifetime costs and quality-adjusted life-years (QALYs). Base-case analysis compared second-line treatment with tofacitinib 5 mg twice daily plus MTX vs adalimumab 40 mg every 2 weeks plus MTX. Patients switched or discontinued treatment due to a lack or loss of effectiveness or a serious adverse event. Efficacy was measured by change in Health Assessment Questionnaire-Disability Index (HAQ-DI) score. HAQ-DI scores were used to predict mortality and resource utilization, and were mapped onto utility values to estimate QALYs. Efficacy and safety data were derived from clinical trials and other secondary sources. Uncertainty in model parameters was explored using one-way deterministic and probabilistic sensitivity analyses. Results: Patients gained 0.09 more QALYs with second-line tofacitinib plus MTX compared with adalimumab plus MTX (5.13 vs 5.04, respectively) at an additional cost of New Taiwan Dollars (NT$) 12,881. The incremental cost-effectiveness ratio was NT$143,122/QALY. One-way sensitivity analysis confirmed the base-case result was robust. Limitations: The lack of available clinical data, particularly for HAQ-DI scores, may introduce some bias in the analysis. No patients were in an early stage of RA, which may limit the generalizability of these results. Base-case results from our study are not necessarily generalizable to countries with healthcare systems that differ considerably from Taiwan. Conclusions: From a payer perspective, second-line treatment with tofacitinib plus MTX is a costeffective treatment strategy, compared with adalimumab plus MTX, in patients with moderate-tosevere RA in Taiwan.

Cost-effectiveness analysis of treatment sequences containing tofacitinib for the treatment of rheumatoid arthritis in Spain

“…As it was done in previous evaluations with the global model [ 11 , 12 ], the clinical efficacy data, in terms of HAQ score, for the initial treatment response, were obtained from a meta-analysis derived from a systematic literature review of studies on the efficacy of different treatments for moderate-to-severe RA [ 24 , 25 ]. For therapies in which no efficacy data were found in terms of the HAQ score, efficacy was determined using the ACR values obtained from the literature, by means of the conversion proposed in National Institute for Health and Care Excellence (NICE) Technology Appraisal 198 [ 26 ].…”

“…The efficiency of the treatment sequences containing tofacitinib was calculated by adapting a cost-effectiveness analysis model, previously used in other countries' healthcare settings [11][12][13], to the Spanish context. Main characteristics of this model have been published [11,12].…”

“…The efficiency of the treatment sequences containing tofacitinib was calculated by adapting a cost-effectiveness analysis model, previously used in other countries' healthcare settings [11][12][13], to the Spanish context. Main characteristics of this model have been published [11,12]. Its consists of a microsimulation, the structure of which is based on models used previously to assess the efficiency of other bDMARs in RA [14][15][16].…”

“…The model assesses the safety profile of tofacitinib in comparison to bDMARDs. Given the heterogeneity of their SAEs reported, we opted to model them all together, considering the onset of severe infections (SI) as being representative of the most common SAEs in RA patients, and applying the frequencies published [35], in line with the approaches previously done [11,34].…”

“…The effect on health-related quality of life was considered in the model by estimating the quality-adjusted life years (QALYs). The correlation between the HAQ score and utilities was estimated [38] (Table 2), moreover and similarly to previous modellings [11] over a four-week period, which would equate to a QALY loss of 0.012 in patients with SAEs.…”