BACKGROUND: Rheumatoid arthritis is associated with a societal burden greater than $39 billion annually. Novel treatments, known as targeted immune modulators (TIMs), are expensive but effective, producing improvements in response rates compared with conventional disease-modifying antirheumatic drugs (cDMARDs). Sarilumab, a TIM approved
in 2017, shows superior improvements compared with cDMARDs and produced significantly greater likelihood of achieving response and improvement in the Health Assessment Questionnaire Disability Index than adalimumab monotherapy. Although sarilumab monotherapy has shown improvements over cDMARDs and the TIM market leader adalimumab, treatment with sarilumab is costly, with an annual wholesale acquisition cost of $39,000.

OBJECTIVE: To estimate the lifetime cost-effectiveness of starting treatment with sarilumab monotherapy for adult patients with moderately to severely active rheumatoid arthritis who have had an inadequate response to cDMARDs.

METHODS: A sequential treatment cohort model followed a hypothetical cohort from initiation of sarilumab monotherapy until death. The model allowed patients to switch therapies up to 3 times due to effectiveness or adverse events. The first switch was to a TIM within the same treatment category; the second switch was to a TIM within a different treatment category; and the third switch was to a cDMARD. Sarilumab monotherapy was compared with a cDMARD (methotrexate) and the TIM market leader (adalimumab monotherapy). Key risk and benefit evidence came from clinical studies and network meta-analyses of data on radiographic progression and response. We used a lifetime time horizon and the U.S. health sector payer perspective assuming therapy net pricing. We also incorporated loss of productivity to reflect a restricted societal perspective.

RESULTS: Over a lifetime time horizon, a treatment pathway starting with sarilumab resulted in 17.16 life-years and 13.66 quality-adjusted life-years (QALYs). Treatment pathways starting with the cDMARD resulted in 16.54 life-years and 11.77 QALYs; treatment pathways starting with adalimumab resulted in 17.05 life-years and 13.35 QALYs. Total costs for sarilumab ($492,000 for payer perspective, $634,000 for societal perspective) were less than total costs for adalimumab ($536,000 for payer perspective, $689,000 for societal perspective) but higher than total costs for the cDMARD ($63,000 for payer perspective, $272,000 for societal perspective). When compared with cDMARD therapy, sarilumab resulted in a cost-effectiveness estimate of $227,000 per QALY gained from the payer perspective and $191,000 per QALYs gained from the societal perspective. When compared with adalimumab, sarilumab was dominant from both perspectives.

CONCLUSIONS: Sarilumab resulted in better health outcomes than conventional therapy alone. However, its additional cost with assumed class-level net prices led to cost-effectiveness estimates above commonly cited thresholds. When compared with the market leader, sarilumab achieved favorable value. This evaluation informs stakeholders of the value of sarilumab and its alternatives to promote high value practices in health care