Sarilumab, a human monoclonal antibody against interleukin-6 receptors, is currently approved for patients with moderate-to-severe rheumatoid arthritis (RA), based on efficacy and safety data from several clinical trials.
In the pivotal MONARCH study, subcutaneous (SC) sarilumab 200 mg plus placebo was administered every 2 weeks (q2w) versus adalimumab 40 mg SC plus placebo q2w. The end point of effective treatment at 24 weeks was defined on 3 response outcomes: 20%/50% improvement in American College of Rheumatology (ACR20/ACR50) response criteria, and 0.6+ improvement in Disease Activity Score 28–erythrocyte sedimentation rate (DAS28-ESR). Comparing sarilumab and adalimumab, this analysis calculated cost per responder for each of these response outcomes in addition to incremental cost per effectively treated patient, which is derived from the difference in 24-week drug cost multiplied by the number needed to treat (NNT).
The intent-to-treat population included 184 patients in the sarilumab-treated arm and 185 patients in the adalimumab-treated arm. The estimated NNT for sarilumab on ACR20 was 7.5, on ACR50 was 6.3, and on DAS28-ESR was 7.5. The cost analysis was based on 24-week drug costs of $18,000 for SC sarilumab 200 mg q2w and $26,647 for SC adalimumab 40 mg q2w. The percentages of patients achieving ACR20 and NNT in the sarilumab and adalimumab treatment groups were 71.7% and 58.4%, respectively; 49.7% and 29.7%, respectively, for ACR50; and 84.2% and 70.9%, respectively, for DAS28-ESR. For ACR20, the base costs per responder for sarilumab were 45% lower, at $25,105 versus $45,629 for adalimumab; for ACR50, the base costs per responder were 56% lower for sarilumab, at $39,387 versus $89,722; and for DAS28-ESR, the base costs per responder were 43% lower for sarilumab, at $21,378 versus $37,584.
Based on the lower 24-week drug costs and higher levels of responses on ACR20, ACR50, and 0.6 DAS28-ESR, the researchers concluded that sarilumab was the economically dominant treatment with respect to incremental cost per effectively treated patient compared with adalimumab.
Source: Fournier M, Chen CI, Kuznik A, et al. Sarilumab for the treatment of active, moderate-to-severe rheumatoid arthritis (RA): an analysis of cost per effectively treated patient. Arthritis Rheumatol. 2017;69(suppl 10). Abstract 2457.
