Biologic therapies have demonstrated efficacy and safety in several chronic systemic disorders. The authors indirectly compared response rates and costs per responder associated with biologic treatments for moderate-to-severe Crohn's disease (CD), psoriasis (Ps), and/or rheumatoid arthritis (RA).
A systematic literature search was performed to identify phase 3 randomized controlled trials of biologics for CD (adalimumab, infliximab), Ps (adalimumab, etanercept, infliximab, ustekinumab 45 mg, ustekinumab 90 mg), or methotrexate-refractory RA (abatacept, adalimumab, certolizumab, etanercept, golimumab, infliximab, rituximab, tocilizumab). Food and Drug Administration-approved dosing schedules were evaluated. Published response rates were extracted, with response defined in CD, Ps, and RA as: ≥70-point reduction in CD Activity Index at 12 months; ≥75% improvement in Psoriasis Area and Severity Index at 3 months; and ≥50% improvement in American College of Rheumatology component scores at 6 months. Within each indication, mixed-treatment comparison meta-analyses were conducted to derive pooled estimates and 95% CIs of response rate difference versus placebo for each biologic, adjusting for cross-trial variation in control-arm response rates. Cost per responder was estimated for each biologic as projected per patient drug costs (2011 US$) divided by response rate difference.
Altogether, 23 publications were selected. In CD, 12-month cost per responder was estimated at $116,291 (95% CI $71,637-208,348) for adalimumab and $125,169 (95% CI $60,532-267,101) for infliximab. Among biologics approved in Ps, 3-month cost per responder was lowest for adalimumab ($9,756; 95% CI $8,668-11,131), infliximab ($12,828; 95% CI $11,772-13,922), and ustekinumab 45 mg ($13,821; 95% CI $12,599-15,167). In RA, biologics with the lowest 6-month cost per responder were adalimumab ($27,853; 95% CI $19,284-40,270), etanercept ($29,140; 95% CI $14,170-61,030), and tocilizumab ($31,363; 95% CI $14,713-64,232).
Meta-analyses of clinical trials found considerable variation in cost-effectiveness of biologic therapies for CD, Ps, and RA. These results may help determine biologic utilization in these chronic diseases.