Cost per responder associated with biologic therapies for Crohn's disease, psoriasis, and rheumatoid arthritis

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.