Cost per remission for mirikizumab versus ustekinumab for moderately to severely active ulcerative colitis treatment from the United States commercial payer perspective

Mirikizumab, approved for the treatment of moderately to severely active ulcerative colitis (UC), may be prescribed in a similar placement to ustekinumab in second-line settings. Payers may compare the economic value when making formulary decisions. This study estimated and compared the cost per remission of the second-line therapies mirikizumab versus ustekinumab in patients with UC. An Excel-based analytic model was developed to estimate the cost per additional patient achieving clinical remission at the end of one year in biologic/Janus kinase inhibitor (JAKi)-experienced patients (second-line therapy) with UC from a United States commercial payer perspective. A network meta-analysis of published pivotal randomized clinical trials was used to derive the number needed to treat (NNT) for clinical response, clinical remission, and endoscopic remission/endoscopic improvement/mucosal healing for ustekinumab and mirikizumab in the study population. The model included the treatment cost (wholesale acquisition costs [WAC] and treatment administration costs) during the induction and maintenance phases. A scenario involving the availability of a ustekinumab biosimilar was also evaluated, assuming the NNT remained the same as ustekinumab but with a WAC set at 50% lower than its current WAC. The costs per patient achieving clinical remission for mirikizumab vs. ustekinumab as a second-line therapy were $461,096 vs. $67,273 during induction and $501,456 vs. $1,079,189 during maintenance. The cost per clinical remission in case of dose escalation during maintenance was lower for mirikizumab vs. ustekinumab ($501,456 vs. $1,569,127). Considering the ustekinumab 130 mg IV biosimilar, the scenario resulted in a lower cost per clinical remission for mirikizumab vs. a ustekinumab biosimilar during the maintenance phase ($501,456 vs. $539,594). Mirikizumab is projected to have a lower cost per remission during maintenance therapy than ustekinumab. Given the need for long-term treatment for this chronic condition, mirikizumab appears to be a cost-efficient treatment option.