Dual Biologic Therapy in a Patient With Niemann-Pick Type C and Crohn Disease: A Case Report and Literature Review.

Dual biologic therapy has become a new area of interest in inflammatory bowel disease (IBD). Monogenic/polygenic IBD and the role of genetics in IBD is an evolving field, with many of these patients having difficult treatment courses. We present a case of a teenage patient with Niemann-Pick disease type C and Crohn colitis, who sustained clinical remission only after escalating to dual biologic therapy (anti-tumor necrosis factor alpha [infliximab] and anti-interleukin-12/anti-interleukin-23 [ustekinumab]). A literature review of dual biologic therapy in pediatric IBD revealed 8 case series and 1 cohort study. In pediatric patients with genetic disorders and IBD who are not responding adequately to biologic therapy, adding a second biologic medication with a different mechanism of action may be efficacious. Targeting both anti-tumor necrosis factor alpha (which induces pro-inflammatory cytokines) and the pro-inflammatory cytokines themselves (interleukin-12/interleukin-23) may be important in impaired macrophage function and increased cytokine response. Our case adds to the sparse literature on the utility of combining ustekinumab and infliximab in pediatric IBD and is the first to describe its use for treating ongoing active luminal disease.