Exacerbation of Crohn's Disease Following Exposure to Anti-OX40 Monoclonal Antibody Therapy.

A 26-year-old man with Crohn's Disease (CD) presented to hospital with a CD flare after exposure to an anti-OX40 therapy (rocatinlimab) for eczema. This flare was characterized by upper gastrointestinal tract involvement and necrobiotic pulmonary nodules, a rare pulmonary manifestation of CD. Murine models have demonstrated mixed effects of anti-OX40 and anti-OX40 ligand therapies on colitis, and anti-OX40 therapy has been trialed in ulcerative colitis without significant clinical response seen. The impact of anti-OX40 therapies in patients with CD remains unclear, though this case suggests that caution may be required when using anti-OX40 therapies in this population.