Cemiplimab-Induced Vogt-Koyanagi-Harada-Like Syndrome in a Patient With Cutaneous Squamous Cell Carcinoma of the Lower Back.

Cemiplimab is a programmed death receptor-1 inhibitor that has been approved for the treatment of advanced cutaneous squamous cell carcinoma (CSCC). The immune-related adverse events most commonly reported with cemiplimab are thyroiditis, pneumonitis, and hepatitis. Ocular adverse events have been rarely reported. We present a rare case of Vogt-Koyanagi-Harada (VKH)-like syndrome in a patient with CSCC being treated with cemiplimab. A 53-year-old woman presented with bilateral progressive visual disturbances, eye pain, and headache for 4 weeks after 4 cycles of neo-adjuvant cemiplimab therapy for stage IV CSCC of the lower back. The detailed ophthalmologic evaluation established the diagnosis of VKH-like syndrome with panuveitis, subretinal fibrosis, and exudative retinal detachment. The patient received high-dose intravenous and topical steroids followed by a gradual taper of oral steroids over 6 months. Cemiplimab was discontinued. There was significant improvement in her symptoms with the resolution of subretinal fluid, choroidal elevations, and retinal detachment. VKH-like syndrome is an immune-mediated disorder that affects pigmented structures and is a significant cause of noninfectious uveitis. Drug-related uveitis has been seen more commonly with immune checkpoint inhibitors than with other drug classes and can occur anytime during the treatment. The mainstay of treatment of VKH-like syndrome is high-dose intravenous corticosteroids. In resistant cases, immunosuppressive therapies and biological agents are beneficial. This case highlights the importance of prompt recognition of VKH-like syndrome associated with cemiplimab, enabling timely intervention to prevent permanent vision loss.