Dermatologic Adverse Events Associated with T-Cell Engager Therapy.

T-cell engager therapies, including bispecific T-cell engagers and the immune-mobilizing monoclonal T-cell receptor against cancer tebentafusp, are an emerging class of anticancer immunotherapy, with rapid expansion of the class since initial approval of blinatumomab in 2014 and with distinct dermatologic adverse events increasingly recognized across agents. Tebentafusp and talquetamab demonstrate highest rates of notable dermatologic toxicity reflecting on-target off-tumor cutaneous effects. Tebentafusp produces dermatologic adverse events in the majority of treated patients, characterized by diffuse erythematous and frequently photodistributed eruptions. Talquetamab is notable for a characteristic constellation of cutaneous, nail, and oral toxicities linked to target G protein-coupled receptor class C group 5 member D expression in keratinized tissues. Subcutaneous cluster of differentiation (CD)20- and B-cell maturation antigen-targeted agents frequently cause injection-site reactions, generally low-grade and self-limited. Blinatumomab and other CD19- and CD20-directed agents have been associated with a spectrum of heterogeneous rashes. Across agents, most dermatologic adverse events can be managed with topical corticosteroids, emollients, antihistamines, or brief courses of systemic corticosteroids without requiring treatment discontinuation. Recognition of these agent-specific and mechanistically linked patterns is essential for dermatologists as T-cell engager therapies become increasingly integrated into oncology practice.