Antibody drug conjugate (ADC) therapies are an emerging treatment for hematologic and solid organ malignant tumors. These ADCs are targeted monoclonal antibodies conjugated to a cytotoxic payload, designed to maximize antitumor effect while minimizing toxic effects to normal host tissue.1 We describe a case series of 6 patients who presented with a similar telangiectatic rash after treatment with ADCs containing the cytotoxic payload tesirine.