In Reply We appreciate the letter by Yang and the opportunity to comment on the safety of immune checkpoint blockade (ICB) in breast cancer. This important subject was not addressed extensively in our original article due to space limitations.1 However, since that publication, a comprehensive review by D’Abreo and Adams2 on the incidence of adverse events (AEs) with particular emphasis on immune-related adverse events (irAEs) in patients with breast cancer has been published. That review describes more than 1000 patients with triple-negative breast cancer included in published clinical trials of ICB alone or in combination with chemotherapy. The most common organ-specific irAEs were pruritus or rash occurring in 18% of patients, followed by hypothyroidism in 12%, and hepatitis or elevated transaminases in 10%. Less frequent events with an incidence greater than 1% were hyperthyroidism (5%), autoimmune hematologic abnormalities (4%), pneumonitis (3%), and diarrhea or colitis (2.5%). Grade 3 or higher irAEs were observed in 7% of patients with breast cancer.