Recurrent Cardiac Tamponade from Multiple Myeloma While Receiving Teclistamab.

Bispecific therapy has changed the treatment paradigm for multiple myeloma. We report a patient with recurrent malignant pericardial effusions with cardiac tamponade and new atrial fibrillation during treatment, suggesting that new or worsening pericardial disease may be a potential cardiovascular adverse effect of bispecific therapy.