Re-introducing immunotherapy in patients surviving immune checkpoint inhibitors-mediated myocarditis.

Abstract

e15228 Background: Immune checkpoint inhibitors (ICI) have transformed the standard care in cancer treatment. Recent case reports describe ICI-mediated myocarditis with an atypical presentation and fatal potential which lead to permanent interruption of immunotherapy. We aim to characterize ICI-mediated myocarditis and re-introduction to immunotherapy. Methods: We retrospectively evaluated the presentation, severity, and prognosis of patients diagnosed with ICI-mediated myocarditis during 2019, and presented the clinical course and outcomes of patients that were chosen for re-introduction. Results: Among seven patients, only one patient had a history of cardiac disease. The majority were diagnosed with lung adenocarcinoma and treated with anti-programmed death-1 antibody (57%). All patients were treated with single agent ICI. Most patients presented with cardiac symptoms, elevated troponin and typical magnetic resonance imaging; however only 43% had reduced ejection fraction. Five patients were defined as grade I-II and two as grade III-IV. Overall, three patients were chosen for re-introduction with concomitant low dose steroids and weekly troponin follow-up. Two patients diagnosed with grade I/II renewed therapy successfully with no recurrence of symptoms and improvement in disease burden, while the one patient diagnosed with grade III developed worsening of cardiac symptoms after the 1st cycle and therefore therapy was interrupted permanently. Overall, survival was higher among the re-introduction patients (67% vs. 25%). Conclusions: ICI-mediated myocarditis is potentially fatal and leads to permanent interruption of life saving cancer therapy. We imply that re-introduction may be considered in low grade patients; however, better definition of the diagnosis and grading is needed.