Consider withholding or permanently discontinuing M7824 based upon if the clinical condition can be safely managed. Consider hospitalization In the presence of life threatening cardiac decompensation, consider transfer to a facility experienced in advanced heart failure and arrhythmia management. Consider cardiology consult to establish etiology and rule -out immune -mediated myocarditis. Consider myocardial biopsy if recommended per cardiology consult. If symptoms improve and immune -mediated etiology is ruled out, consider re -starting therapy. If symptoms do not improve/worsen, viral myocarditis is excluded, and immune -mediated etiology is suspected or confirmed following cardiology consult, consider managing as immune -mediated myocarditis. Immune -mediated myocarditis Consider withholding or permanently discontinuing M7824 based upon if the clinical condition can be safely managed. Consider guideline based supportive treatment as appropriate as per cardiology consult. Consider 1.0 to 2.0 mg/kg/day prednisone or equivalent Consider adding prophylactic antibiotics for opportunistic infections. Once improving, consider tapering steroids over at least 1 month. If no improvement or worsening, consider additional immunosuppressants (e.g. azathioprine, cyclosporine A).