Arthritis drug may be effective in treating immunotherapy-related heart complication A drug typically prescribed for rheumatoid arthritis may also be effective in treating a rare but potentially deadly heart complication some cancer patients experience after taking immunotherapies, according to a study published in Cancer Discovery and co-led by investigators at Vanderbilt University Medical Center (VUMC). The researchers demonstrated that the drug abatacept reduced the severity of myocarditis in a genetic mouse model study - responses that have also been observed in three human patients who were given the same drug after corticosteroid treatments failed to reduce heart muscle inflammation. The mouse model revealed the mechanisms for how the drug works.