Tofacitinib in the treatment of cardiac sarcoidosis: towards steroid-sparing disease management.

Background Cardiac sarcoidosis (CS) creates complex treatment challenges, especially for patients who fail to respond to immunosuppressive drugs, including second-line tumour necrosis factor inhibitors. These refractory cases frequently lead to serious complications and worse prognosis, prompting exploration of new therapies like Janus kinase (JAK) inhibitors. Methods This study included eight patients with refractory CS or probable CS treated with the JAK inhibitor tofacitinib at the University Hospital Zurich from 2020 to 2024. Treatment outcomes were assessed through changes in myocardial as well as nodal and pulmonary inflammation via 18-F-fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) scans, left ventricular ejection fraction (LVEF), corticosteroid use and blood neopterin levels. Results Seven out of eight patients (87.5%) who received tofacitinib achieved inactive or remitting disease as assessed by repeat myocardial 18F-FDG PET/CT, with a decrease in both standardised uptake value (SUVmax and cardiac metabolic activity. In the treated patients, LVEF stabilised or improved, and the corticosteroid dose was substantially reduced, with the average daily prednisone dose dropping from 5.94 mg to 2.5 mg. Blood neopterin levels, indicative of macrophage activation, as well as extra cardiac SUVmax (nodal and pulmonal) as assessed by repeat 18F-FDG PET/CT also decreased in a majority of the treated patients. Conclusion Tofacitinib shows promising results in managing treatment-refractory CS, with seven out of eight patients achieving significant reduction in myocardial inflammation and corticosteroid dependency. However, further studies with larger prospective cohorts are essential to solidify these findings and assess the drug's efficacy and safety profile in this complex patient group.