[Articles] Skeletal muscle effects of Janus kinase inhibition in rheumatoid arthritis (RAMUS): a single-arm, experimental medicine study

Tofacitinib treatment in patients with rheumatoid arthritis was associated with increased muscle volume after 6 months. The increase in serum creatinine associated with tofacitinib treatment might reflect increased muscle volume via a direct pharmacological effect on skeletal muscle or via reduced inflammation, or a combination. Larger studies are needed to verify our findings, demonstrate functional benefit, and determine whether they are unique to tofacitinib.