Biosimilar switching is due to costs, formulary, relocation. Study of 23 studies, 3657 pts found only observational data, no RCTs. Ref product to biosimilar usually RCTs; Biosimilar switches usually real world evidence w/ good efficacy & no new risks. https://t.co/odAYHdbVd1 https://t.co/BabkVYsMBL