In a real-world comparative effectiveness study that compared TCZ monotherapy to anti-TNF biologics plus methotrexate among using RA registry data in the United States, patients with prior exposure to anti-TNF biologics who were started on TCZ monotherapy did not have a better clinical response as measured by the CDAI at 6 months compared to their counterparts on anti-TNF biologics plus methotrexate regardless of methotrexate dose. Here, TNF is linked to rheumatoid arthritis.