Effectiveness of a second biologic after failure of a non-tumor necrosis factor inhibitor as first biologic in rheumatoid arthritis

Objective In Rheumatoid Arthritis (RA), evidence regarding the effectiveness of a second biologic Disease Modifying Anti-Rheumatic Drugs (bDMARDs) in patients whose first ever bDMARD was a non-tumor-necrosis-factor-inhibitor (TNFi) bDMARD is limited. The objective of this study was therefore to assess the outcome of the second bDMARD (non-TNFi [rituximab, abatacept or tocilizumab, separately] and TNFi) after failure of a non-TNFi bDMARD as first bDMARD. Methods We identified RA patients from the five Nordic biologics registers started treatment with a non-TNFi as first ever bDMARD but switched to a second bDMARD. For the second bDMARD, we assessed survival-on-drug (at 6 and 12 months), and primary response (at 6 months). Results We included 620 patients starting a second bDMARD (ABA 86, RTX 40, TCZ 67 and TNFi 427) following failure of a first non-TNFI bDMARD. At 6 and 12 months after start of their second bDMARD, around 70% and 50%, respectively, remained on treatment, and at 6 months less than one third of patients were still on their second bDMARD and had reached low disease activity or remission according to DAS28. For those patients whose second bMDARD was a TNFI, the corresponding proportion was slightly higher (40%). Conclusion The survival-on-drug and primary response of a second bDMARD in RA patients switching due to failure of a non-TNFi bDMARD as first bDMARD is modest. Some patients may benefit from TNFi when used after failure of a non-TNFi as first bDMARD.