OBJECTIVES

This study aimed to compare treatment outcomes in rheumatoid arthritis-associated interstitial lung disease (RA-ILD) between initiators of rituximab, abatacept, tocilizumab, and tofacitinib using the Target Trial Emulation Framework.

METHODS

We emulated three trials comparing abatacept, tocilizumab, and tofacitinib with rituximab (reference). Patients fulfilling validated RA-ILD algorithms initiating one of these non-TNFi b/tsDMARDs were propensity score (PS)-matched (1:1) using national Veterans Affairs (VA) data from 2006 to 2020. PS models included demographics, comorbidities, general health status indicators, and several RA- and ILD-related severity measures. Composite study outcomes were death and respiratory-related hospitalization, ascertained by VA data and linkages to the National Death Index and Medicare, over three-year (primary) and one-year follow-up periods (secondary). Cox regression models were used to analyze study outcomes adjusting for any unbalanced variables. Several sensitivity and subgroup analyses were performed.

RESULTS

In the primary cohort, we 1:1 matched abatacept (n = 150), tocilizumab (n = 73), and tofacitinib (n = 94) with equal numbers of rituximab initiators (mean age 68.1-69.4 years, 88-92 % male). There were no significant differences in the primary composite outcome among any of the comparisons (abatacept aHR: 1.03 [0.72, 1.47]; tocilizumab aHR: 1.15 [0.68, 1.93]; tofacitinib aHR: 0.89 [0.54, 1.46]). Secondary, subgroup, and sensitivity analyses supported the main findings.

CONCLUSIONS

We did not find significant differences in mortality or respiratory hospitalization between RA-ILD patients initiating different non-TNFi b/tsDMARDs, though estimates were imprecise, and residual confounding may be present. These findings emphasize the need for clinical trials of advanced immunomodulatory therapies in RA-ILD.