To assess the real-world, long-term effectiveness of rituximab (RTX) as a rescue therapy in patients with progressive rheumatoid arthritis-related interstitial lung disease (RA-ILD) in whom more conventional therapy has failed.
Longitudinal retrospective observational study of a cohort of patients with RA-ILD that started treatment with RTX due to ongoing progressive ILD despite treatment with glucocorticoids and csDMARDs or immunosuppressants (IS). All patients were treated with two or more cycles of RTX and evaluated for at least 12 months. Ongoing therapy with csDMARDs or IS remained unchanged.
Thirty-one patients were analyzed. Before initiation of RTX the mean decline (delta) in %pFVC and %pDLCO from the ILD diagnosis (median 21 months) was -16.5% and -19.7%, respectively. After 1 year of treatment, RTX was able to reverse the decline of pulmonary function test (PFTs) parameters: ∆%pFVC +8.06% compared to baseline (95% CI: -10.9 to -5.2; p<0.001) and ∆%pDLCO +12.7% (95% CI: -16.3 to -9.1; p<0.001). In addition, there was a significant reduction in the median dose of prednisone, and it could be suspended in 26% of cases. Dividing the population into UIP and non-UIP patterns, we observed a significant increase in PFTs parameters in both groups. In the 25 patients (80.6%) that completed 2 years of treatment, the statistically significant amelioration in PFTs parameters observed at one year was maintained: ∆%pFVC +11.2% (95% CI: -15.6 to -6.8; p<0.001) and ∆%pDLCO +14.8% (95% CI: -19.3 to -10.3; p<0.001). At the end of the follow-up period (median 32 months; IQR 25th-75th 26-64), only 23 of the 31 patients (74.2%) were still undergoing treatment with RTX: in 3 cases (10%) it was stopped due to adverse events, in another 3 (10%) treatment failed ultimately requiring a lung transplant, and 2 patients (6%) died due to progression of the ILD and infectious complications. The frequency of adverse events reached 32% of cases.
Based on our results, RTX appears to be effective as rescue therapy in a considerable proportion of patients with progressive RA-ILD unresponsive to conventional treatment.