Abstract Background Rituximab, a B-cell-depleting monoclonal antibody, is increasingly used for interstitial lung diseases (ILDs) associated with systemic autoimmune conditions when standard therapy fails or is poorly tolerated. Trials and observational studies suggest that rituximab can stabilize or improve lung function in connective-tissue disease-associated ILD with a safety profile superior to cyclophosphamide 1-3. However, real-world data describing outcomes and safety across diverse ILD subtypes remain limited. We sought to characterize short- and intermediate-term clinical outcomes, adverse events, and survival among rituximab-treated patients managed by pulmonologists at a high-volume ILD program. The most common underlying diagnoses included nonspecific interstitial pneumonia (29%), rheumatoid arthritis-associated ILD (21%), antisynthetase syndrome-associated ILD (19%), systemic sclerosis-associated ILD (13%), and polymyositis/dermatomyositis-associated ILD (10%), with additional cases of post-infectious fibrosis, fibrotic hypersensitivity pneumonitis, and Sjögren’s syndrome-associated ILD. Methods Patients with ILD (all subtypes) who received rituximab infusions prescribed by pulmonologists within the Cleveland Clinic Respiratory Institute between 2013 and 2024 were included. Demographic and diagnostic data were obtained from a review of individual electronic medical records. Clinical status (improved, unchanged, worsened) and adverse events were assessed at the first 2 post-infusion office visits. Adverse events included infections, infusion reactions, malignancy, and hospitalizations. Vital and transplant status were determined at one year. Results Among 275 patients who received rituximab during the study period, the median time to the first and second post-infusion visits was 2.3 (IQR, 1.1-3.9) and 6.1 (IQR, 4.2-9.1) months, respectively. At the first follow-up (N = 270), 55% of patients were improved, 33% unchanged, and 12% worsened; corresponding proportions at the second visit (N = 249) were 50%, 36%, and 14%. Adverse events occurred in 10% and 6% at the two visits, predominantly mild infusion reactions and community-acquired infections. Hospitalizations occurred in 12% and 17%, most commonly for respiratory failure or infection. Table 1 summarizes the post-infusion course and adverse events at both follow-up visits. At one year, 213 (77.5%) were alive without transplant, 12 (4.4%)had undergone lung transplantation, and 38 (13.8%) had died. Mortality was primarily attributed to progressive respiratory failure. Conclusions In this real-world ILD cohort, about half of rituximab-treated patients improved, and one-third remained stable within six months. Adverse events were infrequent, and most patients remained alive without transplant at one year. These findings support rituximab as a well-tolerated immunomodulatory option for progressive or refractory ILD and provide benchmark safety data for future studies. This abstract is funded by: None
Abushamma et al. (Fri,) studied this question.