Real-World Clinical Profile and Safety of Nintedanib in Systemic Sclerosis-Associated Interstitial Lung Disease: A Subgroup Analysis of Interstitial Lung Disease Data From an Interstitial Lung Disease (ILD) Specialty Clinic in India

Introduction: Systemic sclerosis (SSc) is a multisystem autoimmune disorder characterized by dysregulated innate and adaptive immunity. Interstitial lung disease (ILD) is a common and serious complication of SSc, often leading to significant morbidity and mortality. Consistent demographic characteristics that aid in the early diagnosis of ILD in SSc are lacking. This study aims to identify clinical and demographic parameters associated with ILD in SSc patients and assess the safety and tolerability of nintedanib with other immunosuppressants. Materials and methods: This study is a subgroup analysis of data from the ILD clinic at All India Institute of Medical Sciences Raipur, collected between January 2022 and January 2024. We assessed the clinical and demographic profiles, high-resolution computed tomography thorax patterns, autoantibody profiles, lung function, and treatments used in the patients. Results: We enrolled 57 patients with SSc-associated ILD. The mean age of the participants was 39.0 +/- 11.1 years, with 53 (92.9%) being women. The mean body mass index was 20.4 +/- 4.32 kg/m2. 2 . Dyspnea was the most common symptom, followed by skin tightening and cough. Antinuclear antibody tests were positive in 92.9% of patients, and anti-Scl-70 antibodies were positive in 57.9%. Rheumatoid arthritis-SSc overlap was observed in 15.8% of patients. The mean predicted forced vital capacity was 46.5 +/- 19.9%, the mean predicted total lung capacity was 64.5 +/- 20.4%, and the mean predicted diffusing capacity for carbon monoxide was 46.2 +/- 15.7%. The mean six-minute walk distance was 360.3 +/- 81.2 meters, and the mean King's Brief Interstitial Lung Disease score was 63.9 +/- 10.7. Common radiological abnormalities included ground-glass opacities in 57.8%, traction bronchiectasis in 43.8%, and honeycombing in 28.07%. The predominant ILD pattern was nonspecific interstitial pneumonia. Patients received a combination of prednisolone (5 mg/day) with mycophenolate mofetil (63.2%), hydroxychloroquine (17.5%), cyclophosphamide (12.3%), and methotrexate (7.02%). Nintedanib, the only antifibrotic used, was administered to 17 (29.8%) patients. Conclusions: ILD is relatively common in SSc, particularly in patients with diffuse cutaneous SSc and those with anti-topoisomerase antibodies. Female patients comprised the predominant population in this study. Patients tolerated mycophenolate mofetil and cyclophosphamide well. Nintedanib was the only antifibrotic used, and all patients tolerated the combination of antifibrotics and immunosuppressants well. Early diagnosis is crucial to slow disease progression and preserve lung function. Our results highlight the need for vigilant screening in high-risk groups and suggest that MMF, cyclophosphamide, and nintedanib can be safely incorporated into treatment regimens, offering a potential strategy to improve patient outcomes.