Comparing the safety and efficacy of nintedanib starting dose in patients with connective tissue disease-associated interstitial lung diseases

Objective: This study aimed to analyse whether initiating nintedanib treatment at a reduced dose could improve the treatment continuation rate while maintaining efficacy in patients with connective tissue disease (CTD)-associated interstitial lung disease. Method: In total, 51 patients (age 61.6 ± 13.2 years; 38 women, 13 men) were retrospectively analysed. The primary endpoint was the cumulative discontinuation rate due to adverse events. Secondary endpoints included changes in drug dosage, efficacy evaluated based on annual changes in forced vital capacity (FVC), and safety assessed based on the frequency of adverse events. Results: Eighteen patients who started treatment at the standard dose of 300 mg (standard dosage group) were compared with 33 patients who started treatment at a reduced dose (reduced dosage group). Systemic sclerosis was the most common CTD (n = 32), followed by idiopathic inflammatory myopathies and, rarely, rheumatoid arthritis. Both groups exhibited comparable cumulative discontinuation rates due to adverse events and similar frequencies of adverse events. No significant differences were observed in maintenance doses between the two groups; however, patients in the reduced dosage group had a lower cumulative dose for up to 52 weeks than those in the standard dosage group. No significant differences were observed in changes in FVC between the two groups. Conclusion: There was no evidence for a difference between the two groups in terms of discontinuation rates, efficacy, and safety. To provide further evidence, future studies using more precise dose-escalation protocols are warranted.