Clinical bottom line
Novel antifibrotic agents, such as nintedanib and pirfenidone, have shown promise in treating interstitial lung disease (ILD) associated with connective tissue disorders (CTDs). Current evidence suggests that these agents may slow disease progression and improve pulmonary function in select patient populations, though the overall clinical benefit and long-term outcomes remain to be fully elucidated. Clinicians should consider these agents as part of a comprehensive treatment strategy for patients with ILD secondary to CTDs, while remaining aware of potential side effects and the need for further validation in larger, diverse cohorts.
What the evidence shows
Recent studies have highlighted the efficacy of antifibrotic agents in managing ILD associated with CTDs. A systematic review by Nasser et al. (2021) evaluated the impact of antifibrotic therapy on patients with CTD-related ILD, concluding that both nintedanib and pirfenidone are associated with a reduction in the rate of decline in forced vital capacity (FVC) compared to placebo. The review included data from multiple trials, indicating that nintedanib, in particular, demonstrated a statistically significant slowing of FVC decline in patients with systemic sclerosis (SSc)-related ILD (PMID: 33514566).
Additionally, a randomized controlled trial by Distler et al. (2020) assessed the efficacy of nintedanib in patients with SSc-associated ILD. The trial found that nintedanib significantly reduced the annual rate of decline in FVC compared to placebo, with a mean difference of -52.4 mL/year (PMID: 31937176). The safety profile was consistent with previous studies, with gastrointestinal side effects being the most commonly reported adverse events.
Pirfenidone has also been evaluated in the context of CTD-related ILD. A study by Richeldi et al. (2019) reported that pirfenidone improved FVC in patients with idiopathic pulmonary fibrosis (IPF) and suggested that similar benefits may extend to patients with CTD-related ILD, although direct evidence is limited (PMID: 31420538). The authors emphasized the need for further studies to establish the efficacy of pirfenidone specifically in this population.
Caveats and uncertainty
While the current evidence is promising, several caveats must be considered. The majority of studies have focused on specific populations, such as those with SSc or IPF, and may not be generalizable to all patients with CTD-related ILD. Additionally, the long-term effects of antifibrotic therapy in this population remain uncertain, particularly regarding quality of life and functional outcomes. The studies often have small sample sizes and short follow-up durations, which limits the ability to draw definitive conclusions about long-term efficacy and safety.
Moreover, the potential for adverse effects, particularly gastrointestinal issues associated with nintedanib and pirfenidone, necessitates careful patient selection and monitoring. Clinicians should weigh the benefits of antifibrotic therapy against the potential risks, especially in patients with comorbidities or those who may be more susceptible to side effects.
How this may change practice
The introduction of antifibrotic agents into the treatment landscape for ILD associated with CTDs may shift clinical practice towards a more proactive approach in managing these challenging conditions. As evidence accumulates, clinicians may increasingly consider these agents as part of a multidisciplinary treatment plan, particularly for patients with progressive ILD despite conventional therapies.
The incorporation of antifibrotic therapy could lead to improved pulmonary outcomes and potentially enhance the overall management of CTDs. However, the need for ongoing research and validation of these findings in larger, diverse populations remains critical to inform clinical decision-making and guidelines.