In a new subgroup analysis of a previously published multinational trial, the preservation of lung function with nintedanib (Ofev) was about the same in patients with interstitial lung disease related to rheumatoid arthritis (RA-ILD) as it was in patients with other etiologies, according toat the annual European Congress of Rheumatology.
“There was no significant heterogeneity across any of several characteristics we evaluated,” reported, of the Institute of Cellular Medicine at Newcastle University (England).
The INBUILD trial, which enrolled more than 600 patients in 15 countries with a range of fibrosing lung diseases, wasalmost 2 years ago. On the primary endpoint of rate of decline in forced vital capacity (FVC), the medians were –80.8 mL per year among those randomized to nintedanib and –187.8 mL per year (P < .001) on placebo.
The INBUILD study provided evidence that fibrosing lung diseases have a common pathobiologic mechanism that can be slowed by targeting intracellular kinases. Nintedanib inhibits several growth factor receptors as well as nonreceptor tyrosine kinases, but its exact mechanism for slowing fibrosing lung diseases remains unclear. Initially approved for, nintedanib received approvals from the FDA for systemic sclerosis–associated ILD in 2019 and for chronic fibrosing ILD with progressive phenotypes in 2020 after being initially approved for the treatment of idiopathic pulmonary fibrosis in 2014.
When asked for comment,, an associate professor of medicine in the division of rheumatology, immunology, and allergy at Harvard Medical School, Boston, indicated these data are helpful in considering strategies for RA patients with ILD, but he encouraged collaboration between joint and lung specialists.
“Antifibrotic agents for patients with progressive ILD in autoimmune diseases like RA is a welcome addition to our care of this challenging complication,” said Dr. Dellaripa, who has published frequently on the diagnosis and treatment of lung diseases associated with RA. Yet, treatment must be individualized, he added.
“It will be incumbent for rheumatologists to incorporate lung health as a critical part of patient care and work closely with pulmonologists to consider when to institute antifibrotic therapy in patients with ILD,” he said.
Details of subanalysis
In the RA-ILD subpopulation of 89 patients, there was no further decline in FVC from 24 weeks after randomization to the end of 52 weeks for those on nintedanib, but the decline remained steady over the full course of follow-up among those in the placebo group. At 52 weeks, the decline in the placebo group reached –200 mL at the end of 52 weeks. As a result, the between-group relative reduction in FVC at 52 weeks of 116.7 mL favoring nintedanib over placebo (P < .037) slightly exceeded the 107-mL reduction (P < .001) observed in the overall INBUILD study population.
Among other subgroups the investigators evaluated, outcomes with nintedanib did not differ when patients were split into groups with higher or lower baseline levels of high-sensitivity C-reactive protein, regardless of whether the groups were defined by levels above and below 1 mg/L or 3 mg/L. The same was true for those who were taking nonbiologic disease-modifying antirheumatic drugs or glucocorticoids.
However, for these latter analyses, Dr. Kelly conceded that the differences were based on small numbers of patients and so cannot be considered conclusive.
The adverse event most closely associated with nintedanib in the RA-ILD population was diarrhea, just as in the overall study, and it was more than twice as frequent in the RA-ILD patients receiving the active therapy, compared with placebo (54.8% vs. 25.5%). Nausea was also more common (21.4% vs. 10.6%), and so was decreased appetite (11.9% vs. 2.1%) and weight reduction (9.5% vs. 2.1%).
Lung-related adverse events, such as bronchiolitis (21.4% vs. 17.0%) and dyspnea (11.9% vs. 10.6%), were only slightly more frequent in the nintedanib group. Nasopharyngitis (7.1% vs. 12.8%) was less common. Side effects leading to treatment discontinuation were higher on nintedanib (19.0% vs. 12.8%)
The RA-ILD subgroup represented 13.4% of those randomized in INBUILD. The mean time since diagnosis of RA was about 10 years. More than 60% were smokers or former smokers. At baseline, the mean FVC of predicted was 71%. More than 85% had a usual interstitial pneumonia (UIP) radiologic pattern.
Acute exacerbations and death were not evaluated in the RA-ILD subpopulation, but these were secondary endpoints in the published INBUILD study according to the presence or absence of a UIP-like fibrotic pattern. For the combined endpoint of acute exacerbation of ILD or death, the protection associated with nintedanib approached statistical significance for the population overall (odds ratio, 0.68; 95% confidence interval, 0.46-1.01) and reached significance for those with a UIP pattern (OR, 0.61; 95% CI, 0.38-0.98).
Nintedanib led to lower death rates at 52 weeks in the overall population (8.1% vs. 11.5% with placebo) and in the group with a UIP pattern (9.7% vs. 15.0% with placebo).
Dr. Kelly has financial relationships with multiple pharmaceutical companies, including Boehringer Ingelheim, which provided funding for INBUILD and this subpopulation analysis. Dr. Dellaripa reported financial relationships with Bristol-Myers Squibb and Genentech.